Artemisia annua L. (Asteraceae) – hemijska analiza i antioksidativna aktivnost

Artemisia annua, popularly known as sweet wormwood, is a herbaceous plant from the family Asteraceae. Since ancient times, it has been used in traditional medicine as a plant that has antimalarial activity, due to the presence of the sesquiterpene lactone artemisinin. It also contains phenols and flavonoids because it is classified as a plant with antioxidant, antiinfective and anti-inflammatory effects. The aim of the work was to examine the chemical composition and antioxidative activity of the ethanolic extract of sweet wormwood. In the ethanolic extract of A. annua herb, the content of total phenols was determined using the Folin
Ciocalteu method. The results are expressed as mg gallic acid equivalents/g dry extract (mg GAE/g d.e.). Total flavonoids were determined spectrophotometrically by monitoring the formation of complexes with AlCl3. Results are expressed as mg quercetin equivalents/g dry extract (mg QE/g d.e.). Antioxidant activity was determined by in vitro tests of inhibition of 2,2-diphenyl-1-picrylhydrazyl (DPPH), hydroxyl (OH), nitroso (NO) radicals and lipid peroxidation inhibition test. The results are expressed as the concentration at which 50% of the radicals are neutralized, or the concentration at which 50% of the lipid peroxidation process is 
inhibited (IC50). Detailed chemical characterization was investigated by high-performance liquid chromatography (HPLC). The results are expressed as µg/g dry extract. The extraction yield was about 15%. The content of total phenols was 63.02 mg GAE/g d.e. The content of total flavonoids was 12.57 mg QE/g d.e. The ethanolic extract showed the highest DPPH radical neutralization potential, with an IC50 of 1.78 mg/g d.e. This value for other free radicals was 5.17 mg/g d.e. for OH, 79.94 mg/g for NO and 41.56 mg/g d.e. for lipid peroxidation. The  presence of quercetin, chlorogenic and gallic acids was detected using HPLC analysis. Chlorogenic acid was detected in the highest amount (651 µg/g d.e.). A. annua is a rich source of phenols and phenolic acids. The inhibitory activity on the causes of oxidative stress (DPPH, OH, NO radicals and lipid peroxidation reaction) shows that the plant has a good antioxidant effect. All these preliminary in vitro results need to be confirmed by further tests.