Background/Aim: Due to the numerous beneficial effects of pomegranate that
can be explained through its antioxidative effects, the aim of this study was to
determine the antioxidant potential of pomegranate peel extract (PoPEx) prepared from pomegranate that was harvested in the south-east region of Herzegovina (Bosnia and Herzegovina), through in vitro and in vivo studies.
Methods: In PoPEx total phenols, flavonoids, flavonols, flavan-3-ols and anthocyanins content was determined, as well as several antioxidative assays, including 2,2 diphenyl-1-picrylhydrazyl assay (DPPH), 2,2′-azino bis(3-ethylbenzothiazoline-6-sulphonic acid) assay (ABTS), iron (III) – 2,4,6-tripyridyl-S-triazine
complex assay (FRAP), reduction of copper(II) ions (CUPRAC) assay,
Briggs-Rauscher oscillatory reactions, neutralisation of OH radicals and lipid
peroxidation assay. In vivo studies were performed by administrating 100 mg/
kg of body weight of PoPEx to the rats by gavage for 7 days, after which the rats
were euthanised and prooxidative parameters (thiobabrituric acid reactive
substances – TBARS as an index of lipid peroxidation, nitrites – NO2, hydrogen
peroxide – H2
O2
and superoxide anion radical O2
–
) were determined in plasma, as
well as antioxidative parameters (superoxide dismutase – SOD, reduced glutathione – GSH and catalase – CAT) in erythrocyte lysates.
Results: High content of phenolic compounds was found in PoPEx, which resulted in high antioxidative potential in all in vitro tests performed. In vivo study
showed that PoPEx administration caused a significant decrease in TBARS, NO2
–
,
as well as an increase in reduced glutathione (p < 0.05) in comparison to the
control group, while H2
O2
and O2
*
showed a lowering trend and SOD and CAT
showed an increasing trend in PoPEx group, but without statistical significance.
Conclusion: PoPEx demonstrated high antioxidative capacity measured in vitro
and in vivo and can be potentially used as a supplement treatment in the prevention of various inflammatory conditions.
