Instruct: Given a question, retrieve documents that answer the question.
Query: xanthones
The tropical mangosteen fruit has long been prized in Southeast Asia for its traditional healing properties. Mangosteen fruit juice is now available in the United States and marketed for its purported health benefits. We describe a case of severe lactic acidosis associated with the use of mangosteen juice as a dietary supplement.
Plants contain numerous polyphenols, which have been shown to reduce inflammation and hereby to increase resistance to disease. Examples of such polyphenols are isothiocyanates in cabbage and broccoli, epigallocatechin in green tee, capsaicin in chili peppers, chalones, rutin and naringenin in apples, resveratrol in red wine and fresh peanuts and curcumin/curcuminoids in turmeric. Most diseases are maintained by a sustained discreet but obvious increased systemic inflammation. Many studies suggest that the effect of treatment can be improved by a combination of restriction in intake of proinflammatory molecules such as advanced glycation end products (AGE), advanced lipoperoxidation end products (ALE), and rich supply of antiinflammatory molecules such as plant polyphenols. To the polyphenols with a bulk of experimental documentation belong the curcuminoid family and especially its main ingredient, curcumin. This review summarizes the present knowledge about these turmericderived ingredients, which have proven to be strong antioxidants and inhibitors of cyclooxigenase-2 (COX-2), lipoxygenase (LOX) and nuclear factor kappa B (NF-kappaB) but also AGE. A plethora of clinical effects are reported in various experimental diseases, but clinical studies in humans are few. It is suggested that supply of polyphenols and particularly curcuminoids might be value as complement to pharmaceutical treatment, but also prebiotic treatment, in conditions proven to be rather therapy-resistant such as Crohn's, long-stayed patients in intensive care units, but also in conditions such as cancer, liver cirrhosis, chronic renal disease, chronic obstructive lung disease, diabetes and Alzheimer's disease.
Sulforaphane [1-isothiocyanate-(4R)-(methylsulfinyl)butane] is a natural dietary isothiocyanate produced by the enzymatic action of the myrosinase on glucopharanin, a 4-methylsulfinylbutyl glucosinolate contained in cruciferous vegetables of the genus Brassica such as broccoli, brussel sprouts, and cabbage. Studies on this compound is increasing because its anticarcinogenic and cytoprotective properties in several in vivo experimental paradigms associated with oxidative stress such as focal cerebral ischemia, brain inflammation, intracerebral hemorrhage, ischemia and reperfusion induced acute renal failure, cisplatin induced-nephrotoxicity, streptozotocin-induced diabetes, carbon tetrachloride-induced hepatotoxicity and cardiac ischemia and reperfusion. This protective effect also has been observed in in vitro studies in different cell lines such as human neuroblastoma SH-SY5Y, renal epithelial proximal tubule LLC-PK1 cells and aortic smooth muscle A10 cells. Sulforaphane is considered an indirect antioxidant; this compound is able to induce many cytoprotective proteins, including antioxidant enzymes, through the Nrf2-antioxidant response element pathway. Heme oxygenase-1, NAD(P)H: quinone oxidoreductase, glutathione-S-transferase, gamma-glutamyl cysteine ligase, and glutathione reductase are among the cytoprotective proteins induced by sulforaphane. In conclusion, sulforaphane is a promising antioxidant agent that is effective to attenuate oxidative stress and tissue/cell damage in different in vivo and in vitro experimental paradigms. Copyright © 2010 Elsevier GmbH. All rights reserved.
Artemisia dracunculus L. (tarragon) has a long history of use as a spice and remedy. Two well-described "cultivars" (Russian and French) are used widely and differ in ploidy level, morphology, and chemistry. Key biologically active secondary metabolites are essential oils (0.15-3.1%), coumarins (>1%), flavonoids, and phenolcarbonic acids. In vivo studies mainly in rodents, particularly from Russian sources, highlight potential anti-inflammatory, hepatoprotective, and antihyperglycemic effects. Despite concerns about the toxic effects of two of its main constituents, estragole (up to 82%) and methyleugenol (up to 39%), no acute toxicity or mutagenic activity has been reported at doses relevant for human consumption. Water extracts of A. dracunculus contain very low amounts of estragole and methyleugenol and, therefore, are considered to pose a very limited risk. Overall, a stronger focus on clinical studies and precise taxonomic and phytochemical definition of the source material will be essential for future research efforts.
