Chemical characterization of hexane extract of Vernonia glaberrima leaves and in-vitro evaluation of its cytotoxic effect against a panel of human cancer cell lines

Abstract

Vernonia glaberrima is a medicinal plant, native of West Africa which is commonly used in Nigerian traditional medicine to manage conditions such as skin diseases and suspected tumors. The objective of this study was to determine the phytochemical constituents of hexane leaves extract of V. glaberrima and to evaluate its in-vitro cytotoxic effect against different human cancer cell lines. Phytochemical analysis, Gas chromatography-mass spectrometry (GC-MS) and cell culture assays protocols were adopted for the determination of bioactive compounds and anticancer potential of V. glaberrima leaves respectively. The Phytochemical analysis showed the presence of saponins, tannins, flavonoids, alkaloids, cardiac glycosides while the GC-MS revealed the presence of several compounds. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays showed that the three fractions obtained from the crude hexane extract all possess significant cytotoxic effect against human breast cancer (MCF-7), human cervical cancer (HeLa) and human colorectal adenocarcinoma (HT-29) cell lines. Hexane and ethyl acetate fractions displayed greater cytotoxic activity than the methanol fraction, as evidenced by their lower half-maximal inhibitory concentration (IC₅₀) values. The activity of the hexane and ethyl acetate fractions against the three cell lines has provided additional insight into the potentials of V. glaberima as a source of valuable natural compounds for future anticancer drug development.