Biological investigation of ethanolic extract of Spilanthes calva DC

Phytochemical evaluation of the ethanolic extracts of Spilanthes calva DC indicated the presence of alkaloids, steroids, tannins, and gums. The pharmacological interests of these compounds, coupled with the use of this plant in traditional medicine tended to investigate the plant extracts for possible analgesic, antidiarrheal and anti-oxidant activities. The plant extracts exhibited significant inhibition of writhing reflex 59.32% (P<0.001) at a dose of 500 mgkg-1 bdwt while the standard drug diclofenac sodium showed 75.52% (P<0.0005) at a dose of 25 mgkg-1 bdwt. In the castor oil-induced diarrhoel mice, the plant extracts significantly increased the latent period (P<0.0001) at a dose of 500 mgkg-1 bdwt compared to standard drug Loperamide (P< 0.0001). It also significantly reduced the number of stools at the doses of 250 (P< 0.01) and 500 mgkg -1 bdwt (P<0.001) comparing with standard drug Loperamide (P< 0.0001). By spraying 0.02% DPPH solution of ethanol on TLC plate which developed in non-polar, medium polar and polar medium, the extracts showed yellow spot that indicated the presence of anti-oxidant components. The IC50 for ascorbic acid was approximately 1 ?g/ml whereas the plant extracts showed 500 ?g/ml. Our results show that the plant extract has potent analgesic, antidiarrheal and anti-oxidant activities.