- 1. l-Theanine intake increases threshold for limbic seizures but decreases threshold for generalized seizures.
l-Theanine, an ethylamide derivate of glutamate found in abundance in green tea, has been shown to exert beneficial actions in animal models for several neurological disorders. We here investigated for the first time the effect of l-theanine intake on seizure susceptibility using acute pilocarpine and pentylenetetrazol (PTZ) mouse models for studying, respectively, limbic seizures or primarily generalized seizures. Moreover, we studied the effect of l-theanine intake on extracellular hippocampal and cortical glutamate and gamma-aminobutyric acid (GABA) levels, using in vivo microdialysis. Feeding mice with a 4% l-theanine solution significantly decreased their susceptibility to pilocarpine-induced seizures whereas susceptibility to PTZ-induced seizures was increased. The latter effect was linked to decreased extracellular GABA concentrations in frontal cortex....(more)
Schallier A, et al. Nutr Neurosci 2013 Mar;16(2):78-82.
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- 2. Protective effect of l-theanine on chronic restraint stress-induced cognitive impairments in mice.
The present work was aimed to study the protective effect of l-theanine on chronic restraint stress (CRS)-induced cognitive impairments in mice. The stress was produced by restraining the animals in well-ventilated polypropylene tubes (3.2 cm in diameter ×10.5 cm in length) for 8h once daily for 21 consecutive days. L-theanine (2 and 4 mg/kg) was administered 30 min before the animals subjected to acute immobilized stress. At week 4, mice were subjected to Morris water maze and step-through tests to measure the cognitive function followed by oxidative parameters and corticosterone as well as catecholamines (norepinephrine and dopamine) subsequently. Our results showed that the cognitive performances in CRS group were markedly deteriorated, accompanied by noticeable alterations in oxidative parameters and catecholamine levels in the hippocampus and the cerebral cortex as well as corticosterone and catecholamine levels in the serum. However, not only did l-theanine treatment exhibit a reversal of the cognitive impairments and oxidative damage induced by CRS, but also reversed the abnormal level of corticosterone in the serum as well as the abnormal levels of catecholamines in the brain and the serum. This study indicated the protective effect of l-theanine against CRS-induced cognitive impairments in mice....(more)
Tian X, et al. Brain Res 2013 Mar 29;1503:24-32.
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- 3. Tea and cognitive health in late life: current evidence and future directions.
This review summarizes the literature on the association between tea consumption and cognitive health in late life. Population-based studies reviewed in this article suggest that tea drinking has beneficial effects on cognitive function of elderly persons. However, a cause-effect relationship between tea consumption and cognitive decline and dementia could not be drawn given inconsistent findings from only two longitudinal cohort studies. The neuroprotective effects of tea consumption could be due to catechins, L-theanine and other compounds in tea leaves. More longitudinal observational study is needed. Information on life-time tea consumption and blood concentrations of catechins and L-theanine could be collected in future studies....(more)
Song J, et al. J Nutr Health Aging 2012 Jan;16(1):31-4. Review.
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- 4. L-theanine partially counteracts caffeine-induced sleep disturbances in rats.
L-theanine has been reported to inhibit the excitatory effects of caffeine. The present study examined the effects of L-theanine on caffeine-induced sleep disturbances in rats. Rats received the following drug pairings: saline and saline (Control), 7.5 mg/kg caffeine and saline, or 7.5 mg/kg of caffeine followed by various doses of L-theanine (22.5, 37.5, 75, or 150 mg/kg). Vigilance states were divided into: wakefulness (W), transition to slow-wave sleep (tSWS), slow-wave sleep (SWS), and rapid-eye-movement sleep (REMS). Caffeine significantly increased the duration of W and decreased the duration of SWS and REMS compared to the Control. Although L-theanine failed to reverse the caffeine-induced W increase, at 22.5 and 37.5 mg/kg (but not at 75 and 150 mg/kg), it significantly reversed caffeine-induced decreases in SWS. In conclusion, low doses of L-theanine can partially reverse caffeine-induced reductions in SWS; however, effects of L-theanine on caffeine-induced insomnia do not appear to increase dose-dependently....(more)
Jang HS, et al. Pharmacol Biochem Behav 2012 Apr;101(2):217-21.
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- 5. Assessing the effects of caffeine and theanine on the maintenance of vigilance during a sustained attention task.
Caffeine and L-theanine, both naturally occurring in tea, affect the ability to make rapid phasic deployments of attention to locations in space as reflected in behavioural performance and alpha-band oscillatory brain activity (8-14 Hz). However, surprisingly little is known about how these compounds affect an aspect of attention that has been more popularly associated with tea, namely vigilant attention: the ability to maintain focus on monotonous tasks over protracted time-periods. Twenty-seven participants performed the Sustained Attention to Response Task (SART) over a two-hour session on each of four days, on which they were administered caffeine (50 mg), theanine (100 mg), the combination, or placebo in a double-blind, randomized, cross-over fashion. Concurrently, we recorded oscillatory brain activity through high-density electroencephalography (EEG). We asked whether either compound alone, or both in combination, would affect performance of the task in terms of reduced error rates over time, and whether changes in alpha-band activity would show a relationship to such changes in performance. When treated with placebo, participants showed a rise in error rates, a pattern that is commonly observed with increasing time-on-task, whereas after caffeine and theanine ingestion, error rates were significantly reduced. The combined treatment did not confer any additional benefits over either compound alone, suggesting that the individual compounds may confer maximal benefits at the dosages employed. Alpha-band oscillatory activity was significantly reduced on ingestion of caffeine, particularly in the first hour. This effect was not changed by addition of theanine in the combined treatment. Theanine alone did not affect alpha-band activity....(more)
Foxe JJ, et al. Neuropharmacology 2012 Jun;62(7):2320-7.
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- 6. L-Theanine extends lifespan of adult Caenorhabditis elegans.
PURPOSE:
Compounds that delay aging in model organisms may be of significant interest to anti-aging medicine, since these substances potentially provide pharmaceutical approaches to promote healthy lifespan in humans. We here aimed to test whether pharmaceutical concentrations of L-theanine, a putative anti-cancer, anti-obesity, blood pressure-lowering, and neuroprotective compound contained in green tea (Camellia sinensis), are capable of extending lifespan in a nematodal model organism for aging processes, the roundworm Caenorhabditis elegans.
METHODS:
Adult C. elegans roundworms were maintained on agar plates, were fed E. coli strain OP50 bacteria, and L-theanine was applied to agar to test (1) whether it may increase survival upon paraquat exposure and (2) whether it may promote longevity by quantifying survival in the presence and absence of the compound.
