Histopathological studies of Blue Congo extract on the muscle tissue of streptozotocin (STZ)-induced diabetic rats. Note the presence of edema of connective tissue in the DM and DM + PP groups (arrow); photos on from the left side (C,E). Different periodic acid–Schiff (PAS)-positive reaction (white arrows) in myocytes (D,F). Photos on left side stained with hematoxylin and eosin (H&E), magnification 200× (A,C,E); photos on right side show PAS-positive staining, magnification 400× (B,D,F). C—control rats (healthy rats), DM—diabetic rats, DM + PP—diabetic rats treated with Blue Congo extract for 14 days (at a dose of 165 mg/kg b.w./day).