Australasian Dentist Magazine March April 2021

Category 40 Australasian Dentist Introduction A variety of antimicrobial mouthwashes are available commercially and these have been shown to be clinically beneficial in the management of oral disease. 1–4 However, for a variety of reasons the search for novel and more effective antimicrobial agents continues. In addition, adverse effects associated with some available preparations, in particular unpleasant taste and staining of the teeth, have reduced patient acceptability and compliance. 5 Furthermore, the presence Antimicrobial activity of Citrox® bioflavonoid preparations against oral microorganisms clinical By S. J. Hooper, 1 M. A. O. Lewis, 2 M. J. Wilson 3 and D. W. Williams 4 1* Research Associate in Oral Microbiology, 2 Professor of Oral Medicine, 3 Senior Lecturer/Consultant in Oral Microbiology, 4 Reader in Oral Microbiology, School of Dentistry, Cardiff University, Heath Park, Cardiff, CF14 4XY *Correspondence to: Dr Samuel Hooper Email: hoopersj@cardiff.ac.uk In brief u Citrox®is a bioflavonoid-containing product derived from citrus fruit, available in two formulations that have been used in a range of cleansers and disinfectants. u Citrox®showed substantial antimicrobial activity against a range of oral bacteria and Candida species. u Citrox®bioflavonoid preparations may be useful antimicrobial agents in future mouthwash and oral care products. Background Citrox® is a formulation of soluble bioflavonoids obtained from citrus fruits. The non-toxic and antimicrobial properties of natural bioflavonoids are well documented, and consequently there has been interest in the therapeutic application of these substances. Objective To determine the antimicrobial activity of two Citrox® formulations (BC30 and MDC30) with different bioflavonoid combinations against a range of oral microorganisms. Methods The antimicrobial activity of both formulations was tested against 14 bacterial species and six Candida species. The two Citrox® formulations (dilution range 0.007–8% v/v) were firstly evaluated by determining the in vitro Minimal Inhibitory Concentration (MIC) against planktonic microorganisms in a broth microdilution assay. Secondly, the ability of the same serial dilutions to inhibit microbial growth was assessed in a modified microtitre biofilm assay. Results BothCitrox® formulations exhibited antimicrobial activity. The BC30 formulation demonstrated greater activity than MDC30 and significantly inhibited growth of all bacterial species and most candidal species tested at a concentration of 1% (v/v) in both the broth and the biofilm assay. Conclusion Bioflavonoid preparations of Citrox® have a broad-spectrum of antimicrobial activity against oral microorganisms, and as such have the potential to be used within therapeutic preparations for the control of the oral microflora. of alcohol in some mouthwashes has been shown to cause mucosal irritation in certain patients, particularly those with mucositis, and is felt to be inappropriate by some because of the association of denatured alcohol with the development of oral cancer. 4,6–8 Finally, the long term use of antimicrobial agents has raised concern regarding the potential for an undesirable shift in the composition, site colonisation and emergence of resistance within the complex oral microflora. 9,10 In recent years an association between members of the oral microflora and the development of some forms of systemic diseases has been reported. There is increasing evidence that poor control of the oral flora and severe periodontal disease may be important factors in the onset and progress of coronary heart disease and diabetes. 11 In addition, it is well documented that the composition of the oral flora in hospitalised and debilitated patients undergoes an early microbial shift to one predominated by Gram- negative bacteria. It is now recognised that plaque can therefore act as a reservoir for potential pathogens, including highly resistant microorganisms, for infection at other body sites. 12–15 Specifically, it has been demonstrated that the oropharyngeal microflora has a role in ventilator- associated pneumonia, and the use of therapeutic preparations containing either chlorhexidine or essential oils can reduce the incidence of this significant infection. 16 As the number of immunocompromised individuals in the population continues to increase, so too does the incidence of mucosal infections in the mouth, in particular oral candidosis. Given the concern over the emergence of resistance of yeasts to systemic antifungal agents, there is a clinical requirement for new and effective topical anticandidal strategies. 17 It is against this background that the need for alternative antimicrobial agents with improved antimicrobial profiles and fewer adverse effects becomes greater. There has been considerable interest in the use of ‘natural’ antimicrobial agents. Natural antimicrobial agents can be defined as bioactive compounds derived from biological sources. Although traditional antibiotics strictly fall into this definition, there is concern regarding the prophylactic use of antibiotics due to the