RESULTS:
L-Theanine increases survival of C. elegans in the presence of paraquat at a concentration of 1 micromolar. L-theanine extends C. elegans lifespan when applied at concentrations of 100 nM, as well as 1 and 10 micromolar.
CONCLUSIONS:
In the model organism C. elegans, L-theanine is capable of promoting paraquat resistance and longevity suggesting that this compound may as well promote healthy lifespan in mammals and possibly humans....(more)
Zarse K, et al. Eur J Nutr 2012 Sep;51(6):765-8.
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- 7. Protective effect of L-theanine on carbon tetrachloride-induced acute liver injury in mice.
We studied effects of L-theanine, a unique amino acid in tea, on carbon tetrachloride (CCl(4))-induced liver injury in mice. The mice were pre-treated orally with L-theanine (50, 100 or 200 mg/kg) once daily for seven days before CCl(4) (10 ml/kg of 0.2% CCl(4) solution in olive oil) injection. L-theanine dose-dependently suppressed the increase of serum activity of ALT and AST and bilirubin level as well as liver histopathological changes induced by CCl(4) in mice. L-theanine significantly prevented CCl(4)-induced production of lipid peroxidation and decrease of hepatic GSH content and antioxidant enzymes activities. Our further studies demonstrated that L-theanine inhibited metabolic activation of CCl(4) through down-regulating cytochrome P450 2E1 (CYP2E1). As a consequence, L-theanine inhibited oxidative stress-mediated inflammatory response which included the increase of TNF-α and IL-1β in sera, and expression of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) in livers. CCl(4)-induced activation of apoptotic related proteins including caspase-3 and PARP in mouse livers was also prevented by L-theanine treatment. In summary, L-theanine protects mice against CCl(4)-induced acute liver injury through inhibiting metabolic activation of CCl(4) and preventing CCl(4)-induced reduction of anti-oxidant capacity in mouse livers to relieve inflammatory response and hepatocyte apoptosis....(more)
Jiang W, et al. Biochem Biophys Res Commun 2012 Jun 1;422(2):344-50.
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- 8. Rapid and selective quantification of L-theanine in ready-to-drink teas from Chinese market using SPE and UPLC-UV.
An ultra performance liquid chromatography (UPLC) method combined with solid phase extraction (SPE) sample pre-treatment was developed and validated for the rapid quantification of L-theanine in ready-to-drink (RTD) teas. UPLC analysis of twenty-seven RTD teas from the Chinese market revealed that the L-theanine levels in various types of RTD teas were significantly different. RTD green teas were found to contain highest mean L-theanine level (37.85±20.54 mg/L), followed by jasmine teas (36.60±12.08 mg/L), Tieguanying teas (18.54±3.46 mg/L) black teas (16.89±6.56), Pu-erh teas (11.31±0.90 mg/L) and oolong teas (3.85±2.27 mg/L). The ratio of total polyphenols content to L-theanine content could be used as a featured parameter for differentiating RTD teas. L-theanine in RTD teas could be a reliable quality parameter that is complementary to total polyphenols....(more)
Chen G, et al. Food Chem 2012 Nov 15;135(2):402-7.
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- 9. l-theanine attenuates abstinence signs in morphine-dependent rhesus monkeys and elicits anxiolytic-like activity in mice.
l-theanine, 2-amino-4-(ethylcarbamoyl) butyric acid, an amino acid found in green tea (Camellia sinensis), is sold in the United States as a dietary supplement to reduce stress and improve cognition and mood. The observations that l-theanine has been shown to inhibit caffeine's stimulatory effects and that caffeine produces precipitated withdrawal signs in opioid-addicted monkeys and some opioid withdrawal signs in some normal monkeys, suggest that l-theanine may suppress opioid withdrawal signs. Additionally, l-theanine produces anxiolytic effects in humans indicating that it has anti-anxiety properties. Thus, in these studies we determined whether l-theanine attenuates opioid-withdrawal signs in morphine-dependent rhesus monkeys, a model for spontaneous opioid withdrawal in human opioid addicts. We also evaluated whether l-theanine decreases anxiety-like behavior in mice, using the elevated plus maze and marble burying assays. l-theanine significantly attenuated designated opioid withdrawal signs, including fighting, rigid abdominal muscles, vocalizing on palpation of abdomen, pacing, retching, wet-dog shakes, and masturbation. It had a relatively quick onset of action that persisted for at least 2.5h. l-theanine also produced anxiolytic-like effects in the elevated plus maze and the marble burying assay in naïve mice at doses that did not significantly affect motor behavior. The results of these studies suggest that l-theanine may be useful in the pharmacotherapy of treating opioid withdrawal as well as anxiety-associated behaviors....(more)
Wise LE, et al. Pharmacol Biochem Behav 2012 Dec;103(2):245-52.
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- 10. Carotenoids and tocopherols in yellow and red raspberries.
The composition of carotenoids, chlorophyll derivatives and tocopherols in raspberries of different varieties, including yellow and red varieties, over different ripening stages has been studied. The profile of pigments in ripening raspberries changes drastically, with a dramatic decrease of β-carotene and chlorophyll derivatives, the xanthophyll lutein has also decreased but not to the same extent. In contrast esterified lutein increased and is present in ripe raspberries esterified with saturated fatty acids with C8-C16 chains. Ripe raspberries contain considerable amounts of free lutein, esterified lutein, and tocopherols (up to 20, 49 and 366mg/kg dry weight, respectively). The different samples analysed show different contents of carotenoids and tocopherols. Whether the differences arise from the variety or other factors such as the environmental conditions needs to be ascertained but isoprenoids should not be neglected when considering raspberry antioxidant and nutraceutical composition....(more)
Carvalho E, et al. Food Chem 2013 Aug 15;139(1-4):744-52.
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- 11. Investigation of Genetic Variation in Scavenger Receptor Class B, Member 1 (SCARB1) and Association with Serum Carotenoids.
OBJECTIVE:
To investigate association of scavenger receptor class B, member 1 (SCARB1) genetic variants with serum carotenoid levels of lutein (L) and zeaxanthin (Z) and macular pigment optical density (MPOD).
DESIGN:
A cross-sectional study of healthy adults aged 20 to 70.
PARTICIPANTS:
We recruited 302 participants after local advertisement.
METHODS:
We measured MPOD by customized heterochromatic flicker photometry. Fasting blood samples were taken for serum L and Z measurement by high-performance liquid chromatography and lipoprotein analysis by spectrophotometric assay. Forty-seven single nucleotide polymorphisms (SNPs) across SCARB1 were genotyped using Sequenom technology. Association analyses were performed using PLINK to compare allele and haplotype means, with adjustment for potential confounding and correction for multiple comparisons by permutation testing. Replication analysis was performed in the TwinsUK and Carotenoids in Age-Related Eye Disease Study (CAREDS) cohorts.
