We aimed to evaluate the antimicrobial effects of Glycyrrhiza uralensis extract on Streptococcus mutans and Candida albicans and its biocompatibility for dental applications. The antimicrobial activity of the G. uralensis extracts at concentrations of 50, 100, 150, and 200 µg/mL was assessed using agar disk diffusion tests, counting the total number of colony-forming units (CFUs), spectrophotometric growth inhibitory assays, and microbial morphology observations using scanning electron microscopy (SEM; Merin, Carl Zeiss, Oberkochen, Germany). We measured the polyphenol and flavonoid contents of G. uralensis extracts using ultraviolet–visible spectrometry and the cytotoxicity of these extracts using an MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. We identified that G. uralensis extracts had significant antimicrobial effects against S. mutans and C. albicans. The optical density of the experimental groups significantly decreased compared with that of the control group. SEM images revealed that the G. uralensis extract affected the morphology and density of S. mutans and C. albicans. The extract concentration of flavonoids, but not polyphenols, increased with increasing concentrations of the G. uralensis extract. Furthermore, cell viabilities were more than 70% for G. uralensis extracts with concentrations of 50 and 100 μg/mL. Naturally derived G. uralensis is biocompatible and exhibits an excellent antimicrobial effect against oral pathogens such as S. mutans and C. albicans. Thus, G. uralensis extracts can be used for the development of oral products that treat and prevent oral diseases.

This study analyzed the antimicrobial, cytotoxic, and antioxidant properties of Cnidiumofficinale (CO) extracts to confirm their antimicrobial activity toward oral microorganisms. The control group contained 0 μg/mL of CO, and the experimental groups contained 50, 100, 150, and 200 μg/mL of CO. To confirm the antibacterial activity of CO extracts against microorganisms in the oral cavity, an inhibition zone test, a colony-forming unit (CFU) analysis, an optical density (OD) evaluation, and a SEM (scanning electron microscopy) analysis were performed. A cytotoxicity test was also conducted to determine cell viability, and the contents of flavonoids and polyphenols were measured to analyze the extract components. In the control group, the growth inhibition zone increased, while the CFU and OD values decreased (p < 0.05). The SEM analysis confirmed that the number of microorganisms for both the microbes decreased. The cell viability was more than 80% in both the control and experimental groups, excluding the 200 μg/mL sample. The flavonoid and polyphenol contents in the experimental groups showed higher values than those of the control group. Therefore, the CO extract showed considerable antimicrobial activity toward both Streptococcus mutans and Candida albicans, suggesting that it may be used as a natural antimicrobial agent for dental applications.

Background and objectives: Bacterial antibiotics have had several side effects. Therefore, interest in natural substances with less side effects is increasing these days. Paeonia lactiflora, the root of Paeonia lactiflora, is used as a raw material for medicines. In this study, we investigated the antibacterial effect and the cytotoxicity of Paeonia lactiflora extract. Materials and Methods: For cytotoxicity, MTT analysis according to ISO 10993-5 was performed. The antibacterial test of the Paeonia lactiflora was determined from bacterial viability, Inhibition zone test, CFU (colony forming unit) and SEM (scanning electron microscope). To confirm the antibacterial component of Paeonia lactiflora, the content of flavonoids and polyphenols was analyzed. Results: Our results showed that Paeonia lactiflora extract contained flavonoids and polyphenols, which exhibited antimicrobial activity against Streptococcus mutans (S. mutans) and Candida albicans (C. ablicans). Further, the cytotoxicity of Paeonia lactiflora extract was low. Conclusions: We believe that our study makes a significant contribution to the literature because it demonstrates that Paeonia lactiflora extract can be used as an antibiotic.

Herein, we investigated the surface characterization and biocompatibility of a denture-lining material containing Cnidium officinale extracts and its antifungal efficacy against Candida albicans. To achieve this, a denture-lining material containing various concentrations of C. officinale extract and a control group without C. officinale extract were prepared. The surface characterization and biocompatibility of the samples were investigated. In addition, the antifungal efficacy of the samples on C. albicans was investigated using spectrophotometric growth and a LIVE/DEAD assay. The results revealed that there was no significant difference between the biocompatibility of the experimental and control groups (p > 0.05). However, there was a significant difference between the antifungal efficiency of the denture material on C. albicans and that of the control group (p < 0.05), which was confirmed by the LIVE/DEAD assay. These results indicate the promising potential of the C. officinale extract-containing denture-lining material as an antifungal dental material.

This study was conducted to determine whether nature-derived Reynoutria elliptica extracts exhibit biocompatibility and antimicrobial effects against oral pathogens such as Streptococcus mutans and Candida albicans. Fine particles of Reynoutria elliptica extract were used to probe for biocompatibility and antimicrobial activity toward these pathogens, and results were evaluated with an MTT (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) assay, spectrophotometric growth inhibitory assay, the total number of colony-forming units (CFU), an agar disk diffusion test, and scanning electron microscopy (SEM). In addition, UV/VIS spectroscopy was used to determine the levels of flavonoid and polyphenol in experimental solutions. Several experimental groups showed cell viability higher than 70%, and the antimicrobial activity toward both S. mutans and C. albicans was significantly higher than was that seen for the control group. In CFU and agar disk diffusion tests with C. albicans, increases in the concentration of Reynoutria elliptica extract led to significantly increased antimicrobial effects. Additionally, SEM results showed that Reynoutria elliptica extract changed the morphology and density of S. mutans and C. albicans. The results of this research can be applied to the use of Reynoutria elliptica extracts for the development of oral products that are biologically friendly and can control oral diseases such as dental caries and candida-associated denture stomatitis.