Ameliorating Effect of Lespedeza cuneata Extract on Male Menopause in Wistar Rats by Increasing Androgen Receptor

Abstract

Male menopause, also referred to as late-onset hypogonadism or andropause, is a clinical syndrome characterized by sexual dysfunction, depressive disorder, and insomnia secondary to a testosterone deficiency in older men. Lespedeza cuneata, which belongs to the Fabaceae family, possesses several biological properties, including antiinflammatory, anti-oxidant, and antidiabetic effects. We investigated the inhibitory effect of standardized L. cuneata extract (LCE) on andropause symptoms in vivo. LCE administration significantly increased serum levels of total testosterone without any effects on serum estrogen levels. Additionally, LCE significantly increased serum 17-beta hydroxysteroid dehydrogenase 13 protein levels and reduced levels of sex hormone-binding globulin (SHBG), a protein that blocks free testosterone movement into the cytosol. LCE significantly upregulated the expression of cAMP response element binding protein and androgen receptor (AR), which functions as a transcription factor to stimulate spermatogenesis-associated genes and results in increased numbers of AR-positive cells, such as Leydig and Sertoli cells in the testis. To summarize, LCE administration increases serum testosterone, reduces SHBG levels and upregulates AR expression. Therefore, LCE may be useful as alternative therapy for andropause in older men.