MAIN OUTCOME MEASURES:
Odds ratios for MPOD area, serum L and Z concentrations associated with genetic variations in SCARB1 and interactions between SCARB1 and gender.
RESULTS:
After multiple regression analysis with adjustment for age, body mass index, gender, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglycerides, smoking, and dietary L and Z levels, 5 SNPs were significantly associated with serum L concentration and 1 SNP with MPOD (P<0.01). Only the association between rs11057841 and serum L withstood correction for multiple comparisons by permutation testing (P<0.01) and replicated in the TwinsUK cohort (P = 0.014). Independent replication was also observed in the CAREDS cohort with rs10846744 (P = 2×10<sup>-4</sup>), an SNP in high linkage disequilibrium with rs11057841 (r<sup>2</sup> = 0.93). No interactions by gender were found. Haplotype analysis revealed no stronger association than obtained with single SNP analyses.
CONCLUSIONS:
Our study has identified association between rs11057841 and serum L concentration (24% increase per T allele) in healthy subjects, independent of potential confounding factors. Our data supports further evaluation of the role for SCARB1 in the transport of macular pigment and the possible modulation of age-related macular degeneration risk through combating the effects of oxidative stress within the retina.
FINANCIAL DISCLOSURE(S):
Proprietary or commercial disclosures may be found after the references.
Copyright © 2013 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved....(more)
McKay GJ, et al. Ophthalmology 2013 Apr 5.
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- 12. Response of green reflectance continuum removal index to the xanthophyll de-epoxidation cycle in Norway spruce needles.
A dedicated field experiment was conducted to investigate the response of a green reflectance continuum removal-based optical index, called area under the curve normalized to maximal band depth between 511nm and 557nm (ANMB511-557), to light-induced transformations in xanthophyll cycle pigments of Norway spruce [Picea abies (L.) Karst] needles. The performance of ANMB511-557 was compared with the photochemical reflectance index (PRI) computed from the same leaf reflectance measurements. Needles of four crown whorls (fifth, eighth, 10th, and 15th counted from the top) were sampled from a 27-year-old spruce tree throughout a cloudy and a sunny day. Needle optical properties were measured together with the composition of the photosynthetic pigments to investigate their influence on both optical indices. Analyses of pigments showed that the needles of the examined whorls varied significantly in chlorophyll content and also in related pigment characteristics, such as the chlorophyll/carotenoid ratio. The investigation of the ANMB511-557 diurnal behaviour revealed that the index is able to follow the dynamic changes in the xanthophyll cycle independently of the actual content of foliar pigments. Nevertheless, ANMB511-557 lost the ability to predict the xanthophyll cycle behaviour during noon on the sunny day, when the needles were exposed to irradiance exceeding 1000 µmol m(-2) s(-1). Despite this, ANMB511-557 rendered a better performance for tracking xanthophyll cycle reactions than PRI. Although declining PRI values generally responded to excessive solar irradiance, they were not able to predict the actual de-epoxidation state in the needles examined....(more)
Kovác D, et al. J Exp Bot 2013 Apr;64(7):1817-27.
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- 13. The effect of dietary supplementation with the natural carotenoids curcumin and lutein on broiler pigmentation and immunity.
The objective of this study was to compare the effects of supplementation with 2 carotenoids, curcumin and lutein, on pigmentation and immunity in lipopolysaccharide (LPS)-stimulated broiler chicks. Two hundred forty 1-d-old Arbor Acres broilers were randomly distributed into 3 dietary treatment groups: a basal diet without carotenoid supplementation (control), a basal diet supplemented with 200 mg/kg of curcumin (CRM), or a basal diet supplemented with 200 mg/kg of lutein (LTN) for 42 d. The birds were vaccinated against Newcastle disease (ND) and avian influenza on d 10. At 16, 18, and 20 d of age, half of the chicks in each group were injected in the abdominal region with either LPS (250 mg/kg of BW) or an equal volume of 0.9% NaCl. The intensity of the shank skin color (Roche color fan score) and the b* (yellow) values of the breasts and thighs were highest in lutein-supplemented broilers, followed by curcumin-supplemented and control broilers, whereas the a* (red) value of the thigh muscle was highest in curcumin-supplemented LPS-induced birds. At 42 d, the relative weight of the abdominal fat was lowest in the CRM-supplemented group, followed by the LTN-supplemented and control groups; the spleen weight was lower in the non-LPS-induced LTN-supplemented group than the LPS-induced control group. The ND and avian influenza titers were significantly higher in the CRM-supplemented group than in the other groups at 20 d; at 30 d, the ND titer was significantly higher in the LPS-induced LTN group. Supplementation with curcumin significantly promoted B and T lymphocyte proliferation in both LPS- and non-LPS-induced birds at 21 d. Curcumin also promoted B lymphocyte proliferation in non-LPS-induced birds at 42 d. Curcumin significantly reduced alanine aminotransferase and aspartate aminotransferase activities at 42 d in non-LPS-treated birds, whereas lutein significantly increased the activities of these enzymes in LPS-induced birds. Both carotenoids significantly lowered lipid oxidation in the liver of supplemented birds. Thus, in broiler chickens, lutein-supplemented birds exhibited better pigmentation efficiency, whereas curcumin-supplemented birds exhibited improved immune responses....(more)
Rajput N, et al. Poult Sci 2013 May;92(5):1177-85.
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- 14. Dietary sources of lutein and zeaxanthin carotenoids and their role in eye health.
The eye is a major sensory organ that requires special care for a healthy and productive lifestyle. Numerous studies have identified lutein and zeaxanthin to be essential components for eye health. Lutein and zeaxanthin are carotenoid pigments that impart yellow or orange color to various common foods such as cantaloupe, pasta, corn, carrots, orange/yellow peppers, fish, salmon and eggs. Their role in human health, in particular the health of the eye, is well established from epidemiological, clinical and interventional studies. They constitute the main pigments found in the yellow spot of the human retina which protect the macula from damage by blue light, improve visual acuity and scavenge harmful reactive oxygen species. They have also been linked with reduced risk of age-related macular degeneration (AMD) and cataracts. Research over the past decade has focused on the development of carotenoid-rich foods to boost their intake especially in the elderly population. The aim of this article is to review recent scientific evidences supporting the benefits of lutein and zexanthin in preventing the onset of two major age-related eye diseases with diets rich in these carotenoids. The review also lists major dietary sources of lutein and zeaxanthin and refers to newly developed foods, daily intake, bioavailability and physiological effects in relation to eye health. Examples of the newly developed high-lutein functional foods are also underlined....(more)
Abdel-Aal el-SM, et al. Nutrients 2013 Apr 9;5(4):1169-85.
