Liuwei Dihuang pill treats diabetic nephropathy in rats by inhibiting of TGF-β/SMADS, MAPK, and NF-kB and upregulating expression of cytoglobin in renal tissues

Liuwei Dihuang pill (LDP) was assessed for its effects on renal deficiency. 90 STZ induced DN rats were divided into groups (n=22) without treatment (STZ) and LDP treated (STZ-L) (n=23), Zhenwu decoction treated (STZ-Z) (n=22), and valsartan treated (STZ-V) (n=23) groups, with 16 normal control rats. Total urine protein (TP), blood urea nitrogen (BUN), and serum creatinine (Cr) were measured. Superoxide dismutase (SOD), nitric oxide synthase (NOS), and malondialdehyde (MDA) concentrations as well as expression/phosphorylation of SMAD3, SMAD2, and alpha-SMA, TGF-beta, RI /II, P38, ERK, and NF-kB in renal tissues were determined. In vitro experiments analyzed the effect of enhanced TGF-beta containing rat serums of the STZ groups on mesangial cells with and without transient transfection with a cytoglobin-containing plasmid. LDP treatment reduced the kidney coefficient, serum creatinine, blood urea nitrogen, and urine protein and prevented pathological changes. Expression of SOD and NOS in kidney tissue was increased but MDA expression reduced. LDP modulated multiple pathways, and its administration inhibited the phosphorylation of SMADS, ERK, p38, and the expression of NF-kB, alpha-SMA, and TGF-beta RI/II, and upregulated the expression of cytoglobin. In vitro studies revealed that overexpression of cytoglobin suppressed phosphorylation of Smad2, ERK, and p38 induced by TGF-beta and expression of NF-kB, alpha-SMA, and TGF-beta RI. LDP prevented renal fibrosis and protected glomerular mesangial cells by upregulation of cytoglobin and suppression of multiple pathways involving TGF-b/SMADS, MAPK, NF-kB signaling.