Protective effect of N-acetylcysteine on retinal cell apoptosis, oxidative stress and inflammation in type 1 diabetic rats

Objectives The purpose of the current study is to explore the therapeutic role of N-acetylcysteine (NAC) against retinal cell apoptosis in a rat model of type 1 diabetes mellitus (T1DM) and to evaluate possible mechanisms of action. Methods A total of 18 Wistar rats (16-months-old) were divided into three groups in equal numbers: Control (group 1), T1DM (Group 2) and T1DM + NAC (group 3). In group 2 and 3 rats, T1DM was induced by intraperitoneal (IP) injection of streptozotocin (65 mg/kg). Group 3 was given oral NAC (60 mg/kg once daily) for 5 months. Serum and retina were collected for further use. Results NAC administration significantly declined fasting glucose level, hyperlipidemia, atherogenic coefficient and cardiac risk ratio, but improved weight gain and fasting insulin level in T1DM rats. Associated with these effects, NAC significantly improved levels of total antioxidant capacity, while significantly decreased malondialdehyde, protein carbonyls and 8-hydroxy-2′-deoxyguanosine contents in the retina of T1DM animals. NAC significantly diminished the percentage of retinal cell apoptosis in T1DM rats. A significant enhancement was found in Bax, TNF-α, and Caspase expression, but IL-10, superoxide dismutase, catalase and Bcl2 expression was significantly decreased in T1DM rats. However, NAC treatment considerably improved the expression of these genes in retina of T1DM rats. Conclusions NAC protects retinal cell by enhancing antioxidant pool, attenuating inflammation, oxidative stress and apoptosis in T1DM.