Hygrophila auriculata
(Schum) Heine (syn)
Asteracantha longifolia
Nees, Acanthaceae was described in ayurvedic literature as Ikshura, Ikshugandha, and Kokilasha. The plant was extensively used in traditional system of medicine for various ailments like rheumatism, inflammation, jaundice, hepatic obstruction, pain, etc. The aqueous extract of aerial parts (HAA) and root(HAR) were screened for its anti-nociceptive property using both chemical and thermal methods of nociception in mice. In chemical method acetic acid writhing test and in thermal methods hot plate and tail flick tests were performed. Both the extracts at doses 100 and 200 mg/kg/p.o inhibited the abdominal constrictions induced by acetic acid and also increased the pain threshold of mice towards the thermal source in a dose dependent manner. The activity exhibited by the extracts was comparable to that of the standard drug aspirin (100 mg/kg/p.o). From the results it was concluded that both extracts exhibited anti-nociceptive activity by central and peripheral mechanism(s).