Protective effects of zingiber officinalis extract on the lens of diabetic rats / 眼科新进展

ABSTRACT

Objective To observe the protective mechanisms of zingiber officinalis extract on the lens of diabetic rats induced by streptozotocin (STZ).Methods Totally 60 SD rats were randomly divided into A group (normal control rats),B group (diabetic rats),C1 group (DM +50 mg · kg-1 ginger gavage),C2 group (DM + 100 mg ·kg-1 ginger gavage) and C3 group (DM + 300 mg · kg-1 ginger gavage).Each group had 12 rats.And rats in A group received intraperitoneal injection of the same volume of normal saline,while the other groups were intraperitoneally injected with 65 mg · kg-1streptozotocin (STZ).When the animal model was successfully established,both A group and B group were administered orally with normal saline,and the C1,C2 and C3 groups were administered orally with ginger rhizome extract.The changes in blood glucose and lens were observed every week.The rats were sacrificed in succession at 4 week,8 week,12 week,and the lens was removed immediately.The content of aldose reductase (AR) was detected by ELISA,and the expression of glycosylation end products (AGEs) was detected by Western blot.The superoxide dismutase (SOS) activity and malondialdehyde (MDA) content were also detected.Fluorescent Tunel staining was used to detect the apoptosis of the lens epithelial cells.And finally,scanning electron microscopy was used to observe the ultrastructural changes in the lens.Results The activity of SOD in the lens of diabetic rats showed a decreasing trend with statistical significance (all P ＜ 0.05).Changes in the content of MDA in the lens of rats in B,C1,C2 group were statistically significant in 4,8 and 12 weeks after successful modeling (all P ＜ 0.05),but no significant difference in A group and C3 group (both P ＞ 0.05).The persistent increase of AR in group B (P =0.003).The content of AR of the lens in C1,C2,C3 group showed a decreasing trend,and the differences were statistically significant (all P ＜ 0.05).There were significant differences in the expression of AGEs in C1,C2 and C3 group (all P ＜ 0.05).The degree of cortical fiber destruction in group B was progressively aggravated,but the degree of cortical destruction in C1,C2 and C3 group decreased with the increase of ginger gavage concentration through the scanning electron microscopy.It was observed that there was no significant difference in the apoptotic rate of LECs in A group (P =0.191),but the apoptosis of LECs in the rest group showed a rising trend,and the differences were statistically significant (all P ＜ 0.05).Conclusion The effects of ginger gavage extract can delay the opacification of lens and slow down the diabetic development in rats with a dose-independence manner.Ginger gavage extract may play a protective role on the lens of diabetic rats by inhibiting the activity of AR,oxidative stress and the production of AGEs as well as suppress the apoptosis of lens epithelial cells.