Effects of Total Saponins from Dioscorea Nipponica Makino on Monosodium Urate-Induced M1-Polarized Macrophages through Arachidonic Acid Signaling Pathway:An in vitro Study

Objective To investigate and reveal the underlying mechanism of the effect of total saponins from Dioscoreae nipponica Makino(TSDN)on the arachidonic acid pathway in monosodium urate(MSU)crystal-induced M1-polarized macrophages.Methods M1 polarization of RAW264.7 cells were induced by 1µg/mL lipopolysaccharide(LPS).The methylthiazolyldiphenyl-tetrazolium bromide method was then used to screen the concentration of TSDN.MSU(500µg/mL)was used to induce the gouty arthritis model.Afterwards,10µg/L TSDN and 8µmol/L celecoxib,which was used as a positive control,were added to the above LPS and MSU-induced cells for 24 h.The mRNA and protein expressions of cyclooxygenase(COX)2,5-lipoxygenase(5-LOX),microsomal prostaglandin E synthase derived eicosanoids(mPGES)-1,leukotriene B(LTB)4,cytochrome P450(CYP)4A,and prostaglandin E_(2)(PGE_(2))were tested by real-time polymerase chain reaction and Western blotting,respectively.The enzyme-linked immunosorbent assay was used to test the contents of M1 markers,including inducible nitric oxid synthase(NOS)2,CD80,and CD86.Results TSDN inhibited the proliferation of M1 macrophages and decreased both the mRNA and protein expressions of COX2,5-LOX,CYP4A,LTB4,and PGE_(2)(P<0.01)while increased the mRNA and protein expression of mPGES-1(P<0.05 or P<0.01).TSDN could also significantly decrease the contents of NOS2,CD80,and CD86(P<0.01).Conclusion TSDN has an anti-inflammation effect on gouty arthritis in an in vitro model by regulating arachidonic acid signaling pathway.

Anti-inflammatory Effect of Total Saponin Fraction from Dioscorea nipponica Makino on Gouty Arthritis and Its Influence on NALP3 Inflammasome

Objective: To investigate the mechanism of Chinese herbal medicine Dioscorea nipponica for the treatment of monosodium urate crystals-induced gouty arthritis(GA) in rats. Methods: Sixty male Wistar rats were divided into 6 groups: normal, model, indomethacin and three total saponin(900, 300 and 100 mg/kg) groups. The liver, kidney and serum levels of lysosomal enzymes, antioxidant capacities, and inflammatory factors were measured. In addition, the m RNA and protein levels of the NALP3 inflammasome components in the mononuclear cells of rats’ peripheral blood were analyzed using real-time polymerase chain reaction and Western blotting methods, respectively. Results: Total saponins groups could reduce the activities of β-galactosidase,β-N acetyl glucosamine enzyme,β-glucuronidase, acid phosphatase, and malonaldehyde as wel as the contents of TNF-α, IL-1β and IL-8(all P<0.05). They could also increase the activities of glutathione peroxidase and total superoxide dismutase(both P<0.05). Further studies showed that total saponins groups of high, middle and low doses could all increase the m RNA and protein levels of caspase-1, adapter apoptosis-associated speck-like protein containing a caspase-recruitment domain(ASC) and NALP3 in the mononuclear cells of peripheral blood(all P<0.05). Conclusion: Dioscorea nipponica may treat GA by regulating lysosomal enzymes, antioxidant capacities and the NALP3 inflammasome.