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Effects of N-acetylcysteine and glutathione ethyl ester drops on streptozotocin-induced diabetic cataract in rats.

Zhang S, Chai FY, Yan H, Guo Y, Harding JJ - Mol. Vis. (2008)

Bottom Line: There were statistically significant differences between the treated groups and the untreated group (p<0.05).However, there was no statistically significant difference (p>0.05).Moreover, the diabetes resulted in an increased level of glycated proteins in both the treated groups and the untreated group, but there was no statistically significant difference between all the diabetic groups (p>0.05).

View Article: PubMed Central - PubMed

Affiliation: Department of Ophthalmology, Tangdu Hospital, Fourth Military Medical University, Xi'an, China.

ABSTRACT

Purpose: To evaluate the effect of N-acetylcysteine (NAC) and glutathione ethyl ester (GSH-EE) eye drops on the progression of diabetic cataract formation induced by streptozotocin (STZ).

Methods: One hundred and thirty Sprague-Dawley (SD) rats were selected, and diabetes was induced by streptozotocin (65 mg/kg bodyweight) in a single intraperitoneal injection. The control group (group I) received only vehicle. Then, 78 rats with random blood glucose above 14 mmol/l were divided into four groups (group II-V). The drug-treated rats received NAC and GSH-EE eye drops five days before STZ injection. Group I and V animals received sodium phosphate buffer drops (pH 7.4), and those in groups II, III, and IV received 0.01% NAC, 0.05% NAC, and 0.1% GSH-EE drops, respectively. Lens transparency was monitored with a slit lamp biomicroscope and classified into six stages. At the end of four weeks, eight weeks, and 13 weeks, animals were killed and components involved in the pathogenesis of diabetic cataract including thiols (from glutathione and protein), glutathione reductase (GR), catalase (CAT), and glycated proteins were investigated in the lens extracts. Blood glucose, urine glucose, and bodyweight were also determined.

Results: The progression in lens opacity induced by diabetes showed a biphasic pattern in which an initial slow increase in the first seven weeks after STZ injection was followed by a rapid increase in the next six weeks. The progression of lens opacity in the treated groups (group II-IV) was slower than that of the untreated group (group V) in the earlier period and especially in the fourth week. There were statistically significant differences between the treated groups and the untreated group (p<0.05). However, these differences became insignificant after the sixth week, and the progression of lens opacification in all diabetic groups became aggravated. The content of thiol (from glutathione and protein), glutathione reductase (GR), and catalase (CAT) were lower in the lens extracts of the diabetic rats four weeks, eight weeks, and 13 weeks after the STZ injection while the levels of thiol and CAT activity were both higher in the treated groups (group II-IV) than in the untreated group (group V) at every stage. However, there was no statistically significant difference (p>0.05). Moreover, the diabetes resulted in an increased level of glycated proteins in both the treated groups and the untreated group, but there was no statistically significant difference between all the diabetic groups (p>0.05).

Conclusions: NAC and GSH-EE can slightly inhibit the progression of the diabetic cataract at the earlier stage. They may maintain lens transparency and function by serving as a precursor for glutathione biosynthesis and by protecting sulfhydryl groups from oxidation.

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Related in: MedlinePlus

Changes of rat’s bodyweight before and after the injection of streptozotocin. Data are the average of results in all the animals in a given group. The weights of the normal rats were significantly different from the four diabetic groups (p<0.05), and there were no significant differences between the four diabetic groups (p>0.05) at any time.
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f2: Changes of rat’s bodyweight before and after the injection of streptozotocin. Data are the average of results in all the animals in a given group. The weights of the normal rats were significantly different from the four diabetic groups (p<0.05), and there were no significant differences between the four diabetic groups (p>0.05) at any time.

Mentions: In all five groups, weight was gained in a biphasic manner, an initial steep increase for the first six weeks, followed by a slower change during the next seven weeks (Figure 2). The diabetic rats had lower weight gain compared with the normal rats during the experimental period (p<0.05; Figure 2). In the normal group, the bodyweight increased quickly. On the other hand, there were only slight increases in the other four diabetic groups with a plateaued weight of about 200 g. There was no statistically significant difference in the weight gain among the groups of diabetic rats (p>0.05; Figure 2).


