Intervention Study Of Soybean Isoflavone On Kidney Injury During Earlier Period In IGT Rat

Objectives:To investigate the effects of soybean isoflavone on blood glucose, oxidation, glycosylation and the intervention effects on kidney injury during earlier period in IGT rats induced by D-galactose, approach the mechanisms and provide experimental evidence for further exploitation and clinic application of soybean isoflavone.Methods:To establish the IGT rats model by i.p. gradient D-galactose for 8w. Two doses of SI were given intragastrically (i.g.) for 6w since the 3rd w, and metformin as positive control. Observe the effects of SI on FBG, FINS and 2hBG; SOD and GSH-Px activity and MDA content of serum and kidney; GHb and AGEs contents; BUN and mAlb contents, renal DNA damage degree and LDH activity, approach the intervention effects of SI on pristine renal damage initiated by IGT.Results:1) Compared with the Normal group, 2hBG, FINS level and HOMA-IR of Model group increased obviously(P＜0.05), ISI decreased notably(P＜0.05); serum GSH-Px and renal SOD activity decreased obviously (P＜0.05), MDA and AGEs contents, mAlb content, renal cell DNA tailing rate and LDH activity increased significantly (P＜0.05).2) Compared with the Model group, 2hBG, FINS and HOMA-IR of two SI groups decreased obviously (P＜0.05), serum GSH-Px and renal SOD activity increased obviously (P＜0.05), renal MDA, serum and renal AGEs contents, mAlb content, renal cell DNA tailing rate and LDH activity also decreased significantly (P＜0.05).3) The effects of SI on lowing FINS level and HOMA-IR, increasing ISI, decreasing AGEs content and renal DNA tailing rate were better than metformin's (P＜0.05), but there were no significant difference among other indexes (P＞0.05).Conclusion:1) D-gal can induce IGT rats model with increased oxidation, glycosylation, and slight kidney damage.2) SI could improve IGT condition through regulating 2hBG, FINS level, ISI and HOMA-IR of IGT rats induced by D-gal.3) No matter high or low dosage of SI could inhibit oxidation and glycosylation, but there is no significant dose-effect relation, the mix effect with dosage should be studied further.4) SI could exert kidney protection effect by improving IGT condition, inhibiting oxidation and glyeosylation.5) SI has the similar effect with metformin in improving IGT, but in inhibiting glyeosylation and protecting kidney SI is better than metformin.