In vitro Antioxidant and Cholinesterase Inhibitory Activities of Methanolic Extract of Grewia nervosa L. (Family: Tiliaceae) Leaf

Abstract

Aims: The methanolic extract of Grewia nervosa L. leaves belongs to the family of Tiliaceae. The purpose of this study was to evaluate total phenolics, total flavonoids,  total proanthocyanidins, total antioxidant capacity, iron reducing power capacity, free radical scavenging activity, hydroxyl radical scavenging activity, Lipid peroxidation inhibition activity, anti-acetylcholinestrase activity, anti-butyrylcholinestrase activity, metal chelating activity, total flavonols, nitric oxide radical scavenging activity and phytochemical screening. Place and Duration of Study: The study was carried out between April 2015 to June 2015 in the Department of Pharmacy, Southeast University, Dhaka, Bangladesh. Methodology: Antioxidant activity and neuroprotective activities were determined by several standard methods. Phytochemical screening was done by characteristic colour changes or colour precipitate using standard phytochemical reaction methods. Results: The anti-acetylcholinesterase activity of different extracts of G. nervosa was assessed by a slightly modified Ellman coupled enzyme assay. IC50 of the crude extract and its fractions petroleum ether fraction (PEF), chloroform fraction (CLF), ethyl acetate fraction (EAF) and aqueous fraction (AQF) was found to be 17.07 µg/ml, 15.08 µg/ml, 135.57 µg/ml, 274.78 µg/ml respectively. In butyrylcholinesterase inhibitory assay, the lowest activity was found in PTEF with IC50 value 15.79 and the highest activity was found in CLF with IC50 value 7.55. The crude methanol extract and its different fractions showed considerable total antioxidant activity and reducing capacity. In DPPH scavenging assay and hydroxyl radical scavenging assay, the crude methanol extract showed 79.54% and 89.54% scavenging having IC50 of 11.36 and 15.06 μg/ml respectively. Among the fractions, ethyl acetate exhibited the highest DPPH scavenging activity with IC50 of 14.98 μg/ml, while the petroleum ether fraction exhibited the lowest activity with IC50 of 553.09 μg/ml. In hydroxyl radical scavenging activity aqueous fraction exhibited the highest scavenging activity with IC50 of 14.84 μg/ml, while petroleum ether fraction exhibited the lowest activity with IC50 of 33.39 μg/ml. In the lipid peroxidation assay, crude methanol extract showed significant inhibition of peroxidation at all concentrations, with IC50 of 54.41 μg/ml. Among the fractions, ethyl acetate fraction demonstrated the highest activity with IC50 of 33.46 μg/ml. Conclusion: Observing the in-vitro studies, it can be concluded that the methanolic extract of G. nervosa leaves could be used in different diseases because of its effective pharmacological properties. So, further studies are recommended to isolate the exact compounds responsible for this activity and their efficacy needs to be tested.