Antifertility Activity of an Oxidized Polyphenolic Acid from Lithospermum ruderale.

The antifertility activity of an oxidized polyphenolic acid from Lithospermum ruderale was investigated. A polyphenolic acid was isolated from the roots of Lithospermum ruderale and was named lithospermic acid(LA). No biological activity of LA was observed in the rat or the chicken. When LA was oxidized enzymically a substance was obtained which inactivated exogenous and endogenous gonadotropins in the female rat and prevented ovulation in the laying hen. A cold water root extract was partitioned into 5 fractions which were administered orally to immature female rats. Only the original extract and 1 fraction composed of oxidized LA revealed a signigicant (p less than .05) inactivation of exogenous gonadotropin. In an additional study the same cold water extract fraction as well as enzymically oxidized lithospermic acid revealed antiovulatory properties when injected into the laying hen. These results indicate that oxidized LA present in the Lithospermum ruderale roots is responsible for some of the antigonadotropic effect oberved with the cold water extracts.