The Safety of Licorice Extract Gel for Potential Use in Oral Care

Herbal medicine offers alternative ways to combat antimicrobial resistance in the treatment of human diseases. Licorice (Glycyrrhiza glabra) is a medicinal plant with anti-inflammatory, antimicrobial, and antioxidant properties, which has been increasingly explored in dentistry for its potential benefits in managing oral diseases. The aim of this in vitro study was to assess the cytotoxicity of licorice extract gel against Human Oral Fibroblast (HOrF) cells for potential use in oral and dental care.

The gel was formulated by incorporating ethanolic licorice extract into a carbomer-based gel base. To measure cytotoxicity, HOrF cells were used. Cytotoxicity was assessed by measuring the number of live cells at 24, 48, and 72 h time intervals. The plate containing HOrF cells without any substance was considered the control group.

The results showed that the licorice extract gel (100 µg/mL) did not exhibit cytotoxicity on HOrF cells at the experimentally tested time points. Statistical analysis showed that there was no significant difference in the cytotoxicity of licorice extract gel (100 µg/mL) between the control and test group at any time of 24, 48, and 72 h.

Licorice extract gel at 100 µg/mL was non-toxic to human oral fibroblasts, suggesting its safety for oral applications. Fibroblasts are vital for oral tissue maintenance and wound healing, and the gel’s biocompatibility supports its potential use in oral care products. Licorice bioactive compounds, including glycyrrhizin and glabridin, offer anti-inflammatory, antimicrobial, and antioxidant benefits. While these results are promising, further studies, including animal models and clinical trials, are needed to confirm safety and evaluate long-term use. The results suggest that licorice extract gel could be a promising natural alternative for oral care products, though further studies are needed to confirm its clinical effectiveness.

Due to the non-toxicity of licorice extract gel (at 100 µg/mL) on HOrF, other oral formulations can be prepared from this material in the studied concentration. It is worth noting that the clinical use of this substance requires further animal and human investigations.