Investigation of antioxidant activity of <i>Rosa canina</i> L. fruit and gall extracts

Galls are abnormal plant growth structures formed as defense mechanisms against organisms like insects, nematodes, mites, bacteria, or fungi. This study investigated the antioxidant properties and chemical components of galls (G) formed on Rosa canina L. by Diplolepis sp., in comparison to adjacent normal mature fruit (R), through comprehensive laboratory analyses. The total phenolic content was found to be 338.34 +/- 23.10 mg GAE/g in G and 141.17 +/- 1.12 mg GAE/g in R, while the total flavonoid content was measured at 7.62 +/- 0.17 mg QE/g in G and 6.04 +/- 0.23 mg QE/g in R. It was determined that G exhibited higher ferric reducing power (FRAP), cupric reducing power (CUPRAC), and 1,1-diphenyl-2-picrylhydrazil (DPPH) free radical scavenging activity than R. The gas chromatography-mass spectrometry (GC/MS) analysis identified the primary constituents in the fruit and gall structures. The GC/MS analysis identified the key compounds in the fruit and gall structure. In the sample G, a high concentration of 2-methyloctacosane, which possesses antimicrobial properties and is absent in R, was determined. Additionally, compounds such as hexadecanoic acid, methyl ester, eicosane, and beta-sitosterol, which are not present in R and have pharmaceutical applications, were identified in G. In conclusion, it was established that the antioxidant capacity of R. canina galls is higher than that of mature fruits, and they contain distinct chemical components. Further research is required to elucidate the mechanisms of gall formation and to explore potential applications.