方法：Wistar大鼠随机分为正常对照组、糖尿病组、3-AB干预组。糖尿病组和3-AB干预组大鼠予以腹腔注射链脲佐菌素(STZ)建立糖尿病大鼠模型，正常对照组注射等体积柠檬酸盐缓冲液。建模成功后3-AB组每日按照30mg/kg给予3-AB灌胃，正常对照组和糖尿病组则给予等体积9g/L 生理盐水(NS)灌胃。观察并记录各组大鼠晶状体混浊进展情况，分别于给药后2，4，8wk处死各组大鼠，取出晶状体检测谷胱甘肽过氧化物酶(GSH-Px)和超氧化物歧化酶(SOD)的活性以及丙二醛(MDA)和糖基化终末产物(AGE)的含量，并检测晶状体上皮细胞中基质金属蛋白酶-2(MMP-2)和碱性成纤维细胞生长因子(bFGF)的表达情况。

结果：灌胃3wk时糖尿病组和3-AB组大鼠均开始出现不同程度的晶状体混浊，4wk和8wk时糖尿病组晶状体混浊程度比3-AB组重(P<0.01)。3-AB组大鼠晶状体中GSH-Px和SOD活性在2，4，8wk时均高于糖尿病组(均P<0.05)，但均低于正常对照组(P<0.01)。3-AB组大鼠晶状体中MDA的含量在2，4，8wk时均低于糖尿病组(P<0.05)，但均高于正常对照组(P<0.01)。糖尿病组和3-AB组大鼠晶状体中AGE含量在2，4，8wk时高于正常对照组(均P<0.05)，而糖尿病组在2wk和4wk时高于3-AB组(P<0.05)，但在8wk时无差异。MMP-2在正常对照组大鼠晶状体上皮细胞几乎无表达，在2，4，8wk时糖尿病组均强于3-AB组(P<0.05)。 bFGF在三组大鼠晶状体上皮细胞均呈阳性表达； 在2，4，8wk时，糖尿病组和3-AB组均强于正常对照组(均P<0.05)，但糖尿病组与3-AB组之间无差异。

结论：3-AB对STZ诱导的糖尿病大鼠晶状体混浊具有一定抑制作用，其机制可能是通过减轻STZ诱导的糖尿病大鼠晶状体上皮细胞氧化损伤，降低非酶糖基化水平，抑制晶状体上皮细胞中MMP-2的表达，减轻晶状体上皮细胞外基质降解，从而抑制晶状体混浊。

METHODS: Wistar rats were randomly divided into three groups: control group, diabetic group and 3-AB group. The rats of diabetic group and 3-AB group were treated with intraperitoneal injection of streptozotocin(STZ). The rats of control group were given the same volume of citrate buffer. After the model constructed, 3-AB group was treated with 3-AB(30 mg/kg)gavage daily while the control group and diabetic group were given the same volume of 0.9% NS instead. The progress of lens opacity of rats was observed and recorded. After administrated for 2, 4 and 8 weeks, rats were sacrificed and taken lens respectively. The lens were used to detected the activity of glutathione peroxidase(GSH-px), superoxide dismutase(SOD), the level of malondialdehyde(MDA)and advanced glycation end products(AGE), the expression of matrix metalloproteinase-2(MMP-2)and basic fibroblast growth factor(bFGF)in lens epithelial cells.

RESULTS: Lens of diabetic group and 3-AB group appeared various degree of cloudy since the third week. The level of diabetic group was higher than 3-AB group(P<0.01)in the fourth and eighth week. The GSH-Px and SOD activities of diabetic group were lower than 3-AB group(all P<0.05)at the 2, 4, 8 weeks, but all of them lower than control group(P<0.01). The content of MDA increased in diabetic group and 3-AB group, compared with control group(P<0.01), and its content in diabetic group was higher than in 3-AB group(P<0.05)at the 2, 4, 8 weeks. The content of AGE in the lens that come from control group were lower than diabetic group and 3-AB group(all P<0.05)in each time. At 2, 4 weeks, its content in diabetic group was higher than in 3-AB group(P<0.05), but there was no difference at 8 weeks(P>0.05). There was rare expression of MMP-2 in control group, the MMP-2 expression of diabetic group is statistically significant higher than 3-AB group(P<0.05)in the 2, 4, 8 weeks. bFGF was expressed in the three groups, and the bFGF expression of control group was lower than diabetic group and 3-AB group(all P<0.05)in the 2, 4, 8 weeks. There was no difference between diabetic group and 3-AB group in each time.

CONCLUSION: 3-AB has a certain inhibitory effect for lens opacity in the STZ-induced diabetic rats, the possible mechanism: alleviates the oxidative damage of lens epithelial cells, reduces the level of non-enzyme glycation, and inhibits the expression of MMP-2 suggested that it can alleviate the degradation of lens epithelial cells' extracellular matrix, which lead to inhibit the lens opacity.