Total saponin of Dioscoreae hypoglaucae rhizoma ameliorates streptozotocin-induced diabetic nephropathy

Figures & data

Figure 1 The HPLC chromatograms of TSD.

Abbreivations: HPLC, high-performance liquid chromatography; TSD, total saponin of Dioscoreae hypoglaucae Palibin.

Figure 2 Schematic diagram of the induction and treatment schedule of diabetic rats.

Abbreviations: TSD, total saponin of Dioscoreae hypoglaucae Palibin; STZ, streptozoin; FBG, fasting blood glucose.

Table 1 Effects of different treatments on FBG in diabetic rats

Groups	FBG (mmol/L)
	Before treatment	4 weeks after treatment	8 weeks after treatment	12 weeks after treatment
NC	5.30±0.72	6.05±1.05	6.39±0.84	5.75±1.20
DC	25.95±3.63*	31.50±2.77*	30.20±3.82*	25.56±3.85*
Met	25.03±3.15	23.73±4.82**	24.59±3.51***	18.23±4.28**
TSD-40	25.72±4.20	28.50±3.70	28.11±3.39	21.86±2.13***
TSD-80	25.55±3.99	26.68±2.61**	26.01±2.75***	20.16±2.30**
TSD-160	26.27±2.22	24.82±2.73**	23.71±3.14**	19.45±2.16**

Notes: Values are mean ± SD for eight rats in each group.

* P<0.01 as compared with the normal control group.

** P<0.01 as compared with the diabetic control group.

*** P<0.05 as compared with the diabetic control group.

Abbreviations: FBG, fasting blood glucose; NC, normal control group; DC, diabetic control group; Met, metformin hydrochloride group; TSD, total saponin of Dioscorea hypoglaucae Palibin; SD, standard deviation.

Figure 3 Effect of TSD on GHb in diabetic rats.

Notes: Values are presented as mean ± SD for eight rats in each group. *P<0.01 as compared with the normal control group. **P<0.01 as compared with the diabetic control group. ***P<0.05 as compared with the diabetic control group.
Abbreviations: GHb, glycosylated hemoglobin; NC, normal control group; DC, diabetic control group; Met, metformin hydrochloride group; TSD, total saponin of Dioscorea hypoglaucae Palibin.

Table 2 Effect of TSD on kidney index, BUN, serum Cr, CCR, and urine protein in diabetic rats

Groups	KI (g/100 g)	BUN (mmol/L)	Serum Cr (μmol/L)	CCR (mL/min/kg)	Urine protein (mg/kg/24 h)
NC	0.251±0.021	4.87±0.62	100.6±16.7	3.44±0.54	25.0±9.2
DC	0.448±0.043*	5.88±0.61*	149.9±26.9*	2.70±0.31*	192.6±48.8*
Met	0.371±0.042**	5.39±0.58	120.4±23.9***	2.78±0.56	139.5±38.7***
TSD-40	0.397±0.035***	5.31±0.51	116.8±16.0***	2.87±0.39	139.6±36.9***
TSD-80	0.380±0.026**	5.13±0.30***	115.2±13.3**	3.27±0.31**	127.0±27.6**
TSD-160	0.360±0.018**	4.95±0.44**	112.3±10.5**	3.42±0.49**	113.7±43.6**

Notes: Values are mean ± SD for eight rats in each group.

* P<0.01 as compared with the normal control group.

** P<0.01 as compared with the diabetic control group.

*** P<0.05 as compared with the diabetic control group.

Abbreviations: BUN, blood urea nitrogen; CCR, creatinine clearance ratio; Cr, creatinine; KI, kidney index; NC, normal control group; DC, diabetic control group; Met, metformin hydrochloride group; TSD, total saponin of Dioscorea hypoglaucae Palibin; SD, standard deviation.

Figure 4 Representative micrographs of kidney tissue stained with hematoxylin–eosin.

Notes: Arrows show vacuolar degeneration of proximal tubules. (A) NC group, (B) DC group, (C) Met group, (D) TSD-40 group, (E) TSD-80 group, and (F) TSD-160 group.
Abbreviations: NC, normal control group; DC, diabetic control group; Met, metformin hydrochloride group; TSD, total saponin of Dioscorea hypoglaucae Palibin.

Figure 5 Representative micrographs of kidney tissue stained with periodic acid–Schiff.

Notes: Arrows show the thickened basement membrane. (A) NC group, (B) DC group, (C) Met group, (D) TSD-40 group, (E) TSD-80 group, (F) TSD-160 group, (G) glomerular volume, and (H) expansion of matrix index. Values are presented as mean ± SD for eight rats in each group. ^ΔΔP<0.01 as compared with the normal control group. ^#P<0.05 as compared with the diabetic control group. ^##P<0.01 as compared with the diabetic control group.
Abbreviations: NC, normal control group; DC, diabetic control group; Met, metformin hydrochloride group; TSD, total saponin of Dioscorea hypoglaucae Palibin.

