Phytochemistry and antimicrobial activity of Zanthoxylum zanthoxyloides root used as chewing stick in Nigeria

Abstract

This study examined the antimicrobial activity of aqueous and ethanolic extracts of Zanthoxylum zanthoxyloides root fractioned with chloroform against oral microbial isolates. Oral swabs were collected from 25 patients with dental problems attending the Dental clinic of UBTH Benin City. The streak plate method was used to culture on Blood, Chocolate, MacConkey and Sabouraud agar plates and were incubated at 37°C for 24 h for bacteria and room temperature for 72 h for fungi. The paper disc diffusion method was used at 100 mg/ml, 200 mg/ml, 400 mg/ml and 800 mg/ml for antimicrobial determination. The percentage occurrences of the microbial isolates were N. catarrhalis (48%), S. aureus (44%), P. aeruginosa (28%), S. epidermidis (24%), L. acidophilus (24%), K. rhinoscleromatis (20%) and C. albicans (12%). At 800 mg/ml the pre- fractioned and post- fractioned aqueous extracts inhibited all the microbial isolates. Ethanol-chloroform extract at 800 mg/ml inhibited all the microbial isolates except P. aeruginosa that had 42.9%. In all the extracts, C. albicans had 100% inhibition at 400 mg/ml. There was significant difference between the zones of inhibition of the difference microorganisms as P<0.05 and between pre- fractioned and post- fractioned aqueous extracts as P<0.05. The results showed that aqueous extracts had better antimicrobial activity when compared to the ethanol extracts.