Abstract Parquetina nigrescens belonging to the Periplocaceae family is a plant reported to have diverse medicinal uses, this study was aimed at determining the chemical composition, antioxidant activity and cytotoxicity of the essential oils of the leaves and stems of the plant. The chemical composition of the essential oils determined using the Gas Chromatography-Mass Spectrometry method revealed a total of 9 compounds for the leaves and 14 compounds for the stems, with neophytadiene being the major constituent in the leaf oil while lanosterol acetate and α-amyrin acetate were the major constituents in the stem oil. The antioxidant and cytotoxic activities of the oils were tested using the DPPH radical scavenging assay and brine shrimp lethalithy assay respectively. The essential oils displayed good antioxidant activity, their ability to scavenge free radicals was comparable to that of the standard antioxidant used. The essential oils all had lethal concentration at 50% (LC50) values less than 100 µg/mL indicating a moderate cytotoxic activity. The essential oils of Parquetina nigrescens could be exploited as potential therapeutic agents especially in cancer therapy because of their promising antioxidant and cytotoxic activities.
Keyword: Parqueina nigrescens, essential oils, antioxidant, cytotoxicity.