Diosgenin protects against cationic bovine serum albumin-induced membranous glomerulonephritis by attenuating oxidative stress and renal inflammation via the NF-κB pathway

Figures & data

Figure 1. DG has no distinct toxic effects in MGN rats after 4 weeks treatment. (A) Body weight. (B) Kidney weight. (C) Kidney somatic index. ^##p < 0.01 vs. normal control group. Data are expressed as the mean ± standard deviation (SD), n = 6. **p < 0.01 vs. MGN group. NC: normal control; MGN: membranous glomerulonephritis; DG: diosgenin; TPCA1: [(aminocarbony)amino]-5-(4-fluorophenyl)-3-thiophenecarboxamide. The somatic index is defined as follows: somatic index= kidney weight (g)/body weight (g).

Figure 2. DG improves 24 h urinary protein and serum biochemical parameters in MGN rats. (A) Urinary protein. (B) Albumin (ALB). (C) Blood urea nitrogen (BUN). (D) Serum creatinine (SCr). (E) Total cholesterol (TC). (F) Triglyceride (TG). Data are expressed as the mean ± standard deviation (SD), n = 6. ^##p < 0.01 vs. NC group. **p < 0.01 vs. MGN group. NC: normal control; MGN: membranous glomerulonephritis; DG: diosgenin; TPCA1: [(aminocarbony)amino]-5-(4-fluorophenyl)-3-thiophenecarboxamide.

Figure 3. Effects of DG on histopathological changes in MGN rats. (A) Representative haematoxylin and eosin (H&E) staining of kidney samples (original magnification ×200; scale bar represents 100 μm). (B) Transmission electron micrographs of renal tissue (original magnification ×5000; scale bar represents 5 μm). Black arrows represent oedema and vacuolar degeneration of renal tubular epithelial cells and glomerular atrophy. Red arrows represent the presence of glomerular podocyte fusion and electron-dense deposits in the GBM and epithelia. NC: normal control; MGN: membranous glomerulonephritis; DG: diosgenin; TPCA1: [(aminocarbony)amino]-5-(4-fluorophenyl)-3-thiophenecarboxamide.

Figure 4. DG restores nephrin and podocin expression levels in MGN rats. (A) Protein levels of nephrin and podocin were evaluated by western blotting. (B, C) Ratio of nephrin and podocin. Data are expressed as the mean ± standard deviation (SD), n = 3. ^##p < 0.01 vs. NC group. *p < 0.05 or **p < 0.01 vs. MGN group. NC: normal control; MGN: membranous glomerulonephritis; DG: diosgenin; TPCA1: [(aminocarbony)amino]-5-(4-fluorophenyl)-3-thiophenecarboxamide.

Figure 5. Effects of DG on renal oxidant and antioxidant levels in MGN rats. (A) SOD, (B) NO, (C) MDA, (D) GSH, (E) GPx, (F) CAT. Data are expressed as the mean ± standard deviation (SD), n = 3. ^##p < 0.01 vs. NC group. **p < 0.01 vs. MGN group. SOD: superoxide dismutase; NO: nitric oxide; MDA: malondialdehyde; GPx: glutathione peroxidase; CAT: catalase; NC: normal control; MGN: membranous glomerulonephritis; DG: diosgenin; TPCA1: [(aminocarbony)amino]-5-(4-fluorophenyl)-3-­thiophenecarboxamide.

Figure 6. DG activates the Nrf2 signalling pathway in MGN rats. (A) Protein levels of Nrf2, HO-1, NQO1, Keap1, nuclear Nrf2 and cytosolic Nrf2 were evaluated by western blotting. (B–G) Ratio of Nrf2, HO-1, NQO1, Keap1, nuclear Nrf2 and cytosolic Nrf2. Data are expressed as the mean ± standard deviation (SD), n = 3. ^##p < 0.01 vs. NC group. *p < 0.05 or **p < 0.01 vs. MGN group. NC: normal control; MGN: membranous glomerulonephritis; DG: diosgenin; TPCA1: [(aminocarbony)amino]-5-(4-fluorophenyl)-3-thiophenecarboxamide.

Figure 7. DG inhibits inflammatory cytokines secretion in MGN rats. (A) IL-2, (B) IL-6, (C) TNF-α. Data are expressed as the mean ± standard deviation (SD), n = 6. ^##p < 0.01 vs. NC group. **p < 0.01 vs. MGN group. IL-2: interleukin-2; IL-6: interleukin-6; TNF-α: tumor necrosis factor-α; NC: normal control; MGN: membranous glomerulonephritis; DG: diosgenin; TPCA1: [(aminocarbony)amino]-5-(4-fluorophenyl)-3-thiophenecarboxamide.

Figure 8. DG inactivates of the NF-κB signalling pathway in MGN rats. (A) Protein levels of NF-κB p65, IKKβ, p-IKKβ, ICAM-1, VCAM-1, MCP-1, E-selectin, nuclear NF-κB p65 and cytosolic NF-κB p65 were evaluated by western blotting. (B–J) Ratio of NF-κB p65, IKKβ, p-IKKβ, ICAM-1, VCAM-1, MCP-1, E-selectin, nuclear NF-κB p65 and cytosolic NF-κB p65. Data are expressed as the mean ± standard deviation (SD), n = 3. ^#p < 0.05 or ^##p < 0.01 vs. NC group. *p < 0.05 or **p < 0.01 vs. MGN group. NC: normal control; MGN: membranous glomerulonephritis; DG: diosgenin; TPCA1: [(aminocarbony)amino]-5-(4-fluorophenyl)-3-thiophenecarboxamide.

Figure 9. Effect of DG on NF-κB p65 nuclear translocation in MGN rats. NF-κB p65 expression was detected using immunofluorescence staining. NC: normal control; MGN: membranous glomerulonephritis; DG: diosgenin; TPCA1: [(aminocarbony)amino]-5-(4-fluorophenyl)-3-thiophenecarboxamide. Scale bar: 50 μm.

Data availability statement

The datasets used and/or analysed during the current study are available from the corresponding author on reasonable request.