Anti-staphylococcal activity, cytotoxicity, and chemical composition of hexane extracts from arils and seeds of two Samoan Myristica spp

Abstract Hexane extracts derived from the arils and seeds of two Samoan indigenous plant species, Myristica hypargyraea A. Gray and Myristica inutilis Rich ex A. Gray, were assessed for their in vitro anti-staphylococcal effect using a broth microdilution assay. Additionally, their cytotoxic activity against human colon cancer and normal intestinal cell lines was determined. In this study, all plant extracts tested showed a certain degree of growth-inhibitory effect against various strains of Staphylococcus aureus with minimum inhibitory concentrations (MICs) ranging from 8 to 1,024 µg/mL. The aril extract of M. hypargyraea possessed the highest antibacterial activity with MIC value 8 µg/mL against one standard strain and three clinical isolates of S. aureus, the effective concentrations of this extract were found to be safe for the intestinal cells. The aril extract of M. inutilis showed the highest selective antiproliferative effect on intestinal cancer cells with a lower toxicity to normal cell lines. Using gas chromatography-mass spectrometry analysis, malabaricone A, otobain, licarin A, and licarin B were identified as the major components of both the aril and seed extracts of M. hypargyraea and M. inutilis.