Effects of the aqueous extract of the Chinese medicine Danggui-Shaoyao-San on rat pineal melatonin synthesis.
OBJECTIVE
The purpose of this study is to investigate if the aqueous extract of the Chinese medicine Danggui-Shaoyao-San (DSS) can increase the plasma level of melatonin and enhance the function of the pineal gland of naturally aged rats.


METHODS
The rats were treated with DSS at doses of 3ml or same volume of distilled water by oral administration at 11 p.m. for three weeks. The plasma level of melatonin were measured by radioimmunoassay. The function of pineal gland were measured through three parameters: pineal beta adrenergic receptor binding investigated by [3H]DHA binding; pineal expression of NAT mRNA detected by real-time RT-PCR; phosphorylation of CREB (P-CREB) and total level of CREB (T-CREB) measured by western blot analysis.


RESULTS
DSS significantly increased melatonin level at night after oral administration for 3 weeks. By measurement of pineal [3H]DHA binding, it was found DSS improved the beta-adrenergic receptors binding in pineals. The stimulatory effect of DSS on the expression of NAT mRNA in the old rat pineal gland has been demonstrated in this study. Western blot analysis showed that DSS significantly increased phosphorylation of CREB.


CONCLUSIONS
Our results indicate that a downstream pathway for DSS induction of melatonin synthesis in the rat pineal gland acts via cyclic AMP-dependent cascade and transcription mechanism.
Qu
Huai-gang
HG
Department of Anatomy, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong, China.
Cheng
Shao-wu
SW
Tian
Rong-bo
RB
Li
Ze-liang
ZL
Lei
Wan-long
WL
Wang
Hua-qiao
HQ
Yao
Zhi-bin
ZB
He
Hong-wen
HW
D000123:Acetyltransferases / Q000378:metabolism; D000818:Animals; D015153:Blotting, Western; D004082:Dihydroalprenolol / Q000494:pharmacology; D004365:Drugs, Chinese Herbal / Q000494:pharmacology*; D008297:Male; D008550:Melatonin / Q000096:biosynthesis*; D010870:Pineal Gland / Q000187:drug effects / Q000378:metabolism*; D010936:Plant Extracts / Q000494:pharmacology; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D011863:Radioimmunoassay; D051381:Rats; D017207:Rats, Sprague-Dawley; D011943:Receptors, Adrenergic, beta / Q000187:drug effects / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013565:Sympatholytics / Q000494:pharmacology
D004365:Drugs, Chinese Herbal; D010936:Plant Extracts; D012333:RNA, Messenger; D011943:Receptors, Adrenergic, beta; D013565:Sympatholytics; C531150:danggui-shaoyao-san; D004082:Dihydroalprenolol; D000123:Acetyltransferases; D008550:Melatonin