Eucommia bark (Du-Zhong) improves diabetic nephropathy without altering blood glucose in type 1-like diabetic rats

Figures & data

Table 1 Effects of Du-Zhong on renal function parameters and plasma glucose levels in STZ-diabetic rats

Parameters	Normal rats	STZ-diabetic rats
	Vehicle	Vehicle	Du-Zhong
Plasma glucose (mg/dL)	103.35±2.46##	401.72±10.64**	409.53±16.37**
BUN (mg/dL)	14.88±0.21##	28.00±0.95**	17.63±0.75**,##
Plasma creatinine (mg/dL)	0.44±0.02#	0.54±0.02*	0.40±0.03##
Creatinine clearance (mL/min)	4.18±0.62##	1.93±0.57**	3.11±0.72*,#
24-hour urine volume (mL/day)	8.92±1.73##	29.62±2.98**	20.16±3.14*,##
24-hour urine protein (mg/day)	6.81±3.26##	27.24±3.71**	18.47±4.82*,##

Notes: Du-Zhong (1 g/kg/day) was orally administered into STZ-diabetic rats for 20 days. The values represent the mean ± standard deviation of eight animals.

* P<0.05,

** P<0.01 compared with the control (Wistar rats).

# P<0.05 and

## P<0.01 compared with STZ-diabetic rats (vehicle).

Abbreviations: BUN, blood urea nitrogen; STZ, streptozotocin.

Figure 1 Histological changes influenced by Du-Zhong.

Notes: Representative photomicrographs of hematoxylin and eosin (A) and Masson’s trichrome stained (B) kidney sections from rats treated with or without Du-Zhong. STZ-diabetic rats were dosed by oral gavage once daily for 20 days with 1 g/kg Du-Zhong (Du-Zhong). Normal (control) or STZ-diabetic rats (vehicle) were administered the same volume of vehicle used to prepare the test compounds. The photomicrographs were taken at a magnification of ×200.
Abbreviation: STZ, streptozotocin.

Figure 2 Effects of Du-Zhong on protein expression of TGF-beta and CTGF in renal tissues of rats.

Notes: Representative immunoblots of protein expression of TGF-β (A) and CTGF (B) in renal tissues of rats. STZ-diabetic rats were dosed by oral gavage once daily for 20 days with 1 g/kg Du-Zhong (Du-Zhong). Normal (control) or STZ-diabetic rats received the vehicle treatment (vehicle) at the same volume of vehicle that was used to prepare the test solution. Ratio of TGF-β/actin or CTGF/actin is expressed as the mean ± standard deviation (n=4 per group) in each column. **P<0.01 compared with data obtained from vehicle-treated normal rats. ^##P<0.01 compared with data obtained from vehicle-treated STZ-diabetic rats.
Abbreviations: CTGF, connective tissue growth factor; STZ, streptozotocin; TGF-β, transforming growth factor-beta.

Figure 3 Effect of Du-Zhong on phosphorylated Smad 2/3 level in renal tissues of rats.

Notes: (A) Effects of treatments on p-Smad2/3 in renal tissues of rats. (B) STZ-diabetic rats were dosed by oral gavage once daily for 20 days with 1 g/kg Du-Zhong (STZ + DZ). Normal or STZ-diabetic rats received the vehicle treatment at the same volume of vehicle used to prepare the test solution. Ratio of p-Smad2/3/actin is expressed as the mean ± standard deviation (n=4 per group) in each column. ***P<0.001 compared with data obtained from vehicle-treated normal Wistar rats (Wistar). ^##P<0.01 compared with data obtained from vehicle-treated STZ-diabetic rats (STZ).
Abbreviations: DZ, Du-Zhong; p-Smad2/3, phosphorylated Smad2/3; STZ, streptozotocin.

Figure 4 Effect of Du-Zhong on protein expression of STAT3 in renal tissues of rats.

Notes: (A) Representative immunoblots of protein expression of STAT3 in renal tissues of rats. (B) STZ-diabetic rats were dosed by oral gavage once daily for 20 days with 1 g/kg Du-Zhong (STZ + DZ). Normal or STZ-diabetic rats were administered the same volume of vehicle used to prepare the test solution. Ratio of STAT3 over actin is expressed as the mean ± standard deviation (n=4 per group) in each column. ***P<0.001 compared with data obtained from vehicle-treated normal rats (Wistar).
Abbreviations: DZ, Du-Zhong; STAT3, signal transducers and activators of transcription 3; STZ, streptozotocin.