Soy-derived antiapoptotic fractions protect gastrointestinal epithelium from damage caused by methotrexate treatment in the rat.

The ability of a previously described soy-derived antiapoptotic fraction (SDAAF), a soy water extract (Lexirin), and raw soy flour to inhibit methotrexate (MTX)-induced gastrointestinal damage was evaluated by histological examination of duodenal/jejunal sections from MTX-treated rats. Male Sprague-Dawley rats were fed diets containing casein as a sole protein source or diets supplemented with fractions isolated from soy (SDAAF or Lexirin) before and after MTX treatment. The soy fractions were also shown to inhibit serum deprivation-induced programmed cell death (apoptosis) in mouse embryonic C3H10T1/2 cells. Protein sequence (Lexirin) and enzyme activity (Lexirin and SDAAF) were also analyzed. Rats that received SDAAF- and Lexirin-supplemented diets had significantly reduced necrotic and apoptotic damage in the duodenal mucosa, as demonstrated by difference in villi height, mitotic activity, epithelial cell height, and inflammatory response.