Diversification of Total Phenolic Compounds and free Radical Scavenging Activity of Artemisia Campestris L. Leaves

Introduction. Artemisia campestris L. is native to North Europe, Asia, North America, and North Africa, and leaves are commonly used as a decoction in traditional medicine for their antivenin, anti-inflammatory, anti-rheumatic, and antibacterial qualities [1]. The variability in the total phenolic compounds and free radical scavenging activity in the extract of leaves is due to differences in the seasonal climate, soil conditions, and the soil type [2]. This information can be used to better understand the potential health benefits of Artemisia campestris. Materials and methods. A. campestris samples were collected during massive flowering in August 2022 in the natural habitats from various regions of Lithuania, air – dried at room temperature, and grinded to fine powder passing through the sieve number 355, then stored in dry and dark place. Leaves (0,2 g) was extracted for 15 minutes with 20 ml of 70% ethanol in an ultrasonic bath, followed by 15 minutes of centrifugation at 6500 rpm, then filtrated though filter paper and stored in the dark glass bottle to avoid the light. The total phenolic content of the extract was determined by the Folin–Ciocalteau method using gallic acid as a standard [3]. Test solution was prepared by mixing 20 μL of each extract with 5 ml Folin – Ciocalteu working reagent and 4 ml of sodium carbonate (7,5%). After one hour reaction in in the dark, at home temperature, the absorbance was measured at 756 nm. Gallic acid was used as a standard and results were expressed as gallic acid equivalents (GAE) per gram of raw material. The total antioxidant capacity of extract was determined with spectrophotometric ABTS method [4]. To get a 2 mM concentration, ABTS aqueous solution was mixed with potassium persulfate, then left in the dark at room temperature for 16 h. Test solution was made by mixing 20 μL of each extract with 3 ml of ABTS working solution. After leaving mixture in the dark at room temperature, the change of the absorbance was measured at 734 nm. The radical scavenging activity were expressed as mg of trolox equivalent (TE) per g of dried material. Results and their discussion. The range in total amount of phenolic compounds in Artemisia campestris samples from various locations varied significantly. The average total amount of phenolic compounds in the samples that were taken from different habitats was 83,787 ± 17,461 mg/g. The results showed that the highest content of phenolic compounds was determined in leaves collected in Karčemos village (107,192 ± 1,772 mg/g) and less in Gulbiniškiai village (99,049 ± 0,590 mg/g), Būda village (95,604 ± 1,329 mg/g), Pugainiai village, (93,725 ± 0,738 mg/g), Pypliai village (90,906 ± 1,772 mg/g), Plokščiai village (86,313 ± 0,591 mg/g), Lentinė village (81,198 ± 0,738 mg/g), Tauragė city (70,132 ± 1,033 mg/g) and the lowest amount of phenolic compounds was found in the Mančiagirė village (65,539 ± 6,643 mg/g) and Šventoji city, near the Baltic sea (48,209 ± 1,328 mg/g). The total phenolic content varies significantly from 48,209 ± 1,328 mg/g up to 107,192 ± 1,772 mg/g. From the obtained data we can see that the amount of total amounts of phenolic compounds is similar between the habitats. The range in radical scavenging activity in Artemisia campestris samples from various locations. The average radical scavenging activity in the leaves samples collected from different habitats was 1428 ± 152,574 µmol/g. The results showed that the highest content of radical scavenging activity was determined in leaves collected from Gulbiniškiai village (1668 ± 7,071 µmol/g), less in the Pugainiai village (1583 ±113,137 ), Būda village (1508 ± 77,782 µmol/g), Karčemos village (1483 ± 84,853 µmol/g), Plokščiai village (1473 ± 155,563 µmol/g), Pypliai village (1403 ± 113,137 µmol/g), Mančiagirė village (1368 ± 77,782 µmol/g), Tauragė city (1323 ± 56,569 µmol/g) and the lowest amount was found in the Lentinė village (1263 ± 28,284 µmol/g) and Šventoji city (1208 ± 35,355 µmol/g). The radical scavenging activity varies from 1208 ± 35,355 µmol/g up to 1668 ± 7,071 µmol/g. Conclusion. Although variability in total phenolic contents and free radical scavenging activity was observed, the amounts is similar between the habitats. It may be assumed that the plants composition is stable in the Eastern European region. Furthermore, the consistency of phenolic chemicals in different areas impacts their potential usage in pharmacy and other industries.