Dregea volubilis ameliorates concanavalin A-induced liver injury by facilitating apoptosis of activated T cells.

Activation of T cells is a critical event in the pathogenesis of concanavalin A (Con A)-induced liver injury, and facilitating apoptosis of activated T cells may provide a strategy for the treatment. Here, we found that the ethanol extract from the stem parts of Dregea volubilis (DVE) inhibited cell proliferation and induced apoptosis, which was selective for Con A-activated, rather than nonactivated, lymph node cells. Administration of DVE prevented mice from Con A-induced elevation of serum transaminases, liver necrosis and increased TNF-alpha, IFN-gamma, IL-2 and IL-4 in mice sera. DVE also caused apoptosis of in vivo activated T cells. In addition, increased active fragments of caspase-3 were found in the DVE-treated cells. But DVE-induced apoptosis was Fas-independent, as it was still observed in T cells from Fas ligand-mutated gld/gld mice. These results suggest that DVE may have great potential to treat T cell-mediated diseases through facilitating apoptosis of activated T cells.