Continuing evidence of the feminising effects of xenoestrogens on a range of wildlife species increases the need to assess the human health risk of these estrogen mimics. We have estimated the exposure of New Zealand males, females and young men to a range of naturally occurring and synthetic xenoestrogens found in food. Only estrogenic compounds that act by interaction with the estrogen receptor have been included. Theoretical plasma estrogen activity levels were derived from estrogen exposure estimates and estrogenic potency data. Theoretical plasma levels were compared with published data for specific xenoestrogens. There was surprisingly close agreement. Xenoestrogenicity from dietary intake was almost equally attributed to naturally occurring and synthetic xenoestrogens. Relative contributions for a male, for example were isoflavones (genistein and daidzein) (36%) and bisphenol A (34%) with smaller contributions from alkyl phenols (18%) and the flavonoids (phloretin and kaempferol) (12%). It is suggested that dietary xenoestrogens might have a pharmacological effect on New Zealand males and postmenopausal women, but are unlikely to be significant for pre-menopausal women.
Almond (Prunus dulcis[Mill.] D.A. Webb) skins have been proposed as a source of bioactive polyphenols. In this article, the phenolic composition and antioxidant activity of almond skins obtained from different processes (blanching [freeze-drying], blanching + drying, and roasting) were studied. A total of 31 phenolic compounds corresponding to flavan-3-ols (33% to 56% of the total of phenolic compounds identified), flavonol glycosides (9% to 36%), hydroxybenzoic acids and aldehydes (6% to 26%), flavonol aglycones (1.7% to 18%), flavanone glycosides (3% to 7.7%), flavanone aglycones (0.69% to 5.4%), hydroxycinnamic acids (0.65% to 2.6%), and dihydroflavonol aglycones (0% to 2.8%) were determined in the skins from 3 different varieties of almonds. The total contents of phenolic compounds identified were significantly (P < 0.05) higher (around 2-fold) in the roasted samples than in the blanched almonds (freeze-dried). Industrial drying (oven drying) of the blanched almond skins produced an increase (< 2-fold) in the contents of phenolic compounds, although the results were only statistically significant (P < 0.05) for some samples. The antioxidant activity (ORAC values) was higher for the roasted samples (0.803 to 1.08 mmol Trolox/g), followed by the samples subjected to blanching + drying (0.398 to 0.575 mmol Trolox/g) and then the blanched (freeze-dried) samples (0.331 to 0.451 mmol Trolox/g). Roasting is the most suitable type of industrial processing of almonds to obtain almond skin extracts with the greatest antioxidant capacity.
The idea that normal constituents of the diet can influence visual function is not new. As early as 1782, Buzzi identified the yellow of the macula and Schulze (1866) specifically postulated that the yellow pigments led to improvements in human vision. These pigments were later found to be derived from dietary lutein and zeaxanthin that are known to be oxygenated carotenoids (xanthophylls). Walls and Judd (1933) postulated that these yellow intraocular pigments could improve visual performance by absorbing light scattered both within (for example, glare) and outside of the eye (increasing visual range by absorbing blue light scattered in the atmosphere), and by improving spatial vision through enhancing contrast and reducing chromatic blur. In this article, evidence for these ideas is reviewed with particular emphasis towards more recent data on glare effects.
This paper presents a new interpretation of a unique Bronze Age (c. 3000-1100 BCE) Aegean wall painting in the building of Xeste 3 at Akrotiri,Thera. Crocus carturightianus and its active principle, saffron, are the primary subjects at Xeste 3. Several lines of evidence suggest that the meaning of these frescoes concerns saffron and healing: (1) the unusual degree of visual attention given to the crocus, including the variety of methods for display of the stigmas; (2) the painted depiction of the line of saffron production from plucking blooms to the collection of stigmas; and (3) the sheer number (ninety) of medical indications for which saffron has been used from the Bronze Age to the present. The Xeste 3 frescoes appear to portray a divinity of healing associated with her phytotherapy, saffron. Cultural and commercial interconnections between the Therans, the Aegean world, and their neighboring civilizations in the early 2nd millennium BCE indicate a close network of thematic exchange, but there is no evidence that Akrotiri borrowed any of these medicinal (or iconographic) representations. The complex production line, the monumental illustration of a goddess of medicine with her saffron attribute, and this earliest botanically accurate image of an herbal medication are all Theran innovations.
