CNS Depressant and Analgesic Activities of Thysanolaena maxima Roxb. Available in Bangladesh

Abstract

In Bangladesh, numerous tribal people of Chittagong Hill Tracts have been using different parts of
Thysanolaena maxima Roxb. for many years. The present study was designed to investigate CNS depressant and
analgesic activities of methanol extract of the aerial parts of the plant in mice models. CNS depressant activity of the
crude extract (200 and 400 mg/kg) was evaluated using open field, hole cross and thiopental-induced sleeping time
tests using diazepam as the standard. Analgesic activity was determined using acetic acid-induced writhing and hot
plate tests using diclofenac sodium as the standard. The extract showed dose-dependent suppression of locomotion in
open field and hole cross tests and exerted sedative action in thiopental-induced sleeping time. In the open field and
the hole-cross tests, maximum CNS depressant activity was observed at 90 min after administration of extract and the
standard drug. The extract significantly induced the onset of sleep and prolonged the sleeping time in thiopental
induced sleeping test compared to the control group. The extract at doses of 200 and 400 mg/kg body weight,
produced significant (p < 0.05) analgesic activity by inhibiting writhing by 41.89% and 60.81%, respectively, which
was comparable to the inhibition of diclofenac sodium (73.64%). Additionally, in hot plate test, the extract exhibited
a significant (p < 0.05) increase in pain threshold in a dose dependent manner. The findings of the study are
encouraging and demands further investigation of other bioactivities with isolation of pure compounds.