Antibacterial effect of Zingiber officinale and Garcinia kola on respiratory tract pathogens.

OBJECTIVE To investigate the antibacterial activity of Zingiber officinale (ginger) Garcinia kola (bitter kola) on four respiratory tract pathogens. DESIGN A prospective study based on laboratory investigations. SETTING Department of Life Sciences, University of Buea. Throat swabs were collected from 333 individuals with running nostrils, cough and/or catarrh in three localities of Buea namely Bokwango, Molyko and Bolifamba. Staphylococcus aureus, Streptococcus pyogenes, Streptococcus pneumoniae and Haemophilus influenzae were isolated from the specimens using standard microbiological procedures. The antibacterial activity of ethanolic extracts of ginger and bitter kola, were investigated on these pathogens using the Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) assays. RESULTS The extracts exhibited antibacterial activity against the pathogens. The MIC of extracts ranged from 0.0003 microg/ml to 0.7 microg/ml for ginger and 0.00008 microg/ml, to 1.8 microg/mL for bitter kola, while MBC ranged from 0.1.35 microg/ml to 2.04 microg/ml for ginger and 0.135 microg/ml to 4.2 microg/ml for bitter kola. CONCLUSION Results indicated that extracts of ginger root and bitter kola may contain compounds with therapeutic activity.