Over the last 40 years there have been constant reports concerning environmental chemicals with hormone-like effects in wildlife. An endocrine disruptor is an exogenous substance that causes adverse health effects in an intact organism or its progeny, secondary to changes in endocrine function. Endocrine disruptors of widely diverse chemical structures that have oestrogenic properties are known as oestrogenic xenobiotics or xenoestrogens. Some of these substances, such as phytoestrogens and mycoestrogens, can come from diet or from the environment. Although the oestrogenic activity of these substances is weaker than that of oestradiol, new chemicals with endocrine disrupting potential continue to be discovered, inadvertent forms of exposure are constantly being identified, and there is increasing concern about cumulative effects. Studies in the 1960s and 1970s characterized the oestrogenicity of a number of industrial compounds and the pesticides o,p-DDT, kepone, methoxychlor, phenolic derivatives and polychlorinated biphenyls (PCBs). In the last 5 years, several environmental chemicals have been added to the list of xenoestrogens, including the pesticides toxaphene, dieldrin and endosulphan, and several different compounds used in the food industry, antioxidants such a t-butylhydroxyanisole; plasticizers such as benzylbutylphthalate and 4-OH-alkylphenols; and substances used in dental restorations, such as bisphenol-A. The relevance of these newly discovered endocrine disruptors to human health is now starting to emerge. The few studies that have investigated their effect in humans point in the same direction: if there is indeed an association between exposure to substances with hormone-disruptive activity and certain disorders of endocrine organs, the incidence of such disorders would be greater in areas where exposure to agents with this activity is high. A closer scrutiny is required to determine whether these newly discovered endocrine disrupting chemicals contribute, together with oestrogenic pesticides, to the exposure of humans to xenoestrogens.
The exposure to some chemicals can lead to hormone disrupting effects. Presently, much attention is focused on so-called xeno-estrogens, synthetic compounds that interact with hormone receptors causing a number of reactions that eventually lead to effects related to reproduction and development. The current study was initiated to investigate the presence of a number of such compounds in precipitation as a follow-up on a previous study in which pesticide concentrations in air and precipitation were determined. Rainwater samples were collected at about 50 locations in The Netherlands in a four week period. The samples were analysed for bisphenol-A, alkylphenols and alkylphenol ethoxylates, phthalates, flame retardants and synthetic musk compounds. The results clearly indicated the presence of these compounds in precipitation. The concentrations ranged from the low ng l(-1) range for flame retardants to several thousands of ng l(-1) for the phthalates. Bisphenol-A was found in 30% of the samples in concentrations up to 130 ng l(-1), while alkylphenols and alkylphenol ethoxylates were found in virtually all locations in concentrations up to 920 ng l(-1) for the individual compounds. Phthalates were by far the most abundant xeno-estrogens in the precipitation samples and were found in every sample. Di-isodecyl phthalate was found in a surprisingly high concentration of almost 100 000 ng l(-1). Polybrominated flame retardants were found in the low ng l(-1) range and generally in less than 20% of the samples. Noticeable was the finding of hexabromocyclododecane, a replacement for the polybrominted diphenyl ethers at one location in a concentration of almost 2000 ng l(-1). Finally, as expected, synthetic musk compounds were detected in almost all samples. This is especially true for the polycyclic musks HHCB and AHTN. Nitro musks were found, but only on a few locations. Kriging techniques were used to calculate precipitation concentrations in between actual sampling locations to produce contour plots for a number of compounds. These plots clearly show located emission sources for a number of compounds such as bisphenol-A, nonylphenol ethoxylate, phthalates and AHTN. On the contrary, the results for HHCB and some phthalates indicated diffuse emission patterns, probably as the result of the use of consumer products containing these compounds.
