Anticonvulsant activity of methanolic extract from Kalanchoe pinnata Lam. stems and roots in mice: A comparison to diazepam.

INTRODUCTION: In ancient and current traditional medicine in México, extracts from the leaves or whole plant of 'life leaf' (Kalanchoe pinnata [K. pinnata]Lam) have been used to treat an entity known locally as 'yellow epilepsy' (alferecía amarilla) when it is accompanied by seizures. However, the anticonvulsive activity of its stems and roots remains unexplored

METHODS: The anticonvulsant activity of the methanolic root extract (MER) or stem (MES) of K. pinnata Lam. was evaluated in a pentylenetetrazol-induced seizure model in Balb/C mice, and effects were compared to those of diazepam. The stem extract fractions that produced anticonvulsant activity were subsequently evaluated using the pentylenetetrazol -induced seizure model.

RESULTS: We observed increased latency of tonic-clonic seizures that was inversely proportional to the dose of MRE, with a similar impact on the lethal effects of pentylenetetrazol. Different doses of the MSE showed a dose-dependent increase in latency to myoclonus, clonus, and tonic-clonic seizures, acting similarly to diazepam and offering 100% protection against the lethal effects of pentylenetetrazol. Fractioning MSE decreased its effectiveness, but when fractions were mixed with fractions of chloroform and ethyl acetate, anticonvulsive activity was restored. The preliminary phytochemical analysis identified alkaloids and sterols in MRE, and sterols and terpenes in MSE CONCLUSIONS: The anticonvulsant activity of K. pinnata Lam. decreases with increased doses of MRE, whereas the effect of MSE is dose-dependent and preserved in the mixture chloroform and ethyl acetate. We suggest that the metabolites responsible for these effects are sterols in MRE, and sterols and terpenes in MSE.