| Objective:In this study,we investigated the effects of different concentrations of salidroside on cataract formation and mitochondrial function of lens epithelial cells and the degree of apoptosis of lens epithelial cells in diabetic rats that induced by streptozotocin?STZ?.The aim was to discuss the potential mechanisms of protective effect of salidroside on mitochondrial function of lens which provided new ideas and directions for the treatment of cataract whose characteristic is LECs apoptosis.Methods:There were 50 male SPF SD rats weighing about 200g selected from the Experimental Animal Center.The lens and anterior segment of the rats were checked by slit lamp before modeling,and were adapted at the Experimental Animal Center for modeling and feeding.The model of type I diabetes was established 1 week after sexual feeding.After this,we arranged a absolute diet for 12 hours,we took tail vein blood to determine fasting blood glucose in that morning,randomly selected 40 SD rats,weighed the 40 rats and calculated the dose of STZ solution.Besides,we injected these rats with 1%STZ-citrate buffer solution?60 mg/kg?on a low head position,and the remaining 10 rats were treated with same volume fraction of sodium citrate buffer solution and then divided into group A?Blank control group?.Making sure that there was no posterior abdominal organs damage.Then let the rats freely drink water and diet.To ensure that the random blood glucose obtained through the blood of the tail vein after 72 hours,if the glucose was over 16.7 mmol/L,we regarded it that the diabetes model was successfully established.If the blood glucose was lower than 16.7mmol/L,we added more 1%STZ?20mg/kg-30mg/kg?to increase the blood glucose level.The model rats were randomly divided into several groups:group B?diabetes group?,group C1?diabetes+salidroside solution 50 mg/kg group?,group C2?diabetes+salidroside solution 100 mg/kg group?,and group C3?diabetes+salidroside solution 200mg/kg group?,rats in C group were intragastrically administered according to the concentration of salidroside solution in the morning,once a day.While Groups A and B were given the same volume number of 0.9%sodium chloride solution orally in the morning,once a day.We made sure that the body condition,drinking water and diet were observed every day.The random blood glucose from rat tail vein was measured and recorded at 1w/4w/8w/12w.All rats were injected 10%chlorinated chlorine at 4w,8w and 12w respectively.After the aldehyde anesthesia,the degree of lens opacity was observed and classified by slit lamp and then recorded the lens opacity degree.After 12 weeks,the rats were sacrificed and the right eye lens were quickly removed by operation.JC-10staining was observed by fluorescence staining,the apoptosis rate of the lens was determined by TUNEL method,and the mitochondrial membrane potential of Bcl-2 and Bax protein expression in lens epithelial cells were detected by Western blot.Results:First,SD rats general condition:Group A rats grew well throughout the experiment,hair color was normal,drinking water and diet were good,and weight gaining was in line with the growth curve of standard SD rats.The model group?groups B and C?showed typical symptoms of diabetes after successful modeling of the diabetes model,including polyuria,polydipsia,stool thinning and high blood glucose.Group B and C1 group could be observed that the spirit was poor,the movement was sluggish,the hair was dull,and at the end of the experiment,their hair was dull and shedding,the body was thin,the growth was slow,and typical symptoms of diabetes were exhibited.The C2 and C3 groups also showed typical symptoms and manifestations of diabetes after modeling.However,with the implementation of salidroside intervention,the rats had drinked less water and had less urine than the diabetic group,even the nomal condition was fine including the mental state,mortality rate was low.Second,blood glucose monitoring in experimental SD rats:The blood glucose values of SD rats selected in this experiment were 5.18±1.06 mmol/L before modeling.After successful modeling,the random blood glucose measured in groups B and C was>16.7mmol/L?19.72±2.43mmol/L?,which was significantly higher than that in group A?P<0.05?.Group B maintained high blood glucose levels after modeling and additional STZ injection.The blood glucose in the control group of group A fluctuated within the normal range after modeling,and there was no significant difference between the models?P>0.05?.After the model was established,with the implementation of intervention measures,blood glucose decreased to varying degrees,and the downward trends of C1,C2,and C3 were different.Third,changes in lens transparency of experimental SD rats:The lens of group A rats remained basically transparent.Most of the rats in group B were observed to form vesicles around the lens by slit lamp at 4w after modeling.At 8w,the lens showed vesicles expanding to the pupil area.A small amount of haze was observed in the nucleus.At 12w,the opacity of the lens was aggravated and even developed into full turbidity.In the C1 group,the formation of vesicles around the lens was observed at 4w,and the vesicles increased and diffused at 8w,and the foggy turbidity in the nuclear area was aggravated at 12w.In the C2 group,a small amount of small vesicles around the lens appeared at 4w,and the peripheral vesicles increased at 8w.At12w,the vesicles spread and the nucleus of the lens nucleus was cloudy.In the C3 group,the peripheral vesicles of the lens appeared at 8w,and a small amount of haze turbidity in the nucleus of the lens of some rats was observed at 12w,Fourth,the changes of mitochondrial membrane potential in lens epithelial cells of SD rats:The membrane potential of lens epithelial cells in group A was higher than that in group B and C,and the difference was statistically significant?P<0.05?.The mitochondrial membrane potential in the C3 group was lower than that in the A group,but higher than that in the C1,C2 and B groups?P<0.05?.Fifth,the expression of Bcl-2 and Bax protein by Western-Blot:the expression of Bcl and Bax protein were related to the concentration of salidroside.The expression of Bcl-2 protein was highest in group A and lowest in group B and the expression of Bcl-2 protein in C group was C3>C2>C1.The differences between the groups were statistically significant?P<0.05?.The expression of Bax protein was the lowest in group A,the highest in group B,and the expression of Bax protein in C group was C1>C2>C3.The difference between the groups was statistically significant?P<0.05?.Sixth,apoptosis ratio of LECs:group B>C1>C2>C3>A,the difference was statistically significant?P<0.05?.Conclusion:1.The study showed that Salidroside protected the lens of diabetic rats and slowed down the formation and extent of lens opacity and the effects were some concentration-dependent.2.We drew the conclusion that salidroside promoted Bcl-2 protein expression and inhibited Bax protein expression by protecting mitochondrial membrane potential of lens epithelial cells,to affect the opening of mitochondrial PT pore.Thereby it inhibited apoptosis of cells though the mitochondrial related apoptosis pathway and protected lens of streptozotocin-induced diabetic rats. |
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