Phytochemical analysis, antimicrobial and antioxidant activities of Euphorbia golondrina L.C. Wheeler (Euphorbiaceae Juss.): an unexplored medicinal herb reported from Cameroon

This study aimed at determining the phytochemical constituents of Euphorbia golondrina L.C. Wheeler, an alien invasive medicinal herb that is used for the treatment of gastroenteritis related ailments, diabetes, conjunctivitis, gastritis, enterocolitis, tonsillitis, vaginitis, hemorrhoids, prostatism, warts and painful swellings by the Mundani people of the mount Bambouto Caldera in SouthWestern Cameroon, and to evaluate its in vitro antimicrobial and antioxidant activities. Susceptibility testing by agar well diffusion assay revealed good antibacterial activity with inhibition zone diameter of 20 ± 1.1 mm against Bacillus cereus followed by Staphylococcus aureus with inhibition zone diameter of 17 ± 1.6 mm which was significantly lower (P < 0.05) than the positive control (amoxicillin). None of the fungi was inhibited by the acetone extract of E. golondrina except Candida albicans wherein the zone of inhibition was not significantly different from that of the positive control (Amphotericin B). The ABTS scavenging activity of E. golondrina was higher than that of gallic acid and BHT at concentrations greater than 0.1 and 0.2 mg/mL respectively while at all concentrations, nitric oxide scavenging activity was higher than those of both rutin and vitamin C. GC–MS profile of E. golondrina steam distilled volatiles revealed that the plant has potent phytoconstituent classes such as sesquiterpenes, monoterpenes, alkaloids, phenolics and aromatic hydrocarbons. Among the 30 compounds identified, caryophyllene oxide (14.16 %), camphor (9.41 %) and phytol (5.75 %) were the major compounds. Further structural characterisation based on (1)H and (13)C NMR is required to demonstrate structural integrity including correct stereochemistry. The current study partially justifies the ethnomedicinal uses of E. golondrina in Cameroon.