Antioxidant and antimicrobial activity of Hibiscus gossypifolius and Hypericum perforatum against Salmonella enterica, Bacillus cereus, Escherichia coli and Staphylococcus aureus

Essential oils and extracts of medicinal plants with antimicrobial, anticancer and antioxidant activity are important as a new drug compounds in the field of health and protection of raw and processed foods or healthier food products. The aim of this study was to compare the antioxidant and antibacterial properties of ethanol extracts of Hypericum perforatum
and Hibiscus gossypifolius. The antibacterial properties against pathogenic bacteria (Salmonella enterica, Bacillus cereus, Escherichia coli and Staphylococcus aureus) using well diffusion and antioxidant activity were also tested using Trolox Equivalent Antioxidant Capacity (TEAC) method with ABTS+●. The results revealed that Staphylococcus aureus was the most sensitive bacteria to Hypericum and Hibiscus extracts and there was no significant difference between two extracts (P≥0.05). The results revealed that there was a significant difference between antioxidant activity of Hibiscus and Hypericum (P<0.05). Evaluation of antioxidant activity showed that the IC50 of Hypericum and Hibiscus was 1.56±0.31 mg/mL and 0.78±0.2 mg/mL, respectively. Therefore, Hibiscus gossypifolius had higher antioxidant capacity than Hypericum perforatum. The results showed that ethanol extracts of Hypericum and hibiscus had antioxidant and antibacterial activity; therefore, they can be used in food and pharmaceutical industries as natural additive.