Cancer metastasis refers to the spread of cancer cells from the primary neoplasm to distant sites, where secondary tumors are formed, and is the major cause of death from cancer. Natural phytochemicals containing phenolic compounds have been widely demonstrated to have the capability to prevent cancer metastasis. Among phenolic compounds, flavonoids are a very large subclass, and they are abundant in food and nutraceuticals. The number of reports demonstrating that flavonoids are an effective natural inhibitor of cancer invasion and metastasis is increasing in the scientific literature. Catechin derivatives, (−)-epigallocatechin-3-gallate, (−)-epigallocatechin, (−)-epicatechin-3-gallate,and (−)-epicatechin, are the most studied compounds in this topic so far; genistein/genistin, silibinin, quercetin, and anthocyanin have also been widely investigated for their inhibitory activities on invasion/metastasis. Other flavonoids in dietary vegetable foods that are responsible for anti-invasive and anti-metastatic activities of tumors include luteolin,apigenin, myricetin, tangeretin, kaempferol, glycitein, licoricidin,daidzein, and naringenin. To effectively overcome the metastatic cascade, including cell-cell attachment, tissue barrier degradation, migration, invasion, cell-matrix adhesion,and angiogenesis, it is essential that a bioactive compound prevent tumor cells from metastasizing. This review summarizes the effects of flavonoids on the metastatic cascade and the related proteins, the in vitro anti-invasive activity of flavonoids against cancer cells, and the effects of flavonoids on antiangiogenic and in vivo anti-metastatic models. The available scientific evidence indicates that flavonoids are a ubiquitous dietary phenolics subclass and exert extensive in vitro anti-invasive and in vivo anti-metastatic activities.
The typical spices used in winter include nutmeg, cinnamon, clove and anise. These spices contain two groups of chemicals, the allylbenzenes and their isomers, the propenylbenzenes. It was suggested 40 years ago by Alexander Shulgin that these substances act as metabolic precursors of amphetamines. The biotransformation of these precursors to nitrogen-containing metabolites is reviewed. These reactions have not been reported in humans. Whether or not the pharmacology and toxicology of spices such as nutmeg can be explained on the basis of their allylbenzene or propenylbenzene content is speculative. Humans may be exposed to amphetamines derived from these precursors in forno, the formation during baking and cooking, for example in the preparation of Lebkuchen, or Christmas gingerbread. It is possible that this may be responsible, in part, for uplifting our mood in winter. However, the role of these aromatic substances, acting simply as odours, evoking old memories of winters past, cannot be ignored. Whether spices have a true pharmacological effect or they act as aromatherapy remains to be elucidated through clinical and laboratory studies.
We assessed the contribution of culinary and medicinal herbs to the total intake of dietary antioxidants. Our results demonstrate that there is more than a 1000-fold difference among antioxidant concentrations of various herbs. Of the dried culinary herbs tested, oregano, sage, peppermint, garden thyme, lemon balm, clove, allspice and cinnamon as well as the Chinese medicinal herbs Cinnamomi cortex and Scutellariae radix all contained very high concentrations of antioxidants (i.e., >75 mmol/100 g). In a normal diet, intake of herbs may therefore contribute significantly to the total intake of plant antioxidants, and be an even better source of dietary antioxidants than many other food groups such as fruits, berries, cereals and vegetables. In addition, the herbal drug, Stronger Neo-Minophagen C, a glycyrrhizin preparation used as an intravenous injection for the treatment of chronic hepatitis, boosts total antioxidant intake. It is tempting to speculate that several of the effects due to these herbs are mediated by their antioxidant activities.
Diet supplementation and/or modulation is an important strategy to significantly improve human health. The search of plants as additional sources of bioactive phenolic compounds is relevant in this context. The aqueous extract of Hibiscus sabdariffa is rich in anthocyanins and other phenolic compounds including hydroxycitric and chlorogenic acids. Using this extract we have shown an effective protection of cultured peripheral blood mononuclear cells from the cellular death induced by H(2)O(2) and a significant role in the production of inflammatory cytokines. In vitro, the extract promotes the production of IL-6 and IL-8 and decreases the concentration of MCP-1 in supernatants in a dose-dependent manner. In humans, the ingestion of an acute dose of the extract (10g) was well tolerated and decreased plasma MCP-1 concentrations significantly without further effects on other cytokines. This effect was not due to a concomitant increase in the antioxidant capacity of plasma. Instead, its mechanisms probably involve a direct inhibition of inflammatory and/or metabolic pathways responsible for MCP-1 production, and may be relevant in inflammatory and chronic conditions in which the role of MCP-1 is well established. If beneficial effects are confirmed in patients, Hibiscus sabdariffa could be considered a valuable traditional herbal medicine for the treatment of chronic inflammatory diseases with the advantage of being devoid of caloric value or potential alcohol toxicity. Copyright 2009 Elsevier GmbH. All rights reserved.