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- 15. Species Specific Responses to Combined Thermal-irradiance Stress in Microalgae - "Each is to its Own"
Despite the vast variety in many of the characteristics of plants, terrestrial and aquatic, photosynthetic responses to high light are drawn from a more or less limited set of mechanisms (1). Some either attenuate the source or augment the sink for excess excitation energy, others manage high-light induced damaging species (by deactivation) or damaged components (by reactivation). Most of these phenomenon are also associated with the PSII reaction center (1). From the tallest tree to the smallest picoplanktonic microalgae, the mechanisms to accomplish these adjustments are surprisingly similar, including, for examples, xanthophyll quenching within the light harvesting complex and turnover of PSII reaction center core proteins (2). This article is protected by copyright. All rights reserved....(more)
Neale P. Photochem Photobiol 2013 Apr 15.
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- 16. Protection Strategies of Cosmarium strains (Zygnematophyceae, Streptophyta) Isolated from Various Geographic Regions Against Excessive Photosynthetically Active Radiation.
Numerous in vitro investigations have suggested that macroalgae exhibit regular geographic and depth distribution patterns in accordance with the light and temperature predominance at their habitats; however, there have been only a few similar studies concerning microalgae. We examined the potential influence of irradiance on patterns of distribution of four Cosmarium strains isolated from various climatic zones and cultured long-term (>15 years) under a constant temperature-light regime. All of the Cosmarium strains demonstrated physiological responses that were consistent with the light intensity prevailing at their source location, confirming that these responses are genetically preserved, as concluded from chlorophyll fluorescence and oxygen evolution rates measurements. Addition of inhibitors of chloroplast-encoded protein synthesis (chloramphenicol and streptomycin) and violaxanthin de-epoxidase (dithiothreitol) indicated that the Cosmarium strains developed 'sun- or shade-plant' protection strategies, in accordance with the climate at their sampling sites. The polar Cosmarium strains exhibited a 'shade-plant strategy' - to suffer some photoinhibition, but acquire increasing protection from photoinhibited PSII centres, while the tropical strains displayed a 'sun-plant strategy' - to counteract photoinhibition of PSII by a high rate of repair of photoinhibited PSII reaction centres and a high xanthophyll cycle turnover. This article is protected by copyright. All rights reserved....(more)
Stamenkovi? M, et al. Photochem Photobiol 2013 Apr 15.
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- 17. Dietary Intervention with Mediterranean or Healthy Eating Goals has Similar Effects on Serum and Colon Concentrations of Carotenoids and Fatty Acids.
Little is known about dietary effect on colonic nutrient concentrations associated with preventive foods. This study observed 120 persons at increased risk of colon cancer randomized to a Mediterranean versus a Healthy Eating diet for six months. The former targeted increases in whole grains, fruits, vegetables, monounsaturated and n3 fats. Healthy Eating diet was based on Healthy People 2010 recommendations. At baseline, dietary fat and carotenoid intakes were poorly associated (Spearman ρ < 0.4) with serum and colon concentrations. Strong associations were observed between serum and colon measurements of β-cryptoxanthin (ρ = 0.58, p-value < 0.001), α-carotene (ρ = 0.48, p-value < 0.001), and β-carotene (ρ = 0.45, p-value < 0.001). After six months, the Healthy Eating arm increased serum lutein, β- and α-carotene significantly (p-value < 0.05). In the Mediterranean arm the significant increases were in serum lutein, β-cryptoxanthin, β-carotene, monounsaturated and n3 fats. A significant group-by-time interaction (p-value = 0.03) was obtained for monounsaturated fats. Colonic increases in carotenoids and n3 fats were significant only in Healthy Eating arm, while group-by-time interaction were significant for β-carotene (p-value = 0.02), and α-carotene (p-value = 0.03). Changes in colon concentrations were not significantly associated with reported dietary changes. Changes in colon and serum concentrations were strongly associated for β-cryptoxanthin (ρ = 0.56, p-value < 0.001), and α-carotene (ρ = 0.40, p-value < 0.001). The associations between colonic and serum concentrations suggest the potential utility of using serum concentration as a target in dietary interventions aimed at reducing colon cancer risk....(more)
Sen A, et al. Cancer Prev Res (Phila) 2013 Apr 23.
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- 18. Changes in the Energy Transfer Pathways within Photosystem II Antenna Induced by Xanthophyll Cycle Activity.
Energy transfer pathways between photosystem II (PSII) antenna complexes in intact thylakoid membranes have been studied using low-temperature (77 K) excitation fluorescence spectroscopy. The focus of this study was to see whether de-epoxidation of violaxanthin into zeaxanthin causes any alterations in the energetic couplings between the core antenna complexes CP43 and CP47 and the peripheral light-harvesting antenna (LHCII). It was discovered that the appearance of zeaxanthin caused characteristic alterations in the PSII excitation fluorescence spectra in the Soret-band region. While in the dark violaxanthin was found to be largely uncoupled from any emitting chlorophylls, its intensive de-epoxidation resulted in the appearance of two additional bands at 509 and 492 nm. The former was attributed to weak coupling of zeaxanthin to emitters in the CP43 and LHCII complexes and the latter to efficient coupling of violaxanthin of the CP29 complex to emitters in the CP43, CP47, and LHCII complexes. The role of CP29-bound violaxanthin is discussed in light of both its efficient energetic coupling and strong physical binding to this complex. The finding that zeaxanthin is energetically coupled to chlorophyll a emitters of the PSII antenna is discussed with respect to its suggested role as a quencher involved in photoprotective energy dissipation, or non-photochemical quenching (NPQ), in the photosynthetic membrane....(more)
Ilioaia C, et al. J Phys Chem B 2013 May 3.
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- 19. Cross-sectional dietary deficiencies among a prison population in Papua New Guinea.
BACKGROUND:
To investigate the dietary adequacy of prisoners of Beon Prison, Madang, Papua New Guinea in response to a report of possible nutritional deficiency.
METHODS:
We undertook an observational, cross-sectional study. All 254 male inmates (May 2010) were eligible to answer a validated interview-based questionnaire; to have a comprehensive dietary assessment; and to provide blood for biochemical analysis (alpha-tocopherol, beta-carotene, lutein, thiamin, riboflavin, niacin, folate, homocysteine, zinc, ferritin, and vitamins A, B12 and C). Prison guards were invited to participate as a comparison group.
