In vitro antibacterial and cytotoxic effects of Euphorbia grandicornis Blanc chemical constituents

Abstract

Abstract Background Euphorbia grandicornis is widely utilized in traditional medicine for the treatment of microbial infections including sexually transmitted diseases such as syphilis, gonorrhoea and for healing of wounds. Objective The aim of this work was to isolate and evaluate the antibacterial and anticancer activities of Euphorbia grandicornis chemical constituents. Methods Chemical constituents were isolated and identified using various spectroscopic techniques such as IR, MS, and NMR. The single point growth inhibitory potential of the compounds was determined using a 96-well plate based assay. Results The CH2Cl2 crude extracts exhibited potent antibacterial activity against Escherichia coli ATCC 8739 and Staphylococcus aureus ATCC 6538 with percentage growth of 94.90 ± 4.24 and 29.47 ± 4.89 respectively. Hence, the CH2Cl2 crude extract was further subjected to column chromatography which resulted in the isolation of methyl 2,5-dihydroxybenzoate (1), n-octyl benzoate (2), friedelanol (3), and germanicol (4) and identification of compounds 12–24 for the first time in the species based on the LC-MS/MS spectroscopic data. The purified compounds (1–4), and previously reported compounds (5–11) were evaluated for antibacterial activities against S. aureus and E. coli, as well as the cytotoxicity effects against HeLa cells. Of the purified compounds, methyl 2,5-dihydroxybenzoate (1), was the most active against E.coli and S. aureus with a percentage growth of 19.12 ± 0.65 and 23.32 ± 0.23 respectively. β-amyrin (6), and β-sitosterol (8), were active against S. aureus with percentage growth of 27.17 ± 0.07, and 47.79 ± 2.99 respectively. Conclusion The results obtained from this study indicate that E. grandicornis, is a rich source of chemical constituents that may provide new lead compounds for the development of antibacterial agents.