Article

Enhanced elimination of tissue methylmercury in Parachlorella beijerinckii-fed mice

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Abstract

To investigate the influence of Chlorella (Parachlorella beijerinckii) on the excretion and tissue accumulation of methylmercury (MeHg), we orally administered 5 mg/kg of MeHg chloride (4 mg Hg/kg) to female C57BL/6N mice (aged 10 weeks). The mice were housed in metabolism cages to collect urine and feces for 3 weeks with diets containing 0%, 5%, or 10% P. beijerinckii powder (BP) in a basal diet (CE-2). The lowered blood Hg levels in the 5% and 10% BP groups became significant compared to those of the control group (0% BP) as early as day 7. During the 21 days of testing, significant increases in the cumulative Hg eliminations into urine (5% BP) and feces (5% and 10% BP) were found in the BP groups. Twenty-one days after administration, the organ Hg levels in both BP groups tended to decrease compared to that of the control group. The reduction of Hg levels in the kidney and brain were significant, whereas that in the liver was not. Although tissue Hg levels are known to be closely related to glutathione (GSH) metabolism, no difference was found in GSH levels in the blood or organs between the control group and the 10% BP group. These results suggest that continuous BP intake accelerates the excretion of MeHg and subsequently decreases tissue Hg levels in mice, with no alteration of GSH metabolism. We should conduct further research to elucidate details regarding the mechanism of BP-induced enhancement of MeHg excretion.

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... Research questions are often much more amenable to animal and tissue culture research, and this body of evidence has confirmed traditions that some foods and supplemental nutrients are enormously valuable in facilitating excretion and reducing biochemical toxicities of toxicants. Although by no means an exhaustive list, some supplements include curcumin in the spice turmeric [130], alliums [131], plant flavonoids such as quercetin [132], selenium [133], algal products Parachlorella [134,135] and Chlorella [136,137], naturally occurring organic acids [138], folate requisite minerals, and dietary fibre [139] as well as mixed antioxidants [140] appear to be of great value to reduce the damage associated with toxicant exposure. The mechanisms of action may include preventing absorption of toxicants, facilitating elimination of accrued toxic compounds, hindering enterohepatic recycling of some persistent compounds, and diminishing toxicity through protective mechanisms. ...
... One example is a supplemental product called Chlorella, an algae from the sea, that has recently garnered much research attention for its unique properties in facilitating detoxification and preventing absorption of adverse compounds [134][135][136][137]. Recent research papers reported animal results where Chlorella appears to induce the excretion of mercury [135] and lead [134]. ...
... One example is a supplemental product called Chlorella, an algae from the sea, that has recently garnered much research attention for its unique properties in facilitating detoxification and preventing absorption of adverse compounds [134][135][136][137]. Recent research papers reported animal results where Chlorella appears to induce the excretion of mercury [135] and lead [134]. Ongoing study continues to elucidate the range of compounds that are bound and removed with Chlorella as well as with other assorted foods and supplemental nutrients. ...
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The World Health Organization warns that chronic, noncommunicable diseases are rapidly becoming epidemic worldwide. Escalating rates of neurocognitive, metabolic, autoimmune and cardiovascular diseases cannot be ascribed only to genetics, lifestyle, and nutrition; early life and ongoing exposures, and bioaccumulated toxicants may also cause chronic disease. Contributors to ill health are summarized from multiple perspectives—biological effects of classes of toxicants, mechanisms of toxicity, and a synthesis of toxic contributors to major diseases. Healthcare practitioners have wide-ranging roles in addressing environmental factors in policy and public health and clinical practice. Public health initiatives include risk recognition and chemical assessment then exposure reduction, remediation, monitoring, and avoidance. The complex web of disease and environmental contributors is amenable to some straightforward clinical approaches addressing multiple toxicants. Widely applicable strategies include nutrition and supplements to counter toxic effects and to support metabolism; as well as exercise and sweating, and possibly medication to enhance excretion. Addressing environmental health and contributors to chronic disease has broad implications for society, with large potential benefits from improved health and productivity.
... There is evidence that coriander, malic acid (found in grapes and wine), citric acid (found in citrus fruits), succinic acid (found in apples and blueberries), citrus pectin (found in the peel and pulp of citrus fruits) and Chlorella (a type of green algae) exhibit natural chelating properties, suggesting that they may be useful for the elimination of toxic metals (47)(48)(49)(50)(51)(52)(53)(54)(55) . ...
... Chlorella is a unicellular green algae that has been shown to facilitate mercury and lead excretion in mice (51)(52)(53) . Uchikawa et al. (53) fed mercury-poisoned mice a powdered form of Parachlorella beijerinckii (a type of Chlorella) comprising either 5% or 10% of their diets. ...
... Chlorella is a unicellular green algae that has been shown to facilitate mercury and lead excretion in mice (51)(52)(53) . Uchikawa et al. (53) fed mercury-poisoned mice a powdered form of Parachlorella beijerinckii (a type of Chlorella) comprising either 5% or 10% of their diets. After 3 weeks, mercury concentrations in the blood, urine, faeces, brains and kidneys of the mice decreased significantly, whereas a nonsignificant reduction was observed in their livers. ...
