Zhenwutang Ameliorates Diabetic Kidney Disease in Mice with Spleen-kidney Yang Deficiency via Nrf2/HO-1/GPX4 Signaling Pathway / 中国实验方剂学杂志

ABSTRACT

ObjectiveTo investigate the effect and mechanism of Zhenwutang on renal oxidative damage in the mouse model of diabetic kidney disease with the syndrome of spleen-kidney Yang deficiency via the nuclear factor erythroid 2-related factor-2 （Nrf2）/heme oxygenase-1 （HO-1）/glutathione peroxidase 4 （GPX4） signaling pathway. MethodTwenty-five 7-week-old SPF-grade male db/m mice and 95 7-week-old SPF-grade male db/db mice were adaptively fed for a week. A blank group was set with the db/m mice without treatment， and the other mice were administrated with Rhei Radix et Rhizoma decoction and hydrocortisone for the modeling of diabetic kidney disease with the syndrome of spleen-kidney Yang deficiency. The modeled mice were randomized into the model， irbesartan （25 mg·kg-1）， and high-， medium-， low-dose （33.8， 16.9， 8.45 g·kg-1） Zhenwutang groups （n=15） and administrated with corresponding drugs for 8 weeks. The survival status of mice was observed， and the traditional Chinese medicine （TCM） syndrome score was recorded. The indicators related to spleen-kidney Yang deficiency， fasting blood glucose （FBG）， and renal function indicators were determined. Hematoxylin-eosin staining was employed to observe the histopathological changes of the renal tissue in each group. Biochemical kits were used to determine the oxidative stress-related indicators in the renal tissue. Real-time polymerase chain reaction and Western blotting were employed to determine the mRNA and protein levels， respectively， of Nrf2， HO-1， glutamate-cysteine ligase catalytic subunit （GCLC）， and GPX4 in the renal tissue of mice in each group. ResultCompared with the blank group， the modeling increased the TCM syndrome score （P<0.05）， elevated the estradiol （E2） and FBG levels （P<0.05）， lowered the testosterone （T）， triiodothyronine （T3）， and tetraiodothyronine （T4） levels （P<0.05）， and weakened the renal function （P<0.05）. In addition， the modeling led to glomerular hypertrophy and glomerular mesangial and basal thickening， decreased the catalase （CAT） activity， total antioxidant capacity （T-AOC）， and glutathione （GSH） content （P<0.05）， increased the malondialdehyde （MDA） content （P<0.05）， and down-regulated the mRNA and protein levels of Nrf2， HO-1， GCLC， and GPX4 in the renal tissue （P<0.05）. Compared with the model group， high and medium doses of Zhenwutang decreased the TCM syndrome score and E2 content （P<0.05）， increased the T， T3， and T4 content （P<0.05）， improved the renal function （P<0.05）， alleviated the pathological changes in the renal tissue， increased CAT， T-AOC， and GSH （P<0.05）， reduced MDA （P<0.05）， and up-regulated the mRNA and protein levels of Nrf2， HO-1， GCLC， and GPX4 in the renal tissue （P<0.05）. ConclusionZhenwutang can improve the general state and renal function and reduce the oxidative damage and pathological changes in the renal tissue of db/db mice with spleen-kidney Yang deficiency by regulating the Nrf2/HO-1/GPX4 signaling pathway.