Evaluation of antimicrobial activity and toxicity of the propolis and chrysin and p-coumaric acid compounds

Introduction: In recent years, research involving natural products has been the target of many investigations in search of new drugs to help treat infections. Objective: In the present study, we used in vitro assays to evaluate the antimicrobial activity by microdilution and to determine the minimum inhibitory concentration (MIC) of the green propolis extract and two of its isolated compounds - p-coumaric acid and chrysin. Methods: These substances were assessed in isolation and associated with each other and standard antimicrobials against Escherichia coli and Staphylococcus aureus ATCC strains. Cytolytic and hemolytic assays were also performed to verify the cytotoxicity of these compounds. Results: The results showed that propolis and p-coumaric acid presented antimicrobial activity against the Staphylococcus aureus ATCC strain, registering MIC of 190 μg/mL and MIC of 250 μg/mL, respectively.As for the toxicity evaluation, both propolis and isolated compounds did not present a cytolytic effect against the leukocytes or nor hemolytic against the positive human "O" blood cells. Conclusion: It can be verified that propolis and p-coumaric acidpresented good potential as an antimicrobial agent and with low toxicity, being a possible alternative in the treatment of infections caused by Staphylococcus aureus.