甘草酸软膏治疗豚鼠慢性湿疹模型的实验研究

Glycyrrhizic acid ointment in the treatment of chronic eczema in guinea pigs

目的观察甘草酸软膏抗炎、止痒和对豚鼠慢性湿疹的治疗作用。方法雄性昆明种小鼠、雌雄昆明种小鼠、白色豚鼠各60只，分别随机分为模型对照组（10只）、基质对照组（10只）、醋酸地塞米松乳膏组（10只）、甘草酸软膏高（10只）、中（10只）、低（10只）剂量组，各组分别建立二甲苯致小鼠耳廓肿胀模型，右旋糖酐40致小鼠搔抓模型，以及2，4-硝基氯苯反复刺激的慢性湿疹豚鼠模型，分别观察甘草酸软膏对小鼠耳廓肿胀和搔抓反应以及慢性湿疹豚鼠耳廓肿胀的影响。结果甘草酸软膏高、中剂量可以抑制二甲苯致小鼠耳廓肿胀（P〈0．05或o．01）；甘草酸软膏高剂量可以延长右旋糖酐致小鼠搔抓的潜伏期，甘草酸软膏高、中、低剂量可减少搔抓次数（P〈0．05或0．01），减轻慢性湿疹豚鼠模型耳廓的肿胀（P〈0．05或0．01），并对耳廓皮肤的病理改变有一定的改善作用。结论甘草酸软膏对慢性湿疹豚鼠模型有一定的治疗作用。

Objective To evaluate the therapeutic effect of glycyrrhizic acid ointment on chronic eczema in guinea pigs. Methods Totally, 60 Kunming male mice, 60 Kunming mice and 60 albino guinea pigs were respectively classified into 6 groups： model group, ointment base group, dexamethasone group, high-, medium- and low-dose glycyrrhizic acid group. To observe the effect of glycyrrhizic acid ointment on the swelling of mouse auricles, dexamethasone and different doses of glycyrrhizic acid ointment were topically applied to both auricles of male mice in corresponding groups followed by the establishement of mouse auricle swelling model induced by xylene. One and a half hours later, the mice were sacrificed, and the weight of swelling auricles was weighed. Scratching behavior was induced by dextran 40 in Kunming mice following the application of dexamethasone or glycyrrhizic acid ointment. The latent period and frequency of scraching were recorded for every Kunming mice. To establish a model of eczema, guinea pigs were sensitized with dinitrochlorobenzene （DNCB, 5%） in the neck and back and challenged by DNCB （0.1%） on the inner surface of right ears once a week for 4 weeks; subsequently, both auricles were treated with dexamethasone or glycyrrhizic acid ointment once a day for 10 days. Then, the thickness of auricles of guinea pigs was measured, and skin tissue was obtained from the right ear of guinea pigs and subjected to a pathological analysis. Results The high- and medium-dose of glycyrrhizic acid ointment could suppress the xylene-induced swelling of mouse auricles （P 〈 0.05 or P 〈 0.01）. The latent period of scratching could be lengthened by high dose of glycyrrhizic acid （P 〈 0.05）. The three doses of glycyrrhizic acid all reduced scratching frequency in Kunming mice （P 〈 0.05 or P 〈 0.01 ）. Attenuated swelling of auricles （P 〈 0.05 or P 〈 0.01） and relieved pathological changes were observed in guinea pigs after treatment with glycyrrhizic acid ointment. Conclusion Glycyrrhizic acid ointment shows a therapeutic effect on chronic eczema in guinea pigs.