Antibacterial Effect of Annona muricata L. Leaves on Streptococcus mutans ATCC 25175 Strains

Abstract

Introduction: Soursop is a pleasantly flavoured tropical fruit commonly consumed in Peru and is of great importance due to its health benefits. Although there are some research studies reported which showed the antimicrobial properties, there are still few studies on Peruvian varieties. Aim: This study compared the antibacterial effect of different concentrations of Annona muricata L. leaf extracts on Streptococcus mutans ATCC 25175 strains in-vitro. Materials and Methods: Ethanolic extracts were prepared by leaching at concentrations of 10%, 20%, 30%, 40%, 50%, 60%, 70%, and 80%. Plates were prepared with Brain Heart Infusion (BHI) agar medium and seeded with S. mutans inoculum using the swab method. The antibacterial effect was evaluated via the well diffusion method, using 0.12% chlorhexidine gluconate as the positive control and 70% ethanol as the negative control. The plates were incubated in anaerobic jars at 37°C for 48 hours. Inhibition halos were measured using a millimeter ruler. This experimental study was performed at the Department of Oral Microbiology, National University of Trujillo, Perú. Results: The results showed antibacterial activity at all concentrations, with the greatest inhibition halo at the 80% concentration (27.20 mm) and the smallest at 10% (9 mm). Conclusion: The present study revealed that increased antibacterial activity was directly proportional to the increase in concentration.

Keywords

• anti-bacterial agents
• biological products
• inhibition halo