Antioxidant and Hepatoprotective Activity of an Extract from the Overground Parts of Phlomis russeliana Lag. ex Benth

An evaluation of the possible hepatotoxicity/hepatoprotective effects of a defatted extract of the above ground parts of Phlomis russeliana was conducted in vitro and in vivo. The extract was tested in vitro on hepatocytes alone and in a carbon tetrachloride (CCl4)-bioactivation model. The same toxic substance was used for the in vivo evaluation on old Wistar rats. The extract was standardised via high performance liquid chromatography (HPLC) by the quantification of total flavonoids and verbascoside. Gallic acid equivalents were used to express the content of total phenolic compounds. The identification of flavonoids in this species was undertaken for the first time. The extract was not statistically hepatotoxic in vitro on the isolated rat hepatocytes. In the CCl4-induced hepatotoxicity model, the extract had a hepatoprotective effect, which was concentration-dependant (the highest at 50 µg/mL). An in vivo study on old rats confirmed the observed antioxidant and hepatoprotective effects. The histological findings were favourable for the rats, given the extract and CCl4 in combination. They had an unchanged organ structure, which is commensurable with these animals, treated with a combination of CCl4 and silymarin.