Suppressive Effects Of The Stem Of Kadsura Heteroclita On Experimental Inflammatory And Nociceptive Models In Rodents

The stem of Kadsura heteroclita (Roxb) Craib (Schizandraceae) has long been used for the prevention and treatment of rheumatic and arthritic diseases, especially in southern China. Herein we investigated anti-inflammatory and analgesic effects and the possible mechanisms of Kadsura heteroclita stem (KHS) by using different animal models. Pulverized materials of dried Kadsura heteroclita stem were refluxed with 95% ethanol, and the yield rate of the dried ethanol extract of KHS was 2%. HPLC analysis identified six major triterpenoids in KHS. The maximal tolerated single dose of KHS was determined to be 26 g/kg in both sexes of mice. Mice treated with vehicle (control) and with KHS at the dose of 26 g/kg experienced similar increase in body weight in 14 days. The oral administration of KHS at the dose of 100, 200, and 400 mg/kg demonstrated dose- and time-dependent inhibition of paw edema induced by subplantar injection of carrageenan in both female and male Wistar rats. In the nociceptive model of the writhing test, KHS at the dose of 200 mg/kg significantly suppressed abdominal writhing episodes of mice induced by intraperitoneal injection of acetic acid. Mechanistic studies revealed that the anti-inflammatory effect of KHS was associated with inhibition of the production of the proinflammatory cytokines of TNF-α, IL-1β, and IL-6 and decrease in expression of COX-2 and iNOS. These data strongly support further investigation of KHS as a potential antiarthritic drug with favorable safety profiles.

Acknowledgements: This work was funded by grants from the National Natural Science Foundation of China (Nos.81373540, 81374062), Hunan Key Science & Technology Development Program for Strategic Newly-emerging Industries (No. 2014GK1058), Hunan Chinese Medicine Science & Research Key Project (No. 201308).