There is growing evidence that Asligen (an essential ingredient in Qili Qiangxin formulation) affects gene expression of RAS components, 18,19 and plays a key role in the pathophysiology of essential hypertension. In order to further verify the effect of Qili Qiangxin on RAS and to evaluate the possibility of Qili Qiangxin affecting ACE activity, the gene and protein expression levels of ACE were evaluated by real-time reverse transcription PCR and western blot. Chymotrypsin expression was significantly increased in placebo-treated SHR compared to WKY rats. However, significant down-regulation of cardiac chymotrypsin expression was observed in Qili Qiangxin-treated SHR. In conclusion, chronic Qili Qiangxin treatment reduces the expression of chymotrypsin at mRNA and protein levels, thereby alleviating myocardial damage in SHR. However, no significant antihypertensive effect was found in SHR after Qili Qiangxin treatment, suggesting that its target is not in the ACE-mediated Ang II pathway.

As shown in the figure, chymotrypsin mRNA and protein expression were significantly higher in the heart of SHR compared to WKY rats. Interestingly, Qili Qiangxin treatment resulted in a decrease in SHR chymotrypsin mRNA and protein levels. Consistent with this finding, chymotrypsin activity was also reduced in SHRS treated with Qili Qiangxin over a long period of time compared to SHRS receiving the carrier alone (Figure 4).

Real-time reverse transcription (RT) -PCR and western blot results. 1.Wistar -- Kyoto (WKY) (n=7); 2.SHRs high-dose Qili Qiangxin therapy (SHR-H) (n=7); 3. Spontaneously hypertensive rats were treated with low dose Qili Qiangxin (SHR-L) (n=7); 4.SHR control group (SHCR-C) (n=7). (a) We compared the relative expression of ACE mRNA measured by real-time RT-PCR. The relative expression of myocardial chymotrypsin mRNA in the four groups was measured by real-time RT-PCR. Real-time RT-PCR was used to determine the relative expression of TGF-βmRNA in myocardial tissues of the four groups. (d) The relative expression of type I collagen in the myocardium of the four groups was measured by real-time RT-PCR. Real-time RT-PCR was used to determine the relative expression of type II collagen mRNA in the myocardium of the four groups. We compared the relative expression of chymotrypsin and TGF-β in four groups of hearts.