Secondary metabolites from plants are a good source for the NSAID drug development. We studied the analgesic activity of
ethanolic extract of Erythrina variegata L. (Fabaceae) followed by molecular docking analysis. The analgesic activity of Erythrina
variegata L. is evaluated by various methods viz., acetic acid-induced writhing test, hot plate and tail immersion test. Subsequently,
molecular docking analysis has been performed to identify compounds having activity against COX-1 and COX-2 enzymes by
using GOLD docking fitness. The result of preliminary phytochemical screening revealed that the extract contains alkaloids and
flavonoids. In analgesic activity tests, the extract at the doses of 50, 100 and 200 mg/kg body weight (b.w.) produced a increase in
pain threshold in a dose dependent manner. In acetic acid induced writhing test, the inhibitory effect was similar to the reference
drug diclofenac sodium. The extract showed 18.89% writhing inhibitory effect at the dose 200 mg/kg b.w., whereas diclofenac
sodium showed 79.42% inhibition of writhing at a dose of 10 mg/kg b.w. The results of tail immersion and hot plate test also
showed potential analgesic activity of the extract which is also comparable to the standard drug morphine (5 mg/kg b.w.). Docking
studies shows that phaseollin of Erythrina variegata L. has the best fitness score against the COX-1 which is 56.64 and 59.63 for COX-
2 enzyme. Phaseollin of Erythrina variegata L. detected with significant fitness score and hydrogen bonding against COX-1 and
COX-2 is reported for further validation.