Cytotoxic effect of Coscinium fenestratum (Gaertn.) Colebr. and its active principle berberine on L929 cells

Coscinium fenestratum (Gaertn.) Colebr. is a medicinal liana found in the Western Ghats of Southern India, Sri Lanka, Cambodia and Malaysia. Water and methanol extracts prepared from the stem of C. fenestratum were evaluated for cytotoxicity on L929 fibroblast cells. Berberine taken for the cytotoxic evaluation was obtained through cell suspension cultures established from young green leaf segments. MTT (3-(4,5-dimethyl-2-thiazol)-2,5-diphenyl-2H tetrazolium bromide) assay was performed to evaluate the in vitro cytotoxicity. Berberine present in the water and methanol extract was determined by RP-HPLC. Methanol extracts demonstrated better inhibitory effects on cultured L929 cells followed by purified berberine from cell suspension cultures and water extracts. Only 15.33% of the cells was metabolically active at 200 μg/ml methanol extract while 23.57% of the cells was active at 200 μg/ml berberine. Increased inhibitory effect of methanol extracts over berberine demonstrates the occurrence of other cytotoxic principles along with main active principle berberine or other factors enhancing the cytotoxic effect of berberine.