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Detox diets are popular dieting strategies that claim to facilitate toxin elimination and weight loss, thereby promoting health and well-being. The present review examines whether detox diets are necessary, what they involve, whether they are effective and whether they present any dangers. Although the detox industry is booming, there is very little clinical evidence to support the use of these diets. A handful of clinical studies have shown that commercial detox diets enhance liver detoxification and eliminate persistent organic pollutants from the body, although these studies are hampered by flawed methodologies and small sample sizes. There is preliminary evidence to suggest that certain foods such as coriander, nori and olestra have detoxification properties, although the majority of these studies have been performed in animals. To the best of our knowledge, no randomised controlled trials have been conducted to assess the effectiveness of commercial detox diets in humans. This is an area that deserves attention so that consumers can be informed of the potential benefits and risks of detox programmes. © 2014 The British Dietetic Association Ltd.
... Thus, the discovery of a food material that could help detoxify the body from MeHg would be considered to beneficial to human health. We previously reported that Chlorella promoted the excretion of MeHg in both feces and urine, such that long-term administration of Chlorella enhances the elimination of tissue methylmercury in mice (Uchikawa et al., 2010(Uchikawa et al., , 2011. Here we studied the effect of 3-month Chlorella supplementation on mercury concentrations of blood and hair in healthy subjects. ...
... Previously, we found that Chlorella increased mercury excretion and lowered tissue mercury levels in MeHgtreated mice (Uchikawa et al., 2010(Uchikawa et al., , 2011. Fecal excretion constitutes a major route for the elimination of MeHg, about 90% of the total elimination, in most animal species including humans (Norseth and Clarkson, 1970;Miettinen et al., 1971;Komsta-Szumska et al., 1983;WHO, 1990). ...
... Of these ingredients, the dietary fiber and the complex lipid fraction, which is rich in polyunsaturated fatty acids, have been shown to inhibit the re-absorption of bile acid in the intestinal tract, resulting in accelerated bile secretion in the enterohepatic circulation (Sano, 1982). In addition, the dietary fiber contained in whole Chlorella increases the amount of feces excreted by animals (Sano, 1982;Uchikawa et al., 2011) and humans (Fujiwara et al., 1998), and dietary fiber has been shown to absorb some MeHg in vitro (Uchikawa et al., 2010). These above-mentioned characteristics of Chlorella are considered to be related to the increase in excretion of MeHg in the feces. ...
Article
An open-label clinical trial was performed to test the effects of unicellular green alga Chlorella supplementation on mercury concentrations of hair and blood in healthy subjects. Fifty-eight healthy participants (36 male and 22 female) were assigned to Chlorella and control groups. The Chlorella group of 35 subjects received Chlorella tablets (9 g/day) for an experimental period of 3 months while the control group of 23 subjects did not. Total mercury concentrations of hair and blood were analyzed at the beginning and end of the experimental period for estimation of methylmercury (MeHg) levels in the body. The hair mercury concentration of the Chlorella group (n = 33) was significantly decreased during the experimental period (p = 0.041) while the change in the control group (n = 23) was not significant (p = 0.362). Although the decrease in blood mercury concentration in the Chlorella group (n = 19) was not significant (p = 0.084), the change of values (values at end – values at beginning) in this group was significantly greater than that in the control group (n = 20, p = 0.038). The fish intake rates remained relatively constant during the experimental period in both the Chlorella and control groups. These results suggest that supplementation with Chlorella for 3 months in healthy subjects might reduce their body MeHg levels.
... These indirect findings suggest that selenium contributed to detoxification in the present clinical study. Uchikawa et al. (2011) described the enhanced removal of tissue methylmercury in (BP) Parachlorella beijerinckii-fed mice; this continuous BP intake (10%) accelerated MeHg excretion and subsequently decreased tissue mercury accumulation by inducing the GSH metabolism [65]. ...
... These indirect findings suggest that selenium contributed to detoxification in the present clinical study. Uchikawa et al. (2011) described the enhanced removal of tissue methylmercury in (BP) Parachlorella beijerinckii-fed mice; this continuous BP intake (10%) accelerated MeHg excretion and subsequently decreased tissue mercury accumulation by inducing the GSH metabolism [65]. ...
Article
Full-text available
The toxicity of heavy metals such as Hg++ is a serious risk for human health. We evaluated whether 90 days of nutritional supplementation (d90, n = 16) with Chlorella vulgaris (CV) and Fucus sp extracts in conjunction with aminosulphurate (nutraceuticals) supplementation could detox heavy metal levels in patients with long-term titanium dental implants (average: three, average: 12 years in mouth) and/or amalgam fillings (average: four, average: 15 years) compared to baseline levels (d0: before any supplementation, n = 16) and untreated controls (without dental materials) of similar age (control, n = 21). In this study, we compared levels of several heavy metals/oligoelements in these patients after 90 days (n = 16) of nutritional supplementation with CV and aminozuphrates extract with their own baseline levels (d0, n = 16) and untreated controls (n = 21); 16 patients averaging 44 age years old with long-term dental amalgams and titanium implants for at least 10 years (average: 12 years) were recruited, as well as 21 non-supplemented controls (without dental materials) of similar age. The following heavy metals were quantified in hair samples as index of chronic heavy metal exposure before and after 90 days supplementation using inductively coupled plasma-mass spectrometry (ICP-MS) and expressed as μg/g of hair (Al, Hg++, Ba, Ag, Sb, As, Be, Bi, Cd, Pb, Pt, Tl, Th, U, Ni, Sn, and Ti). We also measured several oligoelements (Ca++, Mg++, Na+, K+, Cu++, Zn++, Mn++, Cr, V, Mo, B, I, P, Se, Sr, P, Co, Fe++, Ge, Rb, and Zr). The algae and nutraceutical supplementation during 90 consecutive days decreased Hg++, Ag, Sn, and Pb at 90 days as compared to baseline levels. The mercury levels at 90 days decreased as compared with the untreated controls. The supplementation contributed to reducing heavy metal levels. There were increased lithium (Li) and germanium (Ge) levels after supplementation in patients with long-term dental titanium implants and amalgams. They also (d90) increased manganesum (Mn++), phosphorum (P), and iron (Fe++) levels as compared with their own basal levels (d0) and the untreated controls. Finally, decreased SuperOxide Dismutase-1 (SOD-1) activity (saliva) was observed after 90 days of supplementation as compared with basal levels (before any supplementation, d0), suggesting antioxidant effects. Conversely, we detected increased SOD-1 activity after 90 days as compared with untreated controls. This SOD-1 regulation could induce antioxidant effects in these patients. The long-term treatment with algae extract and aminosulphurates for 90 consecutive days decreased certain heavy metal levels (Hg++, Ag, Sn, Pb, and U) as compared with basal levels. However, Hg++ and Sn reductions were observed after 90 days as compared with untreated controls (without dental materials). The dental amalgam restoration using activated nasal filters in conjunction with long-term nutritional supplementation enhanced heavy metals removal. Finally, the long-term supplementation with these algae and aminoazuphrates was safe and non-toxic in patients. These supplements prevented certain deficits in oligoelements without affecting their Na+/K+ ratios after long-term nutraceutical supplementation.
