Abstract:
Emerging scientific data from pharmacological and physiological studies continue to show that tea has beneficial effects on human health. A number of in vitro studies have shown that tea helps the immune response by acting as anti-allergic, anti-viral and anti-bacterial agents. In vivo study was carried out to determine the effect of tea extracts on an animal model of male Swiss albino mice infected with Trypanosoma brucei brucei isolate KETRI 2710. The isolate produced a similar clinical picture after a pre-patent period of 5 days post infection (DPI). The levels of parasitemia in the control infected mice and those given different teas developed exponentially at similar rates reaching similar densities at the peak of parasitemia on 7 DPI. However, the decline on 9 to 13 DPI was significantly (P<0.05) different with that of treated mice decreasing more rapidly. This demonstrated that tea lowered parasitemia level. A fall in erythrocyte packed cell volume (PCV) occurred within 4 DPI due to the hemolysis of erythrocytes and consequent anaemia by the trypanosomes and this remained below the normal levels until the terminal stages of the disease. A significant difference (P<0.05) was observed on 11 DPI between the infected mice given tea and the infected untreated mice indicating that tea enhanced resistance to erythrocyte hemolysis signifying it could have a therapeutic role in cases of anaemia. The effect of tea on acute phase response and chronic inflammation was observed because tea produced a significant (P<0.01) elevation of parasite-induced hypoalbuminemia as compared to the infected untreated mice. Black tea, which is the principle tea product from Kenya, displayed remarkable properties some even comparable to those of green tea. Interestingly, tea used in this study was more efficacious than dexamethasone which is an anti-inflammatory drug thereby demonstrating its potential as a therapeutic agent.
