Instruct: Given a question, retrieve relevant passages that answer the question.
Query: greta
Traditional herbal preparations used in Ayurveda, traditional Chinese medicine, traditional Tibetan medicine, and other Asian traditional medicine systems may contain significant amounts of mercury, arsenic or lead. Though deliberately incorporated in Asian traditional herbal preparations for therapeutic purposes, these constituents have caused intoxications worldwide. The aim of this study was therefore to determine mercury, arsenic, and lead levels in Asian traditional herbal preparations on the Dutch market. A total of 292 traditional herbal preparations used in Ayurveda, traditional Chinese medicine, and traditional Tibetan medicine were sampled between 2004 and 2007. Samples were mostly multi-ingredient traditional herbal preparations containing herbs and minerals. The labeling of less than 20% of the traditional herbal preparations suggested the presence of mercury, arsenic or lead. These elements were shown by inductively coupled mass spectrometry (ICP-MS) in 186 (64%) of 292 traditional herbal preparations. Estimated weekly mercury, arsenic, and lead intake levels were calculated for each traditional herbal preparation from the analytically determined concentrations and the recommended dose. A total of 59 traditional herbal preparations (20%) were likely to result in intakes of these elements significantly exceeding safety limits. Of these 59 traditional herbal preparations, intake estimates for 50 traditional herbal preparations significantly exceeded the safety limit for mercury (range = 1.4-1747 mg week(-1)); intake estimates for 26 traditional herbal preparations significantly exceeded the safety limit for arsenic (range = 0.53-427 mg week(-1)) and intake estimates for eight traditional herbal preparations were significantly above the safety limit for lead (range = 2.6-192 mg week(-1)). It is concluded that the mercury, arsenic, and lead contents of traditional herbal preparations used in Ayurveda, traditional Chinese medicine, and traditional Tibetan medicine remain a cause for concern and require strict control.
Many deep-sea fishes store large amounts of wax esters in their body for buoyancy control. Some of them are frequently caught as by-catch of tuna and other fishes. The most noteworthy ones include escolar and oilfish. The accumulation of the indigestible wax esters in the rectum through consumption of these fish engenders discharges or leakage per rectum as orange or brownish green oil, but without noticeable loss of water. This physiological response is called keriorrhea, which is variously described as "oily diarrhea," "oily orange diarrhea," or "orange oily leakage" by the mass media and bloggers on the internet. Outbreaks of keriorrhea have been repeatedly reported across continents. Additional symptoms including nausea, vomiting, abdominal cramps, and diarrhea were complained by the victims. They are probably due to anxiety or panic when suffering from keriorrhea. Escolar and oilfish are banned from import and sale in Italy, Japan, and South Korea. Rapid detection of the two fishes is imperative to ensure proper labeling and safeguarding of the public before and after any keriorrhea outbreak.
Glyphosate surfactant herbicide (GlySH) toxicity is an uncommon poisoning. We report two fatalities involving suicidal ingestion of this herbicide. Both deaths occurred despite early recognition of the serious nature of the poisoning and aggressive treatment. The deaths in this series are analysed in the context of a review of existing literature. Although traditionally regarded as minimally toxic, many deaths have been reported following suicidal ingestion. Severe GlySH toxicity may be refractory even to the most intensive supportive care. The triad of pulmonary oedema, metabolic acidosis and hyperkalaemia portends poor outcome. While containing a carbon phosphorus moiety, GlySH does not exhibit organophosphate toxicity. A clinical guide to assessing severity of GlySH toxicity is proposed and treatment modalities discussed.
Guillain-Barré syndrome (GBS) is a classic failure of the immune system with a life-threatening attack upon a critical self-component. The active phase of the disease is short, concordant with the latency of a primary adaptive immune response. Triggers for GBS include infection and (rarely) vaccination; cross-reactivity between infectious and neural epitopes has been well demonstrated, particularly for Campylobacter jejuni and motor axonal forms of GBS in which non-protein gangliosides are antigenic. Most people are probably exposed to a GBS trigger, but only rarely does the disease develop. We propose that GBS illustrates competing determinants of the immune system's decision about whether to mount a response, and that in unlucky affected individuals, co-presentation of cross-reactive antigens with danger signals activating pattern-recognition receptors overcomes normal self-recognition such that a primary response is initiated that attacks the nerve. Then, in most cases of GBS, the response rapidly turns off, and second attacks rarely occur. This suggests active restoration of tolerance, and specific privileged site attributes of nerve and declining danger signals as the trigger wanes may contribute to this restoration. Standard immunosuppression has not been effective in GBS. We suggest this is because immune tolerance is already being restored by the time such therapies are initiated. This in turn suggests that improvements in GBS outcomes are likely to come from better protection of the nerve cells under attack while normal resumption of tolerance is permitted to proceed rather than exploring more aggressive immunosuppressive approaches.
