Objective: Accelerated severe lupus nephritis (ASLN), with an acute onset of severe clinical manifestations and histopathologic renal lesions, may represent transformation of mild LN to a severe form of glomerulonephritis. Abnormal activation of T and B cells and/or oxidative stress may play a major role in the pathogenesis of ASLN. This study tested the hypothesis that antroquinonol, a purified compound and major effective component of Antrodia camphorata with antiinflammatory and antioxidant activities, might prevent the transformation of mild LN into higher-grade (severe) nephritis in a murine lupus model.
Methods: Experimental ASLN was induced in (NZB×NZW)F1 mice by twice weekly intraperitoneal injections of Salmonella-type lipopolysaccharide (LPS). Starting 2 days after the first dose of LPS, mice were treated daily with antroquinonol, administered by gavage, for different durations up to 5 weeks.
Results: Antroquinonol administration significantly ameliorated the proteinuria, hematuria, impairment of renal function, and development of severe renal lesions, especially cellular crescent formation, neutrophil infiltration, fibrinoid necrosis, and T cell proliferation in the glomerulus, as well as periglomerular interstitial inflammation. Mechanistic analyses revealed that antroquinonol 1) inhibited T cell activation/proliferation, but enhanced Treg cell suppression and reduced renal production of interleukin-18 (IL-18); 2) inhibited production of reactive oxygen species and nitric oxide, but increased activation of Nrf2 in the kidney; and 3) suppressed renal inflammation via blocking of NF-κB activation.
Conclusion: Antroquinonol may have therapeutic potential for the early treatment of ASLN via its differential regulation of T cell function and lowering of IL-18 production, but also via the promotion of Nrf2 activation.
Copyright © 2012 by the American College of Rheumatology.