RESULTS:
148 male prisoners (58.3%) and 13 male prison guards participated. Prison rations consisted of white rice fortified with thiamin, niacin, and iron, tinned tuna, tinned corned beef, water crackers, and black tea, with occasional intakes of fruit and vegetables. Some prisoners received supplementary food from weekend visitors. From assessment of the prisoners dietary data, median intakes of calcium (137 mg), potassium (677 mg), magnesium 182 mg), riboflavin (0.308 mg), vitamin A (54.1 mug), vitamin E (1.68 mg), vitamin C (5.7 mg) and folate (76.4 mug) were found to be below estimated average requirements (EAR).Following are the prisoners median (P25, P75) concentration of circulating nutrients and the percentage of prisoners with levels below normal reference ranges or recognized cut-off values: serum retinol 0.73 (0.40, 1.21) mumol/L, 46% below 0.7 mumol/L; plasma folate 2.0 (1.4, 2.6) nmol/L, 98% below 6.8 nmol/L; plasma vitamin C 6.3 (1.0, 19.3) mumol/L, 64% below 11.4 mumol/L; serum zinc 9.9 (8.8, 11.1) mumol/L, 66% below 10.7 mumol/L. Guards had diets with a higher dietary diversity that were associated with greater intakes of nutrients and biomarker concentrations.
CONCLUSIONS:
The prisoners diets are likely lacking in several micronutrients and recommendations for dietary change have been made to the prison authorities. Ongoing vigilance is required in prisons to ensure the basic human right of access to a nutritionally adequate diet is being observed....(more)
Gould C, et al. BMC Int Health Hum Rights 2013 Apr 22;13(1):21.
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- 20. In vivo effects on the intestinal microflora of Physalis alkekengi var. francheti extracts.
This study aimed to investigate the effects on the intestinal microflora balance of Physalis alkekengi var. francheti extracts (PE) using in vivo mouse model. Luteolin-7-O-β-glycoside, Physalin J, Physalin D, and Physalin P were isolated from PE extracts and identified. Bacteroides, Lactobacillus, Helicobacter, Prevotella, Odoribacter and Oribacterium were detected as dominant organisms in the intestinal tract of mice by denaturing gradient gel electrophoresis (DGGE) analysis. The quality and quantity of Lactobacillus genus increased significantly with increasing concentration of PE. This study shows that the intestinal microflora balance could be improved by PE, and thus, it has the significant potential to be used as a natural agent for restoring the intestinal microflora balance....(more)
Li X, et al. Fitoterapia 2013 Apr 2;87C:43-48.
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- 21. In vitro anthelmintic effect of Vicia pannonica var. purpurascens on trichostrongylosis in sheep.
Vicia species are used for the treatment of malaria, diarrhea, hemorrhoids, kidney problems and infertility in Turkish traditional medicine. The present study was carried out to evaluate the in vitro anthelmintic effects of Vicia pannonica Crantz. var. purpurascens (DC). Ser. extracts. Larval motility test was used to determine anthelmintic activity of this plant. Motility of the larvae is measured by observation. The methanol, n-hexane, chloroform, acetone, and aqueous extracts of the aerial parts of the plant including the leaves and flowers were applied to developing trichostrongylus larvae at 1, 0.8, 0.6, 0.4, 0.2 and 0.1mg/ml doses. Thiabendazole and distilled water with 5% DMSO was used as positive and negative control. All of the extracts were 100% effective. Two flavone and flavonol glycosides; luteolin-7-β-O-glucopyranoside (1) and quercetin-3-O-β-glucopyranoside (2) were isolated from the acetone extract and their structures were elucidated by spectral techniques. The solutions prepared from two flavonoid fractions at several doses were performed in vitro to larvae in the same way. Both of them were 100% effective at 1 and 0.8mg/ml doses. Results of the present study support the utilization of these plant species employed in Turkish folk medicine....(more)
Kozan E, et al. Exp Parasitol 2013 Apr 4.
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- 22. Focal brain inflammation and autism.
Increasing evidence indicates that brain inflammation is involved in the pathogenesis of neuropsychiatric diseases. Autism spectrum disorders (ASD) are characterized by social and learning disabilities that affect as many as 1/80 children in the USA. There is still no definitive pathogenesis or reliable biomarkers for ASD, thus significantly curtailing the development of effective therapies. Many children with ASD regress at about age 3 years, often after a specific event such as reaction to vaccination, infection, stress or trauma implying some epigenetic triggers, and may constitute a distinct phenotype. ASD children respond disproportionally to stress and are also affected by food and skin allergies. Corticotropin-releasing hormone (CRH) is secreted under stress and together with neurotensin (NT) stimulates mast cells and microglia resulting in focal brain inflammation and neurotoxicity. NT is significantly increased in serum of ASD children along with mitochondrial DNA (mtDNA). NT stimulates mast cell secretion of mtDNA that is misconstrued as an innate pathogen triggering an auto-inflammatory response. The phosphatase and tensin homolog (PTEN) gene mutation, associated with the higher risk of ASD, which leads to hyper-active mammalian target of rapamycin (mTOR) signalling that is crucial for cellular homeostasis. CRH, NT and environmental triggers could hyperstimulate the already activated mTOR, as well as stimulate mast cell and microglia activation and proliferation. The natural flavonoid luteolin inhibits mTOR, mast cells and microglia and could have a significant benefit in ASD....(more)
Theoharides TC, et al. J Neuroinflammation 2013 Apr 9;10:46.
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- 23. High-throughput determination of phenolic compounds in virgin olive oil using dispersive liquid-liquid microextraction-CZE.
This article reports a simple methodology using dispersive liquid-liquid microextraction (DLLME) combined with CZE. It has been applied for the simultaneous determination of phenolic compounds like : caffeic, gallic, vanillic, syringic, cinnamic, p-coumaric acids and oleuropein, apigenin, luteolin, 3-hydroxytyrosol and tyrosol, in virgin olive oil (VOO). The optimized extraction conditions for 20 g of VOO were: extractant solvent: 400 μL boric acid 30 mM at pH 9.5; dispersive solvent: 300 μL carbon tetrachloride; vortex: 8 min; centrifugation: 3 min. The composition of the BGE was optimized resulting in the selection of a solution made of 30 mM boric acid at pH 9.5. As a strategy for on-line preconcentration a stacking step was applied, injecting a plug of water before sample injection. The short extraction time, centrifugation and electrophoretic steps allow the selective determination of phenolic compounds in VOO with satisfactory LODs (0.004-0.251 mg Kg<sup>-1</sup> ), recoveries (89.4-101.0%) and RSD (less than 7.44% in peak area and less than 0.69% in migration time), compatible with the concentration levels present in the samples....(more)
Monasterio RP, et al. Electrophoresis 2013 Apr 10.
