Comprehensive Chemical Profiling and Biological Activities of Northern Iraqi Propolis: LC-MS/MS-, GC-MS-, and ICP-MS-Based Characterization with Antioxidant, Antimicrobial, and GST Inhibitory Effects.

Chemical composition of propolis varies depending on geographical and environmental factors. This study presents a comprehensive characterization of propolis collected from four Northern Iraqi regions: Erbil, Mosul, Duhok, and Sulaymaniyah. The chemical content was examined through LC-MS/MS, ICP-MS, and GC-MS. Extracts were also evaluated for their antioxidant, enzyme inhibitory, and antimicrobial activities. LC-MS/MS profiling revealed notable regional and solvent-dependent variations in phenolic and flavonoid content, with ethanol extracts, particularly from Mosul and Sulaymaniyah, being richer in galangin, chrysin, and naringenin. GC-MS analysis identified several fatty acids and phenolic esters, with Duhok propolis containing high palmitic acid. ICP-MS analysis indicated variation in macroelements and trace elements, showing abundant calcium, magnesium, and iron. Ethanol extracts exhibited superior antioxidant activity in both DPPH radical scavenging and total antioxidant capacity, with Sulaymaniyah and Duhok extracts being the most active. Antimicrobial assays indicated inhibition against Salmonella typhimurium, Escherichia coli, Listeria monocytogenes, Bacillus subtilis, and Candida albicans, with Erbil and Sulaymaniyah extracts showing the strongest inhibition. Notably, Sulaymaniyah ethanol extract demonstrated the highest glutathione S-transferase (GST) inhibition activity (IC50 = 5.52 μg/mL), correlating with its elevated flavonoid content. Overall, Northern Iraqi propolis displays chemical diversity and potent bioactivities, highlighting its promise for nutraceutical, pharmaceutical, and cosmetic applications.