The anti-membranous glomerulonephritic activity of purified polysaccharides from Irpex lacteus Fr.

The present study aims to identify the major active component from mutant Irpex lacteus, which protects against cationic bovine serum albumin (C-BSA)-induced membranous glomerulonephropathy (MGN). The candidate component ILN3A (MW: 2264 kDa) was purified from mutant Irpex lacteus water extract. The backbone of ILN3A comprises (1→2) and (1→4) linkages, and 1H NMR spectrum suggests the existence of α- and β-glycosidic anomeric carbon. In tissue culture study, ILN3A inhibits mesangial cell proliferation. In MGN rats, ILN3A reverses structural changes in kidney, suppresses abnormal high level of urine protein and restores concentration of serum albumin. ILN3A also reduces total cholesterol, triglycerides, and creatinine in serum, and 6-keto-PGF in kidney cortex. Further study shows ILN3A restores serum Interleukin 2, Interleukin 2 receptor, Interleukin 6, tumor necrosis factor α, and renal cortical nuclear factor kappa B. Our data shows ILN3A, the major active component of mutant Irpex lacteus, is a novel candidate anti-inflammatory medicine to treat MGN in clinics.