o:8786 Assessment of the antioxidant properties of methanolic extracts of the plant species Geranium macrorrhizum from the post-fire area Испитивање антиоксидантне активности метанолних екстраката биљне врсте Geranium macrorrhizum са подручја пожаришта en sr Abstract: Periodic fires in nature have a complex role in the ecosystem, because they can create favorable conditions for populations of particular plant species that did not exist or were very poorly represented before the fire, and by changing the composition of the soil, fires can directly affect the biochemical and physiological properties of the observed plant. Antioxidants are natural or synthetic substances that, when present in small amounts relative to a substrate susceptible to oxidation, can counteract oxidation or inhibit reactions initiated by reactive species. Numerous plant species are excellent sources of antioxidants. Considering the importance of the antioxidant properties of plants, the plant species Geranium macrorrhizum (family Geraniaceae) was analyzed as one of the most abundant representatives of this family in the post-fire area. This plant is used in traditional medicine. This work aims to determine the antioxidant activity of methanolic extracts of G. macrorrhizum, collected in the area of forests that were affected by fire, and to compare it with the antioxidant activity of the same plant species, collected in the area of beech forest that was not affected by fire, using methods for the assessment of antioxidant properties. The antioxidant properties were evaluated through the ability to scavenge free radicals in vitro using the DPPH• and ABTS•+ methods and the total reducing power (TRP) method. The antioxidant properties of plants are usually due to the content of phenolic compounds, and total phenolic content (TPC) and total flavonoid content (TFC) were determined. The total reducing power of the tested plants from the post-fire area and outside was estimated using the Fe(III)/Fe(II) reduction system with ascorbic acid as a standard. By determining the "scavenging" antioxidant free-radical capacity according to 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical, we can see that the antioxidant activity of the plant species G. macrorrhizum from the post-fire area is higher than outside it. The total reduction power of G. macrorrhizum from the post-fire area is lower than that of the control group. It was found that the total flavonoid content, total polyphenolic content, and antioxidant activity determined by the ABTS method of the methanol extract of G. macrorrhizum from the post-fire area were lower than in the control group, which means that the fire had a negative impact. Keywords: Geranium macrorrhizum, post-fire area, antioxidant properties, DPPH, ABTS, TRP, TPC, TFC 1552100 978-86-903786-2-3 2025-12-21T23:21:29.247Z 44 yes 46 Vesna P. Stankov Jovanović 46 Marija Ilić 46 Violeta Mitić 46 Jelena Nikolić 46 Marija Dimitrijević 46 Slobodan Ćirić 46 Marija S. Marković 0000-0002-6070-6844 application/pdf 3973510 https://unilib.phaidrabg.rs/o:8786 no yes 16 70 92000004 71A07 Ethnobotany : book of abstracts / Third conference about medicinal and wild-growing edible plants, Pirot, Serbia, June 26 - 28. 2025. 133 135 Истраживачко друштво "Бабин нос", Темска, Пирот, Институт за шумарство, Београд, Штампарија "Свен", Ниш 2025