Study of the Antioxidant Properties of Filipendula ulmaria and Alnus glutinosa

The demographic situation of the last few decades is characterized by the increased numbers of elderly and senile people, i.e., by the aging of the population. In humans, ageing is closely associated with the enhanced production of reactive oxygen species (ROS), development of systemic inflammation and related vascular atherosclerotic alterations and metabolic disorders, like obesity, diabetes mellitus and neurodegenerative diseases. As these age-related alterations are directly associated with up-regulation of ROS production and development of chronic oxidative stress, their onset can be essentially delayed by continuous daily consumption of dietary antioxidants—natural products of plant origin. Such antioxidants (in the form of plant extracts, biologically active complexes or individual compounds) can be supplemented to functional foods, i.e., dietary supplementations for daily diet aiming prolongation of active life and delay of the senescence onset. Thereby, use of widely spread medicinal plants might essentially improve cost efficiency of this strategy and availability of antioxidant-rich functional foods. Therefore, here we addressed, to the best of our knowledge for the first time, the antioxidant activity of the extracts prepared from the aerial parts of Filipendula ulmaria and Alnus glutinosa growing in the Kaliningrad region of Russia, and assessed the contents of the biologically active substances underlying these properties. It was found that the extract prepared with the leaves of Filipendula ulmaria and female catkins of Alnus glutinosa demonstrated high antioxidant activity, although the former plant was featured with a higher antioxidant potential. The highest antioxidant activity detected in the methanol extracts of Alnus glutinosa reached 1094.02 ± 14.53 µmol TE/g, radical scavenging of activity was 584.45 ± 35.3 µmol TE/g, reducing capacity at interaction with iron complex—471.63 ± 7.06 µmol TE/g. For the methanol extracts of Filipendula ulmaria the antioxidant activity reached 759.78 ± 19.08 µmol TE/g, antioxidant activity for free radical removal was 451.08 ± 24.45 µmol TE/g and antioxidant activity for restorative ability with iron complex was 332.28 ± 10.93 µmol TE/g. These values are consistent with the total yields of the extracts and their content of ellagic acid. The ethyl acetate extracts of the both plants showed just minimal antioxidant activity. Thus, the considered extracts have an essential potential. This creates good prospects for the further use of herbal extracts of Filipendula ulmaria and Alnus glutinosa as a source of natural antioxidants.