To discuss the effects of sauchinone on myocardial fibrosis and inflammatory injury in rats with acute myocardial infarction by adjusting the sonic hedgehog/glioma-associated oncogene homolog 1 (Shh/Gli1) signaling pathway.

A rat model of acute myocardial infarction was established by ligation of the left anterior descending coronary artery. A total of 72 rats were randomly divided into six groups: sham group (thoracotomy and suture without ligation), model group, experimental-L group (5 mg·kg^-1 sauchinone), experimental-M group (10 mg·kg^-1 sauchinone), experimental-H group (25 mg·kg^-1 sauchinone) and activator group [25 mg·kg^-1 sauchinone + 10 mg·kg^-1 purmorphamine (PUR)], with 12 rats in each group. Each group received the corresponding drug by gavage or intraperitoneal injection for 7 consecutive days. After the final administration, inflammatory cytokine levels were measured using enzyme-linked immunosorbent assay (ELISA); myocardial infarct size was assessed by 2,3,5-triphenyltetrazolium chloride (TTC) staining; myocardial tissue changes were observed using hematoxylin-eosin (HE) staining; apoptotic cells were detected by one-step terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) staining; superoxide anion levels were measured using dihydroethidium; collagen deposition was examined by Masson staining; and the protein expressions of Shh, Gli1 and α-smooth muscle actin (α-SMA) were detected by Western blot.

The serum levels of interleukin (IL)-6 in the sham group, model group, experimental-H group, and activator group were (56.31±9.21), (113.05±12.03), (59.67±9.67) and (103.71±11.68) pg·mL^-1, respectively; tumor necrosis factor (TNF)-α levels were (136.25±16.92), (220.16±22.14), (153.67±17.40) and (208.77±21.65) pg·mL^-1, respectively; IL-1β levels were (28.59±4.10), (52.07±5.38), (30.61±4.31) and (46.22±5.17) pg·mL^-1, respectively; myocardial infarct sizes were (0±0)%, (28.86±3.42)%, (10.24±1.28)% and (26.94±2.98)%, respectively; inflammation scores were (0±0), (2.88±0.32), (1.34±0.15) and (2.76±0.29), respectively; myocardial apoptosis rates were (2.46±0.25)%, (36.38±3.95)%, (12.23±1.45)% and (34.14±3.73)%, respectively; relative dihydroethidium fluorescence intensity in myocardial tissue was (4.58±0.68)%, (39.65±4.27)%, (15.36±1.73)% and (37.31±3.96)%, respectively; the percentage of myocardial fibrosis area was (11.34±1.32)%, (65.83±6.98)%, (18.48±2.24)% and (61.95±6.36)%, respectively; Shh protein relative expression levels were 1.04±0.11, 3.46±0.38, 1.29±0.16 and 3.28±0.35, respectively; Gli1 protein relative expression levels were 1.02±0.11, 2.73±0.31, 1.19±0.14 and 2.64±0.29, respectively; and α-SMA protein relative expression levels were (1.03±0.13), (2.33±0.27), (1.14±0.15), and (2.15±0.23), respectively. Comparisons between the sham group and the model group, between the model group and the experimental-H group, and between the experimental-H group and the activator group were statistically significant for all the above indicators (all P<0.05).

Sauchinone may alleviate myocardial fibrosis and inflammatory injury in rats with acute myocardial infarction by inhibiting the Shh/Gli1 signaling pathway.