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- 24. An eco-metabolomic study of host plant resistance to Western flower thrips in cultivated, biofortified and wild carrots.
Domestication of plants and selection for agronomic traits may reduce plant secondary defence metabolites relative to their ancestors. Carrot (Daucus carota L.) is an economically important vegetable. Recently, carrot was developed as a functional food with additional health-promoting functions. Biofortified carrots contain increased concentrations of chlorogenic acid as an antioxidant. Chlorogenic acid is involved in host plant resistance to Western Flower Thrips (Frankliniella occidentalis), one of the key agri- and horticultural pests worldwide. The objective of this study was to investigate quantitative host plant resistance to thrips in carrot and to identify candidate compounds for constitutive resistance. As such we explored whether cultivated carrot is more vulnerable to herbivore attack compared to wild carrot. We subjected a set of 14 biofortified, cultivated and wild carrot genotypes to thrips infestation. We compared morphological traits and leaf metabolic profiles of the three most resistant and susceptible carrots using nuclear magnetic resonance spectroscopy (NMR). In contrast to our expectation, wild carrots were not more resistant to thrips than cultivated ones. The most thrips resistant carrot was the cultivar Ingot which is known to be tolerant against carrot root fly (Psila rosae). Biofortified carrots were not resistant to thrips. Plant size, leaf area and number of leaf hairs did not differ between resistant and susceptible carrots. The metabolic profiles of the leaves of resistant carrots were significantly different from those of susceptible carrots. The leaves of resistant carrots contained higher amounts of the flavanoid luteolin, the phenylpropanoid sinapic acid and the amino acid β-alanine. The negative effect of these compounds on thrips was confirmed using in-vitro bioassays. Our results have potential implications for carrot breeders. The natural variation of metabolites present in cultivated carrots can be used for improvement of thrips resistance. This is especially promising in view of the candidate compounds we identified since they do not only confer a negative effect on thrips but as antioxidants also play an important role in the improvement of human health....(more)
Leiss KA, et al. Phytochemistry 2013 Apr 11.
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- 25. The antioxidant effect of the Malaysian Gelam honey on pancreatic hamster cells cultured under hyperglycemic conditions.
Type 2 diabetes consists of progressive hyperglycemia, insulin resistance, and pancreatic β-cell failure which could result from glucose toxicity, inflammatory cytokines, and oxidative stress. In the present study, we investigate the effect of pretreatment with Gelam honey (Melaleuca spp.) and the individual flavonoid components chrysin, luteolin, and quercetin, on the production of reactive oxygen species (ROS), cell viability, lipid peroxidation, and insulin content in hamster pancreatic cells (HIT-T15 cells), cultured under normal and hyperglycemic conditions. Phenolic extracts from a local Malaysian species of Gelam honey (Melaleuca spp.) were prepared using the standard extraction methods. HIT-T15 cells were cultured in 5 % CO2 and then preincubated with Gelam honey extracts (20, 40, 60, and 80 μg/ml) as well as some of its flavonoid components chrysin, luteolin, and quercetin (20, 40, 60, and 80 μM), prior to stimulation by 20 and 50 mM of glucose. The antioxidative effects were measured in these cultured cells at different concentrations and time point by DCFH-DA assay. Pretreatment of cells with Gelam honey extract or the flavonoid components prior to culturing in 20 or 50 mM glucose showed a significant decrease in the production of ROS, glucose-induced lipid peroxidation, and a significant increase in insulin content and the viability of cells cultured under hyperglycemic condition. Our results show the in vitro antioxidative property of the Gelam honey and the flavonoids on the β-cells from hamsters and its cytoprotective effect against hyperglycemia....(more)
Batumalaie K, et al. Clin Exp Med 2013 Apr 13.
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- 26. Artemisia copa aqueous extract as vasorelaxant and hypotensive agent.
ETHNOPHARMACOLOGICAL RELEVANCE:
Artemisia copa Phil. (Asteraceae) is a medicinal plant commonly used in traditional medicine in Argentina.
AIM OF THE STUDY:
The vasorelaxant and hypotensive activities of the aqueous extract of Artemisia copa have been investigated.
MATERIALS AND METHODS:
The in vitro effect of the extract and isolated compounds from Artemisia copa was investigated using isolated rat aortic rings. The acute effect caused by the intravenous (i.v.) infusion (0.1-300mg/kg) on blood pressure and heart rate was evaluated in spontaneous hypertensive rats. In addition, a phytochemical analysis of the extract was performed by HPLC.
RESULTS:
Artemisia copa had a relaxant effect in endothelium-intact aortic rings that had been pre-contracted with 10<sup>-7</sup>M phenylephrine (Emax=96.7±1.3%, EC50=1.1mg/ml), 10<sup>-5</sup>M 5-hydroxytriptamine (Emax=96.7±3.5%, EC50=1.5mg/ml) and 80mM KCl (Emax=97.9± 4.4%, EC50=1.6mg/ml). In denuded aortic rings contracted by phenylephrine, a similar pattern was observed (Emax=92.7±6.5%, EC50=1.8mg/ml). l-NAME, indomethacin, tetraethylammonium and glibenclamide were not able to block the relaxation induced by the extract. Nevertheless, the pre-treatment with Artemisia copa attenuated the CaCl2-induced contraction in a concentration-dependent manner (Emax: 86% of inhibition for 3mg/ml and 52% de-inhibition for 1mg/ml). This pre-treatment also induced a significant attenuation of the norepinephrine-induced contraction in a concentration-dependent manner (Emax: 72.7% of inhibition for 3mg/ml and 27% de inhibition for 1mg/ml) in a Ca<sup>2+</sup> free medium. Upon analyzing the composition of the extract, the presence of p-coumaric acid, isovitexin, luteolin and chrysoeriol were found. Luteolin (CE50: 1.5μg/ml), chrysoeriol (CE50: 13.2μg/ml) and p-coumaric acid (CE50: 95.2μg/ml), isolated from the aqueous extract, caused dilatation of thoracic aortic rings pre-contracted with phenylephrine. Artemisia copa administered i.v. also induced a decrease in the mean arterial pressure but did not affect the heart rate in hypertensive rats.
CONCLUSIONS:
The aqueous extract of Artemisia copa proved to have vasorelaxing and hypotensive effects through the inhibition of Ca<sup>2+</sup> influx via membranous calcium channels and intracellular stores. The presence of luteolin, chrysoeriol and p-coumaric acid found in this plant could be involved in this effect.
Copyright © 2013. Published by Elsevier Ireland Ltd....(more)
Gorzalczany S, et al. J Ethnopharmacol 2013 Apr 12.
