In vitro phytochemical analysis, antioxidant and enzymatic activities of Iranian Callistemon citrinus and Platycladus orientalis

The compositional characterization of volatile constituents, evaluation of antioxidant potential, phenolic profiling, determination of total phenolic and total flavonoid contents, and assessment of antioxidant enzyme activities of the aerial parts of Callistemon citrinus and Platycladus orientalis were conducted with the aim of identifying new sources of natural bioactive compounds. Essential oils (EOs) and plant extracts were obtained using hydrodistillation and maceration techniques, respectively. In the essential oils, 1,8-cineole and α-pinene were identified as the dominant constituents of C. citrinus and P. orientalis, respectively. Both plant extracts exhibited pronounced antioxidant capacities. Gallic acid and sinapic acid were the major phenolic compounds in C. citrinus, whereas gallic acid and rutin predominated in P. orientalis. Enzymatic analyses revealed variable activities of catalase (CAT), peroxidase (POD), and polyphenol oxidase (PPO) in both species. Overall, the phytochemical findings highlight the potential of these plants as accessible and sustainable sources of natural bioactive agents, supporting their prospective applications in pharmaceutical, cosmetic, and dietary industries.