Evaluation of Seasonal Differences in the Antioxidant Activity of Needle Juices of Picea abies L. and Pinus sylvestris L. with Luminol-enhanced Chemiluminescence

Background: Coniferous tree species typical of the central part of Russia can be evaluated not only as sources of wood but also as a raw material for obtaining biologically active substances.Methods: A comparative evaluation of needle juices of Pinus sylvestris and Picea abies in the summer and winter periods was the objective of this study and carried out in this study by chemiluminescence analysis and testing for membrane-protective activity. Juices were evaluated for the content of flavonoids and ascorbic acid, which some authors suggest are markers of stress in plants. An increase in the content of flavonoids and ascorbic acid in Pinus sylvestris L. in the summer period is a sign of an adaptive reaction of plants to the high intensity of ultraviolet radiation, which is typical for the growing conditions of pine as a photophilous plant. An increase in these indicators in Picea abies L. in winter is a sign of the plant stress response to low temperatures.Result: The membrane-protective activity of needle juices concerning peroxidation and osmotic hemolysis was revealed, which is more prominent in Pinus sylvestris L. needle juice. The analysis revealed more prominent antioxidant properties in the juice of Pinus sylvestris L. needles compared to that of Picea abies L. both in summer and in winter.