Isolation, characterization and quantification of an anxiolytic constituent - mahanimbine, from Murraya koenigii Linn. Spreng Leaves.
J Ethnopharmacol. 2016 Dec 4 ;193:706-711. Epub 2016 Oct 11. PMID: 27737817
ETHNOPHARMACOLOGICAL RELEVANCE: Leaves of M. koenigii Linn. Spreng (Rutaceae) have been used as traditional medicine for anxiety disorders. Aim of the study was to isolate antianxiety principle(s) from the leaves of M. koenigii using bioactivity guided approach.
MATERIAL AND METHODS: Hydroalcoholic extract of M. koenigii leaves was prepared using soxhlet apparatus, and the same was evaluated for antianxiety activity at 250, 500 and 750mg/kg, po, using Elevated plus-maze (EPM). The extract was further partitioned successively with pet ether, chloroform, ethyl acetate and 1-butanol. All the fractions were evaluated for antianxiety activity. The bioactive ethyl acetate fraction was column chromatographed to get 5 fractions (F-F). All the fractions were evaluated for antianxiety activity using EPM. A pure compound, separated out from Fwas characterized using standard spectroscopic techniques, and its anxiolytic activity was evaluated using EPM. Antianxiety activity of isolated compound was further evaluated using Actophotometer and m-CPP induced anxiety model. TLC-densitometric method was developed to quantify mahanimbine in the plant.
RESULTS: The present study resulted in the isolation of mahanimbine, which exhibits potent antianxiety activity at 3mg/kg, and the activity was statistically comparable to that of diazepam (2mg/kg). The developed TLC-densitometric method is specific, linear, precise, accurate, repeatable and robust.
CONCLUSIONS: This study validates the ethnopharmacological use of M. koenigii leaves in the management of anxiety disorders. Mahanimbine is responsible for the antianxiety effect of M. koenigii leaves.