Antimicrobial potency of the ethanolic crude bark extract of Ziziphus mucronata Willd. subsp. mucronata Willd

Abstract

Ziziphus mucronata Willd. subsp. mucronata Willd. is a medicinal plant widely used in South Africa for the treatment of various diseases. Like many medicinal plants to which traditional claims including the treatment of ailments of infectious origin but without scientific reports have been associated, Z. mucronata is not an exemption. The ethanolic stems bark extract of Z. mucronata against medically important pathogens was investigated for the antimicrobial activity by the agar dilution method while the degree of its antimicrobial activity was determined by the macrobroth dilution method. The extract showed good antibacterial and antifungal activities. Both Gram-negative and Gram-positive bacteria were highly inhibited by the extract at very low concentrations. All the bacteria had inhibition zones greater than 20 mm at a concentration of 5 mg/ml with the exception of Pseudomonas aeruginosa (ATCC 19582) and Bacillus pumilus (ATCC 14884). For the bacteria, the minimum inhibitory concentration (MIC) values ranged between 0.078 and 0.625 mg/ml. For the fungi, the MIC values were between 2.5 to 10 mg/ml. The bacteria were more susceptible to the extract than the fungi. The antimicrobial activity of the extract indicated a broad spectrum, great therapeutic potential and justified the use of this plant by the rural communities in the treatment of microbial infections.