Effect of aqueous extracts of black and green teas in arsenic-induced toxicity in rabbits

Natural Dietary Compounds in the Treatment of Arsenic Toxicity

Chronic exposure to arsenic (As) compounds leads to its accumulation in the body, with skin lesions and cancer being the most typical outcomes. Treating As-induced diseases continues to be challenging as there is no specific, safe, and efficacious therapeutic management. Therapeutic and preventive measures available to combat As toxicity refer to chelation therapy, antioxidant therapy, and the intake of natural dietary compounds. Although chelation therapy is the most commonly used method for detoxifying As, it has several side effects resulting in various toxicities such as hepatotoxicity, neurotoxicity, and other adverse consequences. Drugs of plant origin and natural dietary compounds show efficient and progressive relief from As-mediated toxicity without any particular side effects. These natural compounds have also been found to aid the elimination of As from the body and, therefore, can be more effective than conventional therapeutic agents in ameliorating As toxicity. This review provides an overview of the recently updated knowledge on treating As poisoning through natural dietary compounds. This updated information may serve as a basis for defining novel prophylactic and therapeutic formulations.

Black tea and curcumin synergistically mitigate the hepatotoxicity and nephropathic changes induced by chronic exposure to aflatoxin-B1 in Sprague-Dawley rats

The study aimed to clarify the characteristics of black tea (BTE) and/or curcumin (CMN) against aflatoxin-B1 (AFB1). Forty eight adult male Sprague-Dawley rats were divided into eight groups. G1 was non-treated control. G2, G3, and G4 were olive oil, BTE, and CMN, respectively. G5 was olive oil-dissolved AFB1 (25 µg/kg b.w). G6, G7, and G8 were AFB1 along with BTE (2%), CMN (200 mg/kg b.w.), and BTE plus CMN, respectively. All treatments were orally given for consecutive 90 days. After treatment period, rats were sacrificed. Serobiochemical analysis and histopathology showed hepatorenal dysfunction in response to AFB1. Glutathione-antioxidants were significantly decreased versus increased lipid peroxides (p < .05-.001). AFB1 significantly increased the expression of the antitumor p53, but decreased that of antiapoptotic Bcl2 in liver or kidney tissue, either (p < .05). BTE or CMN ameliorated those changes induced by AFB1 in both liver and kidney with highly pronounced improvement when combined BTE/CMN was used. PRACTICAL APPLICATIONS: Black tea (BTE) and curcumin (CMN) were known for their antioxidant effects, and several studies reported their independent effects against different toxicities including aflatoxicosis. The current study clarifies the ameliorative characteristics of both agents; BTE and/or CMN, against the toxicity resulted from the chronic exposure to aflatoxin-B1 (AFB1) (25 µg/kg b.w. for consecutive 90 days). The dose of either agents, BTE or CMN, was 200 mg/kg b.w. along with AFB1. The pathologic changes, serobiochemical parameters, oxidative stress, histological changes, and the molecular disruption, induced by AFB1 in both liver and kidney were obviously and significantly ameliorated after BTE and/or CMN treatments in variable potencies where both agents showed the most effective antitoxic capacities.

Protective effects induced by alcoholic Phlomis fruticosa and Phlomis herba-venti extracts in isolated rat colon: Focus on antioxidant, anti-inflammatory, and antimicrobial activities in vitro

Phlomis fruticosa L. and P. herba-venti are species belonging to the Lamiaceae family, which have been traditionally used to prepare tonic and digestive drinks. Multiple studies also demonstrated the inhibitory effects of P. fruticosa extracts and essential oil against oxidative/proinflammatory pathways and bacterial strains deeply involved in ulcerative colitis. Considering these findings, the present study evaluated the effects of alcoholic P. fruticosa and P. herba-venti leaf extracts in isolated rat colon challenged with Escherichia coli lipopolysaccharide (LPS), an ex vivo experimental paradigm of ulcerative colitis. In this context, we assayed colon levels of pro-oxidant and proinflammatory biomarkers, including nitrites, malondialdehyde (MDA), lactate dehydrogenase (LDH), and serotonin (5-HT). Additionally, the extracts have been tested in order to evaluate possible inhibitory effects on specific bacterial and fungal strains involved in ulcerative colitis. Alcoholic P. fruticosa and P. herba-venti extracts were able to blunt LPS-induced nitrite, MDA, 5-HT, and LDH levels in isolated rat colon. The same extracts also inhibited the growth of Pseudomonas aeruginosa, E. coli, Staphylococcus aureus, Candida albicans and Candida tropicalis. In conclusion, our findings show a potential role exerted by alcoholic P. fruticosa and P. herba-venti in managing the clinical symptoms related to ulcerative colitis.

