Evaluation of Phytochemical Characterization and CNS Activity with Emphasis on Psychotropic and Cognitive studies of Standardized Extract of Clerodendron serratum Linn Leaves

Abstract

The aim of the present study was to confirm the traditional uses of Clerodendron serratum for the treatment of neurological disorders and to standardize the leaf extract for chemical constituents mainly flavonoids, responsible for these activities. The two flavonoids standardized in ethanol extract of C. serratum by reverse phase high performance liquid chromatography were apigenin and luteolin in n-butanol and ethyl acetate fractions of C. serratum leaf extract. Although apigenin and luteolin has been previously reported in C. serratum, this is the first report on standardization of these two flavonoids in this plant. Various CNS activities investigated in the plant leaves include spontaneous locomotor activity, hypnotic activity, anticonvulsant activity, antiparkinsonism activity, anxiolytic activity, antidepressant activity and nootropic activity. Locomotor activity was assessed using actophotometer test, hypnotic activity using pentobarbital induced sleeping test, anticonvulsant activity using pentylene tetrazole and maximal electroshock-induced convulsion tests. Antiparkinsonism activity was evaluated with the help of haloperidol induced catalepsy test. newlineAbove all, correlation of mechanism of action of each CNS activity could be done, only by estimating the level of neurotransmitters like nor-epinephrine, serotonin, dopamine and gamma-amino butyric acid. For confirming the nootropic property of C. serratum leaves, acetylcholine esterase level was also estimated. Among all the CNS activities, C. serratum leaves exhibited anticonvulsant activity, antiparkinsonism activity, antidepressant activity and also revealed cognitive improvement. Thus, the results of CNS activity investigations provided scientific basis for the traditional use of C. serratum for the treatment of neurological disorders. Furthermore, apigenin and luteolin present in the plant might be partly responsible for its anticonvulsant, antiparkinsonism, antidepressant and cognitive enhancing ability. newline