ABSTRACT
The cytotoxic activities of several diterpenoid constituents of the medicinal plant, “hempedu bumi,” or Andrographis paniculata. Nees (Acanthaceae), were evaluated. The seven diterpenoid compounds used were andrographolide, 14-deoxyandrographolide, andrographiside, deoxyandrographiside, 14-deoxy-12-methoxyandrographolide, neoandrographolide, and 14-deoxy-11,12-didehydroandrographolide. The activities of these compounds were evaluated with various human tumor cell lines such as Caov-3 (human ovarian carcinoma cell line), T-47D (human breast carcinoma cell line), Hs-578T (human breast carcinoma cell line), Hep G2 (human hepatocarcinoma cell line), and NCI–H23 (human lung adenocarcinoma cell line). Cell survival was measured using the MTS assay after 72 h of incubation. Andrographolide, neoandrographolide, andrographiside, deoxyandrographiside, and 14-deoxy-12-methoxyandrographolide appeared to be noncytotoxic against all the cell lines. Only 14-deoxyandrographolide and 14-deoxy-11,12-didehydroandrographolide exhibited cytotoxic activities (based on EC50 values), but this was limited to the T-47D cell line (EC50 values of 2.8 µg/ml and 1.5 µg/ml, respectively). As one of the principle diterpenoids of Andrographis paniculata., 14-deoxy-11,12-didehydroandrographolide appeared to be the most potent when compared with the rest of the compounds examined. The effects of 14-deoxy-11,12-didehydroandrographolide on T-47D cells were further confirmed to be nonapoptotic, non-necrotic, but programmed in nature, as demonstrated using a DNA fragmentation detection assay, Trypan blue exclusion assay, and annexin V–propidium iodide staining.