Antibiotic Activity of Euphorbia grantii from Kirinyaga County, Kenya

Background: Euphorbia grantii is widely used in ethnic medicine for the treatment of diseases such as syphilis, gonorrhoea and wound infections. This study aimed at isolating and evaluating antibiotic activity of E. grantii crude extracts. E. grantii plants samples were collected from Kirinyaga county and crude extracts obtained using methanol, hexane and distilled water. Sensitivity test against Shigella dysentriae (ATCC 13313), Salmonella typhi (6539), Klebsiella pneumoniae (70063), Staphylococcus aureus (25923) and Streptococcus epidermidis (12228) was carried out using agar well diffusion bio assay and minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) determined. Cytotoxicity of the crude extracts was established using brine shrimp lethality test. The crude extracts contained cardiac glycosides, saponins, tannins, anthroquinones, alkaloids, flavonoids and phenolics. The zones of inhibition of the test pathogens by the crude extracts from Euphorbia grantii varied significantly (F= 5.573 P=0.008197). The MIC varied significantly between hexane, methanol and distilled water crude extracts (F=6.6400 P=0.005). However, the MIC and MBC were not significantly different among the crude extracts (P=0.067). The toxicity of the crude extracts increased with increase in concentration. The crude extracts from E. grantii inhibited growth of the test pathogens. There is need to carry out structure elucidation of the crude extracts.