... Moreover, while fasting or LCDs may allow weight loss, they can also lead to various health problems, such as malnutrition, muscle weakness, nervousness, headaches, dizziness, fatigue, gastrointestinal disturbances, and reduced quality of life [29,30]. Several pre-clinical studies have reported the effects of detox diets [31][32][33], mostly with respect to detoxi cation, and some clinical studies have been published [10-16, 18-20, 22, 24-26]. ...
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Background: Detox diet are known as a popular dieting strategies that helps toxins elimination and weight manage but there is very little clinical evidence. The Wellnessup diet (WD) used in the present study designed as a healthy meals based on organic plant based diets including various vegetables, fruits, whole grains, nuts and phytonutrients. Methods: To evaluate the effects of 4 week intake of the WD on toxic trace element detoxification, body fat reduction, and safety parameters. Forty-five women with body mass index (BMI) of 23.5-30 kg/m 2 were recruited. Thirty of them were assigned 1:1 to the test group (WD, 15 subjects) and control group 1 (calorie-restricted diet, CRD, 15 subjects) in a single blind and randomized, and the remaining 15 subjects were assigned to control group 2 (maintaining regular diet, MRD). The primary outcome were toxic trace element levels in hair (29 types of heavy metals), and the secondary outcomes were changes in anthropometric and urinary organic acids. Results: The levels of four toxic trace elements in hair decreased in the WD group after the diet compared to before the diet. Ni, Rh, Sn, and Ga were significantly lower in the WD group than in the CRD or MRD group (p<0.05). At the end of the trial, both WD and CRD groups had lower BMI, Waist Circumference(WC), Hip Circumference(HC) and WHR compared to the baseline values (p<0.05). Compared to the WD group, the CRD group had a greater mean change (p<0.05) from the baseline for weight loss (-3.22±0.48kg vs -1.88±0.95kg vs) and fat free mass (-2.08 kg vs -1.09 kg). The weight, BMI, body fat mass, fat free mass, WC, and HC of the CRD group were significantly decreased compared to the MRD (p<0.05). No significant changes in any safety parameter were observed. Conclusions: Use of WD might have several beneficial effects and safety such as body fat reduction and improving some the element detoxification through caloric restriction but did not reducing body fat mass more than calorie-restricted diet.
... It is also wealthy in chlorophylls, lutein, and β-carotene. Many health-promoting benefits as oxidative stress and lipid lowering has been report in animals and humans 17,18,19 . Moreover, as CH exhibits high antioxidant activity, its radical scavenging property has been manipulated to promote its anticancer and antiatherogenic properties 20,21 . ...
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Chlorella vulgaris (CH) and Spirulina platensis (SP) are microalgae being touted as functional foods with a number of health benefits. CH and SP have potent antioxidant activity and provoke a free radical scavenging enzyme system. The present study was sought to assess the potential protective activities of CH and SP aqueous extracts against MSG toxicity in male mice. Mice were orally gavages with MSG at dose of (1200 mg/kg b.w) alone or with either CH or SP (500mg/kg b.w) daily for 28 days. Algae total phenolic and flavonoids content were measured, it was noticed that Sp have the higher total phenolic content while CH have the high flavonoids content. Bone marrow and liver were collected for genetical, biochemical, histological and histochemical analysis. The results appeared that MSG increased lipid peroxidation, apoptosis, DNA fragmentation and decreased hepatic glutathione concentration and total antioxidant activities. In addition, it is up regulating mRNA Bax and caspase-3genes, down-regulating Bcl-2 genes expression. Moreover, MSG showed liver histopathological alterations and increased the liver DNA content. In contrast, co-treatment of MSG plus either CH or SP succeeded to normalize the biochemical parameters levels, reduced the cytotoxicity, genotoxicity and ameliorated the hepatic histopathological and histochemical alterations. Therefore, CH and SP aqueous extracts have protective efficiency due to their content of bioactive compounds and could be considered as available resource of natural antioxidants (PDF) Potential Modulator Role of Chlorella vulgaris and Spirulina platensis On Monosodium Glutamate Oxidative Stress, Genotoxicity, Apoptotic Gene Expression and Histopathological Alterations. Available from: https://www.researchgate.net/publication/337991960_Potential_Modulator_Role_of_Chlorella_vulgaris_and_Spirulina_platensis_On_Monosodium_Glutamate_Oxidative_Stress_Genotoxicity_Apoptotic_Gene_Expression_and_Histopathological_Alterations [accessed Dec 18 2019].
