In Vitro Antioxidant Activity of Feronia Limonia Bark Relevant to the Treatment of Oxidative Stress Mediated Neurodegenerative Disorders

The present study was designed to explore the potent antioxidant of crude methanol extract (CME) of Feronia limonia bark and its four fractions such as petroleum ether (PEF), chloroform (CLF), ethyl acetate (EAF) and aqueous fractions (AQF) in the treatment of neurodegenerative disorders, caused by oxidative stress. The highest phenolic and flavonoid content were detected in CLF (18.16 µg of gallic acid equivalent/gm of dried sample &160.20 µg of GAE/gm of extract) suggestive for good source of antioxidant. To the best of the knowledge, the compound C-1, Umbelliferone (7-hydroxycoumarin), reported for the first time from this plant source, was isolated & characterized from the chloroform fraction by column chromatography, PTLC and by 1H-NMR, 13C-NMR and HMBC respectively. All the fractions and the compound isolated were investigated for in vitro antioxidant activity by total antioxidant capacity assay, ferric reducing power assay, 1,1-diphenyl-2-picrylhydrazyl(DPPH) free radical & hydroxyl radical scavenging assay and lipid peroxidation assay. The total antioxidant activity and reducing capacity of CLF & EAF was higher than CME, AQF & PEF. In case of DPPH assay, all the extracts tested exhibited strong and similar free radical scavenging activity (IC50 values 15.8-17.4 µg/ml) compared with the reference standard ascorbic acid(IC50 value 12.6 µg/ml). The AQF had the highest hydroxyl radical scavenging activity with IC50 value 12.5 µg/ml. The isolated compound and seven column fractions (F2 to F8) of CLF also possessed good antioxidant activity. The highest lipid peroxidation inhibition capacity was found from F7 (IC50 value 14 µg/ml) appearing more potent than the standard catechin. Irrefutably, the study revealed that the plant bark inhibits multiple components of the oxidative stress pathway, which is suggestive for using in the effective and safe treatment of neurodegenerative diseases after in vivo effectiveness test is done.