Comparative Analysis of Phytochemical Constituents and Antibacterial Activity of Crude and Purified Ethanol and Ethyl-acetate Extracts of Euphorbia hirta L. Whole Plant

Abstract

Aims: To study the phytochemical constituents and antibacterial efficacy of crude and purified Euphorbia hirta whole plant extract on Gram-positive bacteria isolated from otitis media.
 Study Design: Experimental Research design.
 Place and Duration of Study: Sample: Department of Microbiology (Mtech Laboratory) and Department of Chemistry (Organic Chemistry Laboratory), School of Sciences, Federal University of Technology, Akure, Ondo State, Nigeria. Between November 2018 and March 2019.
 Methods: The streak plate method was used for bacterial isolation, maceration method for Euphorbia hirta whole plant extraction using ethanol and ethyl-acetate as solvents. The E. hirta whole plant extracts were purified using column chromatography method. The extracts were assayed on the test bacterial isolates by agar diffusion technique. The Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) of the extracts were carried out by agar dilution and agar diffusion techniques, respectively.
 Results: The ethanolic extract had the highest extraction yield (19%). The Staphylococcus aureus was resistant to multiple antibiotics: amoxicillin (30 µg), gentamycin (10 µg), and streptomycin (30 µg). The phytochemical screening of crude plant extracts showed presence of flavonoids, glycosides, saponins, tannins and terpenoids. At 100 mg/ml, crude and purified ethanol extracts showed antibacterial activity with 18±0.57 mm and 14±0.57 mm respectively on Streptococcus pyogenes. The MIC and MBC of purified ethanol extract ranged between 6.25-50 mg/ml and 25 mg/ml-100 mg/ml respectively.
 Conclusion: This research showed that E. hirta whole plant extract possesses antibacterial activity. The purified E. hirta whole plant extract showed higher inhibitory effect compared to crude extracts. This is an indication that purified E. hirta whole plant extract can be used in the development of novel therapeutic drugs in the treatment of otitis media.