... Chlorella is a green algae which due to its high chlorophyll content acts as a natural chelator of heavy metals, especially lead and mercury. Chlorella and cilantro as food materials can detoxify some neurotoxins such as heavy metals (example: mercury) and toxic chemicals (like: phthalates, plasticizers and insecticides) (38). ...
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Some heavy metals are nutritionally essential elements playing key roles in different physiological and biological processes, like: iron, cobalt, zinc, copper, chromium, molybdenum, selenium and manganese, while some others are considered as the potentially toxic elements in high amounts or certain chemical forms. Nowadays, various usage of heavy metals in industry, agriculture, medicine and technology has led to a widespread distribution in nature raising concerns about their effects on human health and environment. Metallic ions may interact with cellular components such as DNA and nuclear proteins leading to apoptosis and carcinogenesis arising from DNA damage and structural changes. As a result, exposure to heavy metals through ingestion, inhalation and dermal contact causes several health problems such as, cardiovascular diseases, neurological and neurobehavioral abnormalities, diabetes, blood abnormalities and various types of cancer. Due to extensive damage caused by heavy metal poisoning on various organs of the body, the investigation and identification of therapeutic methods for poisoning with heavy metals is very important. The most common method for the removal of heavy metals from the body is administration of chemical chelators. Recently, medicinal herbs have attracted the attention of researchers as the potential treatments for the heavy metals poisoning because of their fewer side effects. In the present study, we review the potential of medicinal herbs such as: Allium sativum (garlic), Silybum marianum (milk thistle), Coriandrum sativum (cilantro), Ginkgo biloba (gingko), Curcuma longa (turmeric), phytochelatins, triphala, herbal fibers and Chlorophyta (green algae) to treat heavy metal poisoning.
... However, studies examining the effects of an identical Se diet (0.06 or 0.6 mg/kg) fed to pregnant dams on in utero exposure to MeHg through drinking water have reported no effect of Se diet on MeHg-induced behavioral alterations [30,33]. Chlorella, a unicellular green algae that has been eaten as a nutritional food in Japan, enhances the tissue elimination of MeHg through stimulation of excretion [69,70]. In addition, along with MeHg drinking water, continuous intake of 10% chlorella powder (CP) in the diet of mice for 4 weeks before mating through birth suppressed MeHg transfer to offspring, with both mothers and neonates in the CP diet group showing significantly lower blood and brain [Hg], compared to controls, 24 h after birth [71]. ...
... It is also wealthy in chlorophylls, lutein, and β-carotene. Many health-promoting benefits as oxidative stress and lipid lowering has been report in animals and humans 17,18,19 . Moreover, as CH exhibits high antioxidant activity, its radical scavenging property has been manipulated to promote its anticancer and antiatherogenic properties 20,21 . ...
... Moreover, while fasting or LCDs may allow weight loss, they can also lead to various health problems, such as malnutrition, muscle weakness, nervousness, headaches, dizziness, fatigue, gastrointestinal disturbances, and reduced quality of life [29,30]. Several pre-clinical studies have reported the effects of detox diets [31][32][33], mostly with respect to detoxification, and some clinical studies have been published [10-16, 18-20, 22, 24-26]. ...
Article
Full-text available
Background: Detox diet are known as a popular dieting strategies that helps toxins elimination and weight manage but there is very little clinical evidence. The Wellnessup diet (WD) used in the present study designed as a healthy meals based on organic plant based diets including various vegetables, fruits, whole grains, nuts and phytonutrients. Methods: To evaluate the effects of 4 week intake of the WD on toxic trace element detoxification, body fat reduction, and safety parameters. Forty-five women with body mass index (BMI) of 23.5-30 kg/m2 were recruited. Thirty of them were assigned 1:1 to the test group (WD, 15 subjects) and control group 1 (calorie-restricted diet, CRD, 15 subjects) in a single blind and randomized, and the remaining 15 subjects were assigned to control group 2 (maintaining regular diet, MRD). The primary outcome were toxic trace element levels in hair (29 types of heavy metals), and the secondary outcomes were changes in anthropometric and urinary organic acids. Results: The levels of four toxic trace elements in hair decreased in the WD group after the diet compared to before the diet. Ni, Rh, Sn, and Ga were significantly lower in the WD group than in the CRD or MRD group (p < 0.05). At the end of the trial, both WD and CRD groups had lower BMI, Waist Circumference(WC), Hip Circumference(HC) and WHR compared to the baseline values (p < 0.05). Compared to the WD group, the CRD group had a greater mean change (p < 0.05) from the baseline for weight loss (- 3.22 ± 0.48 kg vs - 1.88 ± 0.95 kg vs) and fat free mass (- 2.08 kg vs - 1.09 kg). The weight, BMI, body fat mass, fat free mass, WC, and HC of the CRD group were significantly decreased compared to the MRD (p < 0.05). No significant changes in any safety parameter were observed. Conclusions: Use of WD might have several beneficial effects and safety such as body fat reduction and improving some the element detoxification through caloric restriction but did not reducing body fat mass more than calorie-restricted diet. Trial registration: This study was registered at Clinical Research Information Service (CRIS) of Republic of Korea (KCT0003002).
