Prevention of Aflatoxin B1-Induced DNA Breaks by ß-D-Glucan.

Aflatoxins are a group of naturally-occurring carcinogens that are known to contaminate different human and animal foodstuffs. Aflatoxin B1 (AFB1) is the most genotoxic hepatocarcinogenic compound of all of the aflatoxins. In this report, we explore the capacity of ß-D-glucan (Glu) to reduce the DNA damage induced by AFB1 in mouse hepatocytes. For this purpose, we applied the comet assay to groups of animals that were first administered Glu in three doses (100, 400 and 700 mg/kg bw, respectively) and, 20 min later, 1.0 mg/kg of AFB1. Liver cells were obtained at 4, 10 and 16 h after the chemical administration and examined. The results showed no protection of the damage induced by AFB1 with the low dose of the polysaccharide, but they did reveal antigenotoxic activity exerted by the two high doses. In addition, we induced a co-crystallization between both compounds, determined their fusion points and analyzed the molecules by UV spectroscopy. The data suggested the formation of a supramolecular complex between AFB1 and ß-D-glucan.

Spirulina (arthrospira) protects against valproic acid-induced neural tube defects in mice.

Valproic acid (VPA) is a potent inducer of neural tube defects in human and mouse, its teratogenicity is associated with its potential to generation of free radicals and increase oxidative stress. Furthermore, spirulina (SP) has shown pharmacological properties against teratogenicity, which are attributed to its antioxidant potential. Accordingly, the present study was performed to investigate the influence of SP on the teratogenicity of VPA in imprinting control region mice and the possible mechanisms of action. VPA (sodium valproate) was administered intraperitoneally to mice on gestation day (GD) 8 at a dose of 600 mg/kg. SP was given orally at 125, 250, and 500 mg/kg daily from GD0 through GD18. The most common finding in fetuses with VPA exposure was exencephaly. SP decreased the incidence of this and other malformations and increased levels of superoxide dismutase, catalase, and glutathione peroxidase. In conclusion, these results illustrate the protective action of SP through its antioxidant activity against VPA-induced teratogenicity.

Spirulina (Arthrospira) protects against cadmium-induced teratogenic damage in mice.

The role of Spirulina (Arthrospira) in preventing cadmium (Cd) teratogenicity in ICR mice was studied. Cd was administered intraperitoneally to female mice at 1.5 mg/kg on gestation day (GD)-7, and Spirulina was given by peroral (intragastric) administration at 62.5, 125, 250, or 500 mg/kg from GD-0 through GD-17 (the day when animals were sacrificed). Because among the mechanisms suggested to account for reproductive damage are oxidative stress and lipoperoxidation, embryonic hydroperoxides were also determined. Treatment with Spirulina at the three highest doses significantly decreased the frequency of fetuses with exencephaly, micrognathia, and skeletal abnormalities induced by Cd. Furthermore, Spirulina treatment significantly and dose-dependently decreased lipid peroxidation, which was dramatically increased by administration of the metal. The results of the present study clearly point to the therapeutic potential of Spirulina in Cd-induced teratogenicity and probably through its antioxidant activity.

Antigenotoxic studies of different substances to reduce the DNA damage induced by aflatoxin B(1) 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 AFB(1) and ochratoxin A and contains an analysis of some antigenotoxic substances that reduce the DNA damage caused by these mycotoxins.