Endocrine Abstracts

The present study was designed to investigate the effects of Diol-ginsenosides, major active components of Panax Ginseng, on the development of diabetes in the Diabetes Prone-BB rats(DP-BB rats). Administration of Diol-ginsenosides to DP-BB rats from age 3-4 weeks to age 11-12 weeks (daily, 1mg/g body weight) resulted in a markedly delayed the onset of diabetes. Islets of the treated rats showed no insulitis or only early/intermediate-stage insulitis and preserved higher pancreatic insulin levels compared to those of the untreated rats. In the trials to elucidate the antidiabetogenic mechanism, we found that Diol-ginsenosides did not cause any change in the proportions of T cells, NK cells, or macrophage phenotypes in spleen or blood, and had no effect on adoptive transfer of Concanavalin A -activated spleen cells. This fact suggested that Diol-ginsenosides might not suppress the effector mechanisms of beta-cell destruction. Diol-ginsenosides protected RIN5mF cells from combinated cytokines-induced cytotoxicity without affecting nitric oxide (NO) formation, and also decreased exogeneous NO- and reactive oxygen intermediates(ROI)-induced cytotoxicity. However,Diol-ginsenosides did not exert any scavenging effcts on cytokines, NO, or ROI.

The obtained results suggested that the antidiabetogenic action of Diol-ginsenosides might be based on the increase in beta-cell resistance induced by diol-ginsenosides against cytokines and free radicals, rather than the suppression of cytotoxic effector mechanisms in DP-BB rats.