Protection of extract from leaves of Ardisia compressa against benomyl-induced cytotoxicity and genotoxicity in cultured rat hepatocytes

The potential of the Ardisia compressa extract (EA) was examined regarding its capacity to reduce the cytotoxic effect of benomyl on rat hepatocytes. The protective effect was evaluated by Janus Green dye exclusion method. An approximate 50% cytotoxic effect of benomyl on hepatocytes was observed at 35 mu g/ml after 2 hr of incubation. (-)Epigallocatechin 3-gallato (EGCG) and EA decreased the viability of hepatocytes at concentrations above 3 mu g/ml and 2.52 mu g, equivalent to (+)catechin/ml, respectively. A protective effect against benomyl was observed when hepatocytes were previously exposed to EGCG (3 mu g/ml) or EA (2.52 mu g, equivalent to (+)catechin/ml) followed by incubation with benomyl (35 mu g/ml) alone. When EGCG or EA were in contact with cells. either simultaneously or after pretreatment with benomyl, did not protect hepatocytes. EGCG (1.3 x 10(-2) mu g/ml) or EA (9.8 x 10(-2) mu g, equivalent to (+)catechin/ml) inhibited 57% and 34%, respectively, the unscheduled DNA synthesis (UDS) induced by benomyl at a concentration of 23 x 10(-2) mu M, when both were incubated with hepatocytes prior to benomyl. The simultaneous incubation of benomyl with EGCG or EA did not protect the cell against the genotoxic effect of benomyl. These results indicate that the dried leaves extract of Ardisia compressa protect rat hepatocytes from benomyl-induced cytotoxicity and genotoxicity. (C) 1999 Elsevier Science Ltd. All rights reserved.