... It is also rich in plant pigments, including chlorophylls, lutein, and -carotene. Many health-promoting benefits, such as the lowering of oxidative stress and serum lipid and the excretion of toxic substances including dioxin and methyl mercury, have been reported in both animals and humans [7][8][9][10][11][12][13]. Hot water extract of Chlorella contains a high amount of polysaccharides, including galactose, mannose, rhamnose, ribose, and xylose [14], and has been reported to 2 Evidence-Based Complementary and Alternative Medicine improve host resistance to viral infection, bacterial infection, and tumors in animals [15][16][17][18][19]. Recently, we confirmed that hot water extract of Chlorella improves the perforin and granulysin preservation ratio in NK cells and killer T-cells in healthy subjects by a placebo-controlled double-blind study (unpublished data). ...
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A self-control, randomized, and open-label clinical trial was performed to test the effects of the unicellular green algae Chlorella and hot water extract supplementation on quality of life (QOL) in patients with breast cancer. Forty-five female patients with breast cancer who were living at home and not hospitalized were randomly assigned to 3 groups receiving vitamin mix tablet (control), Chlorella granules (test food-1), or Chlorella extract drink (test food-2) daily for one month. The Functional Assessment of Cancer Therapy-Breast (FACT-B), the Izumo scale for abdominal symptom-specific QOL, and a narrative-form questionnaire were used to determine outcomes. Data of thirty-six subjects were included for final analysis. FACT-B scores at presupplementation found no significant group differences in all subscales. Scores on the breast cancer subscale in the Chlorella granule group significantly increased during the supplementation period (P = 0.042). Fifty percent of the Chlorella extract group reported positive effects by the test food such as reduction of fatigue and improvements of dry skin (P < 0.01 versus control group). The findings suggested the beneficial effects of Chlorella on breast cancer-related QOL and of Chlorella extract on vitality status in breast cancer patients. These findings need to be confirmed in a larger study.
... It is also wealthy in chlorophylls, lutein, and β-carotene. Many health-promoting benefits as oxidative stress and lipid lowering has been report in animals and humans 17,18,19 . Moreover, as CH exhibits high antioxidant activity, its radical scavenging property has been manipulated to promote its anticancer and antiatherogenic properties 20,21 . ...
... A large number of research teams (P. KUMAR & al.[19]; S. M. Suru[20]; T. UCHIKAWA & al.[21]; K. ABASCAL & E. YARNELLM K[22]; M. AGA & al.[23]) have tested chlorella, cilantro and garlic for their metals detox ability. Garlic contains many active sulfur compounds derived from cysteine with potential metal-chelating properties; these garlic constituents may also protect from metal-catalyzed oxidative damage (S. ...
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The purpose of this study was to histological compare the aspect of gill epithelium of Prussian carp's specimens, subjected to chronic Cd intoxication with and without garlic, cilantro and chlorella dietary supplementation. 150 Prussian carps, with weight of 10-12 g were divided according to the following treatments for 21 days: C (without treatment), E1 (10 ppm Cd into water), E2 (10 ppm Cd into water+2% lyophilized garlic in feed), E3 (10 ppm Cd into water+2% lyophilized coriander in feed), E4 (10 ppm Cd into water+2% lyophilized chlorella in feed). Fragments of gill were removed at the end of experimental period and analyzed in light microscopy and a specific QuickPHOTO Micro 2.2 software has been used for the histological study. Mentioned epithelium suffered evident histo-morphological alterations under the action of Cd while the active principles from garlic, cilantro and chlorella powder have showed chelating and antioxidant potential, cilantro and garlic being the most effective.
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Toxic metals such as arsenic, cadmium, lead, and mercury are ubiquitous, have no beneficial role in human homeostasis, and contribute to noncommunicable chronic diseases. While novel drug targets for chronic disease are eagerly sought, potentially helpful agents that aid in detoxification of toxic elements, chelators, have largely been restricted to overt acute poisoning. Chelation, that is multiple coordination bonds between organic molecules and metals, is very common in the body and at the heart of enzymes with a metal cofactor such as copper or zinc. Peptides glutathione and metallothionein chelate both essential and toxic elements as they are sequestered, transported, and excreted. Enhancing natural chelation detoxification pathways, as well as use of pharmaceutical chelators against heavy metals are reviewed. Historical adverse outcomes with chelators, lessons learned in the art of using them, and successes using chelation to ameliorate renal, cardiovascular, and neurological conditions highlight the need for renewed attention to simple, safe, inexpensive interventions that offer potential to stem the tide of debilitating, expensive chronic disease.
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A wide variety of natural sources are under investigation to evaluate their possible use for new functional ingredient formulation. Some records attested the traditional and ancient use of wild harvested microalgae as human food but their cultivation for different purposes started about 40 years ago. The most popular species are Arthrospira (traditional name, Spirulina), Chlorella spp., Dunaliella spp. and Haematococcus spp. Microalgae provide a bewildering array of opportunities to develop healthier food products using innovative approaches and a number of different strategies. Compared to other natural sources of bioactive ingredients, microalgae have many advantages such as their huge biodiversity, the possibility to grow in arid land and with limited fresh water consumption and the flexibility of their metabolism, which could be adapted to produce specific molecules. All these factors led to very sustainable production making microalgae eligible as one of the most promising foods for the future, particularly as source of proteins, lipids and phytochemicals. In this work, a revision of the knowledge about the use of microalgae as food and as a source of functional ingredients has been performed. The most interesting results in the field are presented and commented upon, focusing on the different species of microalgae and the activity of the nutritionally relevant compounds. A summary of the health effects obtained together with pros and cons in the adoption of this natural source as functional food ingredients is also proposed.
