Susceptibility of cariogenic microorganisms to phytoconstituents

Abstract

This study aimed to evaluate the in vitro antibacterial activity of the phytochemicals thymol, linalool, and citronellol against Streptococcus mutans, Streptococcus salivarius and Streptococcus oralis. Disk diffusion screening on solid medium and measurement of the diameter of the bacterial growth inhibition halos was the technique utilized. The Minimum Inhibitory Concentration (MIC) of the substances was determined using serial substance dilutions and microdilution technique in Brain Heart Infusion culture medium. After incubation for 24 hours in an oven at 37 °C, plate reading was completed and confirmed by visual method using 2,3,5 triphenyl tetrazolium chloride dye. The Minimum Bactericidal Concentration (MBC) was determined from MIC subcultures. Assays were performed in triplicate, and chlorhexidine was used as a positive control. The diameters in mm of the growth inhibition halos ranged between 7.3 and 10.7 for S. mutans, 7.3 and 10.0 for S. oralis, and 8.2 and 9.8 for S. salivarius. The MIC and MBC values obtained converged , ranging from maximum values in the presence of Linalool (1,250.0 mg/mL, 2,500.0 mg/mL and 2,500.0 mg/mL, respectively, for S. mutans, S. oralis, and S. salivarius); and minimum values with Thymol (312.5 μg/ml, 156.2 μg/mL and 156.2 μg/ml, respectively for S. mutans, S. oralis, and S. salivarius). All the tested phytochemicals displayed antibacterial activity, thus representing substances with potential applications in preventing tooth decay.Keywords: preventive dentistry, dental caries, citronellol, linalool, thymol. Susceptibilidade de microrganismos cariogênicos a fitoconstituintes ResumoEste estudo objetivou avaliar a atividade antibacteriana in vitro dos fitoquímicos timol, linalol e citronelol sobre Streptococcus mutans, Streptococcus salivaris e Streptococcus oralis. Utilizou-se a técnica de discos de difusão em meio sólido e medição do diâmetro dos halos de inibição. A concentração inibitória mínima (CIM) das substâncias foi determinada utilizando diluições em série das substâncias e técnica de microdiluição em meio de cultura de Brain Heart Infusion. Após incubação durante 24 horas em estufa a 37 °C, a leitura da placa foi confirmada pelo método visual usando o corante 2,3,5 trifenil cloreto de tetrazólio. A concentração bactericida mínima (CBM) foi determinada a partir de subculturas de MIC. Os ensaios foram realizados em triplicata, e clorexidina foi usada como um controle positivo. Os diâmetros dos halos de inibição do crescimento variaram entre 7,3 e 10,7 por S. mutans, 7,3 e 10,0 por S. oralis, e 8,2 e 9,8 para S. salivaris. Os valores de CIM e CBM obtidos variaram de valores máximos na presença de linalol (1.250,0 mg/mL, 2.500.0 mg/mL e 2.500.0 mg/mL, respectivamente, para o S. mutans, S oralis e S. salivaris); a valores mínimos com timol (312,5 μg/ml, 156,2 μg/mL e 156,2 μg

In Vitro Activity of Caffeic Acid Phenethyl Ester against Different Oral Microorganisms

“…In fact, one of the microorganisms that causes tooth caries is S. mutans. In an earlier investigation, while the role of S. Salivarius is more apparent in active carious lesions, it aids in the progression of caries in the teeth [27]. This study's findings are consistent with prior studies that have found CAPE to be bactericidal as well as growth-inhibiting for all cariogenic bacteria [28,29].…”

Inhibition effect of Rosella (Hibiscus sabdariffa L.) petal extract in Hard-Candy against Streptococcus mutans

“…Saponins have the effect of releasing proteins and enzymes from within S. mutans cells (25). In addition to this, the antibacterial mechanism of anthocyanin contained in the rossele petal extract works by entering the inner membrane and decreasing the activity of alkaline phosphatase (AKP), adenosine triphosphate (ATPase) and superoxide dismutase (SOD) in inhibiting the growth of pathogens (26).…”

Annual review of selected scientific literature: A report of the Committee on Scientific Investigation of the American Academy of Restorative Dentistry

“…Ferreira et al 403 studied the antibacterial capability of 3 essential oils on S. mutans, S salivaris, and S. oralis following an in vitro protocol. When testing antibacterial agents against S. mutans, S. salivaris and S. oralis are often included because of their genetic similarity.…”