Antigenotoxic Studies of Different Substances to Reduce the DNA Damage Induced by Aflatoxin B1 and Ochratoxin A

Mycotoxins are produced mainly by the mycelial structure of filamentous fungi, or more specifically, molds. These secondary metabolites are synthesized during the end of the exponential growth phase and appear to have no biochemical significance in fungal growth and development. The contamination of foods and feeds with mycotoxins is a significant problem for the adverse effects on humans, animals, and crops that result in illnesses and economic losses. The toxic effect of the ingestion of mycotoxins in humans and animals depends on a number of factors including intake levels, duration of exposure, toxin species, mechanisms of action, metabolism, and defense mechanisms. In general, the consumption of contaminated food and feed with mycotoxin induces to neurotoxic, immunosuppressive, teratogenic, mutagenic, and carcinogenic effect in humans and/or animals. The most significant mycotoxins in terms of public health and agronomic perspective include the aflatoxins, ochratoxin A (OTA), trichothecenes, fumonisins, patulin, and the ergot alkaloids. Due to the detrimental effects of these mycotoxins, several strategies have been developed in order to reduce the risk of exposure. These include the degradation, destruction, inactivation or removal of mycotoxins through chemical, physical and biological methods. However, the results obtained with these methods have not been optimal, because they may change the organoleptic characteristics and nutritional values of food. Another alternative strategy to prevent or reduce the toxic effects of mycotoxins is by applying antimutagenic agents. These substances act according to several extra- or intracellular mechanisms, their main goal being to avoid the interaction of mycotoxins with DNA; as a consequence of their action, these agents would inhibit mutagenesis and carcinogenesis. This article reviews the main strategies used to control AFB1 and ochratoxin A and contains an analysis of some antigenotoxic substances that reduce the DNA damage caused by these mycotoxins

Antigenotoxicity of Dietary Coconut Oil

Benzo(a)pyrene, dimethylnitrosamine, methylmethanesulfonate and tetracycline induced formation of micronucleated polychromatic erythrocytes indicating that these substances are genotoxic to bone marrow cells of the experimental mice.Genotoxicity of these substances to germ cells was also observed when low fertility index and high percentage dead implants were induced in experimental mice.When each genotoxin was administered to mice fed with diets containing 18 % coconut oil for 23 days, the formation of micronucleated polychromatic erythrocytes was greatly reduced. Antigenotoxic activity of dietary coconut oil was very much greater than dietary soybean oil.Germ cell genotoxicity of each genotoxin was also reduced when male mice fed the 18 % coconut oil diet were used. When male mice treated with the genotoxin was mated with virgin females, fertility index was increased in the group fed with coconut oil diet. Percentage dead implants was reduced. The antigenotoxic activity of dietary coconut oil on germ cells far exceeds that of dietary soybean oil.Dietary restriction of coconut oil diets enhanced the antigenotoxic activity of coconut oil in bone marrow cells and germs cells.Among the triacylglycerols of coconut oil, trilaurin gave the best antigenotoxic activity in bone marrow cells. Trilaurin is the major triacylglycerol in coconut oil

Inhibitory Effects of Some Philippine Medicinal Plants on Germ Cell Genotoxicity of Methylmethansulfonate, Tetracycline, and Chloromycetin

Methylmethansulfonate, tetracyline, and chloromycetin were shown to be genetoxic to germ cell. These genotoxins induced reduction in fertility index, gestation index, and implantation index. The percentage dead implants and percentage of females with resorptions were increased.Decoctions from bayabas, kalatsutsi, kamias, kogon, makabuhay, malunggay, mayana, sambong, tanglad, and ulasimang bato increased fertility index, gestation index, implantation index, and reduced percentage dead implants and percentage of female with resorption

Mutagens from roasted seeds of Moringa oleifera

A number of biosynthetically and chemically related compounds were isolated from the roasted seeds of Moringa oleifera. The micronucleus test, an in vivo method, using albino mice as the test system, was used for monitoring the mutagenicity of the isolated compounds. Structure-activity correlation studies showed that 4(α-L-rhamnosyloxy)phenylacetonitrile, 4-hydroxyphenylacetonitrile, and 4-hydroxyphenyl-acetamide exhibited mutagenic activity

Studies on Moringa oleifera seeds. 2. Thermal degradation of roasted seeds.

The thermal degradation products of roasted seeds of the ben tree were compared to the non-roasted seeds. Analysis showed that 4(alpha-L-rhamnosyloxy) phenylacetonitrile is a thermal degradation product of 4(alpha-L-rhamnosyloxy) benzyl glucosinolate during roasting

Antimutagens from Momordica charantia

The antimutagenic principle of the green fruits of Momordica charantia was shown by the micronucleus test to be an intractable mixture of novel acylglucosylsterols. The antimutagens were extracted from the green fruits with ethanol and isolated from the bioactive petroleum ether and carbon tetrachloride extracts by repeated and sequential flash column chromatography. The major component of the mixture is 3-O-[6′-O-palmitoyl-β-d-glucosyl-stigmasta-5, 25 (27)-dien and the minor component is the stearyl derivative (Guevara, 1989). At a dosage range in mice of 50–12.5 μg extract/g, the mixture reduced by about 80% the number of micronucleated polychromatic erythrocytes induced by the well-known mutagen mitomycin C. Structure-activity correlation studies suggested that the antimutagenic activity may reside in the peculiar lipid-like structure of the acylglucosylsterols. Ingestion of these compounds may result in their absorption in the plasma membrane lipid bilayer which could adversely affect the membrane permeability towards mitomycin C and disrupt the cellular activity of the latter

Acylglucosyl sterols from Momordica charantia

A mixture of acylglucosylsterols was isolated from the green fruits of Momordica charantia (balsam pear or bitter gourd) and the structure elucidated by high field 1H NMR, 13C NMR, FTIR and mass spectrometry and chemical modification studies followed by spectral and chromatographic analysis. The major acylglucosyl sterol was 3-O-[6′-O-palmitoyl-β-d-glucosyl]-stigmasta-5,25(27)-diene while the minor component was 3-O-[6′-O-stearyl-β-d-glucosyl]-stigmasta-5,25(27)-diene. The isolation and structure elucidation of these acylglucosyl sterols are reported for the first time

Structure of a mutagen from roasted seeds of Moringa oleifera

A mutagenic compound was isolated from roasted seeds of Moringa oleifera Lam. Its structure has been elucidated by spectral analysis as 4(α-L-rhamnosyloxy)phenylacetonitrile. The results of the Micronucleus Test, an in vivo method, showed that the number of micronucleated polychromatic erythrocytes (PCE)/1000 PCE for this compound is higher than that of the solvent control, dimethylsulfoxide, and approximates that of the positive control, tetracycline. This indicates that 4(α-L-rhamnosyloxy)phenylacetonitrile is a genotoxic compound