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- 27. Luteolin is a novel p90 ribosomal S6 kinase (RSK) inhibitor that suppresses Notch4 signaling by blocking the activation of Y-box binding protein-1 (YB-1).
Triple-negative breast cancers (TNBC) are notoriously difficult to treat because they lack hormone receptors and have limited targeted therapies. Recently, we demonstrated that p90 ribosomal S6 kinase (RSK) is essential for TNBC growth and survival indicating it as a target for therapeutic development. RSK phosphorylates Y-box binding protein-1 (YB-1), an oncogenic transcription/translation factor, highly expressed in TNBC (~70% of cases) and associated with poor prognosis, drug resistance and tumor initiation. YB-1 regulates the tumor-initiating cell markers, CD44 and CD49f however its role in Notch signaling has not been explored. We sought to identify novel chemical entities with RSK inhibitory activity. The Prestwick Chemical Library of 1120 off-patent drugs was screened for RSK inhibitors using both in vitro kinase assays and molecular docking. The lead candidate, luteolin, inhibited RSK1 and RSK2 kinase activity and suppressed growth in TNBC, including TIC-enriched populations. Combining luteolin with paclitaxel increased cell death and unlike chemotherapy alone, did not enrich for CD44(+) cells. Luteolin's efficacy against drug-resistant cells was further indicated in the primary x43 cell line, where it suppressed monolayer growth and mammosphere formation. We next endeavored to understand how the inhibition of RSK/YB-1 signaling by luteolin elicited an effect on TIC-enriched populations. ChIP-on-ChIP experiments in SUM149 cells revealed a 12-fold enrichment of YB-1 binding to the Notch4 promoter. We chose to pursue this because there are several reports indicating that Notch4 maintains cells in an undifferentiated, TIC state. Herein we report that silencing YB-1 with siRNA decreased Notch4 mRNA. Conversely, transient expression of Flag:YB-1(WT) or the constitutively active mutant Flag:YB-1(D102) increased Notch4 mRNA. The levels of Notch4 transcript and the abundance of the Notch4 intracellular domain (N4ICD) correlated with activation of P-RSK(S221/7) and P-YB-1(S102) in a panel of TNBC cell lines. Silencing YB-1 or RSK reduced Notch4 mRNA and this corresponded with loss of N4ICD. Likewise, the RSK inhibitors, luteolin and BI-D1870, suppressed P-YB-1(S102) and thereby reduced Notch4. In conclusion, inhibiting the RSK/YB-1 pathway with luteolin is a novel approach to blocking Notch4 signaling and as such provides a means of inhibiting TICs....(more)
Reipas KM, et al. Oncotarget 2013 Feb;4(2):329-45.
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- 28. Effect of Natural Exogenous Antioxidants on Aging and on Neurodegenerative Diseases.
ABSTRACT Aging and neurodegenerative diseases share oxidative stress cell damage and depletion of endogenous antioxidants as mechanisms of injury, phenomenons that occurring at different rate in each process. Nevertheless, as the central nervous system (CNS) consists largely of lipids and has a poor activity of catalase, a low amount of superoxide dismutase and is rich in iron, its cellular components are damaged easily by over production of free radicals in any of these physiologic or pathologic conditions. Thus, antioxidants are needed to prevent the formation and oppose the free radicals damage to DNA, lipids, proteins, and other biomolecules. Due to endogenous antioxidant defenses are inadequate to prevent damage completely, different efforts have been undertaken in order to increase the use of natural antioxidants and to develop antioxidants that might ameliorate neural injury by oxidative stress. In this context, natural antioxidants like flavonoids (quercetin, curcumin, luteolin and catechins) and magnolol and honokiol, are showing to be efficient inhibitors of the oxidative process and seem to be a better therapeutic option than the traditionally ones (vitamin C, E and β-carotene) in various models of aging and injury in vitro and in vivo conditions. Thus, the goal of the present review is to discuss the molecular basis, mechanisms of action, functions, and targets of flavonoids, magnolol, honokiol and traditional antioxidants with the aim to obtained better results when they are prescribing on aging and neurodegenerative diseases....(more)
Guerra-Araiza C, et al. Free Radic Res 2013 Apr 18.
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- 29. Simultaneous determination of flavonoid analogs in Scutellariae Barbatae Herba by β-cyclodextrin and acetonitrile modified capillary zone electrophoresis.
A capillary zone electrophoresis (CZE) method modified by β-cyclodextrin (β-CD) and acetonitrile (ACN) was developed for simultaneous determination of seven structurally similar flavonoids in Scutellariae Barbatae Herba (SBH) and its preparations. Molecular selectivity of the analytes by β-CD was in the following order: apigenin, luteolin, quercetin, scutellarin, baicalein, rutin and wogonin, based mainly on the "molecular fit" interaction between some ligands in the C ring of the flavonoid and the cavity of β-CD. Flavonoids with hydroxyl substituent(s) at the C-ring, especially the 4' monohydroxyl, were highly selected by β-CD although hydrophobicity of the guest molecule is the primary factor affecting the complexation. The function of acetonitrile in this study was to improve the separation of the analytes in the real SBH. The developed method was validated and applied to real samples. The principle of separation based on this CZE condition is also explained....(more)
Li YY, et al. Talanta 2013 Feb 15;105:393-402.
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- 30. Hydrogen peroxide production protects Chlamydomonas reinhardtii against light-induced cell death by preventing singlet oxygen accumulation through enhanced carotenoid synthesis.
The effect of hydrogen peroxide (H2O2) on carotenoid synthesis in Chlamydomonas reinhardtii under light-induced stress at 3000μmolm<sup>-2</sup>s<sup>-1</sup> has been investigated. This very high light (VHL) illumination triggered a transient increase in H2O2 production during the initial 30min of light stress, followed by singlet oxygen (<sup>1</sup>O2) production, growth inhibition and necrotic cell death. The carotenoid content was slightly reduced during the first 30min of VHL illumination and strongly diminished after 60min, while the expression of the transcripts of enzymes involved in carotenoid biosynthesis, including phytoene synthase (PSY), phytoene desaturase (PDS), and lycopene -cyclase (LCYE), initially increased and then decreased. Lycopene β-cyclase (LCYB) transcripts did not change. Treatment with dimethylthiourea, a H2O2 scavenger, under VHL conditions reduced H2O2 production and PSY and PDS transcript levels and accelerated the reduction of carotenoids, the production of <sup>1</sup>O2, viability loss and necrotic cell death. Pretreatment with 0.1μM methyl viologen or 0.2mM H2O2 under 50μmolm<sup>-2</sup>s<sup>-1</sup> low light for 60min increased VHL tolerance, carotenoid content, and PSY and PDS transcripts, while LCYB and LCYE transcripts were not affected. These results suggest that H2O2, produced under VHL stress, ameliorates the <sup>1</sup>O2-mediated oxidative damage to C. reinhardtii through a reduction in the degree of carotenoid breakdown by activation of de novo carotenoid synthesis....(more)
Chang HL, et al. J Plant Physiol 2013 Mar 20.
