Abstract

THE EFFECTS OF THEAFLAVINS AND HOT WATER EXTRACTS OF KENYAN BLACK TEA ON THE EFFICACY OF ANTIBIOTICS

Andrew Bor, Christine Bii and Charles Mutai*

ABSTRACT

The study was conducted to compare the effects of isolated total theaflavins and hot water extract from processed commercial Kenyan black tea on the efficacy of antibiotics. Theaflavins are the major bioactive compounds in black tea; however, there are other compounds which include catechins, kaempferol, quercitin and myericitin that are known to have effect on efficacy of antibiotics. The presumption of the study was that, these compounds may be having synergistic, additive or antagonistic effect on theaflavins, which in turn contribute to the overall effect of hot water extract of black tea on efficacy of antibiotics. The antibacterial activities of combined concentrates of both black tea extracts with antibiotics were determined using agar diffusion method according to procedures of Bauer-Kirby method. The results obtained demonstrated that both total theaflavins and hot water extracts of Kenyan black tea have got synergistic effect on ampicillin, norfloxacin, ciprofloxacin and chloramphenicol. The total theaflavins extract showed stronger synergism with antibiotics than hot water extract. The difference in inhibitory effect of combined concentrates was significant at (P<0.05). Theaflavins and hot water extracts of black tea restored the activity of lower concentrations of antibiotics below MIC to susceptible breakpoints. The two black tea extracts together with antibiotics can be used in treatment and prevention of bacterial infections.

Keywords: Antibiotics, Bacteria, Black tea, Theaflavins, Hot water extract and sensitivity.