Purpose: Diabetes mellitus (DM) has deleterious effect on various body organs especially salivary glands. Therefore, this study was conducted to evaluate the therapeutic effect of curcumin on parotid salivary glands in diabetic rats. Material and
methods: Fifty-six adult male albino rats weighting 150-200 g were selected and divided into two equal groups n= 28 rats each. Diabetes was induced in both groups I (Diabetic) & II (Diabetic & curcumin) with a single intraperitoneal injection of streptozotocin (STZ) at a dose of 55 mg/kg. After 2 weeks of diabetes confirmation; rats of group II received 200 mg\kg of curcumin orally once daily. Both groups I and II were divided into 2 subgroups (A, B, C and D respectively) 14 rats each and were sacrificed after 15 and 20 days of curcumin administration, and the parotid glands sections were stained with Hematoxylin and Eosin, Anti-iNOS, and Anti-IL-2. Then were subjected to digital image analysis followed by two-way ANOVA statistical analysis. Results: Curcumin treated group revealed improvement in parotid glands in H&E sections especially at 20 days when compared to diabetic group with reduced histomorphological alterations. While, immunohistochemically, curcumin treated group showed decreased expression in the levels of both iNOS and IL-2 with significant statistical difference with diabetic group in all time periods. Post hoc LSD test showed a significant difference between time periods of diabetic group while showed no significance between curcumin group. Conclusion: Curcumin can be possible candidate for hindering the regressive changes that affect salivary glands caused by diabetes.