Orange peel extract corrected lipid dysmetabolism and pro-inflammation, but not deranged antioxidant and hormonal status in orchidectomised rats

Abstract

Background: Testosterone is a metabolic hormone; therefore, its absence would affect food metabolism, and subsequently a wide array of associated endogenous processes, including oxidative and inflammatory events. Contrarily, orange peel is known to be rich in flavonoids, which have strong antioxidant and anti-inflammatory properties, asides from their modulatory roles on lipolysis and lipogenesis. Hence, we investigated the effects of ethanolic extract of orange peel (EEOP) on antioxidant, inflammatory, and lipid and reproductive hormonal profiles in experimental animal.

Methods: The rats were divided into four groups (N=10), which included: Control (Sham orchidectomised) (group 1); Orchidectomised (Orchid) (group 2); Orchidectomised + Low dose of orange peel (Orchid + LDOP) (group 3); and Orchidectomised + High dose of orange peel (Orchid + HDOP) (group 4). EEOP was administered at a low and high dose of 200 and 600 mg/kg BW, p.o. respectively; however, normal saline (vehicle) was administered at 1 ml/kg BW, p.o. to groups 1 and 2 throughout the four weeks duration of the experiment.

Results: Castration was accompanied by dsylipidaemia, without alteration of oxidative, inflammatory, and reproductive hormonal status. Although EEOP reversed alterations in lipid metabolism back to the baseline, it neither showed significant effects on oxidative markers (SOD, catalase, total antioxidant capacity and malondialdehyde) nor reproductive hormone (testosterone, FSH and LH) profile, even though it significantly reduced uric acid. The effects of EEOP were not dose-graded, except in the MDA result, which was significantly higher in group 3, relative to group 4.

Conclusion: EEOP corrected lipid dysmetabolism and pro-inflammation, but not deranged antioxidant and hormonal status in a dose-independent manner in orchidectomised rats.

Kewords: Orange peel extract, Oxidative stress, Inflammation, Lipid profile; Hormone