Effects of N-acetylcysteine and glutathione ethyl ester drops on streptozotocin-induced diabetic cataract in rats.

Zhang S, Chai FY, Yan H, Guo Y, Harding JJ - Mol. Vis. (2008)

Changes of rat’s bodyweight before and after the injection of streptozotocin. Data are the average of results in all the animals in a given group. The weights of the normal rats were significantly different from the four diabetic groups (p<0.05), and there were no significant differences between the four diabetic groups (p>0.05) at any time.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2386505&req=5

f2: Changes of rat’s bodyweight before and after the injection of streptozotocin. Data are the average of results in all the animals in a given group. The weights of the normal rats were significantly different from the four diabetic groups (p<0.05), and there were no significant differences between the four diabetic groups (p>0.05) at any time.
Mentions: In all five groups, weight was gained in a biphasic manner, an initial steep increase for the first six weeks, followed by a slower change during the next seven weeks (Figure 2). The diabetic rats had lower weight gain compared with the normal rats during the experimental period (p<0.05; Figure 2). In the normal group, the bodyweight increased quickly. On the other hand, there were only slight increases in the other four diabetic groups with a plateaued weight of about 200 g. There was no statistically significant difference in the weight gain among the groups of diabetic rats (p>0.05; Figure 2).

Bottom Line: There were statistically significant differences between the treated groups and the untreated group (p<0.05).However, there was no statistically significant difference (p>0.05).Moreover, the diabetes resulted in an increased level of glycated proteins in both the treated groups and the untreated group, but there was no statistically significant difference between all the diabetic groups (p>0.05).

View Article: PubMed Central - PubMed

Affiliation: Department of Ophthalmology, Tangdu Hospital, Fourth Military Medical University, Xi'an, China.

ABSTRACT

Purpose: To evaluate the effect of N-acetylcysteine (NAC) and glutathione ethyl ester (GSH-EE) eye drops on the progression of diabetic cataract formation induced by streptozotocin (STZ).

Methods: One hundred and thirty Sprague-Dawley (SD) rats were selected, and diabetes was induced by streptozotocin (65 mg/kg bodyweight) in a single intraperitoneal injection. The control group (group I) received only vehicle. Then, 78 rats with random blood glucose above 14 mmol/l were divided into four groups (group II-V). The drug-treated rats received NAC and GSH-EE eye drops five days before STZ injection. Group I and V animals received sodium phosphate buffer drops (pH 7.4), and those in groups II, III, and IV received 0.01% NAC, 0.05% NAC, and 0.1% GSH-EE drops, respectively. Lens transparency was monitored with a slit lamp biomicroscope and classified into six stages. At the end of four weeks, eight weeks, and 13 weeks, animals were killed and components involved in the pathogenesis of diabetic cataract including thiols (from glutathione and protein), glutathione reductase (GR), catalase (CAT), and glycated proteins were investigated in the lens extracts. Blood glucose, urine glucose, and bodyweight were also determined.

Results: The progression in lens opacity induced by diabetes showed a biphasic pattern in which an initial slow increase in the first seven weeks after STZ injection was followed by a rapid increase in the next six weeks. The progression of lens opacity in the treated groups (group II-IV) was slower than that of the untreated group (group V) in the earlier period and especially in the fourth week. There were statistically significant differences between the treated groups and the untreated group (p<0.05). However, these differences became insignificant after the sixth week, and the progression of lens opacification in all diabetic groups became aggravated. The content of thiol (from glutathione and protein), glutathione reductase (GR), and catalase (CAT) were lower in the lens extracts of the diabetic rats four weeks, eight weeks, and 13 weeks after the STZ injection while the levels of thiol and CAT activity were both higher in the treated groups (group II-IV) than in the untreated group (group V) at every stage. However, there was no statistically significant difference (p>0.05). Moreover, the diabetes resulted in an increased level of glycated proteins in both the treated groups and the untreated group, but there was no statistically significant difference between all the diabetic groups (p>0.05).

Conclusions: NAC and GSH-EE can slightly inhibit the progression of the diabetic cataract at the earlier stage. They may maintain lens transparency and function by serving as a precursor for glutathione biosynthesis and by protecting sulfhydryl groups from oxidation.

Show MeSH
Related in: MedlinePlus