DNA scission and LDL cholesterol oxidation inhibition and antioxidant activities of Bael (Aegle marmelos) flower extracts

Phenolic compounds and other antioxidants have been implicated in protection against non-communicable diseases (NCDs) in which oxidative stress is a main contributor. The extracts of Bael (Aegle marmelos) flower were examined for their phenolic content, free radical scavenging efficacy and inhibition of low density lipoprotein (LDL) cholesterol oxidation and DNA scission activities. The extracts of Bael flowers were prepared using different solvent systems and their total phenolic content (TPC) and total flavonoid content (TFC) determined. Selected extracts which showed high TPC were subsequently used to determine their efficacy in scavenging hydroxyl, and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals, using electron paramagnetic resonance (EPR) spectroscopy. The corresponding peroxyl radical scavenging activity was measured using oxygen radical absorbance capacity (ORAC) assay. The potency of the extracts in inhibiting hydroxyl and peroxyl radical-induced supercoiled DNA scission and inhibition of LDL cholesterol oxidation was also evaluated. The chemical identity of phenolic compounds present in the extracts was tentatively unraveled using HPLC-MS. Phenolic extracts of Bael flowers effectively inhibited hydroxyl, and peroxyl radicals. Phenolic extracts demonstrated notable inhibitory activity against hydroxyl and peroxyl radical-induced DNA scission and LDL oxidation. Vanillic, p-coumaric, chlorogenic, caffeic, and gentisic acids were identified as major phenolic acids, along with flavonoids, mainly catechin, and quercetin. The knowledge gained here may help better use of Bael flower extracts as functional herbal beverage ingredients in the prevention of NCDs.