In Vitro Synergy of Pongamia pinnata Extract in Combination with Antibiotics for Inhibiting and Killing...

Area of Science:

• Microbiology
• Pharmacology
• Ethnobotany

Background:

• The rise of multidrug-resistant pathogens presents a critical global health challenge.
• Developing novel antimicrobial agents is a lengthy and expensive process.
• Medicinal plants offer a viable alternative for discovering new antibiotics or potentiating existing ones.

Purpose of the Study:

• To investigate the antibacterial activity of Pongamia pinnata seed coat extracts.
• To evaluate the synergistic effects of P. pinnata extracts in combination with various antibiotics against MRSA.
• To explore P. pinnata as a source for novel antimicrobial agents.

Main Methods:

• Aqueous extracts of P. pinnata seed coat were prepared.
• Antibacterial activity was assessed using broth dilution, checkerboard, and time-kill assays.
• Combinations of P. pinnata extracts with antibiotics were tested against methicillin-resistant Staphylococcus aureus (MRSA).

Main Results:

• Synergistic effects (FIC index < 0.5) were observed in 70%–100% of P. pinnata and antibiotic combinations (ampicillin, meropenem, cefazolin, cefotaxime, cefpirome, cefuroxime).
• Time-kill assays demonstrated synergistic activity even at low concentrations of P. pinnata, except when combined with aztreonam.
• No antagonistic interactions were detected between P. pinnata extracts and the tested antibiotics.

Conclusions:

• Aqueous seed coat extracts of P. pinnata exhibit significant antimicrobial potential.
• P. pinnata extracts can enhance the efficacy of conventional antibiotics against MRSA.
• These findings support the development of P. pinnata-derived compounds as novel antimicrobial agents.