The anti-genotoxic effect of Ocimum sanctum L. extract was studied against the genotoxic effect induced by a synthetic progestin cyproterone acetate, on human lymphocytes using chromosomal aberrations, mitotic index, sister chromatid exchanges and replication index as a parameters. About 30 microM of cyproterone acetate was treated with O. sanctum L. infusion, at dosages of 1.075 x 10(-4), 2.125 x 10(-4) and 3.15 x 10(-4) g/ml of culture medium. A clear dose-dependent decrease in the genotoxic damage of cyproterone acetate was observed, suggesting a possible modulating role of the plant infusion. The results of the present study suggest that the plant infusion per se does not have genotoxic potential, but can modulate the genotoxicity of cyproterone acetate on human lymphocytes in vitro.
Life span extending mutations in growth signaling pathways protect against age-dependent DNA damage in yeast and decrease insulin resistance and cancer in mice. To test their effect in humans, we monitored for 22 years Ecuadorian subjects with mutations in the growth hormone receptor gene leading to severe growth hormone receptor (GHR) and IGF-I deficiencies and combined this information with surveys to identify the cause and age of death for subjects who died before this period. The individuals with GHR deficiency (GHRD) exhibited only one non-lethal malignancy and no cases of diabetes, in contrast to 17% cancer and 5% diabetes prevalence in the controls. A possible explanation for the very low incidence of cancer may be revealed by in vitro studies: serum from GHRD subjects reduced DNA breaks but increased apoptosis in human mammary epithelial cells (HMECs) treated with hydrogen peroxide. We also observed reduced insulin concentrations (1.4 μU/ml vs. 4.4μU/ml in unaffected relatives) and a very low homoeostasis model assessment of insulin resistance (HOMA-IR) index (0.34 vs. 0.96 in unaffected relatives) in GHRD individuals, indicating increased insulin sensitivity, which could explain the absence of diabetes in these subjects. Incubation of HMECs with GHRD serum also resulted in reduced expression of RAS, PKA and TOR, and up-regulation of SOD2, changes that promote cellular protection and life span extension in model organisms. These results provide evidence for a role of evolutionarily conserved pathways in promoting aging and diseases in humans and identify a candidate drug target for healthy life span extension.
Oestrogens govern reproductive functions in vertebrates, and are present in all animal tissues. The theoretical maximum daily intake (TMDI) of oestradiol-17beta by consumption of cattle meat is calculated to be 4.3 ng. Following the use of oestradiol-containing growth-promoting agents, TMDI is increased by a factor of 4.6 to 20 ng oestradiol-17beta, assuming that single dosage and 'good animal husbandry' are observed. Pork and poultry probably contain similar amounts of oestrogens as untreated cattle. The mean concentration of oestradiol-17beta in whole milk is estimated at 6.4 pg/ml. Scarce data available on eggs report up to 200 pg/g oestradiol-17beta. The risk evaluation of oestrogenic growth-promoting agents is limited by analytical uncertainties. Residues of oestradiol-17alpha and the importance of oestrogen conjugates are widely unknown. The performance of mass spectrometry still needs to be improved for confirmation of oestrogen concentrations in most food. At present, the potential relevance of oestradiol acyl esters, the actual daily production rate of oestradiol in prepubertal children, and the role of oestradiol metabolites in cancer are obscure. The presence of different cytoplasmic oestrogen receptor subtypes and potential oestradiol effects in non-reproductive functions require further examination.
