Inhibition of clastogenic effects of arsenic through continued oral administration of garlic extract in mice in vivo

Garlic (Allium sativum L.): A Brief Review of Its Antigenotoxic Effects

Traditional Medicine/Complementary and Alternative Medicine is a practice that incorporates medicine based on plants, animals, and minerals for diagnosing, treating, and preventing certain diseases, including chronic degenerative diseases such as obesity, diabetes, hypertension, atherosclerosis, and cancer. Different factors generate its continued acceptance, highlighting its diversity, easy access, low cost, and the presence of relatively few adverse effects and, importantly, a high possibility of discovering antigenotoxic agents. In this regard, it is known that the use of different antigenotoxic agents is an efficient alternative to preventing human cancer and that, in general, these can act by means of a combination of various mechanisms of action and against one or various mutagens and/or carcinogens. Therefore, it is relevant to confirm its usefulness, efficacy, and its spectrum of action through different assays. With this in mind, the present manuscript has as its objective the compilation of different investigations carried out with garlic that have demonstrated its genoprotective capacity, and that have been evaluated by means of five of the most outstanding tests (Ames test, sister chromatid exchange, chromosomal aberrations, micronucleus, and comet assay). Thus, we intend to provide information and bibliographic support to investigators in order for them to broaden their studies on the antigenotoxic spectrum of action of this perennial plant.

Protective action of curcumin and nano-curcumin against arsenic-induced genotoxicity in rats in vivo

We explored whether nanoformulation of curcumin can cause better protective effect than free curcumin against arsenic-induced genotoxicity. Curcumin-loaded Poly(lactic-co-glycolic acid) nanoparticles (CUR-NP) were prepared by emulsion technique. The CUR-NP were water soluble and showed biphasic release pattern. Rats were divided into 5 groups of 6 each. Group I served as the control. Group II rats were exposed to sodium arsenite (25 ppm) daily through drinking water for 42 days. Groups III, IV and V were maintained as in Group II, however, they were also administered empty nanoparticle, curcumin (100 mg/kg bw) and CUR-NP (100 mg/kg bw), respectively, by oral gavage during the last 14 days of arsenic exposure. On the 43rd day, genotoxic effects were evaluated in bone marrow cells. Arsenic increased chromosomal aberrations, micronuclei formation and DNA damage. Both free curcumin and CUR-NP attenuated these arsenic-mediated genotoxic effects. However, the result suggests that nanoformulation have better protective effect than free curcumin at the same dose level.

A core in vitro genotoxicity battery comprising the Ames test plus the in vitro micronucleus test is sufficient to detect rodent carcinogens and in vivo genotoxins

In vitro genotoxicity testing needs to include tests in both bacterial and mammalian cells, and be able to detect gene mutations, chromosomal damage and aneuploidy. This may be achieved by a combination of the Ames test (detects gene mutations) and the in vitro micronucleus test (MNvit), since the latter detects both chromosomal aberrations and aneuploidy. In this paper we therefore present an analysis of an existing database of rodent carcinogens and a new database of in vivo genotoxins in terms of the in vitro genotoxicity tests needed to detect their in vivo activity. Published in vitro data from at least one test system (most were from the Ames test) were available for 557 carcinogens and 405 in vivo genotoxins. Because there are fewer publications on the MNvit than for other mammalian cell tests, and because the concordance between the MNvit and the in vitro chromosomal aberration (CAvit) test is so high for clastogenic activity, positive results in the CAvit test were taken as indicative of a positive result in the MNvit where there were no, or only inadequate data for the latter. Also, because Hprt and Tk loci both detect gene-mutation activity, a positive Hprt test was taken as indicative of a mouse-lymphoma Tk assay (MLA)-positive, where there were no data for the latter. Almost all of the 962 rodent carcinogens and in vivo genotoxins were detected by an in vitro battery comprising Ames+MNvit. An additional 11 carcinogens and six in vivo genotoxins would apparently be detected by the MLA, but many of these had not been tested in the MNvit or CAvit tests. Only four chemicals emerge as potentially being more readily detected in MLA than in Ames+MNvit--benzyl acetate, toluene, morphine and thiabendazole--and none of these are convincing cases to argue for the inclusion of the MLA in addition to Ames+MNvit. Thus, there is no convincing evidence that any genotoxic rodent carcinogens or in vivo genotoxins would remain undetected in an in vitro test battery consisting of Ames+MNvit.

