Anti-inflammatory effects of Solanum procumbens on a low dose complete Freund's adjuvant-induced arthritis rat model

Objective:To investigate the anti-inflammatory and analgesic effects of Solanum procumbens on complete Freund’s adjuvantinduced arthritis rat models.Methods:We isolated and identified five compounds in the ethanolsoluble Solanum procumbens extract(SP)with anti-inflammatory effects,including ursolic acid,β-sitosterol,hexadecanoic acid,cisvaccenic acid,and vanillic acid.Additionally,we investigated the anti-inflammatory effects of SP on rheumatoid arthritis symptoms,including paw volumes,local temperatures,withdrawal latency,and mechanical withdrawal threshold at the hind paw and white blood cell(WBC)number from complete Freund’s adjuvant-induced arthritis rat models.Results:We have successfully established a complete Freund’s adjuvant-induced arthritis rat model at a low dose(1 mg/mL).SP extract significantly reduced paw volumes(P<0.05),prolonged withdrawal latencies(P<0.05),decreased local temperature,and increased the mechanical withdrawal threshold(P<0.05),but only SP extract at the dose of 300 mg/kg significantly decreased WBC numbers.Conclusions:SP extract could be a potential medication candidate with anti-inflammatory effects for arthritis,but it requires further investigation into the mechanism of the SP and its effectiveness on other models as well as clinical trials.