Multidirectional biological investigation and phytochemical profile of Rubus sanctus and Rubus ibericus

In the present study, the biological properties, including, the enzyme inhibitory and antioxidant activities, as well as, the phytochemical profile of the ethyl acetate, methanol, and water extracts of Rubus sanctus Schreb. and Rubus ibericus Juz. leaves were determined using in vitro bioassays. Wide range of phytochemicals, including, hydroxybenzoic acids, hydroxycinnamic acids, acylquinic acids, ellagitannins, flavonoids, and triterpenoid saponins were determined using UHPLC-ESI/HRMS technique. The ethyl acetate and methanol extracts of the studied Rubus species effectively inhibited acetyl and butyryl cholinesterase. On the other hand, R. sanctus water extract showed low inhibition against α-amylase and prominent inhibitory action against α-glucosidase. Data collected from this study reported the radical scavenging and reducing potential of the studied Rubus species. Investigation of the protective effects of the different extracts of R. sanctus and R. ibericus in experimental model of ulcerative colitis was performed. The extracts were also tested on spontaneous migration of human colon cancer cells (HCT116) in wound healing experimental paradigm. Only R. sanctus methanol extract inhibited spontaneous HCT116 migration in the wound healing test. Our results suggested that R. sanctus and R. ibericus may be potential candidates as sources of biologically-active compounds for the development of nutraceuticals, pharmaceuticals, and/or cosmetics.

Multiple pharmacognostic characterization on hemp commercial cultivars: Focus on inflorescence water extract activity

One of the most promising economic perspectives of hemp production chain is female inflorescence valorization, despite there being actually no chemical composition or biological data from water fraction. In this context, the focus of this study is the evaluation of protective effects related to hemp water flower extracts from four commercial cultivars (Futura 75, Kc virtus, Carmagnola Cs and Villanova). We evaluated the phytochemical profile through validated spectrophotometric and HPLC methods. Then, we studied the biological activity on C2C12 and HCT116 cell lines, and in an ex vivo experimental model of ulcerative colitis, constituted by isolated LPS-stimulated colon. Particularly, we assayed the blunting effects induced by hemp water extract treatment on LPS-induced levels of nitrites, malondialdehyde (MDA), prostaglandin (PG)E₂ and serotonin (5-HT). All tested cultivars displayed similar total phenolic and flavonoid profile. However, Futura 75 water extract displayed a better antioxidant and anti-inflammatory profile. Considering this, Futura 75 extract activity has been subsequently assayed on bacterial and fungal species involved in ulcerative colitis, finding a significant inhibition on C. albicans and selected Gram positive and negative bacterial strains. Concluding, our results support the potential efficacy of hemp inflorescence water extracts in managing the clinical symptoms related to ulcerative colitis.

Medicinal plants and natural products in amelioration of arsenic toxicity: a short review

CONTEXT

Chronic arsenic toxicity (arsenicosis) is considered a serious public health menace worldwide, as there is no specific, safe, and efficacious therapeutic management of arsenicosis.

OBJECTIVES

To collate the studies on medicinal plants and natural products with arsenic toxicity ameliorative effect, active pre-clinically and/or clinically.

METHODS

Literature survey was carried out by using Google, Scholar Google and Pub-Med. Only the scientific journal articles found on the internet for last two decades were considered. Minerals and semi-synthetic or synthetic analogs of natural products were excluded.

RESULTS

Literature study revealed that 34 medicinal plants and 14 natural products exhibited significant protection from arsenic toxicity, mostly in preclinical trials and a few in clinical studies.

CONCLUSION

This research could lead to development of a potentially useful agent in clinical management of arsenicosis in humans.

Dietary compounds as modulators of metals and metalloids toxicity

A large part of the population is exposed to metals and metalloids through the diet. Most of the in vivo studies on its toxicokinetics and toxicity are conducted by means of exposure through drinking water or by intragastric or intraperitoneal administration of aqueous standards, and therefore they do not consider the effect of the food matrix on the exposure. Numerous studies show that some components of the diet can modulate the toxicity of these food contaminants, reducing their effect on a systemic level. Part of this protective role may be due to a reduction of intestinal absorption and subsequent tissue accumulation of the toxic element, although it may also be a consequence of their ability to counteract the toxicity directly by their antioxidant and/or anti-inflammatory activity, among other factors. The present review provides a compilation of existing information about the effect that certain components of the diet have on the toxicokinetics and toxicity of the metals and metalloids of greatest toxicological importance that are present in food (arsenic, cadmium, lead, and mercury), and of their most toxic chemical species.

