Identification and evaluation of apoptotic compounds from Garcinia paucinervis

Four new compounds, paucinervins A–D (1–4), and 15 known ones were isolated from the leaves of Garcinia paucinervis. The structures of the new compounds were elucidated by spectroscopic evidences. All of the 19 compounds were evaluated for their apoptosis-inducing effects using HeLa-C3 cells which have been genetically engineered to possess a fluorescent biosensor capable of detecting caspase-3 activation. Eight of them were found to activate caspase-3 in HeLa-C3 cells within 72 h at the concentration of 25 μM. Moreover, the values of IC₅₀ were measured for all four new compounds on HeLa cells using the MTT assay. Among them, compound 2 (paucinervin B) had the lowest IC₅₀ value of 9.5 μM, while the other three new compounds had much higher IC₅₀ values of 29.5, 52.5, and 95.6 μM, respectively. This result shows that paucinervin B has the strongest inhibitory effect against HeLa cell growth among these four newly identified paucinervins and it may have the potential to be developed into a new anticancer candidate.