Phytochemical Screening, Chromatographic Profiling and Anxiolytic Effect of Raphia australis Ethanol Extract in Adult Male Mice

Aim: This study seeks to evaluate the anxiolytic effect of the ethanol extract of the pulp of Raphia australis when tested in adult male mice, and to identify some of the anxiolytic secondary metabolites present in the plant’s pulp extract.

Methodology: Phytochemical screening was carried out to determine the various classes of secondary metabolites present in the ethanol extract of R. australis. Both column chromatography and Liquid chromatography-mass spectrometer (LC-MS) were utilized to identify the bioactive compounds present in the ethanol extract of the pulp of Raphia australis. The extract was further subjected to Novelty Induced behaviour and anxiolytic tests using 4 groups of mice for each experiment comprising 5 mice in each group (n=5). Group one was administered normal saline (0.09% w/v NaCl. p.o) while 2 and 3 were administered 500 mgKg-1 and 1000 mgKg-1 (p.o) of ethanol extract of Raphia australis respectively. Group four was administered 2 mgKg-1, (p.o.) of diazepam (control).

Results: The phytochemical screening result was positive for all the classes of secondary metabolites tested for. The LC-MS results revealed the presence of proanthocyanidin (m/z 577.1354), catechin (m/z 289.0704), epicatechin (m/z 289.0700), protocatechuic acid (m/z 153.0200), umbelliferon (m/z 353.0868) and quinic acid (m/z 191.0571). When mice were injected with Raphia australis extract at the doses of 500 mg Kg-1 and 1000 mgKg-1, statistically significant results were obtained for grooming (p>0.01), head dipping (p>0.01) and anxiolytic (p>0.05) tests.