Bupleurum polysaccharides(BPs)is isolated from Bupleurum smithii var.parvifolium,a key traditional Chinese medicine.The study was to investigate the effects of BPs on diabetic kidney injury.After two intraperitoneal injections of streptozotozin(STZ)100 mg·kg^–1,renal injury in diabetic mice was induced and BPs was orally administrated at dosages of 30 and 60 mg·kg^–1·d^–1.The STZ injected mice developed renal function damage,renal inflammation and fibrosis known as diabetic kidney disease(DKD).BPs significantly reduced serum creatinine level and urinary albumin excretion rate,with the attenuated swelling of kidneys.BPs treatment obviously alleviated the pathological damage of renal tissue.The progression of renal injury in BPs treated mice was inhibited with less expression of type IV collagen(Col IV),fibronectin(FN)andα-smooth muscle actin(α-SMA).The inhibition of inflammation in kidney was associated with the reduced level of tumor necrosis factor-α(TNF-α)and interleukin-6(IL-6).BPs administration suppressed the over-expression of toll like receptor 4(TLR4)and high-mobility group box 1(HMGB1)with lowered activity of nuclear factor kappa B(NF-κB)in renal tissue of diabetic mice.Oral administration of BPs effectively prevented the development of renal injury in diabetic mice.This study suggested that the protection provided by BPs might affect through the interruption of HMGB1-TLR4 pathway,leading to the inhibition of renal inflammation and fibrotic process.
LIU Zhen-ZhenWENG Hong-BoZHANG Li-JiePAN Ling-YuSUN WeiCHEN Hai-XiaCHEN Mei-YuZENG TaoZHANG Yun-YiCHEN Dao-FengLI Hong
The present study aimed to investigate the effects of polysaccharides extracted from Bupleurum chinense DC(BCPs) on macrophage functions. In the in vivo experiment, 1 m L of 5% sodium thioglycollate was injected into the abdomen of the mice on Day 0 and macrophages were harvested on Day 4. The macrophages were cultured in plates and treated with different concentrations of BCPs and stimulus. Effects of BCPs on macrophage functions were assessed by chemotaxis assay, phagocytosis assay and Enzyme-Linked Immunosorbent Assay(ELISA). Our results showed the enhanced chemotaxis, phagocytosis and secretion of nitric oxide(NO) and inflammatory cytokines by macrophages when treated with BCPs. However, when chemotaxis and phagocytosis were up-regulated by complement components or opsonized particles, BCPs inhibited these effects. Also, the NO production induced by lipopolysaccharides(LPS) was suppressed by BCPs mildly. Moreover, BCPs had an inhibitory effect on the [Ca^(2+)]i elevation of macrophages. These results suggested that BCPs exerted modulatory effects on macrophage functions, which may contribute to developing novel approaches to treating inflammatory diseases.
Lipopolysaccharides(LPS) contamination in herbal crude polysaccharides is inevitable. The present study was performed to explore the effect of polymyxin B on abolishing the influence of LPS contamination in mononuclear cells. LPS was pretreated with polymyxin B sulfate(PB) at different concentrations for 1, 5 or 24 h, and then used to stimulate RAW264.7 and mouse peritoneal macrophages(MPMs). The nitric oxide(NO) and tumor necrosis factor-α(TNF-α) in cell culture supernatant, as the indications of cell response, were assayed. Bupleurum chinensis polysaccharides(BCPs) with trace amount contamination of LPS was treated with PB. 30 μg·mL^(–1) of PB, treating LPS(10 and 1000 ng·mL^(–1) in stimulating RAW264.7 and MPMs respectively) at 37 ℃ for 24 h, successfully abolished the stimulating effect of LPS on the cells. When the cells were stimulated with LPS, BCPs further promoted NO production. However, pretreated with PB, BCPs showed a suppression of NO production in MPMs and no change in RAW264.7. In the in vitro experiments, LPS contamination in polysaccharide might bring a great interference in assessing the activity of drug. Pretreatment with PB(30 μg·mL^(–1)) at 37 °C for 24 h was sufficient to abolish the effects of LPS contamination(10 and 1 000 ng·mL^(–1)).
LU Xiao-XiaoJIANG Yi-FanLI HongOU Ying-YeZHANG Zhi-DeDI Hong-YeCHEN Dao-FengZHANG Yun-Yi
