Rhizophora apiculata, considered a traditional medicinal plant for its various pharmacological effects, is found on the southern coast of Lampung. However, the ethnopharmacology of R. apiculata, belonging to Rhizophoraceae, has not been widely reported. Therefore, the root bark of R. apiculata was collected to study its chemical content and pharmacological activity. Then, to investigate the structure–bioactivity relationship, three integrated phytosterol mixtures were tested for cytotoxic effects. The structures of all phytosterol compounds are clearly elucidated by the spectroscopic data. All phytosterols were examined for their cytotoxicity against three cancer cell lines: HeLa, MCF-7, and A549. Among these isolates, phytosterols with alkene units (C-22 and C-23) and 24-ethylsterol showed increased cytotoxicity in cancer cells, demonstrating the importance of the aliphatic sterol moiety. Furthermore, this investigation presented attractive phytosterols and their important cytotoxic activities and then suggested that the integrated phytosterol mixtures can be developed to modulate the lead compound for anticancer agents.
Key words: Rhizophora apiculata, traditional medicine, integrated phytosterol mixtures, cytotoxic, malignant cancer cell