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Background: Methylmercury (MeHg) is a ubiquitous environmental pollutant, with the nervous system as its main target; however, the neurotoxic mechanisms of MeHg have not been fully elucidated, and no effective therapeutic and preventive drugs are available to mitigate its toxicity. Recent evidence suggests a reduction in the toxicity of MeHg by natural plant extracts. Scope of review: The aim of this review is to provide an overview of effective natural plant extracts and their putative biochemical mechanisms for blocking gut absorption, enhancing excretion and minimizing toxic effects of MeHg. Major conclusions: Natural plant extracts may act as potential therapeutics in response to MeHg exposure. The roles plant components play in the reduction of MeHg toxicity may be multifaceted including: (1) attenuating neurobehavioral deficits; (2) facilitating demethylation of MeHg to inorganic mercury; (3) reducing MeHg absorption from the gastrointestinal tract; (4) redistributing MeHg to less sensitive target organs and tissues; (5) promoting enterohepatic circulation of MeHg to increase its biliary and intestinal excretion; (6) restoring intracellular redox status. General significance: The possible protective effects of natural plant components contribute to the understanding of mechanisms of MeHg toxicity and to the development of novel therapeutic strategies.
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To investigate the effects of chlorella on methylmercury (MeHg) transfer to the fetus during pregnancy, female C57BL/6N mice (aged 10 weeks) were housed for 7 to 8 weeks, from 4 weeks before mating to birth, with diets containing 0% or 10% chlorella powder (CP) and MeHg-containing drinking water (2 µg Hg/ml). The consumption volume of the MeHg-containing water was limited to 15 ml/mouse/week throughout the experiment. Distilled water and a basal diet (0% CP) was given to control mice. Except for the mating period, during the 5(th) week, mice were housed individually until parturition. Two neonates were randomly selected from each mother mouse within 24 hr after parturition for Hg analysis of the blood, brain, liver, and kidneys. Mother mice were sacrificed on the same day as neonates to obtain tissue samples for Hg analysis. The blood and brain Hg levels of both neonates and mothers in the CP diet group were significantly lower than those in the basal diet group. Although the hepatic and renal Hg levels were not significant in mothers between the two dietary groups, in neonates, the CP diet group showed significantly lower Hg levels in these tissues than the basal diet group. The results obtained here revealed that continuous CP intake suppressed MeHg transfer to the fetus, in addition to effective suppressing MeHg accumulation in brains of the mothers.
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Chlorella is one of the archetypical forms of coccoid green algae and one of the best-studied phototrophic eukaryotes. However, its systematics remains enigmatic due to conflicts between morphological and molecular phylogenetic approaches. The sequences of the 18S ribosomal RNA gene of nine strains of Chlorella and related taxa, and the ITS2 region of 17 strains of Chlorellaceae were determined and included in phylogenetic analyses. The secondary structure of the ITS2 region of C. vulgaris was compared to that of Parachlorella beijerinckii. All phylogenetic analyses showed that the Chlorellaceae form a clade within the Trebouxiophyceae. The Chlorellaceae studied here are divided into two sister groups: (1) the Parachlorella-clade with Parachlorella beijerinckii gen. et sp. nov. and P. kessleri comb. nov. as well as Dicloster acuatus and Closteriopsis acicularis; and (2) the Chlorella-clade including the 'true' spherical Chlorella species C. vulgaris, C. lobophora and C. sorokiniana. The latter are intermixed with taxa that differ in morphology and were formerly classified in other families of coccoid green algae: Actinastrum hantzschii (formerly Coelastraceae), Diacanthos belenophorus (formerly Oocystaceae), Dictyosphaerium pulchellum (formerly Botryococcaceae), Didymogenes anomala and D. palatina (formerly Scenedesmaceae) and Micractinium pusillum (formerly Micractiniaceae). It was shown that morphological criteria traditionally used for classification (e.g. spines, mucilaginous envelopes or the formation of colonies or coenobia) are burdened with a high degree of phenotypic plasticity. These plastic traits represent adaptations to environmental factors in order to optimize floating in the water column and to resist grazing pressure. A genus and species concept in Chlorellaceae remains provisional, because, in most cases, there is still a lack of classical and molecular approaches to identify clear phylogenetic lineages.
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We examined the influence of Chlorella intake on the risk factors of metabolic syndrome in white-collar workers. Forty-five subjects (mean age, 43.2 y) took 6g of Chlorella tablets per day for 6 weeks. Clinical examinations were performed before and after the 6-week period. As a result, the serum HDL-C level significantly increased during the examination period while the serum triglyceride (TG) level tended to decrease. The values of γ-GTP, the Atherogenic Index (AT), and HbAlc significantly decreased, although serum glucose (GLU) was not changed. All subjects were divided by blood pressure (cut-off values: systolic blood pressure 140mmHg, diastolic blood pressure 90mmHg) into 2 groups: a hypertensive group (n=17) and a non-hypertensive group (n=28). The values of body mass index (BMI), systolic blood pressure (SBP), diastolic blood pressure (DBP), GLU, T-CHO, TQ ALT and y-GTP of the hypertensive group at the beginning were significantly higher than those of the non-hypertensive group. The hypertensive group was judged to have more risk factors for metabolic syndrome. In the hypertensive group, the value of SBP as well as the values of HbAlc, γ-GTP and AI significantly decreased during the examination period. Furthermore, the amounts of decrease of T-CHO, TG and ALT in the hypertensive group tended to be larger than those in the non-hypertensive group. These findings suggest that Chlorella may be beneficial for reducing risk factors of metabolic syndrome such as hypertension.
