Raghubir P. Sharma

MYCOTOXINS: INTRODUCTION AND SIGNIFICANCE. Mycotoxins: General Considerations. Occurrence of Mycotoxins in Foods and Feeds. Detection and Determination of Mycotoxins. Immunotoxic Effects of Mycotoxins. MYCOTOXINS OF ASPERGILLUS. Aflatoxins. Aflatoxin M1. Secalonic Acids. MYCOTOXINS OF PENICILLIUM. Patulin. Citrinin. Luteoskyrin. Rubratoxin. Cytochalasins. MYCOTOXINS OF FUSARIUM. Trichothecenes. Macrocyclic Trichothecenes. MYCOTOXIN OF ALTERNARIA. Alternaria Toxins. MISCELLANEOUS MYCOTOXINS. Miscellaneous Mycotoxins. Control and Detoxification of Mycotoxins in Foods and Feeds. Mycotoxins: Future Prospects and Research Needs. PHYTOALEXINS. Introductory Remarks: Phytoalexins. Legume Phytoalexins. Peanut Phytoalexins. Solanum Phytoalexins. Phenolics and Polyketides in Carrots. Phytoalexins and Plant Resistance. Prospects and Perspective on Phytoalexins. OTHER TOXICANTS. Solanum Glycoalkaloids. Swainsonine, Slaframine, and Castanospermine. Pyrrolizidine Alkaloids. Toxicants in Plants. INDEX. c. 752 pp., 6x9, due July 1991, ISBN 0-8493-8833-3.

The immune system is primarily responsible for defense against invading organisms. The effects of several mycotoxins on the immune responses have been investigated; however, most data concern laboratory animals. In some instances, farm animals and cells derived from livestock species have been employed to evaluate the immunotoxicity of mycotoxins. Immune responses are highly variable, and cost considerations usually preclude the use of dairy cattle as experimental models. Immunosuppression caused by aflatoxin B1 has been demonstrated in various livestock species (e.g., turkeys, chickens, and pigs) and also in laboratory animals (mice, guinea pigs, and rabbits). The response of bovine lymphocytes to aflatoxin in vitro is similar to that of other laboratory animals. Trichothecenes are potent immunosuppressive agents that directly affect immune cells and also modify immune responses as a consequence of tissue damage elsewhere. Sheep and calves treated with fusarium T-2 toxin develop leukopenia and decreased functioning of peripheral lymphocytes. Immunosuppressive effects of ochratoxin A, rubratoxin B, and patulin have been reported. Citrinin produced lymphopenia but stimulated responses against antigens. Antibodies against mycotoxins conjugated to proteins have been produced and are useful for analytical purposes.

(1981). Naturally Occurring Toxic Alkaloids in Foods. CRC Critical Reviews in Toxicology: Vol. 9, No. 1, pp. 21-104.

Lipopolysaccharide (LPS) produces reactive oxygen species (ROS) and nitric oxide (NO) in macrophages. These molecules are involved in inflammation associated with endotoxic shock. Selenium (Se), a biologically essential trace element, modulates the functions of many regulatory proteins involved in signal transduction and affects a variety of cellular activities, including cell growth and survival. We demonstrate that Se attenuated LPS-induced ROS and NO production in murine macrophage cultures in vitro. This Se-decreased production of NO was demonstrated by decreases in both mRNA and protein expression for inducible NO synthase (iNOS). The preventive effects of Se on iNOS were p38 mitogen-activated protein kinase- and nuclear factor-kappaB-dependent. Se specifically blocked the LPS-induced activation of p38 but not that of c-jun-N-terminal kinase and extracellular signal-regulated kinase; the p38-specific pathway was confirmed using p38 inhibitor SB 203580. These results suggest that the mechanism by which Se may act as an anti-inflammatory agent and that Se may be considered as a possible preventive intervention for endotoxemia, particularly in Se-deficient locations. However, the efficacy and safety of Se need to be further investigated, because long-term intake > 0.4 mg Se/day in adults can produce adverse effects.