Department of Restorative Dentistry, Federal University of Ceará, 949 Alexandre Baraúna St, Fortaleza, CE 60430-160, Brazil.
Department of Restorative Dentistry, University of Fortaleza, 1321 Washington Soares Ave., Fortaleza, CE 60811-905, Brazil.
Arch Oral Biol. 2022 Jan;133:105299. doi: 10.1016/j.archoralbio.2021.105299. Epub 2021 Oct 29.
The aim was to evaluate the antibacterial and antibiofilm activity of natural (n-CNSL) and technical (t-CNSL) cashew nut shell liquid against streptococci and enterococci related to dental caries and chronic apical periodontitis, respectively.
Minimum inhibitory concentrations (MIC) and minimal bactericidal concentration (MBC) were determined to assess the antimicrobial effect of both CNSLs (n-CSNL and t-CNSL) against S. oralis ATCC 10557, S. sobrinus ATCC 6715, S. parasanguinis ATCC 903, S. mutans UA 159 and E. faecalis ATCC 19433. The antibiofilm activity was evaluated by total biomass quantification, colony forming unit (CFU) counting and scanning electron microscopy (SEM). Furthermore, cytotoxic effect of the substances was evaluated on L929 and HaCat cell lines by MTS assay.
The n-CNSL and t-CNSL showed inhibitory and bactericidal effect against all strains tested in this study, with MIC and MBC values ranging from 1.5 to 25 μg/mL. Overall, both CNSLs showed significant reduction in biomass quantification and enumeration of biofilm-entrapped cells for the strains analyzed, in biofilm formation and preformed biofilms (p < 0.05). In biofilm inhibition assay, the t-CNSL and n-CNSL showed reduction in biomass and CFU number for all bacteria, except in cell viability of S. parasanguinis treated with t-CNSL (p > 0.05). Indeed, SEM images showed a reduction in the amount of biomass, bacterial cells and changes in cellular morphology of S. mutans.
In conclusion, both substances showed effective antibacterial and antibiofilm activity against the strains used in the study, except in viability of S. parasanguinis cells treated with t-CNSL.
评估天然（n-CNSL）和技术（t-CNSL）腰果壳液对与龋齿和慢性根尖周炎相关的链球菌和肠球菌的抗菌和抗生物膜活性。
测定最小抑菌浓度（MIC）和最小杀菌浓度（MBC），以评估两种 CNSL（n-CSNL 和 t-CNSL）对口腔链球菌 ATCC 10557、变形链球菌 ATCC 6715、咽峡炎链球菌 ATCC 903、变异链球菌 UA 159 和粪肠球菌 ATCC 19433 的抗菌作用。通过总生物量定量、菌落形成单位（CFU）计数和扫描电子显微镜（SEM）评估抗生物膜活性。此外，通过 MTS 测定评估了物质对 L929 和 HaCat 细胞系的细胞毒性作用。
n-CNSL 和 t-CNSL 对本研究中测试的所有菌株均表现出抑制和杀菌作用，MIC 和 MBC 值范围为 1.5 至 25μg/mL。总体而言，两种 CNSL 均显著减少了分析菌株生物膜形成和预形成生物膜的生物量定量和生物膜包裹细胞的计数（p<0.05）。在生物膜抑制试验中，t-CNSL 和 n-CNSL 均减少了所有细菌的生物量和 CFU 数量，除了 t-CNSL 处理的咽峡炎链球菌的细胞活力（p>0.05）。事实上，SEM 图像显示生物量、细菌细胞数量减少，变形链球菌的细胞形态发生变化。
总之，两种物质对研究中使用的菌株均表现出有效的抗菌和抗生物膜活性，除了 t-CNSL 处理的咽峡炎链球菌细胞活力外。
