Histological, ultrastructural and immunohistochemical studies on the ameliorative role of Cinnamon zeylanicum against high cholesterol diet-induced hypercholesterolemia in the kidney of adult male albino rats

Cholesterol is an important type of lipid as it is involved in the structure of cell membrane, synthesis of steroid hormones, bile acid and vitamin D. Many diseases affect various mammalian organs, including the kidney, as a result of high cholesterol levels (hypercholesterolemia). Cinnamon zeylanicum (C. zeylanicum) proves its efficiency as it has anti-inflammatory and antioxidant prosperities. This study aimed to investigate the possible ameliorative role of C. zeylanicum on hypercholesterolemia-induced the renal toxicity in albino rats. Forty adult male albino rats were equally divided into four groups. The first group served as the control one. The second group was supplemented with C. zeylanicum powder (15% w/w) with the standard diet. The third group was fed high cholesterol diet (HCD) to induce acute hypercholesterolemia. The fourth group was fed HCD provided with C. zeylanicum powder (15% w/w). At the end of the experiment (8(th) weeks), kidneys were removed and prepared for histological, immunohistochemical and ultrastructure studies. Rats-fed HCD showed degenerated glomeruli and tubular cells with vacuolated or coagulated cytoplasm and pyknotic nuclei. Moreover, the renal cortex ultrastructural examination showed degenerated podocytes, parietal and mesangial cells, as well as the proximal and distal tubular cells appeared with rarified cytoplasm, degenerated mitochondria, large fat vacuoles and complete damaged microvilli. The same group showed a significant increase in the expression of desmin and inducible nitric oxide synthase. On the other hand, animals fed HCD provided with C. zeylanicum showed an obvious improvement in the observed histological, ultrastructural and immunohistochemical changes. The architecture of the renal cortex appeared mostly similar to the control one. This study concluded that C. zeylanicum has a promising role in treating the nephron-toxicity of HCD due to its natural constituent that is responsible for its pharmaceutical effects.