Earthworm, an in Vivo System to Screen Proliferative and Antimitotic Compounds

Amputated earthworm, Eudrilus eugeniae, possessing clitellum region has regenerating ability and develop into complete worms. Earthworm regeneration assay was developed based on this phenomenon and utilized to identify the presence of antimitotic compounds from the rhizomes of medicinal plant Acorus calamus. In continuation of that study, rhizomes of A. calamus was extracted with water and crude residue was obtained after evaporation. Subsequently, to separate the compounds from crude residue it was extracted with five different organic solvents individually such as benzene, chloroform, ethyl acetate, ethanol and methanol. All five different fractions were examined on earthworm regeneration assay to identify its antimitotic potential. Fractions extracted with benzene and chloroform did not inhibit regeneration as blastema was observed. In contrast fractions extracted with methanol and ethyl acetate inhibited the development of blastema. It suggests that methanol and ethyl acetate fractions might possess antimitotic compounds. TLC analysis with ethyl acetate fraction revealed two distinct bands. Compounds eluted from TLC plates decreased mitotic index of Allium cepa root tips and supporting the presence of antimitotic compounds. Surprisingly, fractions extracted with ethanol increased the regeneration capacity of the worms. Our results demonstrate that rhizomes of Acorus calamus possess both antimitotic and proliferative compounds. Hence we suggest that earthworms could be used as an in vivo system to screen both proliferative and antimitotic compounds from unknown sources.