Antioxidant and anti-proliferative studies on Kigelia africana (Lam.) Benth. and its constituents

Abstract

Cancer is one of the leading causes of death worldwide. The prevalence of cervical and ovarian cancer among reproductive women is increasing. Therefore, this study intended to examine the effect of methanol extract, solvent fractions and isolated compounds from Kigelia africana (Lam.) Benth. on proliferation of cervical cancer (HeLa) and ovarian cancer (CHO-1) cells. The antioxidant activity, total flavonoid and phenolic contents of methanol extract and solvent fractions were evaluated by standard methods. The isolated compounds were identified by spectroscopic methods (1D-NMR, 2D-NMR and Mass Spectroscopy). Compounds 3-(3, 4-dimethoxyphenyl) acrylic acid (1), sitosterol (2), methyl 3-(3,4-dihydroxyphenyl) acrylate (3), 2,3-dihydro-5-(hydroxymethyl) furan-2, 3, 4-triol (4), 2, 3-(4-hydroxyphenyl) acrylic acid (pCoumaric acid) (5), 3-(3,4-dihydroxyphenyl) acrylic acid (caffeic acid) (6) were isolated. The MTT test was carried out on methanol extracts, solvent fractions and isolated compounds on CHO 1 and HeLa cell lines (ATCC, Manassas, USA), respectively. The methanol extract and solvent fractions of K. africana displayed high antioxidant activity and considerable amounts of phenolics and flavonoids. Hexane (IC50 = 5.3 ± 0.1 µg/mL), ethyl acetate (IC50 = 5.3 ± 1.10 µg/mL) fractions and compound 3 (IC50 = 17.7 ± 2.60 µg/mL) showed inhibitory effect on CHO 1 cell line while Compound 1 (IC50 = 33.5 ± 0.60 µg/mL) inhibited HeLa cell line proliferation. Furthermore, this is the first time of isolating compound 1 from the fruit of K. africana. These results revealed the anticancer potential of Kigelia africana fruit, justifying its usage among reproductive women. Keywords: Ovarian cancer, Cervical cancer, Kigelia africana fruit, Phenylpropanoids