Diet containing grape seed meal by-product counteracts AFB1 toxicity in liver of pig after weaning

Liver is the earliest target for AFB1 toxicity in both human and animals. In the last decade, plant derived by-products have been used in animal feed to reduce AFB1 induced toxicity. In the present study we investigated whether the presence of 8% grape seed meal by-product is able to counteract the hepatotoxic effects produced by AFB1 in liver of pig after weaning exposed to the toxin through the contaminated feed for 28 days. Twenty four weaned cross-bred TOPIGS-40 piglets with an average body weight of 9.13±0.03 were allocated to the following experimentally treatments: control diet without AFB1 (normal compound feed for weaned pigs); contaminated diet with 320 mg kg−1 AFB1; GSM diet (compound feed plus 8% grape seed meal) and AFB1+GSM diet (320 mg kg−1 AFB1 contaminated feed plus 8% grape seed meal). Pigs fed AFB1 diet had altered performance, body weight decreasing with 25.1% (b.w.: 17.17 kg for AFB1 vs 22.92 kg for control). Exposure of piglets to AFB1 contaminated diet caused liver oxidative stress as well as liver histological damage, manly characterized by inflammatory infiltrate, fibrosis and parenchyma cells vacuolation when compared to control and GSM meal group. 94.12% of the total analysed genes (34) related to inflammation and immune response was up-regulated. The addition of GSM into the AFB1 diet diminished the gene overexpression and ameliorate histological liver injuries and oxidative stress. The protective effect of GSM diet in diminishing the AFB1 harmful effect was mediated through the decreasing of gene and protein expression of MAPKs and NF-κB signalling overexpressed by AFB1 diet. The inclusion of grape seed by-products in the diet of pigs after weaning might be used as a novel nutritional intervention to reduce aflatoxin toxicity.