Antihyperglycemic and insulin-releasing effects of beta-sitosterol 3-beta-D-glucoside and its aglycone, beta-sitosterol.

Abstract

The effect of beta-sitosterol 3-beta-glucoside (antihyperglycemic principle isolated from the aerial part of Centaurea seridis L. var. maritima Lge.) and its aglycone on plasma insulin and glucose levels in normo- and hyperglycemic rats was investigated. The results indicate that oral treatment with the glycoside or with the beta-sitosterol increased the fasting plasma insulin levels. There was a corresponding decrease in fasting glycemia when beta-sitosterol was administered orally. In addition, these compounds improved the oral glucose tolerance test with an increase in glucose-induced insulin secretion. But when these products were administered orally, the effect of glycoside, either on fasting insulinemia or on glucose-induced insulin secretion, lasted longer than that of aglycone. The present study compared these effects with those of glibenclamide. It can be assumed that beta-sitosterol 3-beta-D-glucoside acts by increasing circulating insulin levels, and that this effect is due to their aglycone: beta-sitosterol.