|Effect of Trifolium Alexandrinum Extracts on the Kidney of Diabetic Rats: Biochemical and Histological studies.
Maisaa M. AL-Rawi
Associate professor of cytology and histology
Biology Department, Girls College, Makkah, Saudi Arabia.
Diabetic nephropathy is one of the most common and most devastating complications of diabetes. Some flower of clover species were reported to have remarkable medical importance. Trifolium pratense (red clover) 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 was to determine the possible improvement effects of (Trifolium alexandrinum) extracts on histopathological and biochemical changes in kidneys of streptozotocin-induced diabetes in rats.
Sixty adult male albino rats (210 ± 5 g) were injected (IP) with streptozotocin (50 mg/kg b.wt). Animals were distributed in-groups, (water, hexane, an ethanolic) extracts of T. alexandrinum intake in drinking water for 4 weeks after diabetes induction were used. Urine glucose was determined at the end of the treatment every week in all rats. Serum total protein, albumen, urea, uric acid and creatinine were tested. Data were analyzed statistically to elucidate the differences between treated and control groups. The paraffin sections for kidney of control and treated groups were stained with haematoxylin and eosin for histological studies.
A single dose of STZ induced diabetes and remarkable effects on rat kidney structure and function. The kidney exhibited damage of some renal corpuscles and revealed glomerular mesangial cells hypertrophy, dilatation of renal tubules with necrosis of its lining cells. Serum total protein, albumin, urea, uric acid and creatinine were significantly increased. Urine volume, renal excretion of albumin, urea, uric acid and creatinine were significantly increased. Remarkable improvement of renal structure and function of diabetes were observed after treating with CF extracts especially the group treated with water extract. Extracts of T. alexandrinum improved histological and biochemical alterations of kidney noticed in STZ-diabetic rats. These effects may be due to the presence of a high content of flavonoids which act synergistically as antioxidants.
Diabetic kidney disease "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. About 25 percent of people with type 1 diabetes suffer from nephropathy; those with type 2 diabetes are also at risk (Bingham and Hattersley 2004).
Diabetes, still a significant metabolic disease, is characterized by hyperglycaemia, glucosuria, polyuria and so on. Changes in carbohydrate and lipid metabolisms under the effect of diabetes result in atherosclerosis. Therefore, renal lesions are seen commonly in diabetic patients (Agodoa et al., 1997). Hyperglyccmia and glucosuria produce osmotic diuresis and therefore polyuria. Prolonged osmotic diuresis may cause excessive urinary electrolyte loss. Disturbances in renal function are associated with several abnormalities, including proteinurea and progressive renal failure (Mayne, 1994).
Diabetic nephropathy represents a major complication of diabetes mellitus. It includes hyperfiltration, albumin urea and renal hypertrophy (Bardoux et al.,1999; Suanarunsawat et al., 1999; Kurusu et al., 2000; Bankir et al., 2001).
Significant increase in creatinine clearance and urinary albumin excretion was recorded in streptozotocin-induced diabetes in rats (Bardoux et al.,1999). It was suggested that vasopressin play a critical role in diabetic hyperfiltration and albuminurea induced by diabetes mellitus. This hormone seems to be an additional risk factor for diabetic nephropathy and thus a potential target for prevention and or therapeutic intervention. Montero et al. (2000) recorded improved proteinuria and blood urea nitrogen levels in streptozotocin diabetic rats by dietary supplementation with antioxidant vitamin E (1000U/ kg diet).
Previous studies on the short-term effects of diabetes on kidney morphology have suggested cortical hypertrophy accompanied by glomerular mesangial hypertrophy (Rasch, 1979; Seyer- Hansen et al., 1980), whereas long-term diabetes caused increased glomerular basement membrane thickness (Hirose et al., 1982).
Many works were carried out by investigators to study the effects of plant extracts on diabetes - induced by streptozotocin in many organs of animals (Ugochukwu and Babady,2003; Latha et al., 2004; Pari L and Latha, 2004; Tan et al.,2005; Modi et al., 2006; Tunali et al., 2006). Amer et al.(2004) reported that Trifolium alexandrinum caused significant decreases in glucose and glycated hemoglobin levels and increase in insulin level and greatly improved the levels of serum lipid parameters and significantly decreased lipid peroxidation.
The present study was designed to determine the effect of streptozotocin on renal histology and biochemistry and to determine the prevention effects of Trifolium alexandrinum treatment in rat kidney.