Assessment of Antioxidant Effects of Aqueous and Ethanolic Extracts of Zingiber officinale Rhizome in Testosterone Induced Benign Prostatic Hyperplasia Rat Model

Aims: To assess the antioxidant effects of the aqueous and ethanolic extracts of Ginger rhizome in testosterone induced prostate hyperplasic male rats.

Study Design: The study was a cross-sectional study.

Place and Duration of Study: The experimental aspect of this study was conducted at the animal house, Department of Pharmacology, University of Port Harcourt between April and September, 2019.

Methodology: Sixty (60) adult albino male wistar rats were used for this study. They were divided into 12 groups of 5 rats each and fed with commercial rat diet and clean drinking water. Aqueous and ethanolic extractions of Ginger rhizome seed were prepared using the maceration method. BPH was induced in rats after they submitted to bilateral orchiectomy by daily injections of testosterone propionate (TP) (4 mg/kg b.wt.sc). Rats were treated with 500 or 1500 mg/kg b.wt. of aqueous or ethanoI extracts of Zingiber officinale (Zo) rhizome, dutasteride or in combination. Administration of extracts was done by gavage. Plasma total oxidant status (TOS), total antioxidant status (TAS), superoxide dismutase (SOD) activity, were analysed using sandwich ELISA Kits by Shanghai Korain Biotech Co., Ltd, China, while oxidative stress indices (OSI) were calculated. Statistical analysis was done using SPSS version 22.0 of Windows Stat Pac and p values <0.05 were considered statistically significant.

Results: The results showed that exogenous induction of BPH in rats significantly increased (p=0.000) plasma TOS and OSI while TAS and SOD activities were reduced. However, 500 and 1500 mg/kg b.wt. of Zo rhizome administered orally after exogenous induction of BPH had been established for 15 days, significantly decreased (p=0.000) TOS, OSI and significantly improved the activities of antioxidant parameters like SOD and TAS. Non-significantly increased mean TAS and SOD were seen in a combination of both extracts with dutasteride, possibly suggestive of synergistic interaction between the herbs and the drug. Simultaneous administration of aqueous and ethanolic extracts of Zo rhizome with TP for 30 days also showed antioxidant qualities, although the effects were statistically not better than values for treatments done when BPH was established before treatment. Ethanolic extracts of Zo rhizome produced better antioxidant effects compared to the aqueous extracts.

Conclusion: From the findings, we conclude that Zo rhizome can ameliorate oxidative stress and therefore may be beneficial in the management of benign prostatic hyperplasia.