Effects of puerarin on expression of cardiac Smad3 and Smad7 mRNA in spontaneously hypertensive rat.
OBJECTIVE
Puerarin is a pure extract from traditional Chinese medicine Kudzu root. It has been used to treat hypertension and angina pectoris. In our previous study, it showed a protective effect against cardiac hypertrophy in rats. This study was to observe effects of puerarin on expression of cardiac transforming growth factor β(1) (TGF-β(1)), Smad3 and Smad7 mRNA in the spontaneously hypertensive rat (SHR), and to explore its possible mechanism of myocardial protection.


METHODS
Thirty-five 12-week-old SHRs were randomly allocated into 5 groups of 7 rats as follows: 3 groups which received intraperitoneal (i.p.) puerarin (100 mg kg(-1), 50 mg kg(-1) and 25 mg kg(-1)), 1 group which received captopril (30 mg kg(-1), i.g.) and 1 control group of untreated SHRs. In addition, a control group of 7 Wistar-Kyoto (WKY) rats was established. Both control groups received i.p. injections of saline. All rats were treated for six weeks. At the end of this period all rats were sacrificed, and their hearts were quickly removed for semiquantitative reverse transcription-polymerase chain reaction (RT-PCR) analysis.


RESULTS
Compared with WKY control group, expression of TGF-β(1) and Smad3 mRNA was increased (p<0.01) and Smad7 mRNA expression was decreased in SHR control group (p<0.01). High- and middle-dose puerarin decreased the expression of TGF-β(1) and Smad3 mRNA (p<0.01) and increased the expression of Smad7 mRNA (p<0.05).


CONCLUSIONS
Puerarin reduces expression of TGF-β(1) and Smad3 mRNA and increases that of Smad7 mRNA in SHR myocardium. These changes in gene expression may be a mechanism by which puerarin provides myocardial protection from hypertension.
Department of Pharmacology & Pharmacology of TCM Grade Three Laboratory, State Administration of Traditional Chinese Medicine of PR China, Wannan Medical College, Wuhu, Anhui, PR China.
Nian-Bao
NB
Zhang
Zheng-Gui
ZG
Huang
Wei-Dong
WD
Cui
Bo-Ping
BP
Ding
D000818:Animals; D004365:Drugs, Chinese Herbal / Q000494:pharmacology; D015870:Gene Expression / Q000187:drug effects; D006973:Hypertension / Q000378:metabolism*; D007529:Isoflavones / Q000494:pharmacology*; D008297:Male; D009206:Myocardium / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D011918:Rats, Inbred SHR; D011921:Rats, Inbred WKY; D051900:Smad3 Protein / Q000235:genetics*; D051906:Smad7 Protein / Q000235:genetics*; D053773:Transforming Growth Factor beta1 / Q000235:genetics*
D004365:Drugs, Chinese Herbal; D007529:Isoflavones; D012333:RNA, Messenger; D051900:Smad3 Protein; C497787:Smad3 protein, rat; D051906:Smad7 Protein; C497808:Smad7 protein, rat; C508962:Tgfb1 protein, rat; D053773:Transforming Growth Factor beta1; C033607:puerarin