Abstract:
The antimutagenic effects of the aqueous tea extracts from Kenyan black, green and purple cultivars
were
evaluated by the Ames te
st using Salmonella typhimurium tester strains TA 1538. Results obtained
showed that tea had no toxicity or mutagenic activity at a concentration of 20% (w/v) unlike the mut
agen
sodium azide. However, using the formulae, percentage inhibition = [1
-
T/M] ×10
0 where T is number of
revertants per plate in presence of mutagen and test sample and M is number of revertants per plate
in
positive control, tea extracts had a significant (P<0.05) antimutagenic activity where the percent
inhibition was 65% for green te
a, 38% for purple tea and 19.17% for black tea. This was attributed to the
radical scavenging activity of polyphenols. There is need therefore to carry out further research to
help
understand the precise mechanism of action especially for black and purple
teas, and to explore other
beneficial effects that these polyphenols may have, before they can be adopted for therapeutic use.