Evaluating the in vitro antimicrobial activity of the crude extract and solvent fractions of Euphorbia dumalis against selected bacteria and fungi

Background

Infectious diseases pose a major threat to public health worldwide because antimicrobials are unavailable, unaffordable, and resistant. Due to this, searching for medicinal plants is a useful task. In this study, crude extracts and fractions of Euphorbia dumalis were tested for their antibacterial and antifungal activity.

Methods

Agar-well diffusion and broth microdilution techniques were employed to evaluate the antimicrobial activity. The crude extract and solvent fractions were obtained using cold maceration and separatory funnel.

Results

At 200 mg/ml, the highest inhibition zone diameter (16.67 ± 0.33) was observed, while the least inhibition zone (1 mm) was recorded against gram-negative bacteria like E. coli and P. aeruginosa. At a concentration of 0.5 mg/ml, S. epidermidis, E. coli, and E. faecalis were susceptible to the crude extract, while S. aureus and K. pneumonia had inhibitory activity at 1 mg/ml. Butanol and aqueous fractions were the most active against S. aureus and E. faecalis at 0.25 mg/ml. Among the three fungal strains, the root extract displayed the highest inhibition zone diameter (31.33 ± 0.67 mm) against T. mentagrophytes at a concentration of 200 mg/ml. The crude extract was the most active against C. albicans at 2 mg/ml, while this fungus and T. mentagrophytes were the most susceptible to the butanol fraction with a MIC of 1 mg/ml.

Conclusions

The crude extract showed better antibacterial and antifungal activity than the hexane and chloroform fractions against all tested microorganisms. Thus, the present study supports the traditional use of Euphorbia dumalis.