Cistanche tubulosa ethanol extract mediates rat sex hormone levels by induction of testicular steroidgenic enzymes

Abstract

Context: Plants of the genus Cistanche Hoffmg. et Link (Orobanchaceae) are usually used as ethno-medicine in Eastern Asia. Pharmacology studies have shown that Cistanche possesses an androgen-like effect; however, the exact mechanism is unclear.

Objective: The present study determines the effect of ethanol extract of Cistanche tubulosa (Schenk) R. Wight stem (CTE) on hormone levels and testicular steroidogenic enzymes in rats.

Materials and methods: Phenylethanoid glycoside content of CTE was detected by UV spectrophotometry. Rats were fed with different doses of CTE (0.2, 0.4, and 0.8 g/kg) by intragastric administration for 20 d. Sperm parameters were measured by staining and counting method. The level of progesterone and testosterone in serum was quantified by radioimmunoassay. The expression levels of cholesterol side-chain cleavage enzyme (CYP11A1), 17α-hydroxylase/17, 20-lyase (CYP17A1), and a liver metabolic enzyme (CYP3A4) in the microsome were assessed by immunohistochemical staining or/and western blot analysis.

Results: The study illustrates that the administration of CTE (0.4 and 0.8 g/kg) increased sperm count (2.3- and 2.7-folds) and sperm motility (1.3- and 1.4-folds) and decreased the abnormal sperm (0.76- and 0.6-folds). The serum level of progesterone and testosterone in rats was also increased by CTE administration (p < 0.05). Results of immunohistochemistry and western blot analysis confirmed that the expression of CYP11A1, CYP17A1, and CYP3A4 was enhanced by CTE (p < 0.05). It was also found that high-dose of CTE can cause mild hepatic edema.

Conclusion: Our results suggest that the increase in sex hormone levels could be mediated by the induction of testicular steroidogenic enzymes.

• CYP11A1
• CYP17A1
• CYP3A4
• progesterone
• testosterone

Acknowledgements

The authors thank Prof. Jian-Jun Hu for his help in collecting and confirming the stem of Cistanche tubulosa.

Declaration of interest

The work was supported by the Open Project Program of State Key Laboratory of Natural Medicines, China Pharmaceutical University (No. SKLNMKF201221), Ministry of Education and State Administration of Foreign Experts Affairs “Overseas Teacher” project (No. MS2011XBNL057), China, the High-end Foreign Experts Recruitment Program (GDW20146100228), China and Supported by the Key Construction Program of International Cooperation Base in S&T, Shaanxi Province (2015SD0018), China.