Therapeutic properties of green tea against environmental insults

Pesticides, smoke, mycotoxins, polychlorinated biphenyls (PCBs), and arsenic are the most common environmental toxins and toxicants to humans. These toxins and toxicants may impact on human health at the molecular (DNA, RNA, or protein), organelle (mitochondria, lysosome, or membranes), cellular (growth inhibition or cell death), tissue, organ, and systemic levels. Formation of reactive radicals, lipid peroxidation, inflammation, genotoxicity, hepatotoxicity, embryotoxicity, neurological alterations, apoptosis, and carcinogenic events are some of the mechanisms mediating the toxic effects of the environmental toxins and toxicants. Green tea, the nonoxidized and nonfermented form of tea that contains several polyphenols, including green tea catechins, exhibits protective effects against these environmental toxins and toxicants in preclinical studies and to a much-limited extent, in clinical trials. The protective effects are collectively mediated by antioxidant, antiinflammatory, antimutagenic, hepatoprotective and neuroprotective, and anticarcinogenic activities. In addition, green tea modulates signaling pathway including NF-κB and ERK pathways, preserves mitochondrial membrane potential, inhibits caspase-3 activity, down-regulates proapoptotic proteins, and induces the phase II detoxifying pathway. The bioavailability and metabolism of green tea and its protective effects against environmental insults induced by pesticides, smoke, mycotoxins, PCBs, and arsenic are reviewed in this paper. Future studies with emphasis on clinical trials should identify biomarkers of green tea intake, examine the mechanisms of action of green tea polyphenols, and investigate potential interactions of green tea with other toxicant-modulating dietary factors.

Influence of diet, vitamin, tea, trace elements and exogenous antioxidants on arsenic metabolism and toxicity

Health risk of arsenic (As) has received increasing attention. Acute and chronic exposure to As could cause several detrimental effects on human health. As toxicity is closely related to its bioaccessibility and metabolism. In real environment, many factors, such as diet and nutrition, can influence As bioaccessibility, metabolism and toxicity. This paper mainly reviews the influences of diets and elements on As bioaccessibility, metabolism and toxicity and their underlying mechanisms to provide suggestions for future investigations. Vitamins, jaggery, fruit, tea, glutathione, N-acetylcysteine and zinc could reduce the As-induced toxicity by increasing antioxidative enzymes to antagonize oxidative stress caused by As and/or increasing As methylation. However, bean and betel nut could increase risk of skin lesions caused by As. Interestingly, high-fat diet, selenium and iron have incompatible effects on As bioaccessibility, metabolism and toxicity in different experimental conditions. Based on current literatures, the As methylation and As-induced oxidative damage might be two main ways that the diets and elements influence As toxicity. Combined application of in vitro human cell lines and gastrointestinal models might be useful tools to simultaneously characterize the changes in As bioaccessibility and toxicity in the future research.

Antioxidative effect of rice bran oil and medium chain fatty acid rich rice bran oil in arsenite induced oxidative stress in rats

The present study was adopted to evaluate the antioxidant efficacy of medium chain fatty acid (caprylic, capric and lauric) rich rice bran oils in comparison to rice bran oil in terms of altered biochemical parameters of oxidative stress following sodium arsenite treatment in rats. Animals were divided into ten groups; five normal groups and five arsenite treated groups. Results showed that activities of antioxidant enzymes in liver, brain and erythrocyte membrane increased with the administration of rice bran oil and MCFA rich rice bran oils both in normal and arsenite treated cases. Lipid peroxidation increased with the administration of sodium arsenite, but again administration of rice bran oil and MCFA rich rice bran oils decreased the lipid peroxidation. Caprylic acid rich rice bran oil showed the best ameliorative effects.

