Antimicrobial and Antihaemolytic Activities of Crude Extracts of Some Commonly Used Tea and Coffee in Nigeria

Abstract

Current indiscriminate abuse of existing antibiotics in clinical and veterinary treatments lead to an upsurge in antimicrobial resistant strains of microorganisms and aggressive search for alternatives which are readily available, less expensive with little or no side effect. Tea and Coffee are beverages consumed daily in every household in Nigeria. This study examines the antimicrobial and anti-haemolytic properties of commonly available Tea and Coffee in Nigerian market. The antimicrobial potencies of the extracts were assessed through disc diffusion method on pathogens of both man and animal origin while the anti-haemolytic assay was carried out through colorimetric method. The extracts were slightly acidic at full strength and no antifungal property was observed. Broad spectrum and bactericidal effects were observed against Staphylococcus aureus, Salmonella pullorum, Shigella dysenteriae and Streptococcus pneumonia. These activities were concentration dependent. Very poor activity was observed against Escherichia coli. Bactericidal rate of coffee was at 6hrs but ranged between 18 and 24 hrs for tea extracts. Tea extracts greatly inhibited the haemolytic potential of alpha toxins while coffee performed poorly. Tea and Coffee could thus serve as supportive treatment for some bacterial infections without fear of side effects, since they are naturally taken as daily beverages.