The immune system is the primary and essential protective mechanism against different organisms. Aflatoxin B1, a secondary metabolite of fungi, impairs the immune system. However, the mechanisms responsible for the immunomodulating effects of aflatoxin B1 have not been clearly determined. Numerous studies reported that aflatoxin B1 exerts its toxicity on the immune system by different mechanisms. Inhibition of the aforementioned synthesis might directly or indirectly cause prevention of proliferation/ differentiation of immune cells, disrupt monokines and interleukin production and consequently destroy harmonic communication among immune system components (Dugyala & Sharma, 1996).
As with toxicity testing, most studies focusing on mycotoxin …show more content…
The innate intestinal immunity plays an essential role in maintaining the integrity of GIT and also contributes with adaptive immune system for neutralizing the potential microbial pathogens. One of the important components of the local immune system is IECs. These cells generate a variety of antimicrobial peptides and digestive enzymes and also use various mechanisms to reduce the risk of infection by microbial agents and poisoning by toxic compounds. Many mycotoxins such as aflatoxin can change the proliferation and differentiation processes of IECs (Mu¨ ller et al., 2005; Yunus et al., 2011). In this regard, previous studies performed on rats showed that aflatoxin B1 decreases proliferation of epithelial cells throughout the intestine (in the small intestine and colon) (Fleming et al., 1994). Although administration of AFB1 would not be expected to enhance tumor formation in GIT, one study indicated that there was an important relationship between the occurrence of colon carcinoma and dietary deficiency of vitamin A in AFB1-fed rats (Fleming et al., 1994; Rogers & Newberne, 1975). In order to clarify the interaction between AFB1 with IECs, Watzl et al. determined the cytotoxicity and DNA-damage of jejunal epithelial cells of the Brown Norway (BN) rats induced by AFB1 in vitro and in vivo. They found AFB1 can induce genotoxicity in isolated epithelial cells of jejunum (430 mM, in vitro), but short-term oral exposure at moderate doses (100 mg/kg b.w./week) did not impair the local immune system of the gut (Watzl et al.,
As with toxicity testing, most studies focusing on mycotoxin …show more content…
The innate intestinal immunity plays an essential role in maintaining the integrity of GIT and also contributes with adaptive immune system for neutralizing the potential microbial pathogens. One of the important components of the local immune system is IECs. These cells generate a variety of antimicrobial peptides and digestive enzymes and also use various mechanisms to reduce the risk of infection by microbial agents and poisoning by toxic compounds. Many mycotoxins such as aflatoxin can change the proliferation and differentiation processes of IECs (Mu¨ ller et al., 2005; Yunus et al., 2011). In this regard, previous studies performed on rats showed that aflatoxin B1 decreases proliferation of epithelial cells throughout the intestine (in the small intestine and colon) (Fleming et al., 1994). Although administration of AFB1 would not be expected to enhance tumor formation in GIT, one study indicated that there was an important relationship between the occurrence of colon carcinoma and dietary deficiency of vitamin A in AFB1-fed rats (Fleming et al., 1994; Rogers & Newberne, 1975). In order to clarify the interaction between AFB1 with IECs, Watzl et al. determined the cytotoxicity and DNA-damage of jejunal epithelial cells of the Brown Norway (BN) rats induced by AFB1 in vitro and in vivo. They found AFB1 can induce genotoxicity in isolated epithelial cells of jejunum (430 mM, in vitro), but short-term oral exposure at moderate doses (100 mg/kg b.w./week) did not impair the local immune system of the gut (Watzl et al.,