Anticonvulsant potential of Anisomeles malabarica leaves against experimentally induced convulsions in rats

Abstract

for its authenticity and a specimen of the plant material was also deposited at Department of Botany, Sri Venkateswara University for further reference. Preparation of ExtractsCoarsely powdered leaves (500 g) were defatted with petroleum ether (40-60°C) (at 52°C for 36 hours) and the dried marc was further extracted with chloroform (at 65°C for 48 hours) followed by ethyl acetate (at 80°C for 36 hours) and methanol (at 68°C for 48 hours) using Soxhlet's extractor. The three extracts (chloroform, ethyl acetate and methanol) obtained were dried by removing the solvents using rotary evaporator (Medica Instrument, Mumbai, India). The dried extracts so obtained were placed in a vacuum desiccator and used for further studies. Phytochemical ScreeningAll the three extracts were screened for their various Anisomeles malabarica (AM) R.Br. (Lamiaceae) is an aromatic perennial herb, the leaves of which are traditionally used to treat convulsions in southern India. The present study has been designed to investigate the anticonvulsant potential of chloroform, ethyl acetate and methanol extracts of leaves of AM against pentylenetetrazole (PTZ) and maximal electroshock (MES) induced convulsions. All the three extracts were administered (i.e. 100, 200, 400 mg/kg, p.o.) for 7 days and at the end of the treatment convulsions were induced experimentally. Diazepam and phenytoin (1 mg/kg, i.p. and 25 mg/kg, i.p., respectively) were used as reference anticonvulsant drugs against experimentally induced convulsions. High doses (400 mg/kg, p.o.) of chloroform and ethyl acetate extracts both significantly decreased the extent of MES-and PTZ-induced convulsions. On the other hand, ethyl acetate extract at lowest and medium selected doses (i.e. 100 mg/kg, p.o. and 200 mg/kg, p.o., respectively, for 7 days) had also significantly attenuated PTZ-induced convulsions. However, methanol extract at any of the doses used (i.e. 100, 200 and 400 mg/kg, p.o.) did not show any significant effect on PTZ-and MES-induced convulsions. None of the extracts at doses used in the present study have altered locomotor activity and motor coordination. Hence, it may be concluded that chloroform and ethyl acetate extracts of AM leaves are effective against PTZ-and MES induced-convulsions in rats.