Effect of Trifolium alexandrinum extracts on the kidneys of diabetic rats: Biochemical and histological study

Diabetic nephropathy is one of the most common and most devastating complications of diabetes. During the course of diabetic retinopathy, the glomeruli are slowly destroyed, usually with no detectable signs until the later stages of the disease, when the kidneys filtration process can no longer function. Throughout this disease, blood flow through the kidneys increases "hyperfiltration", and the kidneys become enlarged. Damage to the glomeruli becomes evident, as well as a condition known "microalbuminuria", in which a blood protein, albumin, leaks into the urine. This loss of proteins and other nutrients in the blood progresses, as does the damage to the glomeruli. The kidneys progressively lose their ability to filter waste until the final stage, kidney failure, occurs. On the other hand, some species of the plants were reported having remarkable medical importance. Trifolium alexandrinum is a medicinal herb; it has been shown to improve the flow of blood through arteries and veins in diabetic patients. Therefore, the present study aims to determine the possible improvement effects of different extracts of Trifolium alexandrinum (CF) on some biochemical and histopathological changes in the kidneys of streptozotocin-induced diabetic rats. Sixty adult male albino rats (210 ± 5 g) were injected (IP) with streptozotocin (STZ) (50 mg/kg b.wt) for induction of diabetes. Animals were classified into five groups. Daily intake of water, hexane and ethanolic extracts of T. alexandrinum in drinking water for 4 weeks after diabetes induction were used. Urine glucose was detected every week. Serum total protein, albumen, urea, uric acid and creatinine levels were tested. Data were expressed statistical to elucidate the differences between treated and control groups. The kidney paraffin sections of control and treated groups were stained with haematoxylin and eosin for histological studies. A single dose of STZ induced diabetes produced remarkable effects on both structure and function of the rat kidneys. The kidney exhibited damage of some renal corpuscles revealed glomerular mesangial cells hypertrophy, dilatation of renal tubules together with necrosis of their lining cells. Serum total protein, albumen, urea, uric acid and creatinine were significantly increased. Daily urine volume and consequently renal excretion of albumen, urea, uric acid and creatinine were significantly increased. However, remarkable improvement of the renal structure and function of diabetic rats was observed after treating with Trifolium alexandrinum extracts especially the group treated with water extract. Conclusion: Extracts of Trifolium alexandrinum improved histological and biochemical alterations of the kidneys noticed in STZ-diabetic rats. These effects may be due to the presence of a high content of flavonoids which acts synergistically as antioxidants.