Comparative analysis of phenolic compounds, antioxidant activity and enzyme inhibitory effects of Camellia pubicosta Merr. leaf extracts

This study investigated the phenolic content and various bioactivities of extracts from the leaves of Camellia pubicosta Merr., a plant species native to Vietnam. The results revealed that catechin and epicatechin were significantly more abundant in the aqueous methanolic extract (ME70) compared to other extracts. The acetone/methanol (AC/ME) and aqueous ethanolic (ET70) extracts demonstrated the most potent antioxidant activity. However, no significant differences in DPPH radical scavenging activity were observed among AC/ME, ME70 and ET70. The ethyl acetate extract exhibited the strongest α-amylase inhibitory activity, whereas AC/ME was the most effective against α-glucosidase. Correlation analysis suggested that phenolic compounds were key contributors to the radical scavenging activities, while flavonoids played a significant role in the α-amylase inhibitory effects of the extracts. These findings enhanced our understanding of the bioactive phenolics present in C. pubicosta leaves and their potential health benefits.