Population differences in age-related diseases and cancer could stem from differences in diet. To characterize DNA strand-breaking activities in selected foods/beverages, flavorings, and some of their constituent chemicals, we used p53R cells, a cellular assay sensitive to such breaks. Substances testing positive included reference chemicals: quinacrine (peak response, 51X) and etoposide (33X); flavonoids: EGCG (19X), curcumin (12X), apigenin (9X), and quercetin (7X); beverages: chamomile (11X), green (21X), and black tea (26X) and coffee (3 to 29X); and liquid smoke (4 to 28X). Damage occurred at dietary concentrations: etoposide near 5 μg/ml produced responses similar to a 1:1000 dilution of liquid smoke, a 1:20 dilution of coffee, and a 1:5 dilution of tea. Pyrogallol-related chemicals and tannins are present in dietary sources and individually produced strong activity: pyrogallol (30X), 3-methoxycatechol (25X), gallic acid (21X), and 1,2,4-benzenetriol (21X). From structure-activity relationships, high activities depended on specific orientations of hydroxyls on the benzene ring. Responses accompanied cellular signals characteristic of DNA breaks such as H2AX phosphorylation. Breaks were also directly detected by comet assay. Cellular toxicological effects of foods and flavorings could guide epidemiologic and experimental studies of potential disease risks from DNA strand-breaking chemicals in diets.
The functional properties, including antioxidant and chemopreventative capacities as well as the inhibitory effects on angiotensin-converting enzyme (ACE), α-glucosidase and pancreatic lipase, of three Australian-grown faba bean genotypes (Nura, Rossa and TF(Ic*As)*483/13) were investigated using an array of in vitro assays. Chromatograms of on-line post column derivatisation assay coupled with HPLC revealed the existence of active phenolics (hump) in the coloured genotypes, which was lacking in the white-coloured breeding line, TF(Ic*As)*483/13. Roasting reduced the phenolic content, and diminished antioxidant activity by 10-40 % as measured by the reagent-based assays (diphenylpicrylhydrazyl, 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) and oxygen radical absorbance capacity) in all genotypes. Cell culture-based antioxidant activity assay (cellular antioxidant activity) showed an increase of activity in the coloured genotypes after roasting. Faba bean extracts demonstrated cellular protection ability against H₂O₂-induced DNA damage (assessed using RAW264.7 cells), and inhibited the proliferation of all human cancer cell lines (BL13, AGS, Hep G2 and HT-29) evaluated. However, the effect of faba bean extracts on the non-transformed human cells (CCD-18Co) was negligible. Flow cytometric analyses showed that faba bean extracts successfully induced apoptosis of HL-60 (acute promyelocytic leukaemia) cells. The faba bean extracts also exhibited ACE, α-glucosidase and pancreatic lipase inhibitory activities. Overall, extracts from Nura (buff-coloured) and Rossa (red-coloured) were comparable, while TF(Ic*As)*483/13 (white-coloured) contained the lowest phenolic content and exhibited the least antioxidant and enzyme inhibition activities. These results are important to promote the utilisation of faba beans in human diets for various health benefits.
The methanolic extract of fresh tea leaves of Camellia sinensis L. (Theaceae) (CS) was assayed for its potential to inhibit enzymes with hydrolytic activity in Naja naja kaouthia Lesson (Elapidae) and Calloselasma rhodostoma Kuhl (Viperidae) venoms. These snake venom enzymes are responsible for the early effects of envenomation, such as local tissue damage and inflammation. The CS extract inhibited phospholipase A(2), proteases, hyaluronidase and L-amino acid oxidase in both venoms by in vitro neutralization and inhibited the hemorrhagic and the dermonecrotic activities of the venoms in vivo. It is suggested that the inhibitory potential of the CS extract against local tissue damage induced by snake venoms may be attributed to complexation and chelation between the venom proteins and the phenolic contents of the extract.