Figure 6 Effect of TSD on renal immunohistochemical stain of collagen IV in diabetic rats.

Notes: The brown area was the positive expression area, enlarging 400× under light microscope. (A) NC group, (B) DC group, (C) Met group, (D) TSD-40 group, (E) TSD-80 group, (F) TSD-160 group, and (G) IOD of collagen IV. Values are presented as mean ± SD for eight rats in each group. *P<0.01 as compared with the normal control group. **P<0.05 as compared with the diabetic control group. ***P<0.01 as compared with the diabetic control group.
Abbreviations: IOD, integrated optical density; NC, normal control group; DC, diabetic control group; Met, metformin hydrochloride group; TSD, total saponin of Dioscorea hypoglaucae Palibin.

Table 3 Effect of TSD on renal SOD, CAT, GSH-Px, and MDA levels in diabetic rats

Groups	SOD (U/mg prot)	CAT (U/mg prot)	GSH-Px (U/mg prot)	MDA (nmol/mg prot)
NC	211.2±22.1	43.28±10.13	1.77±0.36	2.06±0.25
DC	151.5±31.0*	30.19±6.13*	1.27±0.17*	3.15±0.36*
Met	152.6±43.5	38.12±8.58	1.48±0.38	2.79±0.54
TSD-40	176.7±27.6	37.40±2.73**	1.47±0.43	2.80±0.67
TSD-80	182.2±16.4**	39.18±5.30**	1.60±0.33**	2.61±0.47**
TSD-160	195.5±15.5***	40.86±3.93***	1.75±0.42**	2.35±0.73**

Notes: Values are mean ± SD for eight rats in each group.

* P<0.01 as compared with the normal control group.

** P<0.05 as compared with the diabetic control group.

*** P<0.01 as compared with the diabetic control group.

Abbreviations: CAT, catalase; GSH-Px, glutathione peroxidase; MDA, malondialdehyde; SOD, superoxide dismutase; NC, normal control group; DC, diabetic control group; Met, metformin hydrochloride group; TSD, total saponin of Dioscorea hypoglaucae Palibin; SD, standard deviation.

Table 4 Effect of TSD on renal TGF-β1, CTGF, TNF-α, IL-1β, and IL-6 levels in diabetic rats

Groups	TGF-β1 (ng/mg port)	CTGF (pg/mg port)	TNF-α (pg/mg port)	IL-1β (pg/mg port)	IL-6 (pg/mg port)
NC	3.14±0.55	83.54±12.03	21.63±4.90	9.28±1.14	12.72±1.45
DC	5.88±0.46*	109.81±14.12*	64.79±10.32*	18.15±1.72*	31.42±2.24*
Met	5.12±0.47**	97.11±15.11**	55.12±3.89**	12.92±1.36***	22.45±2.13***
TSD-40	4.93±0.92**	96.27±15.56**	53.37±5.84**	14.16±1.28**	27.83±2.97
TSD-80	4.81±0.48***	92.68±7.05***	43.20±5.73***	12.47±1.48***	25.27±2.49***
TSD-160	4.63±0.58***	90.88±8.28***	36.45±6.43***	10.47±1.45***	22.36±2.45***

Notes: Values are mean ± SD for eight rats in each group.

* P<0.01 as compared with the normal control group.

** P<0.05 as compared with the diabetic control group.

*** P<0.01 as compared with the diabetic control group.

Abbreviations: CTGF, connective tissue growth factor; IL-1β, interleukin-1β; IL-6, interleukin-6; TNF-α, tumor necrosis factor-α; TGF-β1, transforming growth factor-β1; NC, normal control group; DC, diabetic control group; Met, metformin hydrochloride group; TSD, total saponin of Dioscorea hypoglaucae Palibin; SD, standard deviation.

Figure 7 Effect of TSD on renal immunohistochemical stain of AGEs in diabetic rats.

Notes: The brown area was the positive expression area, enlarging 400× under light microscope. (A) NC group, (B) DC group, (C) Met group, (D) TSD-40 group, (E) TSD-80 group, (F) TSD-160 group, and (G) IOD of AGEs. Values are presented as mean ± SD for eight rats in each group. *P<0.01 as compared with the normal control group. **P<0.05 as compared with the diabetic control group. ***P<0.01 as compared with the diabetic control group.
Abbreviations: AGEs, advanced glycation end products; IOD, integrated optical density; NC, normal control group; DC, diabetic control group; Met, metformin hydrochloride group; TSD, total saponin of Dioscorea hypoglaucae Palibin; SD, standard deviation.

Figure 8 Effects of TSD on TGF-β1 (A), type IV collagen (B), and IL-6 (C) in vitro.

Notes: Values are presented as mean ± SD for eight rats in each group. *P<0.01 as compared with the normal control group. **P<0.05 as compared with the diabetic control group. ***P<0.01 as compared with the diabetic control group.
Abbreviations: IL-6, interleukin-6; TGF-β1, transforming growth factor-β1; TSD, total saponin of Dioscorea hypoglaucae Palibin; SD, standard deviation.