| Abstract | A total of 11 methanol extracts obtained from 4 Nepalese Zanthoxylum species were screened for their antiproliferative activity against the growth of human keratinocytes (HaCaT cells). The extract obtained from Z. armatum bark was highly active (IC50 value of 11 micro g/ml). Extracts obtained from Z. oxyphyllum bark and roots exhibited potent activity (IC50s of 53 and 57 micro g/ml, respectively). Antiproliferative activity was not due to cytotoxic effects on cell membranes, as documented by the activity of lactate dehydrogenase released from the cytoplasm of keratinocytes, which did not exceed that of the control value. The extracts protected against radical-induced damage to model membranes stimulated with 2,2'-azo-bis(2-amidinopropane) dihydrochloride. |