In Vitro Anti-Staphylococcal Activity of Alkaloids from the Leaves of Callestimone Rigidus R.Br

Abstract

Multidrug resistant Staphylococcus aureus poses a severe global threat worldwide due to their prevalence, genomic plasticity and limited therapeutic options being refractory to most antibiotic classes. This necessitates the discovery of new anti-staphylococcal interventions. Callistemon rigidus R.Br. (Myrtaceae) has been found to possess antibacterial potential against clinical isolates. Thied me study was a isolate and evaluate the antibacterial alkaloids from the leaves of Callistemon rigidus and assess their in vitro anti-staphylococcal potential. Alkaloid isolation was carried out by modiied method for plant alkaloid extraction. The in vitro anti-staphylococcal potential of the alkaloid bioactive fraction was assessed by using micro broth dilution and plate count assay methods. Pus and wound isolates had MIC of 80 µg/mL and 50 IC of 27.22 µg/mL respectively. Burn isolates showed MIC of 320 µg/mL and 50 50 13.57 µg/mL respectively. Urine and vaginal isolates exhibited a MIC of 80 µg/mL 50 and IC of 13.15 µg/mL respectively. Ceixime had MIC values was 320 µg/mL, 160 50 50 µg/mL and 160 µg/mL for pus and wound, burn, urine and vaginal isolates indicating the refractory behaviour when compared to alkaloid bioactive fraction from the leaves of Callistemon. The alkaloid bioactive fraction exhibits immense activity compared to standard antibiotic Ceixime. This work is the irst report of alkaloids and their antimicrobial activity from Callistemon rigidus leaves. The results suggest further isolation of individual alkaloids from alkaloid bioactive fraction and assessment their anti-staphylococcal activity as leads for development of anti-staphylococcal drugs.