DanQi Pill protects against heart failure through the arachidonic acid metabolism pathway by attenuating different cyclooxygenases and leukotrienes B4

Abstract

Background: Chinese herbal formulae are composed of complex components and produce comprehensive pharmacological effects. Unlike chemical drugs that have only one clear single target, the components of Chinese herbal formulae have multiple channels and targets. How to discover the pharmacological targets of Chinese herbal formulae and their underlying molecular mechanism are still under investigation.

Methods: DanQi pill (DQP), which is one of the widely prescribed traditional Chinese medicines, is applied as an example drug. In this study, we used the drug target prediction model (DrugCIPHER-CS) to examine the underlying molecular mechanism of DQP, followed by experimental validation.

Results: A novel therapeutic effect pattern of DQP was identified. After determining the compounds in DQP, we used DrugCIPHER-CS to predict their potential targets. These potential targets were significantly enriched in well-known cardiovascular disease-related pathways. For example, the biological processes of neuroactive ligand-receptor interaction, calcium-signaling pathway, and aminoacyl-tRNA biosynthesis were involved. A new and significant pathway, arachidonic acid (AA) metabolism, was also identified in this study. This predicted pathway alteration was validated with an animal model of heart failure (HF). Results show that DQP had effect both on thromboxane B2 (TXB2) and Prostaglandin I2 (PGI2) in different patterns. It can down-regulate the TXB2 and up-regulate the PGI2 in diverse way. Remarkably, it also had effect on cyclooxygenase (COX)-1 and COX2 by suppressing their levels, which may be the critical and novel mechanism of cardiacprotective efficacy for DQP. Furthermore, leukotrienes B4 (LTB4) receptor, another key molecule of AA metabolism which finally mediated gastrotoxic leukotrienes, was also reduced by DQP.

Conclusions: The combination of drug target prediction and experimental validation provides new insights into the complicated mechanism of DQP.

Figure 1

The cardiac function in different groups. Cardiac function detected by echocardiography. (A) Normal cardiac function including LVEF and LVFS in sham-operated group. (B) Down-regulation of LVEF and LVFS in model group rats. (C) DQP can significantly up-regulate the EF and FS. A: sham group; B. model group; C. DQP group.

Figure 2

Masson results in different groups. (A) Cardiomyocytes in the sham group were orderly arranged. (B) Thickening and lengthening of myocardial fibers were observed in the model group. The nuclei were stained dark, which indicated local tissue fibrosis. (C) DQP had the inhibitory effect on ventricular hypertrophy. A: sham group (×100); B. model group (×100); C. DQP group (×100); D: sham group (×400); E. model group (×400); F. DQP group (×400).

Figure 3

DQP regulates COX1 and COX2 in HF rats significantly. The results showed that in model group, COX1 and COX2 concentration was significantly higher than that in sham-operated group. In DQP group, level of COX1 and COX2 were decreased significantly. *P < 0.05, **P < 0.01, vs model group.

Figure 4

Westernblot results of LTB4R and PGE2 receptor in different groups. The results showed that in model group, LTB4R concentration significantly increased than that in sham-operated group. In DQP group, it was decreased significantly. While PGE2 receptor-EP4, in the model group decreased compared with that in the sham-operated group, and it was up-regulated by DQP in DQP group. *P < 0.05, **P < 0.01, vs model group.