Introduction: Diabetes mellitus is a common disease worldwide. It is considered as the third leading cause of death, in the developed countries followed by heart diseases and cancer. Aim: The aim of this study was to assess the effectiveness of the aqueous fraction of R. mucronata and A. marina leaves grown in Saudi Arabia alone or in combination as antidiabetic agents and explore its effect on the antioxidants status. Methods: One hundred and twenty male Wistar albino rats were divided into 8 groups were utilized in this study. Streptozotocin (STZ) was utilized for induction of diabetes. The effects of daily oral administration of aqueous extract from the leaves of R. mucronata (400 mg/kg BW), A. marina (400 mg/kg BW) and the combination of both plant extracts for 6 weeks were evaluated on blood glucose, insulin, tissues antioxidants as well as pancreatic immunohistochemistry in normal, (STZ)-induced diabetic rats. Results: Oral administration of the plants extracts significantly reduced (p ≤ 0.001) serum glucose, insulin and improved the antioxidants status in the liver compared to the untreated rats. Immunohistochemically, the pancreas of diabetic rats treated with R. mucronata revealed a few islets β-cells (2-3%/ HPF) with positive caspase-3. Conclusion: The extract of R. mucronata exhibited a promising antidiabetic, antioxidant and tissue enhancing effects compared with A. marina alone or in combination.
Key words: Mangrove, diabetes mellitus, insulin, tissue antioxidants, pancreas.