CONTEXT: Restricting caloric intake is one of the most effective ways to extend lifespan and to reduce spontaneous tumor occurrence in experimental animals, but whether similar associations hold in humans has not been appropriately studied. OBJECTIVE: To determine whether caloric restriction in early life reduces the risk of invasive breast cancer. DESIGN, SETTING, AND PARTICIPANTS: Retrospective cohort study using data from the Swedish Inpatient Registry, the Swedish Cancer Registry, the Swedish Death Registry, and the Swedish Fertility Registry. Participants were 7303 Swedish women hospitalized for anorexia nervosa prior to age 40 years between 1965 and 1998. Women were excluded (n = 31) if they were diagnosed with cancer prior to their first discharge from hospitalization for anorexia nervosa. MAIN OUTCOME MEASURE: Incidence of invasive breast cancer. RESULTS: Compared with the Swedish general population, women hospitalized for anorexia nervosa prior to age 40 years had a 53% (95% confidence interval [CI], 3%-81%) lower incidence of breast cancer; nulliparous women with anorexia nervosa had a 23% (95% CI, 79% higher to 75% lower) lower incidence, and parous women with anorexia nervosa had a 76% (95% CI, 13%-97%) lower incidence. CONCLUSIONS: Severe caloric restriction in humans may confer protection from invasive breast cancer. Low caloric intake prior to first birth followed by a subsequent pregnancy appears to be associated with an even more pronounced reduction in risk.
Background In 2007 the World Cancer Research Fund (WCRF) and American Institute for Cancer Research (AICR) released eight recommendations related to body fatness, physical activity and diet aimed at preventing the most common cancers worldwide. However, limited information exists on the association between meeting these recommendations and risks of specific cancers, including breast cancer. Methods We operationalized six recommendations (related to body fatness, physical activity, foods that promote weight gain, plant foods, red and processed meats, and alcohol) and examined their association with invasive breast cancer incidence over 6.7 years of follow-up in the VITamins And Lifestyle (VITAL) study cohort. Participants included 30,797 post-menopausal women ages 50–76 years at baseline in 2000–2002 with no history of breast cancer. Breast cancers (n=899) were tracked through the Western Washington Surveillance, Epidemiology and End Results (SEER) database. Results Breast cancer risk was reduced by 60% in women who met at least five recommendations compared to those who met none (HR: 0.40; 95% CI: 0.25–0.65; Ptrend<0.001). Further analyses that sequentially removed individual recommendations least associated with reduced risk suggested that this reduction is due to meeting recommendations related to body fatness, plant foods and alcohol (HR for meeting vs. not meeting these three recommendations: 0.38; 95% CI: 0.25–0.58; Ptrend <0.001). Conclusions Meeting the WCRF/AICR cancer prevention recommendations, specifically those related to alcohol, body fatness and plant foods, is associated with reduced post-menopausal breast cancer incidence. Impact Increased adherence to the WCRF/AICR cancer prevention recommendations could substantially reduce post-menopausal breast cancer risk in US women.
Anthocyanins, belonging to the flavonoid family of phytochemicals, have received attention as agents that may have potential in preventing chronic diseases such as cardiovascular diseases and certain cancers. In the present study, an anthocyanin-rich extract from Concord grapes [referred to as Concord grape extract (CGE)] and the anthocyanin delphinidin were evaluated for their capacity to inhibit DNA adduct formation due to the environmental carcinogen benzo[a]pyrene (BP) in MCF-10F cells, a noncancerous, immortalized human breast epithelial cell line. CGE at 10 and 20 microg/mL and delphinidin at 0.6 microM concentrations significantly inhibited BP-DNA adduct formation. This was associated with a significant increase in activities of the phase II detoxification enzymes glutathione S-transferase and NAD(P)H:quinone reductase 1. In addition, these grape components also suppressed reactive oxygen species (ROS) formation, but did not induce antioxidant response element-dependent transcription. Taken together, these data suggest that CGE and a component grape anthocyanin have breast cancer chemopreventive potential due in part to their capacity to block carcinogen-DNA adduct formation, modulate activities of carcinogen-metabolizing enzymes, and suppress ROS in these noncancerous human breast cells.
Peppermint oil is easily available as a constituent of medicines. A near fatal case due to ingestion of toxic dose of oral peppermint oil is being reported. The patient came in a comatosed state and was in shock. She was managed with mechanical ventilation and ionotropes. Her vital parameters reached normal within 8 hours and became conscious by 24 hours. The side effects of peppermint oil are considered to be mild but this case report warns that ingestion of oral toxic doses of peppermint oil could be dangerous.