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- 31. Carotenoids in unexpected places: Gall midges, lateral gene transfer, and carotenoid biosynthesis in animals.
Carotenoids are conjugated isoprenoid molecules with many important physiological functions in organisms, including roles in photosynthesis, oxidative stress reduction, vision, diapause, photoperiodism, and immunity. Until recently, it was believed that only plants, microorganisms, and fungi were capable of synthesizing carotenoids and that animals acquired them from their diet, but recent studies have demonstrated that two arthropods (pea aphid and spider mite) possess a pair of genes homologous to those required for the first step of carotenoid biosynthesis. Absent in all other known animal genomes, these genes appear to have been acquired by aphids and spider mites in one or several lateral gene transfer events from a fungal donor. We report the third case of fungal carotenoid biosynthesis gene homologs in an arthropod: flies from the family Cecidomyiidae, commonly known as gall midges. Using phylogenetic analyses we show that it is unlikely that lycopene cyclase/phytoene synthase and phytoene desaturase homologs were transferred singly to an ancient arthropod ancestor; instead we propose that genes were transferred independently from related fungal donors after divergence of the major arthropod lineages. We also examine variation in intron placement and copy number of the carotenoid genes that may underlie function in the midges. This trans-kingdom transfer of carotenoid genes may represent a key innovation, underlying the evolution of phytophagy and plant-galling in gall midges and facilitating their extensive diversification across plant lineages....(more)
Cobbs C, et al. Mol Phylogenet Evol 2013 Mar 27.
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- 32. Detection of Key Factors Affecting Lycopene in Vitro Accessibility.
On the basis of a Plackett-Burman experimental design for a resolution IV level obtained via a foldover strategy, the effect of 11 factors on lycopene in vitro accessibility was investigated. The selected factors were thermal treatment (X1), olive oil addition (X2), gastric pH (X3), gastric digestion time (X4), pepsin concentration (X5), intestinal pH (X6), pancreatin concentration (X7), bile salts concentration (X8), colipase addition (X9), intestinal digestion time (X10), and intestinal digestion speed (X11). Tomato passata was used as a natural source of lycopene. Samples were collected after gastric and intestinal digestion, and from the micellar phase, to quantify the (all-E)-lycopene and its (Z)-isomers by HPLC. Except for X3, X6, X7, and X11, the other factors studied explained lycopene in vitro accessibility, mainly regarding intestinal digestion, with R<sup>2</sup> values ≥ 0.60. Our results showed that the accessibility of lycopene is influenced by the conditions applied during in vitro intestinal digestion....(more)
Periago MJ, et al. J Agric Food Chem 2013 Apr 16.
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- 33. Levels of Lycopene β-Cyclase 1 Modulate Carotenoid Gene Expression and Accumulation in Daucus carota.
Plant carotenoids are synthesized and accumulated in plastids through a highly regulated pathway. Lycopene β-cyclase (LCYB) is a key enzyme involved directly in the synthesis of α-carotene and β-carotene through the cyclization of lycopene. Carotenoids are produced in both carrot (Daucus carota) leaves and reserve roots, and high amounts of α-carotene and β-carotene accumulate in the latter. In some plant models, the presence of different isoforms of carotenogenic genes is associated with an organ-specific function. D. carota harbors two Lcyb genes, of which DcLcyb1 is expressed in leaves and storage roots during carrot development, correlating with an increase in carotenoid levels. In this work, we show that DcLCYB1 is localized in the plastid and that it is a functional enzyme, as demonstrated by heterologous complementation in Escherichia coli and over expression and post transcriptional gene silencing in carrot. Transgenic plants with higher or reduced levels of DcLcyb1 had incremented or reduced levels of chlorophyll, total carotenoids and β-carotene in leaves and in the storage roots, respectively. In addition, changes in the expression of DcLcyb1 are accompanied by a modulation in the expression of key endogenous carotenogenic genes. Our results indicate that DcLcyb1 does not possess an organ specific function and modulate carotenoid gene expression and accumulation in carrot leaves and storage roots....(more)
Moreno JC, et al. PLoS One 2013;8(3):e58144.
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- 34. Evaluation of nutraceutical components and antioxidant potential of north Indian wild culinary-medicinal termitophilous mushrooms.
Mushrooms have long been treated as a delicacy. Nowadays, however, many researchers consider them to be nutraceutical foods. The objective of this study was to determine the nutraceutical components in 7 edible species of Termitomyces (T. microcarpus, T. radicatus, T. badius, T. medius, T. heimii, T. striatus, and T. mammiformis) collected from different localities in North India during the monsoon season; their antioxidant properties also were determined by DPPH free radical scavenging ability and reducing power ability. The various nutraceutical components evaluated include phenolics (15.0-25.85 mg/g), flavonoids (1.38-2.02 mg/g), ascorbic acid (0.018-0.15 mg/g), β-carotene (0.11-0.27 µg/g), and lycopene (0.03-0.19 µg/g)....(more)
Kumari B, et al. Int J Med Mushrooms 2013;15(2):191-7.
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- 35. Improvement of NADPH bioavailability in Escherichia coli through the use of phosphofructokinase deficient strains.
NADPH-dependent reactions play important roles in production of industrially valuable compounds. In this study, we used phosphofructokinase (PFK)-deficient strains to direct fructose-6-phosphate to be oxidized through the pentose phosphate pathway (PPP) to increase NADPH generation. pfkA or pfkB single deletion and double-deletion strains were tested for their ability to produce lycopene. Since lycopene biosynthesis requires many NADPH, levels of lycopene were compared in a set of isogenic strains, with the pfkA single deletion strain showing the highest lycopene yield. Using another NADPH-requiring process, a one-step reduction reaction of 2-chloroacrylate to 2-chloropropionic acid by 2-haloacrylate reductase, the pfkA pfkB double-deletion strain showed the highest yield of 2-chloropropionic acid product. The combined effect of glucose-6-phosphate dehydrogenase overexpression or lactate dehydrogenase deletion with PFK deficiency on NADPH bioavailability was also studied. The results indicated that the flux distribution of fructose-6-phosphate between glycolysis and the pentose phosphate pathway determines the amount of NAPDH available for reductive biosynthesis....(more)
Wang Y, et al. Appl Microbiol Biotechnol 2013 Apr 5.
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