Purpose The objective of this study was to formulate and evaluate freeze-dried black raspberry (FBR) ethanol extract (RE) loaded poly(DL-lactic-co-glycolic acid) (PLGA) and poly(DL-lactic acid) (PLA) injectable millicylindrical implants for sustained delivery of chemopreventive FBR anthocyanins (cyanidin-3-sambubioside (CS), cyanidin-3-glucoside (CG) and cyanidin-3-rutinoside (CR)). Methods Identification and quantitation of CS, CG, and CR in RE was performed by mass spectroscopy and HPLC. RE:triacetyl-β-cyclodextrin (TA-β-CD) inclusion complex (IC) was prepared by a kneading method and characterized by X-ray diffraction (XRD), nuclear magnetic resonance spectroscopy (NMR) and UV-visible spectroscopy. RE or RE:TA-β-CD IC-loaded PLGA or PLA implants were prepared by a solvent extrusion method. In vitro and in vivo controlled release studies were conducted in phosphate-buffered saline Tween-80 (pH 7.4, 37°C) and after subcutaneous administration in male Sprague-Dawley rats, respectively. Anthocyanins were quantified by HPLC at 520 nm. Results The content of CS, CG, and CR in RE was 0.2, 1.5, and 3.5 wt%, respectively. The chemical stability of anthocyanins in solution was determined to be pH-dependent, and their degradation rate increased with an increase in pH from 2.4 to 7.4. PLGA/PLA millicylindrical implants loaded with 5 or 10 wt% RE exhibited a high initial burst and short release duration of anthocyanins (35–52 and 80–100% CG + CR release after 1 and 14 days, respectively). The cause for rapid anthocyanins release was linked to higher polymer water uptake and porosity associated with the high osmolytic components of large non-anthocyanin fraction of RE. XRD, 1H NMR and UV-visible spectroscopy indicated that the non-anthocyanin fraction molecules of RE formed an IC with TA-β-CD, decreasing the hydrophilicity of RE. Formation of an IC with hydrophobic carrier, TA-β-CD, provided better in vitro/in vivo sustained release of FBR anthocyanins (16–24 and 97–99% CG + CR release, respectively, after 1 and 28 days from 20 wt% RE:TA-β-CD IC/PLA implants) over 1 month, owing to reduced polymer water uptake and porosity. Conclusion PLA injectable millicylindrical implants loaded with RE:TA-β-CD IC are optimal dosage forms for 1-month slow and continuous delivery of chemopreventive FBR anthocyanins.
Inhibition of monoamine oxidase is one way to treat depression and anxiety. The information now available on the pharmacokinetics of flavonoids and of the components of tobacco prompted an exploration of whether a healthy diet (with or without smoking) provides active compounds in amounts sufficient to partially inhibit monoamine oxidase. A literature search was used to identify dietary monoamine oxidase inhibitors, the levels of these compounds in foods, the pharmacokinetics of the absorption and distribution, and tissue levels observed. An estimated daily intake and the expected tissue concentrations were compared with the measured efficacies of the compounds as inhibitors of monoamine oxidases. Norharman, harman and quercetin dietary presence, pharmacokinetics, and tissue levels were consistent with significant levels reaching neuronal monoamine oxidase from the diet or smoking; 1,2,3,4-tetrahydroisoquinoline, eugenol, 1-piperoylpiperidine, and coumarin were not. Quercetin was equipotent with norharman as a monoamine oxidase A inhibitor and its metabolite, isorhamnetin, also inhibits. Total quercetin was the highest of the compounds in the sample diet. Although bioavailability was variable depending on the source, a healthy diet contains amounts of quercetin that might give sufficient amounts in brain to induce, by monoamine oxidase A inhibition, a small decrease in neurotransmitter breakdown.
