Unveiling the antioxidant secrets: Phytochemical profiling and bioactive potential of water extracts from Muğla propolis samples

Propolis, a resinous substance collected by bees, is known for its diverse biological activities, including antioxidant properties, which are largely attributed to its phenolic and flavonoid content. This study aimed to investigate the chemical composition and antioxidant activities of water extracts from propolis samples collected from different locations in Muğla, Turkey. Total phenolic and flavonoid contents were quantified, and antioxidant activities were evaluated using various assays, including β-carotene bleaching, superoxide anion radical scavenging, DPPH radical scavenging, reducing power, and ferrous ion chelation. The total phenolic content of the samples ranged from 27.72 to 91.57 mg PEs/g extract, with Arpacık showing the highest phenolic content (91.57 mg PEs/g). In contrast, flavonoid content ranged from 9.33 to 25.78 mg QEs/g extract, with Fethiye exhibiting the highest value (25.78 mg QEs/g). The antioxidant assays revealed that the Fethiye extract consistently demonstrated the strongest activity, with a β-carotene inhibition rate of 96.73% and an IC50 of 49.50 μg/mL in the DPPH assay. Arpacık also showed considerable antioxidant capacity, albeit slightly lower than Fethiye, while the Dalaman and Döğüşbelen samples exhibited weaker activities. Correlation analysis indicated that total phenolic content had a strong positive correlation with DPPH scavenging (r = 0.994) and reducing power (r = 0.986), while flavonoid content was significantly correlated with superoxide anion scavenging (r = 0.931) and ferrous ion chelation (r = 0.894). These results suggest that phenolic and flavonoid compounds are key contributors to the antioxidant mechanisms in propolis. Future studies should explore the effects of different extraction methods and expand the geographical scope to better understand the factors influencing the bioactive composition of propolis.