The inhibitory potential of Thai mango seed kernel extract against methicillin-resistant Staphylococcus aureus

Area of Science:

• Pharmacology
• Microbiology
• Natural Products Chemistry

Background:

• Methicillin-resistant Staphylococcus aureus (MRSA) is a significant global health threat, necessitating novel therapeutic strategies.
• Plant-derived compounds offer a promising avenue for discovering new antibacterial agents.
• Thai mango seed kernel extract (MSKE) has not been extensively studied for its antibacterial potential against MRSA.

Purpose of the Study:

• To evaluate the in vitro antibacterial activity of MSKE and its phenolic constituents against Staphylococcus aureus and clinical MRSA isolates.
• To investigate the mechanism of action of MSKE on MRSA morphology.
• To assess the synergistic potential of MSKE with penicillin G against MRSA.

Main Methods:

• Disc diffusion, broth microdilution, and time-kill assays were employed to determine antibacterial activity.
• Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to examine ultra-structural changes in MRSA cells.
• Minimum inhibitory concentration (MIC) reduction assays were performed to evaluate synergistic effects with penicillin G.

Main Results:

• MSKE and its phenolic principles, including pentagalloylglucopyranose, exhibited potent in vitro activity against S. aureus and MRSA.
• Electron microscopy revealed MSKE induced cell wall thickening and impaired cell division in MRSA.
• MSKE significantly lowered the MIC of penicillin G against MRSA by at least 5-fold, indicating synergy.

Conclusions:

• MSKE possesses significant antibacterial properties against MRSA, attributed to its phenolic compounds.
• The extract disrupts MRSA cell integrity and division.
• MSKE shows potential as a standalone or adjunctive therapy for MRSA infections, particularly in combination with penicillin G.