The Antioxidant and Acetylcholinesterase Inhibitory Activity of the Flavonoid-Rich Fraction of Bayag-Usa (Voacanga Globosa) Leaf Extract

Introduction: Dementia cases in the Philippines are projected to rise significantly, with Alzheimer's disease (AD) comprising 85.5% of cases (Anlacan et al., 2024). AD is linked to oxidative stress, characterized by an imbalance in reactive oxygen and nitrogen species and reduced acetylcholine activity. Voacanga globosa ("Bayag-usa") was evaluated for its antioxidant and acetylcholinesterase (AChE) inhibitory properties, which may help prevent neurodegeneration. Methodology: Leaf extracts were partitioned into methanol, hexane, ethyl acetate, and aqueous fractions. Phytochemical analysis confirmed the presence of alkaloids, flavonoids, tannins, cardiac glycosides, and saponins. Instrumental analysis and the Total Phenolics/Flavonoid Content Assay showed the ethyl acetate fraction was richest in flavonoids and phenolics. Results: Consequently, antioxidant assays such as 2,2-diphenyl-1-picrylhydrazyl (DPPH) and Cupric Reducing Antioxidant Capacity (CUPRAC), revealed weaker activity than ascorbic acid. AChE inhibition assay, though exhibiting a lower activity than galantamine, demonstrated a concentration-dependent effect, increasing from 15.12% at 100 ppm to 68.39% at 1000 ppm. Statistical analysis confirmed significant differences (p < 0.05) between V. globosa and the positive controls. Discussion: Despite its lower potency, the dose-dependent trend suggests potential bioactivity, warranting further research for therapeutic applications.