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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 Fig 1. Effect of different concentrations of strawberry
and numerous references show that DNA damages induced extract on the level of DNA damage
by oxidative stress can influence the development of
chronicle diseases and cancer [3].Hydrogen peroxide is an Although, all investigated concentrations of strawberry
agent that causes damages, one-chained and two-chained extract decreased the level of DNA damages, only the con-
breaks on DNA molecules.The objective of the work is to centration of 0.1 mg/mL showed the statistically relevant
investigate the effect of a strawberry extract in attenuation effect (Fig 2). The lack of dose dependant effect of the
of DNA damages induced by hydrogen peroxide in human extract implies that there is a concentration with the best
lymphocytes, as well as observing the existence of dose effect. According to that, the concentration of 0.1 mg/mL
dependency in order to determine the optimal represents the optimal concentration in described
concentration. experimental conditions.

Experimental

The metanolic, polyphenolic-rich strawberry extract was
obtained from Marche Polytechnic University, Ancona, Ita-
ly. 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, Fig 2. Effect of different concentrations of strawberry
0.05, 0.1, 0.125, 0.15, 0.2 mg/mL) for 30 minutes before extract (SE) decreased the level of DNA damages by H 2 O 2
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 Conclusions
were treated in vitro with hydrogen peroxide for 20 minutes
before the in vitro treatment with the strawberry extract These obtained results confirm that the strawberry extract
(concentrations of 0.025, 0.05, 0.1, 0.125, 0.15, 0.2 does have genoprotective and antioxidative properties,
mg/mL)and the incubation for 30 minutes. The control which makes it recommendable for use and suggests further
group were the cells treated only with hydrogen peroxide. research on the mechanism of its effects.

Results References

The results after investigating the potential genotoxcity [1] Giampieri F, et al.,Nat ProdRes. 2013;27(4-5):448-55.
show that the strawberry extract does not increase the level [2] Basu A, et al.,Crit Rev Food SciNutr. 2014;54(6):790-
of DNA damages in described conditions (Fig. 1). 806
The strawberry extract significantly attenuated the induced [3] Khansari N, et al.,Recent Pat Inflamm Allergy Drug
DNA damages in comparison with the control group, Discov. 2009;3(1):73-80.
according to the obtained results, which implies that it [4] Singh NP, et al.,Exp Cell Res. 1988;175(1):184-91
exerts genoprotective properties.