Analgesic activity of ethanol extracts from root of Daphne genkwa / 中草药

ABSTRACT

Objective To elucidate the analgesic activity of the ethanol extracts from the root of Daphne genkwa (EERD). Methods The analgesic activity of EERD was evaluated by the effects on adjuvant-induced nociceptive response and paw swelling, the formation of PGE_2 and IL-1? in adjuvant arthritis (AA) rats, the activities of SOD and CAT, the levels of NO/iNOS in serum and brain tissue as well as by the effects on c-Fos protein expression in spinal cord of AA rats. Results EERD at used doses significantly delayed the adjuvant-induced nociceptive response and eased the paw swelling in AA rats. EERD also evidently inhibited the production of PGE_2 and IL-1?, and enhanced the activities of SOD and CAT in the tissue of paws being injected by adjuvant. Furthermore, it remarkably reduced the content of NO and inactivated the activity of iNOS in brain tissue of AA rats. In addition, EERD at used doses exhibited prominent inhibition on adjuvant-induced expression of c-Fos protein in the spinal cord of AA rats. Conclusion EERD is an effective agent for analgesia. The possible mechanisms for its analgesia might be the actions of inhibiting the production of PGE_2 and the release of IL-1?, reducing the activity of iNOS and hence the generation of NO in brain tissue, and blocking superoxidation through enhancing the activity of SOD and CAT.