Effect of strawberry extract on hydrogen peroxide induced DNA damages
AnjaDekanski
Regional Center for Talented YouthBelgrade II, Ustanička 64, Belgrade, Serbia
Introduction
Strawberries (Fragariaananassa, Dutch) are common and
important fruit due to their high content of essential nutrient
and beneficial phytochemicals which seem to have relevant
biological activity on human health. Recent research shows
that strawberry extracts identify as efficient antioxidative
agents against increased level of oxidative stress [1,2]. In
order to understand the mechanism of the effects, but also
to determine their effects on human health, it is necessary to
investigate the impact of the strawberry in appropriate
systems. It is known that DNA is highly sensible when it
comes to oxidative stress in comparing to other molecules
and numerous references show that DNA damages induced
by oxidative stress can influence the development of
chronicle diseases and cancer [3].Hydrogen peroxide is an
agent that causes damages, one-chained and two-chained
breaks on DNA molecules.The objective of the work is to
investigate the effect of a strawberry extract in attenuation
of DNA damages induced by hydrogen peroxide in human
lymphocytes, as well as observing the existence of dose
dependency in order to determine the optimal
concentration.
Fig 1. Effect of different concentrations of strawberry
extract on the level of DNA damage
Although, all investigated concentrations of strawberry
extract decreased the level of DNA damages, only the concentration of 0.1 mg/mL showed the statistically relevant
effect (Fig 2). The lack of dose dependant effect of the
extract implies that there is a concentration with the best
effect. According to that, the concentration of 0.1 mg/mL
represents the optimal concentration in described
experimental conditions.
Experimental
The metanolic, polyphenolic-rich strawberry extract was
obtained from Marche Polytechnic University, Ancona, Italy. The level of DNA damages in treated cells is determined
by the electrophoresis of single cells, known as the Comet
test method [4], which is widely used in similar research.
Firstly, the strawberry extract was tested on its genotoxicity
potential, or in other words its ability to cause damages on
the DNA molecule. Peripheral blood leukocytes from six
young and healthy volunteers were treated in vitro with
different concentrations (from lowest to highest:0.025,
0.05, 0.1, 0.125, 0.15, 0.2 mg/mL) for 30 minutes before
measuring the level of DNA damages in treated cells.
After that, in order to investigate the antigenotoxic effect of
the strawberry extract, the same cell samples were treated
were treated in vitro with hydrogen peroxide for 20 minutes
before the in vitro treatment with the strawberry extract
(concentrations of 0.025, 0.05, 0.1, 0.125, 0.15, 0.2
mg/mL)and the incubation for 30 minutes. The control
group were the cells treated only with hydrogen peroxide.
Fig 2. Effect of different concentrations of strawberry
extract (SE) decreased the level of DNA damages by H2O2
Conclusions
These obtained results confirm that the strawberry extract
does have genoprotective and antioxidative properties,
which makes it recommendable for use and suggests further
research on the mechanism of its effects.
Results
References
The results after investigating the potential genotoxcity
show that the strawberry extract does not increase the level
of DNA damages in described conditions (Fig. 1).
[1] Giampieri F, et al.,Nat ProdRes. 2013;27(4-5):448-55.
[2] Basu A, et al.,Crit Rev Food SciNutr. 2014;54(6):790806
[3] Khansari N, et al.,Recent Pat Inflamm Allergy Drug
Discov. 2009;3(1):73-80.
[4] Singh NP, et al.,Exp Cell Res. 1988;175(1):184-91
The strawberry extract significantly attenuated the induced
DNA damages in comparison with the control group,
according to the obtained results, which implies that it
exerts genoprotective properties.