OBJECTIVEThe present study was designed to investigate whether Sini decoction (SND) containing several chinese medicinal herbs, could induce delayed preconditioning-like effect in rat heart and the possible mechanism.

METHODIn anesthetized open-chest Sprague Dawley rats, left anterior descending coronary artery (LAD) was occluded for 1 h and reperfused vided into four groups: Sham ( n = 8) group in which the surgical procedure was identical to other groups,but the LAD ligature was not ligated; I/R group (n = 8) in which the LAD of rat hearts was subjected to the index occlusion; IPC/SWOP group (n = 8) in which the LAD was occluded for three cycles of 5-minute episodes of preconditioning ischemia followed by 5-minute episodes of reperfusion 24 hours prior to the index occlusion; SND group (n = 8) in which rats were pretreated with Sini decoction (5 g x kg(-1) d(-1)) for three days, the last treatment was pretreated 24 h before the index occlusion. Myocardial infarct size, the activity of superoxide dismutase( SOD) and the content of malondialdehyde (MDA) in myocardial tissue were measured. The mRNA expression of MnSOD and Cu-ZnSOD were detected by RT-PCR. The expression of P65 subunit of NF-kappaB was determined by immunohistochemistry assay.

RESULTAs compared with I/R group, myocardial infarct size and the amount of MDA in myocardial tissue were significantly decreased, the activity of SOD and the mRNA expression of MnSOD were increased, the translocation of NF-kappaB was detected and furthermore the expression of NF-kappaB was significantly elevated in SND group as well as in IPC/SWOP group. The mRNA expression of Cu-ZnSOD was lowered in I/R, SND and IPC/SWOP groups, and there was no significant difference among these groups.

CONCLUSIONThe results suggest that Sini decoction can induce delayed preconditioning-like effect in rat heart and the activation of NF-kappaB may play an important role in it.