Cytotoxicity and antimicrobial action of selected phytochemicals against planktonic and sessileStreptococcus mutans

Abstract

BackgroundDental caries remains the most prevalent and costly oral infectious disease worldwide, encouraging the search for new and more effective antimicrobials. Therefore, the aim of this work was to study the antimicrobial action of selected phytochemicals (eugenol, citronellol, sabinene hydrate, trans-cinnamaldehyde, terpineol and cinnamic acid) against Streptococcus mutans in planktonic and biofilm states as well as the cytotoxicity of these compounds.MethodsThe antibacterial activity of the selected compounds was evaluated by the determination of the minimal bactericidal concentration. The resazurin assay was used to assess the metabolic activity of sessile S. mutans. The cytotoxicity was determined using a fibroblast cell line.ResultsAmong the tested phytochemicals, citronellol, cinnamic acid and trans-cinnamaldehyde were the most effective against both planktonic and sessile S. mutans, an effect apparently related to their hydrophobic character. Additionally, these three compounds did not compromise fibroblasts cell viability.DiscussionCitronellol, cinnamic acid and trans-cinnamaldehyde demonstrated significant antimicrobial activity and low cytotoxicity proposing their potential as a novel group of therapeutic compounds to control oral infectious diseases. Moreover, their effects are particularly relevant when benchmarked against eugenol, a phytochemical commonly used for prosthodontic applications in dentistry.

The use of selected phytochemicals with EDTA against Escherichia coli and Staphylococcus epidermidis single‐ and dual‐species biofilms

“…; Ribeiro et al . ). The most hydrophobic compounds are commonly described to be more toxic and possessing a high affinity for cell membranes, a result particularly reported for compounds with logP > 3 (Ultee et al .…”

“…; Ribeiro et al . ). Furthermore, the multiple mechanisms of action of these natural products help to prevent the selection of resistant bacterial strains (Dahiya and Purkayastha ; Upadhyay et al .…”

Effect of trans-Cinnamaldehyde on Methicillin-Resistant Staphylococcus aureus Biofilm Formation: Metabolic Activity Assessment and Analysis of the Biofilm-Associated Genes Expression

“…TC as an antimicrobial agent shows low toxicity in a low dose, and is classified as safe for the addition to foods by the US Food and Drug Administration (FDA) [20]. Ribeiro et al [21], by using a fibroblast cell line, showed that TC did not compromise fibroblast cell viability. Ferro et al [22], who investigated influence of TC on the survival of Galleria mellonella larvae infected with S. aureus, showed that this compound improved larval survival due to a reduction of bacterial load in their hemolymph, and obtained no results indicating the toxic effect of TC in doses equivalent to 25-50 mg/kg.…”

“…Metabolic assay is excellent for the quantification of bacterial viability in biofilm, and the amount of metabolite produced by a biofilm depends on both the metabolic activity of the individual bacteria and the number of live bacteria in the biofilm. The resazurin assay (the Alamar Blue assay) has been described as a reliable and reproducible method for evaluating biofilm susceptibility [21,45,46]. The resazurin assay is based on the reduction of resazurin, a blue dye that can be reduced by metabolically active cells to pink resorufin, which is fluorescent.…”

Evaluation of Antibacterial and Antibiofilm Activity of Cinnamon, Clove, Eucalyptus, and Tea Tree Oils Against Oral Streptococci

“…Therefore, their supragingival application has a promising beneficial effect (Sreevidhya and Geetha, 2014). Evidence on the chemical properties of phytochemicals indicate that the hydrophobicity seems to result in higher antimicrobial effect (Ribeiro et al, 2018).…”