Dietary fibres are indigestible food ingredients that reach the colon and are then fermented by colonic bacteria, resulting mainly in the formation of short-chain fatty acids (SCFA) such as acetate, propionate, and butyrate. Those SCFA, especially butyrate, are recognised for their potential to act on secondary chemoprevention by slowing growth and activating apoptosis in colon cancer cells. Additionally, SCFA can also act on primary prevention by activation of different drug metabolising enzymes. This can reduce the burden of carcinogens and, therefore, decrease the number of mutations, reducing cancer risk. Activation of GSTs by butyrate has been studied on mRNA, protein, and enzyme activity level by real-time RT-PCR, cDNA microarrays, Western blotting, or photometrical approaches, respectively. Butyrate had differential effects in colon cells of different stages of cancer development. In HT29 tumour cells, e.g., mRNA GSTA4, GSTP1, GSTM2, and GSTT2 were induced. In LT97 adenoma cells, GSTM3, GSTT2, and MGST3 were induced, whereas GSTA2, GSTT2, and catalase (CAT) were elevated in primary colon cells. Colon cells of different stages of carcinogenesis differed in post-transcriptional regulatory mechanisms because butyrate increased protein levels of different GST isoforms and total GST enzyme activity in HT29 cells, whereas in LT97 cells, GST protein levels and activity were slightly reduced. Because butyrate increased histone acetylation and phosphorylation of ERK in HT29 cells, inhibition of histone deacetylases and the influence on MAPK signalling are possible mechanisms of GST activation by butyrate. Functional consequences of this activation include a reduction of DNA damage caused by carcinogens like hydrogen peroxide or 4-hydroxynonenal (HNE) in butyrate-treated colon cells. Treatment of colon cells with the supernatant from an in vitro fermentation of inulin increased GST activity and decreased HNE-induced DNA damage in HT29 cells. Additional animal and human studies are needed to define the exact role of dietary fibre and butyrate in inducing GST activity and reducing the risk of colon cancer.
This is a rapidly emerging field. The application of knowledge regarding the relationship between neural and immune systems in order to gain a better understanding of human conditions has been slow. In this discussion we describe how the brain and microbiota interact, and try to bring this into a context that is clinically relevant. We begin by describing established facts pertaining to the gut–brain axis and the role of gut bacteria. We then focus upon emerging data that will contribute to the generation of a new conceptual framework about the microbiota–gut–brain axis. In the final section we anticipate future directions of this field.
Glyphosate is an active ingredient of the most widely used herbicide and it is believed to be less toxic than other pesticides. However, several recent studies showed its potential adverse health effects to humans as it may be an endocrine disruptor. This study focuses on the effects of pure glyphosate on estrogen receptors (ERs) mediated transcriptional activity and their expressions. Glyphosate exerted proliferative effects only in human hormone-dependent breast cancer, T47D cells, but not in hormone-independent breast cancer, MDA-MB231 cells, at 10⁻¹² to 10⁻⁶M in estrogen withdrawal condition. The proliferative concentrations of glyphosate that induced the activation of estrogen response element (ERE) transcription activity were 5-13 fold of control in T47D-KBluc cells and this activation was inhibited by an estrogen antagonist, ICI 182780, indicating that the estrogenic activity of glyphosate was mediated via ERs. Furthermore, glyphosate also altered both ERα and β expression. These results indicated that low and environmentally relevant concentrations of glyphosate possessed estrogenic activity. Glyphosate-based herbicides are widely used for soybean cultivation, and our results also found that there was an additive estrogenic effect between glyphosate and genistein, a phytoestrogen in soybeans. However, these additive effects of glyphosate contamination in soybeans need further animal study. Copyright © 2013 Elsevier Ltd. All rights reserved.
We previously demonstrated that high serum enterolactone levels are associated with a reduced incidence of breast cancer in healthy women. The present study was aimed at investigating whether a similar association might be found between serum enterolactone levels and the mortality of women with early breast cancer. The levels of enterolactone in cryopreserved serum aliquots obtained from 300 patients, operated on for breast cancer, were measured using a time-resolved fluoro-immunoassay. Levels were analyzed in respect to the risk of mortality following surgery. Cox proportional hazard regression models were used to check for prognostic features, to estimate hazard ratios for group comparisons and to test for the interaction on mortality hazards between the variables and enterolactone concentrations. The Fine and Gray competing risk proportional hazard regression model was used to predict the probabilities of breast cancer-related and breast cancer-unrelated mortalities. At a median follow-up time of 23 years (range 0.6-26.1), 180 patients died, 112 of whom died due to breast cancer-related events. An association between a decreased mortality risk and enterolactone levels ≥ 10 nmol/l was found in respect to both all-cause and breast cancer-specific mortality. The difference in mortality hazards was statistically significant, but it appeared to decrease and to lose significance after the first 10 years, though competing risk analysis showed that breast cancer-related mortality risk remained constantly lower in those patients with higher enterolactone levels. Our findings are consistent with those of most recent literature and provide further evidence that mammalian lignans might play an important role in reducing all-cause and cancer-specific mortality of the patients operated on for breast cancer.
