Analgesic and antipyretic activities of Drymaria cordata (Linn.) Willd (Caryophyllaceae) extract.

Drymaria cordata (Linn.) Willd (Caryophyllaceae) is an herbaceous plant widely used in traditional African medicine (TAM) for the treatment of diverse ailments including painful and febrile conditions. This study was conducted to investigate the analgesic and antipyretic properties of the whole plant extract of D. cordata. The acetic acid-induced writhing, formalin, and tail clip tests were used to evaluate analgesic activity while the 2,4-dinitrophenol (DNP)-, d-amphetamine-, and yeast-induced hyperthermia tests were used to investigate antipyretic activity in rodents. D. cordata (100, 200, and 400 mg kg(-1), p.o) produced significant (p<0.05) analgesic activity in the mouse writhing, formalin (second phase), and tail clip tests. The effects of D. cordata were generally comparable to those of acetylsalicylic acid (ASA, 100 mg kg(-1), p.o) and morphine (2 mg kg(-1), s.c). Also, D. cordata produced significant (p<0.05) dose-dependent inhibition of temperature elevation in the 2,4-DNP and yeast-induced hyperthermia models with peak effects produced at the dose of 400 mg kg(-1). The effect at this dose was comparable to that of ASA in the two models. In the d-amphetamine method, D. cordata produced significant (p<0.05) dose- and time-dependent reduction of temperature elevation with peak effect produced at the dose of 200 mg kg(-1). The effect of the extract at this dose was greater than that of ASA. The results obtained in this study demonstrate that the aqueous whole plant extract of Drymaria cordata possesses analgesic and antipyretic properties mediated through peripheral and central mechanisms.