Abstract: Objective  To explore the protective effect of procyanidin B2(PCB2) on  cardiotoxicity induced by acute exposure to PM2.5 in rats. 
Methods  A total of 24 healthy adult male SD rats were divided into three groups: the normal saline control group(the rats were given distilled water by gavage three time a day for 21 consecutive days and were exposed to 0.9% saline by intratracheal instillation on the 8th, 10th, and 12th days), PM2.5 group(the rats were given distilled water by gavage three times a day for 21 consecutive days and were exposed to PM2.5 suspension by intratracheal instillation on the 8th, 10th, and 12th days), and PCB2 group(the rats were pretreated with PCB2 by gavage for 21 consecutive days and were exposed to PM2.5 suspension by intratracheal instillation on the 8th, 10th, and 12th days) according to random number table method. At 24 h after the last gavage, the rats were sacrificed and cardiac tissues were collected for prepartion of tissue section. The expressions of superoxide dismutase(SOD), glutathione peroxidase(GSH-Px), malondialdehyde(MDA), interleukin-1β(IL-1β), interleukin-6(IL-6) and interleukin-18(IL-18) were detected. 
Results  Compared with the normal saline control group, the contents of IL-1β, IL-6, IL-18 and MDA in the heart tissue homogenate of PM2.5 group were significantly increased, while the contents of GSH-Px and SOD in PM2.5 group were decreased significantly, suggesting significant differences(P＜0.05). Compared with the PM2.5 group, the contents of IL-1β and IL-18 in the heart tissue homogenate of PCB2 group were significantly reduced, and the contents of SOD and GSH-Px in PCB2 group were increased significantly, suggesting significant differences(P＜0.05). 
Conclusion  PM2.5 by acute intratracheal instillation can obviously cause inflammatory damage and oxidative stress changes in rats. PCB2 has a protective effect against heart damage caused by PM2.5.

Key words: procyanidin, cardiotoxicity, particulate matter