Effect of Astragalus membranaceus injection on the activity of the intestinal mucosal mast cells after hemorrhagic shock-reperfusion in rats.

Background: The mechanism of mucosal damage induced by ischemia-reperfusion (IR) after hemorrhagic shock is complex; mast cells (MC) degranulation is associated with the mucosal damage. Astragalus membranaceus can protect intestinal mucosa against intestinal oxidative damage after hemorrhagic shock, and some antioxidant agents could prevent MC against degranulation. This study aimed to observe the effects of astragalus membranaceus injection on the activity of intestinal mucosal mast cells (IMMC) after hemorrhage shock-reperfusion in rats.

Methods: Thirty-two Wistar rats were randomly divided into the normal group, model group, low dosage group, (treated with Astragalus membranacaus injection, 10 g crude medication/kg) and high dosage group (treated with Astragalus membranacaus injection, 20 g crude medication/kg). The rat model of hemorrhagic shock-reperfusion was induced by hemorrhage for 60 minutes followed by 90 minutes of reperfusion. The animals were administrated with 3 ml of the test drug solution before reperfusion. At the end of study, intestinal pathology, ultrastructure of IMMC, and expression of tryptase were assayed. The levels of malondisldehyde (MDA), TNF-alpha, histamine, and superoxide dismutase (SOD) activity in intestine were detected, and the number of IMMC was counted.

Results: The Chiu's score of the rats in the model group was higher than in other groups (P < 0.01). The Chiu's score in the high dosage group was higher than that in the low dosage group (P < 0.05). Hemorrhage-reperfusion induced IMMC degranulation: Astragalus membranaceus injection attenuated this degranulation. Expression of tryptase and the number of IMMC in the model group increased compared with the other groups (P < 0.01) and was significantly reduced by the treatments of Astragalus membranaceus injection at both doses. There was no significant difference between the two treatment groups (P > 0.05). MDA content and concentration of TNF-alpha in the model group were higher than that in the other three groups (P < 0.05), and the concentration of TNF-alpha in the low dosage group was higher than that in the high dosage group (P < 0.05). SOD activity and the concentration of histamine in the model group were lower than the other three groups (P < 0.05). There was a negative correlation between the Chiu's score and the concentration of histamine and a positive correlation between the Chiu's score and the concentration of TNF-alpha and between the SOD activity and the concentration of histamine in the four groups (P < 0.05).

Conclusion: Astragalus membranaceus injection may reduce the damage to small intestine mucosa by inhibiting the activated IMMC after hemorrhagic shock.