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* Graduate Institute of Food Science and Technology, Center for Food and Biomolecules, College of Bioresources and Agriculture, National Taiwan University, Taipei 106, Taiwan; Cardinal Tien College of Healthcare and Management, Taipei 231, Taiwan; Tsuzuki Institute for Traditional Medicine, College of Pharmacy, China Medical University, Taichung 404, Taiwan; Department of Physiology, School of Medicine, National Yang-Ming University, Taipei 112, Taiwan; and || Department of Medical Research and Education, Taipei City Hospital, Taipei 103, Taiwan
To whom requests for reprints should be addressed at 1 Wenchang Chiang, Graduate Institute of Food Science and Technology, National Taiwan University, Taipei 106, Taiwan, Republic of China. E-mail: chiang{at}ntu.edu.tw. Paulus S. Wang, Department of Physiology, School of Medicine, National Yang-Ming University, Shih-Pai, Taipei 11221, Taiwan, Republic of China. E-mail: pswang{at}ym.edu.tw
Adlay (Coix lachryma-jobi L. var. ma-yuen Stapf.) has been used as a traditional Chinese medicine for dysfunction of the endocrine system. However, there have been few studies on the effects of adlay seed on the endocrine system. In the present study, both the in vivo and in vitro effects of methanolic extracts of adlay hull (AHM) on progesterone synthesis were studied. AHM was partitioned with four different solvents: water, 1-butanol, ethyl acetate, and n-hexane. Four fractions, namely, AHM-Wa (water fraction), AHM-Bu (1-butanol fraction), AHM-EA (ethyl acetate fraction), and AHM-Hex (n-hexane fraction), were respectively obtained. Granulosa cells (GCs) were prepared from pregnant mare serum gonadotropin-primed immature female rats and were challenged with different reagents, including human chorionic gonadotropin (hCG; 0.5 IU/ml), 8-bromo-adenosine-3',5'-cyclic monophosphate (8-Br-cAMP; 0.1 mM), forskolin (10 µM), 25-OH-cholesterol (10 µM), and pregnenolone (10 µM), in the presence or absence of AHM (100 µg/ml). The functions of steroidogenic enzymes, including protein expression of the steroidogenic acute regulatory protein (StAR), cytochrome P450 side chain cleavage enzyme (P450scc), protein kinase A (PKA), and aromatase activity, were investigated. The expression of StAR mRNA was also explored by using real-time reverse transcription–polymerase chain reaction. In the in vivo study, AHM decreased plasma progesterone and estradiol levels after an intravenous injection of AHM (2 mg/ ml/kg). In the in vitro studies, AHM decreased progesterone and estradiol via inhibition of (i) the cAMP-PKA signal transduction pathway, (ii) cAMP accumulation, (iii) P450scc and 3ß-HSD enzyme activities, (iv) PKA, P450scc and StAR protein expressions and StAR mRNA expression, and (v) aromatase activity in rat GCs. These results suggest that AHM decreased the production of progesterone via mechanisms involving the inhibition of the cAMP pathway, enzyme activities, and the protein expressions of P450scc and StAR in rat GCs.
Key Words: adlay hulls • progesterone • estradiol • aromatase • P450scc • StAR
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  S.-M. Hsia, Y.-H. Kuo, W. Chiang, and P. S. Wang Effects of adlay hull extracts on uterine contraction and Ca2+ mobilization in the rat Am J Physiol Endocrinol Metab, September 1, 2008; 295(3): E719 - E726. [Abstract] [Full Text] [PDF]
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