A Comprehensive Study of the Neuropharmacological Profile of Methanol Leaf Extract of Aloe vera and Identification of Associated Neuroprotective Compounds through Gas chromatography–mass spectrometry Analysis

Abstract

The objective of this study is to determine the neuropharmacological activities of the methanol extract of Aloe vera leaf and identify the potential bioactive compounds present in the same responsible for the activities through Gas chromatography–mass spectrometry analysis. The study is done on Wistar albino rats and composed of 5 groups, methanol extract of Aloe vera leaf at 200, 400, 800 mg/kg, normal saline (control) and standard drugs Phenytoin and Diazepam. Antiepileptic activities are done using maximal electroshock and pentylenetetrazole induced convulsion models and anxiolytic sedative activities using the staircase test, actophotometer test and sleep prolongation test. The chemometric analysis is performed using Clarus 500 Perkin Gas Chromatograph coupled with a mass detector, Turbo mass gold–Perkin Elmer Turbomass 5.1 spectrometer with an Elite-1 (100 % dimethyl polysiloxane), 30 m×0.25 mm ID×0.25 μm of the capillary column. The results demonstrated anxiolytic potential at 200 and 400 mg/kg and sedative activity at 800 mg/kg comparable to Diazepam. The methanolic extract of Aloe vera leaf at 800 mg/kg displayed antiepileptic activity compared to Phenytoin. The Gas chromatography–mass spectrometry analysis confirmed the presence of phytol (23.76), alpha-tocopherol (4.67), maltol (3.69), humulene (6.58), caryophyllene (2.73), n-hexadecanoic acid (2.16), hexadecanoic acid methyl ester (3.70), squalene (3.51), 9,12,15-octadecatrienoic acid methyl ester (2.12), which are antioxidant and anti-inflammatory compounds. These plant derived bioactive compounds are demonstrated to have antianxiety, antiepileptic, sedative hypnotic and neuroprotective potential in neurodegenerative models and might serve as future prospective drug candidates in neurodegenerative disorders).