甘草甜素抑制小鼠接触性超敏反应的实验研究

目的：探讨甘草甜素(GL)对二硝基氟苯(DNFB)所致小鼠接触性超敏反应(CHS)的抑制效果。 方法： BALB/c小鼠分为GL1(11 mg/kg)组、GL2(22 mg/kg)组、GL3(44 mg/kg)组、生理盐水(NS)组和地塞米松(DXM)组5组；利用DNFB诱发小鼠右耳CHS，各组于 -1 d 至5 d每天腹腔注射0.2 mL上述不同剂量药物(溶于生理盐水)。以耳厚度差、耳重量差及右耳病理变化，观察GL对小鼠CHS的抑制效果；同时计算胸腺指数、脾指数，了解GL对CHS小鼠免疫系统的影响。 结果： 3个剂量组GL和DXM均可明显抑制CHS小鼠右耳厚度及重量的增加，与NS组间差异显著(P<0.01)，同时亦可明显抑制右耳组织水肿和炎细胞浸润。3种剂量GL均可减低CHS小鼠胸腺重量，与NS组间有统计学差异(P<0.05)，而对脾脏重量无明显影响；DXM可显著降低CHS小鼠胸腺和脾脏重量。 结论： 甘草甜素可明显抑制DNFB诱发的小鼠接触性超敏反应。

Suppressive effect of glycyrrhizin on murine contact hypersensitivity

AIM: To study the suppressive effect of glycyrrhizin (GL), a Chinese medicine, on DNFB-induced contact hypersensitivity in mice. METHODS: BALB/c mice were divided into 5 groups according to different medication: GL 1 (11 mg/kg) group; GL 2 (22 mg/kg) group; GL 3 (44 mg/kg) group; dexamethasone (DXM, 0.75 mg/kg) group; and normal saline group. For induction of contact hypersensitivity (CHS) to DNFB, mice were sensitized to abdomen and challenged to right ear by epicutaneously DNFB. Each mouse was administrated intraperitoneally on day 1 to day 5 with different medication. The suppression of mice CHS by different medication were evaluated 24 hours after elicited, according to ear thickness difference, ear weight difference and pathological change of challenged ear section. Thymus index and spleen index were calculated to see the effect on mouse immune system to CHS. RESULTS: Compared with normal saline group, the ear thickness difference and ear weight difference were both significantly reduced in GL1, GL2, GL3 and DXM groups (P<0.01). Simultaneously histological edema and infiltration of inflammatory cell were inhibited. GL injection at three doses decreased mouse thymus weight to CHS, though mouse spleen weight were not affected, compared with NS injection. CONCLUSION: Glycyrrhizin significantly suppressed murine contact hypersensitivity.