Large numbers of US women stopped taking hormone therapies (HT), especially estrogen/progestin (EP) formulations, after the Women's Health Initiative trial detected elevated risks of breast cancer in EP users and was halted in July 2002. Recent reports have indicated substantial and significant declines in population-based breast cancer incidence, particularly hormone-sensitive forms, for 2003 and 2004. Are these events linked? This commentary considers the available evidence linking the mass cessation of HT in 2002 to the breast cancer incidence declines of 2003/2004 and quantifies the potential impact of the cessation on the overall burden of breast cancer in the US.
Previously used standards for the diagnosis of precocious puberty in girls no longer appear to be appropriate in the USA, in that a significant number of girls are being seen in paediatricians' offices with breast budding before 8 years of age. The timing of menarche, however, has changed little over the past few decades. Early maturing girls are more likely to become obese in adolescence and adulthood than normal or late maturing girls. Early maturing white girls are heavier at the onset of puberty, but this is not the case for African-American girls or boys of either race. Boys and girls with premature pubarche may be more hyperinsulinaemic than normal children, and girls with premature pubarche more likely to develop functional ovarian and adrenal hyperandrogenism. Early menarche is preceded by prepubertal hyperinsulinaemia. It is proposed that pubertal onset, although not necessarily the tempo of puberty, is influenced by hyperinsulinaemia and insulin resistance. If this hypothesis is correct, insulin resistance may be more prevalent in US children than previously recognized. An advance in timing of onset of puberty has not been noted in other countries, although it is likely that this phenomenon may become more prevalent as other countries adopt a more American lifestyle and diet.
Ciguatera is a type of food poisoning associated with the consumption of contaminated marine fish. We report two cases in which painful ejaculation in an affected male and dyspareunia in an unaffected female following her partner's ejaculation suggest the sexual transfer of the responsible agent, ciguatoxin (CTX). Immunoassay of semen samples for CTX were not diagnostic, but the sensitivity and timing of the test employed may have precluded detection of small quantities of the toxin. We conclude that CTX may be present in the semen of men affected with ciguatera toxicity and be capable of producing symptomatology in both males and females during sexual intercourse.
Given the history of GMO conflict and debate, the GM animal future is dependent on the response of the regulatory landscape and its associated range of interest groups at national, regional and international levels. Focusing on the EU and the USA, this article examines the likely form of that multi-level response, the increased role of cultural values, the contribution of new and existing interest groups and the consequent implications for the commercialization of both green and red GM animal biotechnology. Copyright © 2012. Published by Elsevier Inc.
It was previously reported that a methanol extract of Gloiopeltis furcata (MEGF), a kind of edible seaweed, inhibited the growth of several human cancer cell lines. In the present study, the effect of MEGF on the growth of human hepatocarcinoma HepG2 cells and its effect on the cyclooxygenases (COXs) expression were investigated. MEGF markedly reduced the viability of HepG2 cells and induced the G2/M arrest of the cell cycle in a concentration dependent manner. These effects were associated with the down-regulation of cyclin A, up-regulation of cyclin-dependent kinase (Cdk) inhibitor p21 (WAF1/CIP1) and dephosphorylation of Cdc25C. Furthermore, it was found that MEGF decreased the levels of COX-2 mRNA and protein expression without significant changes in the levels of COX-1, which was correlated with a decrease in prostaglandin E(2) (PGE(2)) synthesis. These findings indicate that MEGF may have a possible therapeutic potential in hepatoma cancer patients.
Of 272 patients with asthma, thirty (11%) gave a history of exacerbations occurring after ingestion, solutions of orange orange drinks. Fourteen of these were given provocation tests by drinking, on separate occasions of sulphur dioxide, sodium benzoate and tartrazine, which are present in all orange drinks. Eight reacted to sulphur dioxide with a fall in FEV1, four to sodium benzoate and one to tartrazine, and four did not react to any of these agents. Three of the benzoate patients were also sensitive to sulphur dioxide. The sulphur dioxide sensitive patients were predominantly young, with extrinsic asthma. The benzoate sensitive patients were predominantly middle-aged and the proportion with intrinsic asthma was higher. Prior inhalation of sodium cromoglycate by four patients inhibited the reaction to these substances. Sulphur dioxide has not previously been reported to cause exacerbations of asthma when ingested as a food preservative. It is used as a preservative in a wide range of acidic beverages and foods, and should be considered as possibly causal in patients suffering from apparently cryptogenic asthma, and asthma seemingly due to food allergy.
