Study on the affection of TLR of aralia in renal tissue of diabetic mice

Abstract

Objective To investigate the protective effect of aralia total saponins on renal injury induced by streptozotocin (STZ) in type 2 diabetic mice, meanwhile to explore its protective mechanism. Methods Fifty male Kunming mice were randomly divided into the normal group, the model group and the aralia total saponins low, middle and high does groups. All the rats were given high fat diet 8 weeks and then received STZ 45 mg/kg to built type 2 diabetic mice model, except the noraml group. After the models establishment, the aralia total saponins low, middle and high does groups were given the aralia total saponins 30, 60, 120 mg/kg treatment, andthe normal group and the model group were given the equal normal saline, once each day. After 4th and 8th week administration, the urinary protein levels of 24 h in each group were detected. After the last treatment, all the mice were sacrificed to detected the changes of blood glucose, insulin and inflammatory related factors. Immunohistochemistry, Western blotting and real-time quantitative PCR were used to observe the expression of TLR2 and TLR2 in the kidney tissue. Results Compared with the model group, the low, middle and high does groups in 24-hour proteinuria, blood glucose, insulin resistance index decreased (P<0.05), the insulin increased(P<0.05). The serum TNF-α (16.66 ± 0.20 ng/L, 14.49 ± 0.27 ng/L, 13.52 ± 0.22 ng/L vs. 20.33 ± 0.56 ng/L), IL-1β (0.46 ± 0.04 ng/L, 0.44 ± 0.04 ng/L, 0.37 ± 0.04 ng/L vs. 0.55 ± 0.05 ng/L), NF-κB (28.71 ± 6.14 ng/L, 26.26 ± 5.48 ng/L, 25.69 ± 5.61 ng/L vs. 36.55 ± 8.90 ng/L) significantly decreased (P<0.05). The kidney TLR2 mRNA (1.92 ± 0.18, 1.46 ± 0.23, 1.28 ± 0.21 vs. 2.69 ± 0.22), TLR4 mRNA(2.20 ± 0.19, 2.08 ± 0.27, 1.57 ± 0.22 vs. 2.78 ± 0.23), TLR2 porteins (0.82 ± 0.11, 0.52 ± 0.06, 0.44 ± 0.07 vs. 0.77 ± 0.13), TLR4 proteins (0.52 ± 0.04, 0.42 ± 0.09, 0.26 ± 0.06 vs. 0.86 ± 0.12) significantly decreased (P<0.05). Conclusions The aralia total saponins can significantly reduce the blood glucose, insulin resistance index and 24-hour urinary protein in type 2 diabetic nephropathy of mice, increase the insulin, and analyzing its mechanism may be total saponins can inhibit the expression of TLR2 and TLR4 protein in the kidney, and further reduce the inflammatory response. Key words: Diabetic nephropathies; Aralia chinensis; Toll-like receptor 2; Toll-like receptor 4; Inflammation; Mice