PURPOSE: Protecting the lens against oxidative stress is of great importance in delaying the onset of cataract. Isothiocyanates, such as sulforaphane (SFN), are proposed to provide cytoprotection against oxidative stress. We therefore tested the ability of SFN to perform this role in lens cells and establish its ability to delay the onset of cataract. METHODS: The human lens epithelial cell line FHL124 and whole porcine lens culture systems were used. The ApoTox-Glo Triplex Assay was used to assess FHL124 cell survival, cytotoxicity, and apoptosis. The MTS assay was used to assess cell populations. To determine levels of DNA strand breaks, the alkaline comet assay was performed and quantified. Lactate dehydrogenase levels in the medium were evaluated to reflect cell damage/death. To assess level of gene expression, an Illumina whole-genome HT-12 v4 beadchip was used. Protein expression was determined by Western blot and immunocytochemistry. RESULTS: Exposures of 30 μM H2O2 to FHL124 cells caused a reduction in cell viability and increased cytotoxicity/apoptosis; these effects were significantly inhibited by 24-hour pretreatment with 1 μM SFN. In addition, 1 μM SFN significantly reduced H2O2-induced DNA strand breaks. When applied to cultured porcine lenses, SFN protected against H2O2-induced opacification. Illumina whole-genome HT-12 v4 beadchip microarray data revealed eight genes upregulated following 24-hour exposure to 1- and 2-μM SFN, which included NQO1 and TXNRD1. This pattern was confirmed at the protein level. Nrf2 translocated to the nucleus in response to 0.5- to 2.0-μM SFN exposure CONCLUSIONS: The dietary component SFN demonstrates an ability to protect human lens cells against oxidative stress and thus could potentially delay the onset of cataract.
The food mutagens IQ (2-amino-3-methylimidazo[4,5-f]quinoline) and PhIP (2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine) are heterocyclic amines (HCA), generated when heating proteinaceous food. This study investigates the protective potential of the flavonoids quercetin (Q) and rutin (R) against oxidative stress induced in vitro by IQ and PhIP in lymphocytes from healthy individuals and untreated, newly diagnosed colon cancer patients using the Comet assay. In the presence of up to 500μM Q and R, the DNA damage resulting from a high dose of PhIP (75μM) or IQ (150μM) was significantly reduced (P<0.001) to levels comparable to six times lower IQ or 7.5 times lower PhIP doses. Lymphocytes from colon cancer patients had greater baseline DNA damage than those from healthy individuals (P<0.01) and this higher level of damage was also observed throughout in vitro treatment. Except for the >50years of age group and male gender, confounding factors such as smoking, drinking and/or dietary habits were not found to be significant. In conclusion, flavonoids reduced oxidative stress caused by food mutagens in vitro in lymphocytes of healthy individuals and colon cancer patients. Thus, dietary supplementation with flavonoid-rich vegetables and fruits may prove very effective in protecting against oxidative stress. Copyright © 2011 Elsevier Ltd. All rights reserved.
Phenolic ingredients of an aqueous carob extract are well characterized and consist of mainly gallic acid (GA). In order to assess possible chemopreventive mechanisms of carob, which can be used as a cacao substitute, effects on expression of genes related to stress response and drug metabolism were studied using human colon cell lines of different transformation state (LT97 and HT29). Stress-related genes, namely catalase (CAT) and superoxide dismutase (SOD2), were induced by carob extract and GA in LT97 adenoma, but not in HT29 carcinoma cells. Although corresponding protein products and enzyme activities were not elevated, pretreatment with carob extract and GA for 24 h reduced DNA damage in cells challenged with hydrogen peroxide (H(2)O(2)). In conclusion, carob extract and its major phenolic ingredient GA modulate gene expression and protect colon adenoma cells from genotoxic impact of H(2)O(2). Upregulation of stress-response genes could not be related to functional consequences.