A low-grade inflammatory response ('metaflammation') has been found to be associated with certain chronic diseases. Proposed inducers of this have been aspects of the modern lifestyle, including newly introduced foods. Plasma TAG, and the inflammatory cytokines C-reactive protein (CRP), TNF-alpha and IL-6 were compared in a randomised, cross-over trial using ten healthy subjects before and after eating 100 g of kangaroo, or a 'new' form of hybridised beef (wagyu) separated by about 1 week. Postprandial levels for 1 and 2 h of TAG, IL-6 and TNF-alpha were significantly higher after eating wagyu compared with kangaroo (P = 0.002 for TAG at 1 h, P < 0.001 at 2 h; P < 0.001 for IL-6 and TNF-alpha at 1 and 2 h). CRP was significantly higher 1 h postprandially after wagyu (P = 0.011) and non-significantly higher 2 h postprandially (P = 0.090). We conclude that the metaflammatory reaction to ingestion of a 'new' form of hybridised beef (wagyu) is indicative of a low-grade, systemic, immune reaction when compared with lean game meat (kangaroo). Further studies using isoenergetic intake and isolating fatty acid components of meats are proposed.
Sirtuins (SIRTs), a family of nicotinamide adenine dinucleotide (NAD)-dependent deacetylases, are emerging as key molecules that regulate aging and age-related diseases including cancers, metabolic disorders, and neurodegenerative diseases. Seven isoforms of SIRT (SIRT1–7) have been identified in mammals. SIRT1 and 6, mainly localized in the nucleus, regulate transcription of genes and DNA repair. SIRT3 in the mitochondria regulates mitochondrial bioenergetics. Initial studies in yeasts, nematodes, and flies indicated a strong connection of SIRT with the life-prolonging effects of calorie restriction (CR), a robust experimental intervention for longevity in a range of organisms. However, subsequent studies reported controversial findings regarding SIRT roles in the effect of CR. This review describes the functional roles of mammalian SIRTs and discusses their relevance to mechanisms underlying the longevity effect of CR.
The Açaí (Acai) fruit is a popular nutritional supplement that purportedly enhances immune system function. These anecdotal claims are supported by limited studies describing immune responses to the Acai polyphenol fraction. Previously, we characterized γδ T cell responses to both polyphenol and polysaccharide fractions from several plant-derived nutritional supplements. Similar polyphenol and polysaccharide fractions are found in Acai fruit. Thus, we hypothesized that one or both of these fractions could activate γδ T cells. Contrary to previous reports, we did not identify agonist activity in the polyphenol fraction; however, the Acai polysaccharide fraction induced robust γδ T cell stimulatory activity in human, mouse, and bovine PBMC cultures. To characterize the immune response to Acai polysaccharides, we fractionated the crude polysaccharide preparation and tested these fractions for activity in human PBMC cultures. The largest Acai polysaccharides were the most active in vitro as indicated by activation of myeloid and γδ T cells. When delivered in vivo, Acai polysaccharide induced myeloid cell recruitment and IL-12 production. These results define innate immune responses induced by the polysaccharide component of Acai and have implications for the treatment of asthma and infectious disease.
Determination of the environmental factors involved in neurodegenerative diseases has been elusive. Methylmercury and β-N-methylamino-L-alanine (BMAA) have both been implicated in this role. Exposure of primary cortical cultures to these compounds independently induced concentration-dependent neurotoxicity. Importantly, concentrations of BMAA (10-100 μM) that caused no toxicity alone potentiated methylmercury (3 μM) toxicity. In addition, concentrations of BMAA and methylmercury that had no effect by themselves on the main cellular antioxidant glutathione together decreased glutathione levels. Furthermore, the combined toxicity of methylmercury and BMAA was attenuated by the cell permeant form of glutathione, glutathione monoethyl ester. The results indicate a synergistic toxic effect of the environmental neurotoxins BMAA and methylmercury, and that the interaction is at the level of glutathione depletion.