ABSTRACT
Pterocephalus sanctus Decne. was subjected to a bioassay guided fractionation in order to follow and identify the active principles that could be responsible for its anti-hepatotoxic property. The aqueous methanol [80%] extract of the defatted powder of Pterocephalus sanctus was chromatographed over silica gel and eluted with gradient petroleum ether/ethyl acetate. Eight fractions were collected and tested for their biological activity using Primary Cultured Monolayer Hepatocytes where the fifth fraction was subjected to a further fractionation. Three compounds were identified as secologanin, loganin and swerosoid and the latter was only found to possess highly anti-hepatotoxic activity. This is the first report of the study of the anti-hepatotoxic activity of P. sanctus growing in Egypt