Article
Chlorella (Parachlorella beyerinckii CK-5), previously identified as Chlorella vulgaris CK-5, is a unicellular green algae that has for many years been used as a nutritional supplement. In order to investigate the effects of methylmercury (MeHg) detoxification by Chlorella, we examined the absorption and excretion of MeHg in mice. Female C57BL/6N mice were randomly divided into three groups of five, and were housed in metabolism cages. Mice were orally administered MeHg chloride at doses of 5 mg (4 mg Hg)/kg body weight with or without 100 mg/mouse of P. beyerinckii powder (BP), and were assigned to either a MeHg group or MeHg + BP group, accordingly. Twenty-four hr after oral administration, feces and urine were collected, and blood, liver, and kidney samples were obtained. Total mercury contents in the samples obtained were determined using an atomic absorption method. The amounts of Hg excreted in feces and urine of the MeHg + BP group were increased nearly 1.9 and 2.2-fold compared with those of the MeHg group. On the other hand, blood and organ Hg levels were not significantly different between two groups. These results suggest that the intake of BP may induce the excretion of Hg both in feces and urine, although it does not affect MeHg absorption from the gastrointestinal tract. The effect of BP on the tissue mercury accumulation may become evident in a long-term experiment.
Article
The effect of Parachlorella beyerinckii CK-5, previously identified as Chlorella vulgaris, on gastrointestinal absorption of lead was investigated in mice. Female ICR mice aged 7 weeks were orally administered lead acetate solution at doses of 20 mg and 40 mg of lead per mouse, with or without 100 mg of P. beyerinckii powder (BP). The mice were bred for 24 hours. The amount of lead excreted in feces within 24 hours, and the lead levels of the blood, liver and kidney were analyzed by atomic absorption spectrometry. The percentage of total fecal excretion in mice administered BP increased by 27.7% in 20 mg lead administered mice and 17.2% in 40 mg lead administered mice in comparison to control mice, respectively. On the other hand, the lead levels of the blood, liver and kidney of BPadministered mice at 24 hours after lead administration were 48-63% lower as compared with those of control mice. The lead adsorption ability of BP and the pepsin non-digestive residue of BP (dBP) were investigated in vitro. One hundred mg of BP and dBP could adsorb 10.6 mg and 6.0 mg of lead in a 20 mg per 10 mL of lead solution, respectively. The lead absorption abilities of BP and dBP were considered to contribute to the prevention of gastrointestinal absorption of lead and the promotion of the excretion of lead. These results suggested that BP treatment might be useful in animals and humans exposed to lead.
Article
To elucidate the mechanisms by which methyl-mercury (MeHg) is eliminated from organisms, male C57BL/6N mice were orally administered with MeHg chloride (5 mg/kg) and the chemical forms of its metabolites in plasma, urine and kidney were determined by column chromatographic analysis. Orally administered MeHg rapidly entered the circulation, accumulated in the kidney and other tissues, and was slowly excreted in the urine. Ultrafiltration and gel filtration analysis revealed that most of plasma MeHg was accounted for by its albumin conjugate. Cell fractionation analysis revealed that about 80% of renal MeHg was recovered from the 15,000 g supernatant fraction of the kidney homogenate. If the kidney was homogenized in the presence of serine-borate complex, a potent inhibitor of gamma-glutamyltranspeptidase (gamma-GTP), about 50% of the MeHg in the supernatant fraction was recovered as its glutathione S-conjugate while the rest was bound to cytosolic protein(s). The major part of urinary MeHg was accounted for by its cysteine conjugate. However, urinary excretion of its glutathione conjugate increased significantly if animals were pretreated with acivicin, an affinity labeling reagent for gamma-GTP. These and other results suggested that MeHg bound to albumin accumulated in the kidney predominantly via some non-filtrating peritubular mechanism, and localized in renal cytosolic compartment as its glutathione- and protein-bound forms. The glutathione S-conjugate of MeHg in the tubule cells might be transferred to the lumenal space, hydrolyzed to the cysteine S-conjugate, and then excreted in urine. These sequential events might constitute an important eliminatory pathway for a hazardous mercurial metabolite in mice.
Article
To investigate the mechanisms for the sex-related difference in the in vivo fate of methylmercury (MeHg), the effects of hormonal manipulation on the distribution and urinary excretion of the mercurial moiety (Hg) of injected MeHg and on hepato-renal metabolism of glutathione were studied in C57BL/6N mice. Twenty-four hours after oral administration of MeHg, urinary Hg levels were significantly higher in males than in females. Tissue Hg levels of males were higher in the kidney, but lower in the brain, liver and plasma than those of females. The fate of injected MeHg in castrated males was similar to that in normal females except for its brain levels. This feminization of the mercurial behavior in the castrated males was restored by treating with testosterone propionate (TP). When control mice were treated with TP, urinary excretion of Hg increased in both sexes, whereas renal Hg level increased only in females. Administration of estradiol benzoate (EB) to males decreased the renal accumulation and urinary excretion of Hg, whereas its hepatic levels increased. However, no significant change in the fate of MeHg was found in females pretreated with EB. Castration of females slightly decreased the urinary excretion of Hg. Thus, tissue distribution and urinary excretion of the administered MeHg seem to be subject to sex hormone control. Since MeHg has a high affinity for GSH, effects of hormonal manipulation on the metabolism of hepato-renal glutathione were also investigated. A significant sex-related difference in glutathione levels was found in plasma but not in the kidney, liver and erythrocytes. The half-lives of glutathione in the liver and kidney were significantly shorter in males than in females as determined by treatment with buthionine sulfoximine, a specific inhibitor of GSH synthesis. This difference was also modulated by the hormonal treatment. Since half-lives of GSH in the liver and kidney predominantly reflect the rate of its efflux from these tissues, the results suggest that GSH metabolism and/or secretory transport may be regulated by sex hormones. These and other observations suggest that the fate of MeHg may be modulated by way of regulating the inter-organ metabolism and transport of glutathione and its derivatives.
