Effects of Saikosaponins on the Metabolic Actions of Adrenaline, ACTH and Insulin on the Fat Cells

Abstract

Saikosaponins a and d inhibited adrenaline-induced lipolysis in fat cells isolated from epididymal adipose tissue of rats. Saikosaponins a, b₁, b₂, b₄, c and d inhibited ACTH-induced lipolysis in the fat cells. Insulin-stimulated lipogenesis in adipose tissue was significantly reduced by saikosaponin d. Propranolol (a β-blocker) inhibited not only lipolytic actions induced by adrenaline and ACTH but also lipogenesis stimulated by insulin. In contrast to propranolol, saikosaponins b₁, b₂, b₄ and c selectively inhibited ACTH-induced lipolysis without affecting the lipogenetic effect of insulin. The structure-activity relationship of saikosaponins is discussed.