Beneficial Effect Of Bupleurum Polysaccharides On Systemic Lupus Erythematosus-like Syndrome And Its Effect On Immune Functions In Mice

Systemic lupus erythematosus(SLE) is a chronic autoimmune disease characterized by multi-organ involvement and remarkable variability in clinical presentation.The pathogenesis of SLE might involve multiple factors,which cumulatively result in breakdown of self-tolerance and development of auto-immunity with end-organ damage.The most commonly used drugs - immunosuppressive drugs, such as cyclophosphamide,mycophenolate mofetil(MMF),azathioprine, methotrexate and cyclosporine,although effective,may produce adverse side effects including generalized suppression of the immune system.Close attention should therefore be paid to exploring new therapeutic agents for the treatment of SLE with lower toxicity.The complement system bridges innate and adaptive during immune responses and is of central importance in pathogenesis of SLE.Inflammation induced by deposition of immune complexes is in time associated with local and systemic activation of classical pathway and at least to some degree to alternative pathway activation.Products of complement system activation also appear to be important in regulation of cytokine and inflammatory reaction.Radix Bupleuri(dried roots of Bupleurum chinense or Bupleurum scorzonerifolium),known as 'Chai-Hu',is one of the most frequently prescribed crude herbs in the prescriptions of traditional Chinese medicine for the treatment of inflammatory diseases,nephrosis syndrome and auto-immune diseases.Bupleurum smithii var.parvifolium is abundantly distributed in the northwest region of China and its roots are also used as Radix Bupleuri.Previous experiments in our lab confirmed that the crude polysaccharide isolated from this plant was a major component that contributed to the anti-complementary activity,so it could be of potential benefits in treatment of the complement associated diseases,like SLE. group(P＜0.001),and were reduced by BPs 30 or prednisone 5 mg·kg^-1·d^-1 significantly.Treated with BPs 15 mg·kg^-1·d^-1 also significantly decreased production of anti-ss-DNA and anti-histone antibodies when compared with vehicle-treated group (P＜0.001).In the FCA and vehicle-treated group,serum levels of total IgG were significantly increased compared with the nil group(P＜0.001).BPs and prednisone significantly decreased IgG production as compared with the vehicle-treated group(P＜0.05).Effect of BPs on serum total complement hemolytic activity and NO levelThere was no significant difference of serum total complement hemolytic activity among the six groups.Compared with nil group,serum NO in immunized mice was significantly elevated (P＜0.05).Treatment with BPs or prednisone had no effect on elevated NO level compared with vehicle-treated group.Effect of BPs on renal histologyThe level of proteinuria in the vehicle-treated mice was significantly higher than mice of nil and FCA group(P＜0.01).Treatment with BPs or prednisone caused a marked reduction of urinary albumin compared with vehicle-treated group(P＜0.05).In all vehicle-treated mice,mesangial cell proliferation,expansion of the mesangial matrix and glomerular hypertrophy was observed.These lesions were not apparent in nil- and FCA group.Treatment with BPs 30 mg·kg^-1·d^-1 and prednisone 5 mg·kg^-1·d^-1 markedly ameliorated the glomerular injury.For vehicle-treated mice,immunohistochemistry of kidney sections showed a patchy dense immunoperoxidase indicative of mesangial and subendothelial IgG deposition. In contrast,mice in nil- and FCA group had no detectable IgG deposition in their kidneys.Treatment with BPs 30 or 15 mg·kg^-1·d^-1 and prednisone for 35 days significantly decreased IgG deposition(P＜0.001).2.Effect of Bupleurum polysaccharides on immune functions in miceAIM:To determine the effect of Bupleurum smithii var.parvifolium polysaccharides (BPs) on immunological functions in mice. 1.Beneficial effect of Bupleurum polysaccharides on systemic lupus erythematosus-like syndrome induced by Campylobacter jejuni in BALB/c miceAIM:This study was to determine whether the crude polysaccharides(BPs) isolated from the roots of Bupleurum smithii var.parvifolium,had beneficial effects on experimental systemic lupus erythematosus.METHOD:BALB/c mice were immunized with CJ-S₁₃₁ in Freund's complete adjuvant on day 0, and then boosted on day 14.BPs 15 or 30 mg·kg^-1·d^-1,or prednisone 5 mg·kg^-1d^-1 was given to BALB/c mice intragastrically from day 0 to day 34.Serum samples of mice were tested by enzyme-linked immunosorbent assays(ELISA) for the presence of IgG anti-dsDNA,anti-ssDNA,anti-histone antibodies and total IgG Total complement hemolytic activity and nitric oxide(NO) level in serum was measured.Urine protein was measured and kidneys were examined by light microscopy.The color images of immunostaining for IgG deposits were processed with Image J software.RESULTS:Effect of BPs on body weight and organ indexBoost injection on day 14 caused significant weight loss in CJ-S₁₃₁ immunized mice from day 15 to day 29(P＜0.05).BPs 30 mg·kg^-1d^-1 group exhibited a significant weight gain from day 15 to day 18 as compared with vehicle group(P＜0.05). Prednisone treatment significantly decreased the weight of mice compared with nil group(P＜0.001,day 35).The index of spleen and thymus increased significantly in vehicle-treated group when compared with nil group(P＜0.05).Administration of 30 mg·kg^-1·d^-1 BPs inhibited spleen swelling(P=0.008).Prednisone treatment significantly decreased the index of spleen and thymus(P＜0.001),the spleen index was even lower than that of nil group (P＜0.001).Effect of BPs on autoantibodies and total IgG productionAnti-ds-DNA,anti-ss-DNA,anti-histone antibodies levels and were significantly elevated at day 35 in the vehicle-treated mice compared with mice of nil and FCA MATERIALS AND METHODS:Mice were randomly assigned into control, prednisone 5 mg·kg^-1 treated and BPs treated(40 and 20 mg·kg^-1) groups.The delayed type hypersensitivity reaction(DTH) in mice was induced by sheep erythrocyte (SRBC),and the effect of BPs on DTH,lymphocytes proliferation,levels of serum hemolysin were studied;pinocytosis of peritoneal macrophages(MΦ) was detected with neutral-red phagocytosis assay,and nitric oxide(NO) released by peritoneal MΦwas measured with nitrate reductase method.RESULTS:BPs 40 mg·kg^-1,significantly inhibited DTH(P＜0.05),BPs 20 mg·kg^-1 enhanced the pinocytosis of peritoneal macrophage(P＜0.05) and elevated the level of serum hemolysin(P＜0.001).Treatment of BPs promoted splenic lymphocyte proliferation and synergistically improved the concanavalin A-induced T cell proliferation(P＜0.05).CONCLUSIONS:These findings suggested that(â… ) Bupleurum polysaccharides had a beneficial effect on systemic lupus erythematosus-like syndroma induced by CJ-S₁₃₁ in BALB/c mice,(â…¡)BPs had immunoregulatory effect that might contribute to the amelioration of SLE-like syndrome in mice.