N-Butanol and Aqueous Fractions of Red Maca Methanolic Extract Exerts Opposite Effects on Androgen and Oestrogens Receptors (Alpha and Beta) in Rats with Testosterone-Induced Benign Prostatic Hyperplasia

Diego Fano,Cinthya Vásquez-Velásquez,Pedro A Orihuela,Cynthia Gonzales-Castañeda,Emanuel Guajardo-Correa,Gustavo F Gonzales

doi:10.1155/2017/9124240

Abstract

Benign Prostatic Hyperplasia (BPH) affects, worldwide, 50% of 60-year-old men. The Peruvian plant red maca (Lepidium meyenii) inhibits BPH in rodents. This study aimed to determine the effects of methanolic red maca extract and its n-butanol and aqueous fractions on expression of androgen and oestrogen receptors in rats with testosterone enanthate-induced BPH. Thirty-six rats in six groups were studied. Control group received 2 mL of vehicle orally and 0.1 mL of propylene glycol intramuscularly. The second group received vehicle orally and testosterone enanthate (TE) (25 mg/0.1 mL) intramuscularly in days 1 and 7. The other four groups were BPH-induced with TE and received, during 21 days, 3.78 mg/mL of finasteride, 18.3 mg/mL methanol extract of red maca, 2 mg/mL of n-butanol fraction, or 16.3 mg/mL of aqueous fraction from red maca. Treatments with red maca extract and its n-butanol but not aqueous fraction reduced prostate weight similar to finasteride. All maca treated groups restored the expression of ERβ, but only the aqueous fraction increased androgen receptors and ERα. In conclusion, butanol fraction of red maca reduced prostate size in BPH by restoring expression of ERβ without affecting androgen receptors and ERα. This effect was not observed with aqueous fraction of methanolic extract of red maca.

Highlights

Benign Prostatic Hyperplasia (BPH) is a disease of high relevance since, worldwide, it affects 50% of men aged 60year-old [1], reaching levels of 90% in men older than 80 years [2]
As observed in a previous study [20], in the BPH model the prostatic acini lost the characteristic inner projections of the epithelium. This alteration occurred in the treatment groups; there is an evident increase of both epithelial cells height and stromal area in testosterone enanthate (TE) and TE + Aq groups (Figure 2)
The present study aimed to assess the biological effects of red maca methanolic extract and its n-butanol and aqueous fractions on testosterone enanthate-induced BPH in rats determined by prostate gland weight, histological

Summary

Introduction

Benign Prostatic Hyperplasia (BPH) is a disease of high relevance since, worldwide, it affects 50% of men aged 60year-old [1], reaching levels of 90% in men older than 80 years [2]. Androgen receptor (AR) has received special attention, due to its effects on prostate growth signaling pathways; for instance, androgens promote the expression of Epidermal Growth Factor, Keratinocyte Growth Factor, and Insulin-like Growth Factor [3, 4]. Oestrogens and their receptors α and β (ERα, ERβ) are less studied than AR, it is evident that they play a significant role on normal prostate growth [5, 6]. ERα activation is related to the inflammatory and proliferative response whereas ERβ activation has an antiproliferative and proapoptotic response, counteracting AR and ERα effects

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