Efficacy of Securidaca longipedunculata Fresen (Polygalaceae) against Two Standard Isolates of Neisseria gonorrhoeae

Abstract

Aim: A study was carried out to determine the in vitro antibacterial activity of ethanol extract of root and bark of Securidaca longipedunculata against two standard isolates of Neisseria gonorrhoeae NO.0296 and WHO- K. Materials and Methods: Plant materials were collected and dried at room temperature, followed by ethanol extraction using a rotary pump. Antibacterial activity was done on the isolates using agar disc-diffusion method with Dimethyl Sulfoxide (DMSO) as a negative control and ceftriaxone as a positive control. Zone of inhibition was measured in millimeters. Minimum bactericidal concentration of the extract was determined using different concentrations of the extract then plated on Neisseria gonorrhoeae (GC) medium and a standard protocol was used to determine the presence of phytochemical compounds. Results and Discussion: The results obtained showed that both the root and bark extracts of S. longipedunculata have antibacterial activity against the two bacterial strains with a zone of inhibition of ≥ 10mm and a bactericidal activity at 0.01µg-ml of 10% crude extract. Comparison of susceptibility on tetracycline, penicillin and ciprofloxacin with the root and bark extract showed higher susceptibility to the extracts.  The extracts showed presence of saponins, steroids, glycosides, flavonoids, terpenes, alkanoids, phenolics and tanins. The demonstrated antibacterial activity of S. longipedunculata against N. gonorrhoeae provides a scientific basis for the traditional use in treating venereal diseases in western Kenya. Conclusion: This investigation and further studies will pave the way for use of this plant in antibacterial drug development for alleviating human suffering. We recommend further studies to identify the specific compound(s) responsible for the antibacterial activity.