Antihepatotoxic and immunostimulant properties of iridoid glycosides of <i>Scrophularia koelzii</i>

Abstract

Abstract The alcoholic extract of the aerial parts of Scrophularia koelzii (100 mg/kg p.o. × 7 days) significantly protected the rat liver against thioacetamide induced toxicity. On its further fractionation, activity was localized in the chloroform fraction from which four iridoid glycosides, namely scropolioside‐A, koelzioside, harpagoside and 6‐0‐(3″‐0‐ p ‐methoxy‐cinnamoyl)‐α‐L‐rhamnopyranosyl catalpol were isolated. Among these, scropolioside‐A showed maximum hepatoprotective activity. Immunostimulant response was observed with all the four iridoids with harpagoside exhibiting maximum induction of immune response.