Study On The Protective Effect Of Aloe Extract On Diabetic Nephropathy And Its Possible Mechanism

Diabetic nephropathy (DN) is a disease of glomerulosclerosis due to diabetes , the high incidence and the morality of which have attracted intensive attention . Scientists are seeking proper therapy or remedy to treat the patients with diabetes and its related complications such as DN. Since the blood sugar lowering effect of Aloe has been revealed, its effect on the diabetic complications and whether it is an appropriate remedy for diabetic nephropathy should be proved by scientific proof. In this experiment, we studied the protective effect of aloe on visceras and cells in mice in animal, cellular and molecular level, and probe into possible protective mechanism through oxidative stress in cell and tissue, expression of TGF β₁ mRNA and the activity of two key enzymes in polyol pathway.Animal level: Objective: To study the effect of aloe on diabetic nephropathy. Method: In this experiment, we gave the diabetic mice aloe extracts by gavage .Animal models were selected for experimental use after injection of alloxan. Mice were randomLy divided into 4 groups: control group, aloe group, model group, positive drug (Tangmaikang) group. After five weeks of gavage treatment, the day before death, mice were tested with OGTT. After mice were killed, Related quota were measured such as blood sugar level, serum total cholesterol content, serum fructosamine, kidney and body weight ratio, MDA, GSH and sorbitol content in kidney, sorbitol content in eyeball, MDA content in pancreas and so on . Results: Aloe extracts were proved to have marked curing effect on diabetic mice and to better the quota such fructosamine, kidney and body weight ratio, MDA, GSH, sorbitol content and so forth. Conclusions: Aloe extract can cure the diabetic mice and alleviate the diabetic nephropathy in early stage.Cell and Molecular level: Objective: To study the effect of aloe medicated serum on the AGEs treated RGMC cells, and probe into the curing mechanism of aloe on diabetic nephropathy. Method: Serum was obtained from the blood after aloe gavage, then medicated serum was added into the cells treated by AGEs. After 24h incubation, indexes such as GSH, SOD, CAT, SDH, AR activities and expression of TGFβ₁ in cells were measured; and the variation of concentration of intracellular free calcium ions was observed. Results: It showed that GSH content and SOD activity were markedly higher in the medicated serum treated AGEs group than that in untreated AGEs group, while AR and SDH activity decreased in the medicated serumtreated AGEs group, expression of TGFβ₁ is upregulated in the AGEs group compared to that of the control group, while after the 24 h incubation of aloe medicated serum, its expression decreased markedly in the AGEs treated cell .conclusions: It can be concluded that Aloe medicated serum exerted protective effect on AGEs treated cells, and we hypothesize that therapeutical effect of aloe on diabetes and its related complications was probably due to alleviation of the oxidative stress and decrease in the activities of two key enzymes in the polyol pathway in cells and down-regulation the expression of TGFβ₁ mRNA.Based on the stated experiment results above, we can draw conclusions : Aloe extracts were proved to have marked curing effect on diabetic mice, not only lower the blood sugar level but also exert protective effect on the diabetic related complications such as DN; In the experiment, aloe medicated serum also proved effective on the AGEs treated RGMC. In a word, the aloe extract has the protective effect on diabetic complications such as DN propably through the amelioration of oxidative stress, decrease in the activity of the SDH and AR down-regulating of TGFβ₁ mRNA.