In Vitro Antibacterial Effects of Amygdalus scoparia (Zedo Gum) Hydroalcoholic Extract on Oral Streptococci and Staphylococcus aureus Compared With Chlorhexidine.

BACKGROUND AND

OBJECTIVE

Due to escalating concerns regarding bacterial resistance and the adverse effects associated with chlorhexidine, natural antimicrobial agents have gained significant attention as potential alternatives. The present study aimed to evaluate the in vitro antibacterial activity of the hydroalcoholic extract of Amygdalus scoparia (A. scoparia) gum against primary oral streptococci and Staphylococcus aureus, comparing its efficacy with chlorhexidine and conventional antibiotics.

MATERIALS AND

METHODS

The hydroalcoholic extract of A. scoparia gum was tested against standard and clinical isolates of Streptococcus mutans (S. mutans), Streptococcus sobrinus (S. sobrinus), Streptococcus sanguinis (S. sanguinis), and S. aureus. Antibacterial activity was assessed using the agar well diffusion method to determine the zone of inhibition (ZOI) and the broth microdilution method to determine the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). Chlorhexidine (0.2%) and antibiotics (vancomycin and penicillin) served as positive controls. All experiments were performed in triplicate.

RESULTS

The A. scoparia extract demonstrated significant antibacterial activity against all tested microorganisms. Notably, the extract produced a significantly larger ZOI against clinical isolates of S. mutans (9.40 ± 0.97 mm) compared with chlorhexidine (8.50 ± 1.08 mm; p = 0.0448). Although chlorhexidine exhibited the lowest MIC and MBC values (2.00-13.33 µg/mL), the plant extract showed moderate inhibitory effects (MIC range: 10.67-250.00 mg/mL), particularly against cariogenic streptococci. Overall, clinical isolates demonstrated greater resistance than standard strains.

CONCLUSION

The hydroalcoholic extract of A. scoparia gum exhibited promising antibacterial activity against key oral pathogens, especially clinical isolates of S. mutans, showing comparable or superior efficacy to chlorhexidine in agar diffusion assays. These findings suggest that this extract holds potential as a natural adjunct or alternative antimicrobial agent in oral healthcare products.