RESUMEN
OBJECTIVE Cistanche deserticola Y. C. Ma is an official plant that grows in arid or semi-arid areas.Our early work demonstrated that Cistanche extracts protect against sperm damage in mice under bisphenol A induced reproductive damage. Echinacoside (ECH)is one of the major active components. The present study investigated the mechanisms behind the possible protective effects of ECH against oligoasthenospermia in rat and identified the interaction between ECH and AR. METH-ODS The distribution of ECH was assayed by HPLC,the quantity and quality of sperm was evaluated and hormone levels were determined by radioimmunosorbent assay. The levels of androgen receptor (AR)and key steroidogenic-related genes were reduced as determined by Western blotting and qPCR analysis.The interaction between ECH and AR were evaluated by fluorescence localization assay,indi-rect ELISA and molecular docking. RESULTS ECH significantly increased the quantity of sperm and secretions of luteinizing hormone and testosterone.ECH was distributed to the hypothalamus but not in the testes.ECH combined with hypothalamic AR in the pocket of Met-894 and Val-713 to inhibit transfer of AR from the cytoplasm to nuclei in the hypothalamus.While negative feedback of sex hormone regula-tion was inhibited, positive feedback was stimulated to increase the secretion of luteinizing hormone and testosterone subsequently enhancing the quantity of sperm. C. militaris significantly alleviated the BPA-induced reproductive damage by increasing testicular superoxide dismutase (SOD), glutathione peroxidase (GSH-PX) and glutathione (GSH); as well as by reducing serum malondialdehyde (MDA). C. militaris not only obviously enhanced the levels of serum LH and T, but it also improved the sperm count and motility compared to the BPA-treated group.CONCLUSION C.militaris and ECH protect the BPA induced reproductive damage.ECH blocks AR activity in the hypothalamus to increase the quantity of sperm and protect against oligoasthenospermia in rats.