Phytochemical and Antimicrobial Activities of Bryophyllum pinnatum and Vernonia amygdalina Leaves Extracts on Selected Microbial Isolates from Wound Infection

Introduction: The therapeutic actions of plants may be due to the presence of some phytochemical components. Due to the increasing emergence of multi antibiotics resistance, wound pathogens are causing huge public health concerns. There is need for exploring some necessary alternatives for treatment of wound infections.

Aim: This study investigated the phytochemical and antimicrobial activities of Vernonia amygdalina and Bryophyllum pinnatum leaves extracts on Pseudomonas aeruginosa, Escherichia coli and Staphylococcus aureus isolates from wound infection.

Methodology: The fresh leaves of both plants were extracted using Sofowora method and the phytochemicals were screened. Different concentrations of the extract, antibiotic and ethanol were tested against the isolates using disc diffusion technique.

Results: Alkaloids, flavonoids, tannins, anthraquinone and fixed oils were present in the both plant extracts but saponins were only found in V. amygdalina and cardenolide were only in B. pinnatum. Quantitatively, all the phytochemicals investigated in the study were present with V. amygdalina having the highest level of saponins than Bryophyllum pinnatum (P<0.05) and low steroids with P=0.2879 (P>0.05).The crude extract of V. amygdalina had the highest zone of inhibition compared to aqueous and ethanol extracts at 75 mg/ml concentration (P<0.05) but generally, the ethanol extracts of both plants had more inhibitions at varying concentrations. Thus comparing the antimicrobial activity of various extracts of both plants on the wound isolates and the controls (antibiotics and ethanol), there was significant variation in their zones of inhibition produce (P<0.05).

Conclusion: The results show that the zone of inhibition increases with the concentrations of the extracts. Therefore, the antimicrobial effect of these plants may depend on the concentration of the extract and the solvent used for extraction. This study showed that B. pinnatum and V. amygdalina could be used as an alternative therapy to antibiotics to treat wound infection caused by P. aeruginosa, E. coli and S. aureus.