The M. oleifera aqueous leaves extract protects -cells against ROS-mediated damage by enhancing cellular antioxidant defenses and minimizing hyperglycemia in STZ-induced diabetes as proved histologically, histochemically, morhometrically and ultrastructurally. These experimental findings clearly indicate that M. oleifera leaves may be exploited as an important source of natural antioxidants with antidiabetic potential and can be used as a possible food additive or as a functional food and in bio-pharmaceutical industries.