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

CONTEXT: Membranous glomerulonephritis (MGN) is a leading cause of nephrotic syndrome in adults. Diosgenin (DG) has been reported to exert antioxidative and anti-inflammatory effects. OBJECTIVE: To investigate the renoprotective activity of DG in a cationic bovine serum albumin-induced rat model of MGN. MATERIALS AND METHODS: Fourty male Sprague-Dawley rats were randomized into four groups. The MGN model was established and treated with a DG dose (10 mg/kg) and a positive control (TPCA1, 10 mg/kg), while normal control and MGN groups received distilled water by gavage for four consecutive weeks. At the end of the experiment, 24 h urinary protein, biochemical indices, oxidation and antioxidant levels, inflammatory parameters, histopathological examination, immunohistochemistry and immunoblotting were evaluated. RESULTS: DG significantly ameliorated kidney dysfunction by decreasing urinary protein (0.56-fold), serum creatinine (SCr) (0.78-fold), BUN (0.71-fold), TC (0.66-fold) and TG (0.73-fold) levels, and increasing ALB (1.44-fold). DG also reduced MDA (0.82-fold) and NO (0.83-fold) levels while increasing the activity of SOD (1.56-fold), CAT (1.25-fold), glutathione peroxidase (GPx) (1.55-fold) and GSH (1.81-fold). Furthermore, DG reduced Keap1 (0.76-fold) expression, Nrf2 nuclear translocation (0.79-fold), and induced NQO1 (1.25-fold) and HO-1 (1.46-fold) expression. Additionally, DG decreased IL-2 (0.55-fold), TNF-α (0.80-fold) and IL-6 (0.75-fold) levels, and reduced protein expression of NF-κB p65 (0.80-fold), IKKß (0.93-fold), p-IKKß (0.89-fold), ICAM-1 (0.88-fold), VCAM-1 (0.91-fold), MCP-1 (0.88-fold) and E-selectin (0.87-fold), and also inhibited the nuclear translocation of NF-κB p65 (0.64-fold). DISCUSSION AND CONCLUSIONS: The results suggest a potential therapeutic benefit of DG against MGN due to the inhibition of the NF-κB pathway, supporting the need for further clinical trials.

Ameliorated membranous nephropathy activities of two ethanol extracts from corn silk and identification of flavonoid active compounds by LC-MS2.

The current study looks to evaluate the effect of corn silk flavonoids on membranous nephropathy (MN). Polyamide resin (PR) can be used to enrich corn silk ethanol extract (CSEE) to obtain flavonoid-rich extract (PR-CSEE), the total flavonoid content (TFC) of which we found to be 57.4%. The results of scanning electron microscope, Fourier-transform infrared, and high-performance liquid chromatography analyses determined that PR-CSEE and CSEE have different structural characteristics, but that PR-CSEE has higher TFC. MN mice models were induced by cationic bovine serum albumin, and we found that PR-CSEE administration reduced urine protein levels markedly, while renal function, glomerular atrophy, inflammatory infiltration, and in-serum immunoglobulin G and complement 3 content were improved. Through LC-MS2 spectrometry analysis, we pinpointed the 12 major flavonoid active compounds in PR-CSEE. These findings suggest that PR-CSEE can act as a potential functional food material by which to improve MN.

Mycophenolate mofetil prevents the induction of active Heymann nephritis: association with Th2 cytokine inhibition.

The effect of mycophenolate mofetil (MMF) was examined in active Heymann nephritis (HN), an animal model of human membranous nephropathy. HN was induced in Lewis rats with Fx1A/complete Freund's adjuvant (CFA), and controls only received CFA. The induction of HN was prevented by MMF (30 mg/kg per d) from 0 to 4 wk after immunization. Proteinuria was not different in CFA controls up to 16 wk, and was significantly less than in untreated HN from 6 wk onward. Serum anti-Fx1A antibody (Ab) levels and glomerular Ig deposition were suppressed during therapy. The interstitial infiltrate of alphabetaTCR+, CD4+ and CD8+ T cells, natural killer cells, and macrophages (mphi) observed in untreated HN at 8 wk was absent from rats treated from 0 to 4 wk with MMF. Semiquantitative reverse transcription-PCR for renal mononuclear cell cytokine mRNA at 8 wk demonstrated that MMF from 0 to 4 wk prevented the increased expression of Th1 (interferon-gamma, lymphotoxin), Th2 (interleukin-4), and mphi (tumor necrosis factor-alpha) cytokines identified in untreated HN. In lymph node draining sites of immunization, MMF limited both enlargement and the increased proportion of CD3+, CD4+, and CD8+ T cells observed in untreated HN and CFA controls. MMF suppressed Th2 (interleukin-4) but not Th1 (interferon-gamma, lymphotoxin) cytokine mRNA expression in lymph nodes. MMF from 4 to 8, 6 to 12, or 10 to 14 wk did not prevent proteinuria, serum anti-Fx1A Ab, or glomerular IgG deposition when compared with untreated HN. This study showed that MMF from 0 to 4 wk prevented the induction of HN and was associated with preferential suppression of Th2 cytokines. This therapy may prove useful in human idiopathic membranous nephropathy.