Antioxidant activity and total phenolic compounds of aqueous and ethanolic extracts of Iranian yellow rose (Rosa foetida Herrm.) and evaluation of their antimicrobial activity against Salmonella enterica, Bacillus cereus, and Staphylococcus aureus

Rosa foetida Herrm. is one of the native Rosa species in Iran known as Iranian yellow rose. The main growth area of this plant in Iran is the western parts especially Kurdistan. It is used for kidney disorders treatment and as a source of vitamin C. The aim of this study was to evaluate the ability of free radical scavenging, determination of phenolic compounds, and antimicrobial activity of aqueous and ethanolic extracts of yellow rose flowers. The antioxidant activity and total phenolic compounds of extracts of yellow rose were determined using ABTS free radical scavenging assay and Folin-Ciocalteu method, respectively. Dilution method was used to determine the minimal inhibitory concentration (MIC) against Salmonella enterica, Bacillus cereus and Staphylococcus aureus. The results showed a significant positive correlation between free radical scavenging percentage and the concentration of the extracts (P<0.05). In the range of 0.39-12.50 mg ml-1 concentrations, the aqueous extract had more antioxidant activity than ethanolic extract (P<0.05). The 50% inhibitory concentration (IC50) of aqueous and ethanolic extracts was calculated to be 217.069 and 223.116 μmol, respectively. The results of total phenolic compounds test in extracts showed a positive and significant relationship between the concentration of the extracts and their phenolic compounds content, and the aqueous extract contained more phenolic compounds as compared with the ethanolic extract (P<0.05). The highest antimicrobial effect of aqueous and ethanolic extracts was observed against Staphylococcus aureus and Salmonella enterica, respectively (P<0.05). Due to the favorable antioxidant and antimicrobial properties of this plant, its use as a natural additive in the food industry is recommended.