Assessing the antibacterial potency of royal jelly: Minimum inhibitory concentration and minimum bactericidal concentration evaluation against Streptococcus mutans and Staphylococcus aureus

Abstract Introduction: Royal jelly (RJ) has been widely regarded as nature’s elixir, owing to its numerous biological properties, including its antimicrobial efficacy. Royal Jelly, a natural secretion produced by honeybees, is rich in Major Royal Jelly Proteins (MRJPs) and various bioactive compounds, notably 10-hydroxy-2-decenoic acid (10-HDA). These constituents are primarily responsible for its bacteriostatic and bactericidal properties. With the increasing resistance of pathogens such as Streptococcus mutans and Staphylococcus aureus to conventional antibiotics, there is a need to explore alternative substances for controlling these bacteria. Materials and Methods: Standard strains of S. mutans (ATCC strain) and S. aureus (ATCC 25923) were cultivated under aerobic conditions. RJ was acquired and stored at 4°C. It was tested in various concentrations (ranging from 1.25 mg/mL to 20 mg/mL). The minimum inhibitory concentration (MIC) was determined as the lowest concentration of RJ that inhibited visible bacterial growth after incubation. The minimum bactericidal concentration (MBC) was determined by identifying the lowest concentration of RJ capable of killing 99.9% of the initial bacterial population. Results: The MIC for RJ against S. mutans was determined to be 10 mg/mL, and against S. aureus , it was 5 mg/mL. The MBC for RJ against S. mutans was 20 mg/mL, while for S. aureus , it was 5 mg/mL. RJ demonstrated stronger antimicrobial effects against S. aureus compared to S. mutans . Conclusion: The study demonstrates that RJ has effective antimicrobial properties against S. mutans and S. aureus . These findings suggest that RJ could be incorporated into anti-cariogenic treatments. However, additional research is required to explore the practical application of RJ in clinical practice.