ANTIMICROBIAL ACTIVITY OF STRYCHNOS HENNINGSII(GILG) LOGANIACEAE LEAF AND ROOT AQUEOUS EXTRACTS

Abstract

Strychnos henningsii (Gilg)Loganiaceae plant extract hasbeen used for treatment of various ailments such as rheumatism, gastrointestinal complications and syphilis. It is also used to prepare milk soups and fatty-meat. S. henningsii leaf and root water extracts have bioactivechemicals. This study was carried to validate antimicrobial activity of S. henningsiiextracts in the treatment of bacterial ailments. Antimicrobial activity of aqueous extracts was tested using isolates of bacteria (Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa,Salmonella typhi).Commercial discs (30μg Tetracycline, 10μg Gentamycin, 30μg Kanamycin, 30μg Chloramphenicol, 30μg Augumentin, 25μg Cotrimoxazole, 10μg Ampicillin and 30μg Cenfuroxime) were used as positive controls. The antibacterial activity of aqueous extracts inconcentrations of (100, 50, 25 and 12.5) μg/ml was determined by agar disc diffusion assay. The most susceptible bacteria in extracts concentration of 100μg/ml were S. typhi(11.00 ± 1.00 and 10.67 ± 1.20) mm followedby S. aureas(10.00 ± 1.00 and 9.00 ± 1.00) mm. The most resistant bacteria wereP. aeruginosaand S. typhiin leaf and root extracts respectively at concentration of 50μg/ml. S. aureaswas active in all extracts concentrations. The inhibition zones for antibiotics (12.00 ± 0.1 to 21.00 ± 0.3)mm were larger than those of the plant extracts (6.67 ± 0.30 to 11.00 ± 1.00)mm except for Tetracycline (7.00 ± 0.0)mm. S. aureaswas resistant to Kanamycin and Chloramphenicol,S. typhiwas resistant to Tetracycline and Chloramphenicol,P. aeruginosawas resistant to Chloramphenicol. Gentamycin, Tetracycline, Kanamycin and Chloramphenicol were active against E. coli. Gentamycin was active in all the bacterial strain tested. The results show considerable antimicrobial activity against the bacteria species tested. The present study justifies the use of aqueous extracts by herbalists in the treatment of diseases caused by bacterial infections.