Abstract
BACKGROUND/OBJECTIVES: There is a growing interest in plant-derived antioxidants as functional food ingredients, given their potential to address oxidative stress-related diseases, notably neurodegenerative disorders. This study aims to investigate the antioxidant properties of medicinal plants that have been approved by the Thai FDA for dietary supplementation, with the goal of further utilizing them as food-functional ingredients to prevent neurodegenerative conditions. METHODS: A systematic review-based methodology was employed on a list of 211 medicinal plants, and 21 medicinal plants were chosen based on their documented antioxidant activity and acetylcholinesterase (AChE) inhibitory capacity. The 21 commercially available standardized extracts were subjected to evaluation for their phenolic and flavonoid content, as well as their antioxidant activities utilizing metal-chelating activity, DPPH, ABTS free radical scavenging, ferric-reducing antioxidant power (FRAP), and superoxide anion scavenging techniques. RESULTS: Among the 21, six extracts-Bacopa monnieri, Camellia sinensis, Coffea arabica, Curcuma longa, Tagetes erecta, and Terminalia chebula-emerged as the most promising. These extracts exhibited elevated levels of phenolic (up to 1378.19 mg gallic acid equivalents per gram) and flavonoids, with Coffea arabica and Curcuma longa showing the strongest antioxidant and free radical scavenging activities, indicating their potential for use in functional foods aimed at delaying neurodegenerative diseases. CONCLUSIONS: Due to their high levels of phenolic and flavonoid compounds, along with strong metal-chelating abilities and significant free radical scavenging activities, these standardized extracts show potential for functional food applications that may help delay the onset of neurodegenerative diseases.