OBJECTIVETo investigate the characteristics, sensitizin and the mechanism of pseudo allergic reaction induced by Yuxingcao injection.

METHODBeagle dogs were randomly assigned to control group, 0.5% tween 80 group, Yuxingcao injection without tween 80 group, Yuxingcao injection included 0.5% tween 80 group. The animals in control group were intravenously injected with saline. The other group were intravenously injected with the corresponding test substances. Observe pseudo anaphylaxis of Beagle dogs within 30 min after administration. Blood pressure and respiration rate of Beagle dogs were measured before and after injection drugs 10 min and 30 min respectively. The pseudo allergic reactions were scored at same time points, and the sera of animals were collected to determine the HIS, CH50 and C5b-9 concentration using ELISA.

RESULTThe scores of allergic reaction in 0.5% tween 80 group and Yuxingcao injection included 0.5% tween 80 group was evidently higher than that in control group in 2-5 min after administration. Animals of above two groups showed the symptoms of red swelling on ear part, pruritus, throwing the head, nausea, lapping the tongue, dysphoria and bradykinesia. Some of them had behaved with repose, urination, defecation, cyanosis, the frequency of breathes accelerating and blood pressure decreasing. The rate of pseudo allergic reactions was 100%. Serum CH50 concentration of 0.5% tween 80 group decreased 10 min after injection, while C5b-9 concentration increased. No obvious differences were observed 30 min after injection. There was no significant difference in HIS concentration between control group and treatment groups.

CONCLUSIONThe pseudo allergic reactions appeared after intravenous 0.5% tween 80 and Yuxingcao injection when mixed with tween 80. Furthermore, Yuxingcao injection without tween 80 did not induce pseudo allergic reactions. It was suggested that the pseudo allergic reactions of Yu Xing Cao Injection was related to the cosolvent tween 80. The pseudo allergic reactions of tween 80 may relate to the activation of complement.