The mammalian lignans enterolactone and enterodiol, which are produced by the microflora in the colon of humans and animals from precursors in foods, have been suggested to have potential anticancer effects. This study determined the production of mammalian lignans from precursors in food bars containing 25 g unground whole flaxseed (FB), sesame seed (SB), or their combination (FSB; 12.5 g each). In a randomized crossover study, healthy postmenopausal women supplemented their diets with the bars for 4 wk each separated by 4-wk washout periods, and urinary mammalian lignan excretion was measured at baseline and after 4 wk as a marker of mammalian lignan production. Results showed an increase with all treatments (65.1-81.0 mumol/day; P < 0.0001), which did not differ among treatments. Lignan excretion with the whole flaxseed was similar to results of other studies using ground flaxseed. An unidentified lignan metabolite was detected after consumption of SB and FSB but not of FB. Thus, we demonstrated for the first time that 1) precursors from unground whole flaxseed and sesame seed are converted by the bacterial flora in the colon to mammalian lignans and 2) sesame seed, alone and in combination with flaxseed, produces mammalian lignans equivalent to those obtained from flaxseed alone.
Broccoli sprouts are widely consumed in many parts of the world. There have been no reported concerns with respect to their tolerance and safety in humans. A formal phase I study of safety, tolerance, and pharmacokinetics appeared justified because these sprouts are being used as vehicles for the delivery of the glucosinolate glucoraphanin and its cognate isothiocyanate sulforaphane [1-isothiocyanato-(4R)-(methylsulfinyl)butane] in clinical trials. Such trials have been designed to evaluate protective efficacy against development of neoplastic and other diseases. A placebo-controlled, double-blind, randomized clinical study of sprout extracts containing either glucosinolates (principally glucoraphanin, the precursor of sulforaphane) or isothiocyanates (principally sulforaphane) was conducted on healthy volunteers who were in-patients on our clinical research unit. The subjects were studied in three cohorts, each comprising three treated individuals and one placebo recipient. Following a 5-day acclimatization period on a crucifer-free diet, the broccoli sprout extracts were administered orally at 8-h intervals for 7 days (21 doses), and the subjects were monitored during this period and for 3 days after the last treatment. Doses were 25 micromol of glucosinolate (cohort A), 100 micromol of glucosinolate (cohort B), or 25 micromol of isothiocyanate (cohort C). The mean cumulative excretion of dithiocarbamates as a fraction of dose was very similar in cohorts A and B (17.8 +/- 8.6% and 19.6 +/- 11.7% of dose, respectively) and very much higher and more consistent in cohort C (70.6 +/- 2.0% of dose). Thirty-two types of hematology or chemistry tests were done before, during, and after the treatment period. Indicators of liver (transaminases) and thyroid [thyroid-stimulating hormone, total triiodothyronine (T3), and free thyroxine (T4)] function were examined in detail. No significant or consistent subjective or objective abnormal events (toxicities) associated with any of the sprout extract ingestions were observed.
Age-related macular degeneration (AMD) is a common disorder that causes irreversible loss of central vision. Increased intake of foods containing zeaxanthin may be effective in preventing AMD because the macula accumulates zeaxanthin and lutein, oxygenated carotenoids with antioxidant and blue light-absorbing properties. Lycium barbarum L. is a small red berry known as Fructus lycii and wolfberry in the West, and Kei Tze and Gou Qi Zi in Asia. Wolfberry is rich in zeaxanthin dipalmitate, and is valued in Chinese culture for being good for vision. The aim of this study, which was a single-blinded, placebo-controlled, human intervention trial of parallel design, was to provide data on how fasting plasma zeaxanthin concentration changes as a result of dietary supplementation with whole wolfberries. Fasting blood was collected from healthy, consenting subjects; fourteen subjects took 15 g/d wolfberry (estimated to contain almost 3 mg zeaxanthin) for 28 d. Repeat fasting blood was collected on day 29. Age- and sex-matched controls (n 13) took no wolfberry. Responses in the two groups were compared using the Mann-Whitney test. After supplementation, plasma zeaxanthin increased 2.5-fold: mean values on day 1 and 29 were 0.038 (sem 0.003) and 0.096 (sem 0.009) micromol/l (P<0.01), respectively, for the supplementation group; and 0.038 (sem 0.003) and 0.043 (sem 0.003) micromol/l (P>0.05), respectively, for the control group. This human supplementation trial shows that zeaxanthin in whole wolfberries is bioavailable and that intake of a modest daily amount markedly increases fasting plasma zeaxanthin levels. These new data will support further study of dietary strategies to maintain macular pigment density.