Interaction of aflatoxin B-1 and fumonisin B-1 in mice causes immunotoxicity and oxidative stress: Possible protective role using lactic acid bacteria

Aflatoxins (AF) are important foodborne mycotoxins implicated in human health and have immunocytotoxic effects. The aims of this study were to evaluate a new aflatoxin B-1 (AFB(1)) and fumonisin B-1 (FB1)-binding/degrading micro-organism for biological detoxification, to examine its ability to degrade AFB1 and FB1 in liquid medium, and to evaluate its potential in vivo protective role against any combined effects from AFB(1) and FB1 on host splenocyte caspase-3 activity (reflecting DNA damage/cell death) and mRNA levels of select inflammation-regulating cytokines. Balb/c mice were divided into groups (10/group) and treated daily for 2 weeks by oral gavage with AFB(1) (80 mg/kg BW), FB1 (100 mg/kg), AFB(1)+ FB1, or lactic acid bacteria (Lactobacillus paracasei BEJ01, 2 x 10(9) CFU/L, similar to 2 mg/kg) - alone or in combination with the AFB(1) and/or FB1. After the exposures, spleens were collected for measures of caspase-3 activity, lipid peroxidation (LP), and glutathione (GSH) content, expression of anti-oxidation protective enzymes (GPx and SOD), and mRNA levels of inflammation-regulating cytokines (e. g. IL-10, IL-4, IFN gamma, TNF alpha). Thymii were also removed for analysis of apoptosis. The results indicated that, in the spleen, exposure to the mycotoxins led to increased caspase-3 activity, LP, and IL-10 and IL-4 mRNA levels, but decreased GSH content and down-regulated expression of GPx and SOD, and of IFN gamma and TNF alpha mRNA. Co-treatment using Lactic Acid Bacteria (LAB) with AFB(1) or FB1 suppressed levels of DNA fragmentation, normalized splenic LP and increased GSH levels, up-regulated expression of GPx and SOD, and normalized mRNA levels of the analyzed cytokines. It is concluded that AFB(1) and FB1 might have combinational (synergistic moreso than additive) toxic effects in situ. Further, it can be seen that use of LAB induced protective effects against the oxidative stress and (immuno) toxicity of these agents in part through adhesion (and so likely diminished bioavalability).