In this study, we investigated the antioxidant effect of the Morus nigra L. (black mulberry) fruit extracts in 2,2-diphenyl-1-picrylhydrazyl (DPPH^·) and hydroxyl (OH^·)radicals environments gathered from the district of Elazig. Fruits were extracted with 80% methanol, and methanolic extract’s scavenging effect of DPPH^· radical was examined depending on the quantity. It was observed that less matured fruit extract’s (SMF) radical scavenging activity increased from the 50 to 250 µL, but decreased after 500 µL (p<0,001). As for matured fruits (MF), the most scavenging activity were observed in 50 and 100 µL extracts on DPPH^· and after 250 µL, it decreased (p<0,001). Methanol phases of extracts by evaporation were dissolved indimethyl sulfoxide (DMSO) in the environment in which with Fenton reaction, OH^·radical is constituted; preventing the formation of lipopolysaccharide (LPO) and protective effect on unsaturated fatty acid were examined. In the Fenton reagent environment, preventing effect on the formation of LPO, it was determined that MF extract was more effectual than SMF extract (p<0,001). Accordingly, it was established that M. nigra fruit extract has protecting effect on unsaturated fatty acids (p<0,001). We considered that fruit extracts having scavenging effects on DPPH^·radical and diminishing the formation of LPO that was originated from OH^· radicals resulted from flavonoids in extracts. In the flavonoid analyses carried out with high performance liquid chromatography (HPLC) equipment, it was observed that fruit extracts has polyphenolic compounds such as rutin, resveratol, myricetin and naringerin.

Key words: Morus nigra L. (black mulberry), matured fruit extract (MF), less matured fruit extract (SMF), Fenton reagent (H₂O₂+FeCl₂), DPPH^·, flavonoids, lipid peroxidation, unsaturated fatty acid.