Abstract:
Background Nasopharyngeal cancer is a major health problem. The concurrent therapy also leads to apoptotic cancer cell death that presents a target for molecular therapeutics. Research in the development of medicinal plant especially Ipomoea pes-caprae has been focused on screening because they are inexpensive and rich resources of biological actity like antiinflammation, antinociception, anticancer and antioxidant. These activities are depending on solvent and method of extraction. Objectives To compare the anti-cancer activities and apoptotic mechanisms of the different solvent extraction from Ipomoea pes-caprae against human carcinoma of nasopharynx (KB cells). Methods The dry plant was powdered and extracted by maceration with ethanol & water (A extraction), hexane (B extraction). Supercritical carbon dioxide (SCO2) + ethanol are used as the extraction solvent for polarity extraction (C extraction) and low polarity extraction (D extraction). A-D extractions were treated with KB cells. The viable cell number is based on MTT colorimetric assay. Apoptosis was assessed by nuclear staining with DAPI, agarose gel electrophoresis for DNA fragmentation assay. The mitochondria membrane potential was analyzed by flow cytometry of cells stained with JC-1. Protein caspase-3 and caspase-3 activity were analyzed. Results The A and C extraction were non-toxic but the B and D extraction inhibited KB cells with IC50 of 200 ± 12.3 and 70 ± 4.2 which were low and moderate activities. The molecular mechanisms of cell death were associated with the increasing of chromatin condensation, DNA fragmentation and mitochondria membrane depolarization compared with control cells. Apoptosis enhancement was accompanied by increasing in caspase-3 protein and the relative activity of caspase-3 which was significantly attenuated in a caspase-3 inhibitor. Conclusions The B and D extraction were extracted using low-polarity solvents and the induction of apoptosis involved the activation of effector caspases-3. The SCO2 + ethanol (low polarity extraction) exhibited stronger anti-cancer activity as compared to hexane extraction. Thus, D extraction would represent a promising source for its ability to discovery of interesting anticancer compounds. The elucidation of low-polarity phytoconstituents will be addressed in future studies