| dc.description.abstract | Tea (Camellia sinensis) is one of the most commonly
consumed drinks in the world, which has many
health benefits. BOPF graded black, green and
white teas are types of processed teas in Sri
Lanka. The antioxidants in tea are able to inhibit
oxidation of lipids and proteins and thereby assist
to prevent diseases. This study aims to determine
the inhibition of oxidation of proteins and lipids
by high grown black and green tea extracts in vitro.
Lipid peroxidation was evaluated by measuring
the level of thiobarbituric acid reactive species
(TBARS), using ascorbic acid as the standard.
Protein oxidation was assessed by measuring
protein carbonyl contents using gallic acid as the
standard. The results of the TBARS assay showed
that there is an increase in the inhibition up to
200 μg/ml of dried tea leaves for green tea and
up to 150 μg/ml of dried tea leaves for black tea
with a maximum inhibition of 40.58% and 30.36%
respectively. Both types of teas showed a negative
deviation for higher concentrations over above
concentrations. The EC50 values for inhibition
of protein oxidation were 684.68 and 967.79 μg/
ml of dried tea leaves for green tea and black tea
respectively. These results also indicate that the
extracts have a protective ability against oxidative
damage to lipids and proteins by reducing the
activity of Reactive Oxygen Species (ROS). In
this study, it has been proved that antioxidant
properties of green tea have a higher ability than
black tea to inhibit the oxidation of biomolecules.
The analysed plant extracts were comparable to
or even more effective in scavenging DPPH which
have been studied previously. Therefore, this
may be beneficial in the prevention of diseases
related to oxidative stress such as cancer, and
cardiovascular and inflammatory diseases. | en_US |