Chemoprevention against arsenic-induced mutagenic DNA breakage and apoptotic liver damage in rat via antioxidant and SOD1 upregulation by green tea (Camellia sinensis) which recovers broken DNA resulted from arsenic-H2O2 related in vitro oxidant stress

Green tea (Camellia sinensis; CS) strongly reverses/prevents arsenic-induced apoptotic hepatic degeneration/micronecrosis and mutagenic DNA damage in in vitro oxidant stress model and in rat as shown by comet assay and histoarchitecture (HE and PAS staining) results. Earlier, we demonstrated a link between carcinogenesis and impaired antioxidant system-associated mutagenic DNA damage in arsenic-exposed human. In this study, arsenic-induced (0.6 ppm/100 g body weight/day for 28 days) impairment of cytosolic superoxide-dismutase (SOD1), catalase, xanthine-oxidase, thiol, and urate activities/levels led to increase in tissue levels of damaging malondialdehyde, conjugated dienes, serum necrotic-marker lactate-dehydrogenase, and metabolic inflammatory-marker c-reactive protein suggesting dysregulation at the transcriptional/signal-transduction level. These are decisively restrained by CS-extract (≥10 mg/ml aqueous) with a restoration of DNA/tissue structure. The structural/functional impairment of dialyzed and centrifugally concentrated (6-8 kd cutoff) hepatic SOD1 via its important Cys modifications by H2O2/arsenite redox-stress and that protection by CS/2-mercaptoethanol are shown in in vitro/in situ studies paralleling the present Swiss-Model-generated rSOD1 structural data. Here, arsenite(3+) incubation (≥10(-8) μM + 10 mM H2O2, 2 hr) is shown for the first time with this low-concentration to initiate breakage in rat hepatic-DNA in vitro whereas, arsenite/H2O2/UV-radiation does not affect DNA separately. Arsenic initiates Fe and Cu ion-associated free-radical reaction cascade in vivo. Here, 10 μM of Cu(2+)/Fe(3+)/As(3+) +H2O2-induced in vitro DNA fragmentation is prevented by CS (≥1 mg/ml), greater than the prevention of ascorbate or tocopherol or DMSO or their combination. Moreover, CS incubation for various time with differentially and already degraded DNA resulted from pre-incubation in 10 μM As(3+)-H2O2 system markedly recovers broken DNA. Present results decisively suggest for the first time that CS and its mixed polyphenols have potent SOD1 protecting, diverse radical-scavenging and antimutagenic activities furthering to DNA protection/therapy in arsenic-induced tissue necrosis/apoptosis.

Protective effects of Vernonia amygdalina against sodium arsenite-induced genotoxicity in rat

Objectives:

Contamination of the environment with arsenic (As) from both human and natural sources is known as a global problem. This study investigated the chemoprotective potential of Vernonia amygdalina leave extract against sodium arsenite-induced genotoxicity and hepatotoxicity.

Materials and Methods:

Genotoxic effects were evaluated in the rat bone marrow using micronuclei. The gamma glutamyl transpeptidase (GGT) and alkaline phosphatase (ALP) activities were assayed in rat serum.

Results:

Pre-treatment with extract of V. amygdalina at doses 5 mg/kg and 10 mg/kg significantly decreased the frequency of micronucleated polychromatic erythrocytes (PCEs). The GGT and ALP activities were elevated more than fourfold, in the liver of rats treated with sodium arsenite, while it was reduced almost to half when the sodium arsenit-treated rats were fed fresh V. amgdalina leave extracts The phytochemical constituents of V. amygdalina assayed in this study may be responsible for high radical scavenging of the DPPH free radical observed.

Conclusion:

The present results indicate that V. amygdalina extract is capable of suppressing the chromosomal aberration induced by sodium arsenite in rat. Thus, V. amygdalina may be a potent chemoprotective agent against the toxicity of sodium arsenite in rats.

Green tea extracts attenuate doxorubicin-induced spermatogenic disorders in conjunction with higher telomerase activity in mice

PURPOSE

The aim of this study was to investigate the protective effect of green tea extracts against doxorubicin-induced damage in the mouse testes correlating with telomerase activity.

METHODS

Green tea extracts were administered orally. Doxorubicin was coadministered intraperitoneally. These testes were evaluated histologically and the telomerase activity was analyzed. Additional immunostaining was carried out.

RESULTS

Both the sperm density and sperm motility were significantly increased in green tea extracts coadministration groups as compared to the doxorubicin-treated groups. By histological analysis, germ cell damage was greatly attenuated by green tea extracts coadministration. Telomerase activity significantly increased in association with the coadministration of green tea extracts as compared to that of doxorubicin-only groups. In all groups, human telomerase reverse transcriptase signals were mainly observed in the spermatocytes and spermatids.

CONCLUSIONS

These findings suggest that green tea extracts exert protective effects against doxorubicin-induced spermatogenic disorders in conjunction with higher telomerase activity levels.