Phytochemical Composition and Functional Properties of Avocado and Dragon Fruit: A Comparative Evaluation of Antioxidant, Anti-Inflammatory, and Neuroprotective Activities

Aim: Neurodegenerative disorders are increasingly associated with oxidative stress, chronic inflammation, and cholinergic dysfunction. In this context, plant-derived bioactive compounds, particularly those found in commonly consumed fruits, have attracted growing scientific interest for their potential neuroprotective effects. Avocado (Persea americana) and dragon fruit (Selenicereus undatus) are rich in phytochemicals that may contribute to antioxidant, anti-inflammatory, and anti-acetylcholinesterase activities relevant to brain health. Objective: The primary goal of this study was to conduct a comparative analysis of the phytochemical composition of avocado and dragon fruit extracts, and to evaluate their antioxidant, anti-inflammatory, and anti-acetylcholinesterase activities. Particular emphasis was placed on elucidating their potential neuroprotective properties, with relevance to mitigating oxidative stress, inflammatory responses, and anti-acetylcholinesterase associated with neurodegenerative disorders. Methods: Qualitative phytochemical screening was conducted to identify diverse classes of bioactive compounds. TLC was performed to visualize and profile phytochemical constituents. Quantitative determinations included measurement of total polyphenol content, total flavonoid content, and total antioxidant capacity, using the phosphomolybdate assay and the ferric reducing potential assay (FRPA). Anti-inflammatory activity was assessed through inhibition of heat-induced hemolysis in human red blood cells. Anti-acetylcholinesterase activity was also evaluated to determine the potential of the extracts in mitigating cholinergic dysfunction. Results: Qualitative analysis confirmed a diverse phytochemical profile in both avocado and dragon fruit. Avocado exhibited higher total phenolic (1.01 mg GAE/g) and flavonoid content (2.3 mg QE/g) compared to dragon fruit (0.48 mg GAE /g and 1.8 mg QE/g, respectively). Despite this, dragon fruit consistently demonstrated superior antioxidant capacity, with values of 0.14 mg/mL ascorbic acid equivalents in the phosphomolybdate assay and 0.623 mg AAE/g in the FRAP assay, versus 0.08 mg AAE/g and 0.0295 mg AAE/g for avocado. Anti-inflammatory activity was more pronounced in avocado (83% inhibition) relative to dragon fruit (73%). Both extracts exhibited notable anti-acetylcholinesterase activity, with avocado showing stronger inhibition (40%) compared to dragon fruit (20%). Conclusion: This study provides novel comparative evidence on the phytochemical composition and bioactivities of avocado and dragon fruit. While avocado demonstrated higher phenolic and flavonoid content together with stronger anti-inflammatory and anti-acetylcholinesterase effects, dragon fruit exhibited superior antioxidant capacity. These complementary properties highlight both fruits as valuable sources of neuroprotective compounds, supporting their potential role in dietary strategies aimed at reducing the risk or progression of neurodegenerative disorders.