Screening for in vitro anti-tumor-promoting activities of edible plants from Indonesia.

A total of 135 methanol extracts from 48 plant families (107 species) of edible Indonesian plants were screened for their in vitro anti-tumor-promoting activities using the tumor promoter 12-O-hexadecanoylphorbol-13-acetate (HPA)induced Epstein-Barr virus (EBV) activation test in Raji cells. Examined at a concentration of 200 mg/ml, 71% of the extracts inhibited EBV activation by 30% or more. The rate is comparable to the rate observed in our previous tests of edible Thai (60%) plants and much higher than the rate (26%) observed with Japanese plants. In particular, the plant families Zingiberaceae (13/13 active) and Umbelliferae (7/8 active) are suggested to be desirable sources of effective cancer-preventive agents because of the strikingly high frequency of inhibitory activity. Thus, a high potential of edible Southeast Asian plants for cancer chemoprevention is indicated.