In vitro and in vivo reduction of sodium arsenite induced toxicity by aqueous garlic extract

BACKGROUND

Arsenic is ubiquitous in the environment, and chronic or acute exposure through food and water as well as occupational sources can contribute to a well-defined spectrum of disease. Despite arsenic being a health hazard and a well-documented human carcinogen, a safe, effective and specific preventive or therapeutic measure for treating arsenic induced toxicity still eludes us.

OBJECTIVE

This study was undertaken to evaluate the therapeutic efficacy of aqueous garlic (Allium sativum L.) extract (AGE) in terms of normalization of altered biochemical parameters particularly indicative of oxidative stress following sodium arsenite (NaAsO(2)) exposure and depletion of inorganic arsenic burden, in vitro and in vivo.

RESULTS

AGE (2mg/ml) co-administered with 10 microM NaAsO(2) attenuated arsenite induced cytotoxicity, reduced intracellular reactive oxygen species (ROS) level in human malignant melanoma cells (A375), human keratinocyte cells (HaCaT) and in cultured human normal dermal fibroblast cells. Moreover, AGE application in NaAsO(2) intoxicated Sprague-Dawley rats resulted in a marked inhibition of tissue lipid peroxide generation; enhanced level of total tissue sulfhydryl groups and glutathione; and also increased the activities of antioxidant enzymes, superoxide dismutase and catalase to near normal. An increase in blood ROS level and myeloperoxidase activity in arsenic-intoxicated rats was effectively prevented by AGE administration. AGE was also able to counter arsenic mediated incongruity in blood hematological variables and glucose level.

CONCLUSIONS

The restorative property of AGE was attributed to its antioxidant activity, chelating efficacy, and/or oxidizing capability of trivalent arsenic to its less toxic pentavalent form. Taken together, evidences indicate that AGE can be a potential protective regimen for arsenic mediated toxicity.

Genetic toxicology of a paradoxical human carcinogen, arsenic: a review

Arsenic is widely distributed in nature in air, water and soil in the form of either metalloids or chemical compounds. It is used commercially, as pesticide, wood preservative, in the manufacture of glass, paper and semiconductors. Epidemiological and clinical studies indicate that arsenic is a paradoxical human carcinogen that does not easily induce cancer in animal models. It is one of the toxic compounds known in the environment. Intermittent incidents of arsenic contamination in ground water have been reported from several parts of the world. Arsenic containing drinking water has been associated with a variety of skin and internal organ cancers. The wide human exposure to this compound through drinking water throughout the world causes great concern for human health. In the present review, we have attempted to evaluate and update the mutagenic and genotoxic effects of arsenic and its compounds based on available literature.

Mutagenicidade e antimutagenicidade dos principais corantes para alimentos

Muitos compostos presentes nos alimentos, tanto naturalmente, como adicionados ou produzidos durante o processamento, já foram testados quanto à mutagenicidade ou antimutagenicidade em diferentes sistemas experimentais. O grande número de corantes para alimentos, naturais ou sintéticos, tem levado os pesquisadores a avaliar a mutagenicidade e/ou antimutagenicidade desses compostos. Alguns corantes sintéticos apresentaram potencial mutagênico e seu uso foi proibido em alguns países. Muitos corantes naturais testados apresentaram potencial antimutagênico em pelo menos um sistema-teste, entretanto, isto não quer dizer que os corantes naturais são inócuos. O corante natural curcumina, por exemplo, apresentou potencial antimutagênico nos testes in vivo e foi mutagênico nos testes in vitro. Este paradoxo ressalta a importância de uma avaliação criteriosa e ampla na avaliação da possível atividade mutagênica e/ou antimutagênica dos corantes.

Garlic and onions: their effect on eicosanoid metabolism and its clinical relevance

Garlic (Allium sativum) and onion (Allium cepa) are among the oldest of all cultivated plants. Additionally, both plants have been used as medicinal agents for thousands of years. Both garlic and onion have been shown to have applications as antimicrobial, antithrombotic, antitumor, hypolipidaemic, antiarthritic and hypoglycemic agents. In recent years, extensive research has focussed on the beneficial and medicinal properties of garlic and onions. In particular, the use of these agents in the treatment and prevention of cardiovascular disease and cancer is an area of considerable investigation and interest.