Hepatoprotective effect of DT56a is associated with changes in natural killer T cells and regulatory T cells

Objective To determine the metabolic and immunological effects of the oral administration of DT56a, an enzymatic isolate of soybeans. Methods DT56a was orally administered to mice in three animal models: leptin deficiency, high-fat diet (HFD) supplementation and immune-mediated hepatitis. Liver damage and immunological status were assessed. Results Oral administration of DT56a to leptin-deficient (ob/ob) and HFD mice led to a significant reduction in serum triglyceride (TG) and total cholesterol (TC) levels. DT56a-treated mice in both models exhibited a significant reduction in hepatic levels of TG and marked alleviation of glycemic control as indicated by significant decreases in fasting blood glucose levels and glucose tolerance tests. The levels of liver enzymes were reduced. These metabolic effects were associated with altered distributions of regulatory T (Tregs) and natural killer T (NKT) cells. DT56a suppressed the immune-mediated liver damage induced by concanavalin A indicated by decreased liver enzymes and serum interferon-? levels and by improved histology and decreased hepatic apoptosis. Oral administration of DT56a also alleviated immune-mediated hepatitis and affected Tregs and NKT cells. Conclusions Oral administration of DT56a promotes a hepatoprotective effect associated with an alteration in the distribution of Tregs and NKT cells.