RESUMEN
The butanolic and purified butanolic extracts (PBEs) of Eclipta prostrata were evaluated for their anti-venom potential. Inhibition of lethal, hemorrhagic, proteolytic, and phospholipase A2 activities of Calloselasma rhodostoma (Malayan pit viper (MPV)) venom by these extracts were determined. Demethylwedelolactone was identified as their major constituent. The butanolic extract, at 2.5 mg per mouse, was able to completely neutralize the lethal activity of 2LD50 of MPV venom, but increasing the dose diminished the effect. The PBE, at 1.5-4.5 mg per mouse, was able to neutralize the lethality of the venom at around 50-58%. Both extracts partially inhibited the hemorrhagic activity but displayed very low anti-phospholipase A2 activity and did not inhibit proteolytic activity of MPV venom.