The antimicrobial screening of a barbadian medicinal plant with indications for use in the treatment of diabetic wound infections

Abstract

Objective: Diabetes mellitus is a chronic non-communicable disease with high prevalence in the North American and Caribbean region. Diabetic Foot Syndrome which is an associated complication can lead to the development of wounds and ulcers which can become infected. Justicia secunda, a plant known locally in Barbados as Bloodroot used in folklore for wound healing, was selected to test its ability to aid diabetic wound healing by antimicrobial activity. It was therefore tested against the bacteria Staphylococcus aureus ATCC 25923, Pseudomonas aeruginosa ATCC 27853, and Enterococcus feacalis (clincal strain) which are commonly found in diabetic wounds. Methods: The plant was collected by local users. Methanol and acetone extracts of the plant were prepared with use of soxhlet extraction. The antimicrobial activity was assessed with the use of a modified Kirby-Baurer method. Concentrations of 200 mg/ml, 100 mg/ml, 10 mg/ml, and 1 mg/ml of the extract were used, with a standard ciprofloxacin 5 μg positive control, and a 5% dimethyl sulfoxide (DMSO) solution negative control. Results: The J secunda methanol and acetone extracts with an extraction yield of 15.3% and 0.75%, respectively yielded no activity within the concentration range against the three strains of bacteria tested. In comparison with the positive control, relative inhibition zone diameter (RIZD) values of 0% resulted for both the negative control and the extracts, with the positive control having a value of 100%. Conclusion: The in vitro screen of the extracts prepared from J secunda, yielded no antimicrobial activity against the three strains of bacteria tested and therefore does not support the folklore claims by this mechanism of action.