Lipid oxidation and antioxidant properties of propolis collected in different regions of Turkey

Propolis is a natural resinous product from Apis mellifera hives that contains various bioactive substances. The main bioactive substances are polyphenols that have high antioxidant properties. However, no study was found in which antioxidant parameters of total antioxidant status (TAS), total oxidant status (TOS), oxidative stress index (OSI), and catalase (CAT) enzyme activity and lipid oxidation were studied in Turkish propolis across different regions. Therefore, this study aimed to determine the lipid oxidation and antioxidant properties of raw propolis collected from four different regions in Turkey. For this purpose, 40 raw propolis samples were gathered from the Mediterranean, Central Anatolia, Marmara, and Black Sea regions. Total phenolic substances (TPS), TAS, TOS, CAT enzyme activity, and lipid oxidation were determined in propolis samples. Significant differences in TPS levels were found among the regions. The highest TPS (126.7 mg gallic acid equivalent (GAE)/g) was observed in the Central Anatolia region. TPS (106.4 mg GAE/g) and CAT enzyme activity (2.85 U/g) were found to be the lowest in propolis samples collected from the Mediterranean region. There were no differences in raw propolis samples collected from different regions in terms of lipid oxidation levels, TAS, TOS, and oxidative stress index. TPS showed significant positive correlations with both TAS and CAT (r = 0.36, p = 0.022, and r = 0.70, p < 0.001, respectively), indicating an enhancement in the overall antioxidant capacity of the system and enzyme-mediated defences. Propolis samples from the Central Anatolia Region were found to be superior in terms of lipid oxidation and antioxidant properties compared to those from other regions. However, further studies are needed to determine the composition and antioxidant properties of propolis from different regions to develop a comprehensive profile of Turkish propolis.