Ethnopharmacological study, evaluation of antimicrobial and free radical scavenging activities of extracts from plants used in the management of dental caries: a comparative study

Dental caries is a highly prevalent and costly biofilm-dependent disease that affects about 2.3 billion people in their permanent teeth and 532 million people in their primary teeth according to the World Health Organization. The condition is often accompanied by inflammation of the pulp and root apex. Given the high cost of dental procedures, and also the toxicity and antimicrobial resistance linked to antibiotic use, emphasis should be placed on prevention and alternative therapies. Hence, the present study was aimed at evaluating, in a comparative way, the ethnopharmacology of some plants used in the management of dental caries. Information on plants used, the reasons for their usage and other information was collected from respondents using a questionnaire. Quantitative phytochemical analysis and evaluation of free radical scavenging (antioxidant) activity of hydroethanolic extracts were done using spectrophotometry. Anti-cariogenic activity was assessed in vitr o by the broth microdilution method, while antibiofilm activity was evaluated using both microdilution and crystal violet assays. Lytic activity and outer membrane permeability assays of extracts were determined using spectrophotometric. Phytochemical analysis showed the presence of phenolic compounds in concentrations ranging from 142,57 ± 2,49 mg GAE/g to 89,64 ± 0,61 mg GAE/g. Flavonoid content on its part varied from 37,48 ± 1,75 mg QE/g to 5,64 ± 0,22 mg QE/g and total tannin content ranged from 18,46 ± 0,75 mg TAE/g to 0,18 ± 0,43 mg TAE/g. Antioxidant evaluation showed DPPH IC₅₀ values ranging from 1,12 ± 0,11 to 12286,28 ± 1,14 µg/ml, and FRAP values were between 110,51 ± 0,25 and 135,03 ± 0,33 mmol FeSO ₄ /g. Hydroxyl scavenging activity on its part was concentration dependent with extracts showing significant activities. Minimum Inhibitory Concentrations (MICs) ranged from 64 to 1024 µg/ml while Minimum Bactericidal Concentrations (MBCs) ranged from 128 to 1024 µg/ml. All extracts showed important antibiofilm activity at MICs and sub-MICs as well as good lytic and outer membrane permeability activities. Hydroethanolic extracts of plants in the present study showed good anticariogenic and antioxidant activities. The high phenolic contents could explain their anti-inflammatory activities. It is therefore concluded that, the plants investigated and their phytochemical constituents can be promising sources of new anticariogenic and antibacterial agents for the prevention and management of dental caries.