Avicenna Journal of Phytomedicine

Avicenna Journal of Phytomedicine

In vitro evaluation of the antimicrobial activity and cytotoxicity of a pomegranate peel extract–based toothpaste

Document Type : Short communication

Authors
1 Neuroscience Research Center, Basic Sciences Research Institute, Mashhad University of Medical Sciences, Mashhad, Iran
2 Metabolic Syndrome Research Center, Basic Sciences Research Institute, Mashhad University of Medical Sciences, Mashhad, Iran; Medical Genetics Research Center, Basic Sciences Research Institute, Mashhad University of Medical Sciences, Mashhad, Iran
3 Department of Periodontics, Faculty of Dentistry, Mashhad University of Medical Sciences, Mashhad, Iran
4 Department of Periodontics, Faculty of Dentistry, Mashhad University of Medical Sciences, Mashhad, Iran; Student Research Committee, Mashhad University of Medical Sciences, Mashhad, Iran
5 Department of Pharmaceutical Sciences in Persian Medicine, School of Persian and Complementary Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
6 Faculty of Medicine, Mashhad University of Medical Sciences, Khorasan Razavi, Iran
7 Medical Genetics Research Center, Basic Sciences Research Institute, Mashhad University of Medical Sciences, Mashhad, Iran
Abstract
Objective: To evaluate the in vitro antimicrobial activity of a toothpaste containing pomegranate (Punica granatum L.) peel 70% hydroalcoholicextract (PPE) against oral microorganisms and to assess its cytotoxicity in mammalian cells.
Materials and methods: Cytotoxicity was evaluated using the MTT assay on L929 fibroblasts after 24 hr of exposure to PPE toothpaste at concentrations ranging from 62.5 to 2000 µg/mL. Antimicrobial activity was assessed using the agar well diffusion method against Streptococcus mutans, Lactobacillus plantarum, and Candida albicans. Two dilutions of PPE toothpaste (1:1 and 1:3 v/v) were compared with a commercial toothpaste. Chlorhexidine (CHX) was used as the positive control, and distilled water served as the negative control.
Results: PPE toothpaste showed no significant cytotoxicity at any tested concentration and produced inhibition zones against all tested microorganisms. Although the commercial comparator produced the largest inhibition zones overall, the 1:1 PPE dilution showed comparable effects, particularly against C. albicans, and its performance was similar to that of CHX. The differences compared with CHX were not statistically significant.
Conclusion: The PPE toothpaste showed no significant cytotoxic effect on L929 fibroblasts (p > 0.05) and exhibited in vitro antimicrobial activity against common oral pathogens, supporting further evaluation in biofilm models and clinical studies.
Keywords
Subjects


Articles in Press, Accepted Manuscript
Available Online from 05 October 2026