Article
A method for the analysis of nanogram quantities of glutathione has been developed which is based on the catalytic action of GSH or GSSG in the reduction of Ellman reagent (DTNB) by a mixture of TPNH and yeast glutathione reductase. Unlike previous methods of analysis the procedure described here effectively measures the total glutathione (GSH + GSSG) content of unknown mixtures and is not subject to appreciable interference by the presence of other thiol components. It is suggested that the catalytic action of glutathione in this system resides in the continual enzymic regeneration of GSH, present initially or formed enzymically from GSSG, following its interaction with the sulfhydryl reagent.The sensitivity of the method is such as to permit the determination of total glutathione in extracellular tissue fluids such as plasma, saliva, and urine normally containing very low levels of this material, essentially without pretreatment of the sample. The same is true for glutathione determinations of whole blood, in which the preliminary procedure is confined to the preparation of a 1:100 hemolyzate from as little as 10 μl of sample.Following published procedures, the pretreatment of tissue extracts with NEM to form an enzymically inactive complex with free GSH allowed the determination of the low levels of oxidized glutathione normally present therein. The use of the foregoing analytical method in the determination of total and oxidized glutathione contents of rat blood, kidney, and liver gave values in good agreement with those obtained by previous investigators.
Article
To determine whether Hg accumulated in renal cells is secreted into the lumen of proximal tubules with intracellular glutathione (GSH) and reabsorbed by tubular cells via a gamma-glutamyltranspeptidase (gamma-GTP)-dependent process as in the case of GSH itself, the effect of postadministration of acivicin (1 mmol/kg i.p.), a gamma-GTP inhibitor, on renal Hg accumulation was investigated in mice. Renal Hg content 4 hr after injection of CH3HgCl or HgCl2 (5 mumol/kg i.v.) was decreased to 35 or 44% of control, respectively, but urinary Hg excretion was increased by acivicin administration 2 hr after injection of the mercurials. When renal GSH was decreased to 19% of control by treatment with DL-buthionine-S,R-sulfoximine (4 mmol/kg s.c.) 2 hr before acivicin injection, the increase in urinary Hg excretion caused by acivicin was suppressed. Acivicin administration 24 hr after injection of the mercurials decreased renal methylmercury content determined 2 hr after acivicin injection and increased urinary Hg excretion. The postadministration of acivicin, however, did not affect the renal content of inorganic Hg which predominantly bound to metallothionein (MT) induced by HgCl2 itself. Pretreatment with Bi(NO3)3 as a renal MT inducer diminished the effect of acivicin administered 2 hr after HgCl2 injection on renal Hg content and urinary excretion. These results suggest that methylmercury and inorganic Hg bound to ligands other than MT in renal cytosol may be secreted into the lumen of proximal tubules with intracellular GSH and be reabsorbed via a gamma-GTP-dependent process.
Article
We investigated the effects of chlorophyll derived from Chlorella on gastrointestinal absorption of seven types of polychlorinated dibenzo-p-dioxin (PCDD) and 10 types of polychlorinated dibenzofuran (PCDF) in Wistar rats. Twenty-eight rats were randomly distributed into seven groups (n = 4). After overnight food deprivation, rats were given 4 g of the basal diet or 4 g of the chlorophyll diet containing 0.01-0.5% chlorophyll one time on day 1; each diet also contained 0.2 mL PCDD and PCDF standard solutions. The amounts of fecal excretion of PCDD and PCDF congeners from days 1 to 5 in the group fed 0.01% chlorophyll were 64.8% for 1,2,3,7,8-pentaCDD, 78.6% for 1,2,3,4,7,8-hexaCDD, 73.5% for 1,2,3,6,7,8-hexaCDD, 58.5% for 1,2,3,7,8,9-hexaCDD, 33.3% for 1,2,3,4,6,7,8-heptaCDD, 85.7% for 1,2,3,7,8-pentaCDF, 77.3% for 2,3,4,7,8-pentaCDF, 88.6% for 1,2,3,4,7,8-hexaCDF, 78.0% for 1,2,3,6,7,8-hexaCDF, 62.5% for 1,2,3,7,8,9-hexaCDF, 84.1% for 2,3,4,6,7,8-hexaCDF, 41.7% for 1,2,3,4,6,7,8-heptaCDF, and 40.0% for 1,2,3,4,6,7,8-heptaCDF greater (p < 0.01) than those of the control group, respectively. The fecal excretion of PCDD and PCDF congeners was remarkably increased along with the increasing dietary chlorophyll. The amounts of PCDD and PCDF congeners in rats on day 5 administered dioxin mixtures were lower in the 0.01% chlorophyll group than in the control group, ranging from 3.5 to 50.0% for PCDD congeners and from 3.7 to 41.7% lower for PCDF congeners, except for 2,3,7,8-tetrachlorodibenzofuran. The amount of PCDD and PCDF congeners in rats was remarkably decreased along with the increasing dietary chlorophyll. These findings suggest that chlorophyll is effective for preventing dioxin absorption via foods.
The effect of Chlorella on alimentary hyperlipemia in rats
  • T Sano
Sano, T. (1982): The effect of Chlorella on alimentary hyperlipemia in rats. Kurume Igaku Zasshi, 45, 1130-1152.