Caracterização química, citotoxicidade e ação antimicrobiana de extratos vegetais sobre micro-organismos superinfectantes do meio ambiente bucal

Abstract

This study aimed to evaluate the in vitro antimicrobial activity of the root extract of Solanum paniculatum (jurubeba), the leaf of Spondias mombin (hog or java plum) and the fruit of Lycium barbarum (gojiberry) on superinfecting micro-organisms in the oral environment, as well as phytochemically analyze plant material and potential cytotoxic effects. The phytochemical screening of the extracts was carried out by chemical reactions and Thin Layer Chromatography (TLC). In the analysis by TLC silica gel 60 plates were used; EtOAc: formic acid: MeOH: Water (10: 0.5: 0.6: 0.2 v / v / v / v), BuOH: formic acid: water (3: 1: 1, v / v / v ) Chloroform: MeOH (8: 2, v / v) toluene: ethyl acetate: formic acid (5: 2.5: 0.25 v / v / v) and ethyl acetate: n-propanol: acid acetic acid: water (4: 2: 2: 0.6 v / v / v / v) as mobile phase; and for detection of secondary metabolites the following were used: vanillin sulfuric acid, FeCl 3 solution of 1%, 0.5% Natural Reagent A, Reagent A 0.2% Natural UV / 365 nm KOH 5% (v / v) and Dragendorff . Subsequently, the minimum inhibitory concentration, Minimum Inhibitory Concentration of Adherence (MICA) Bactericidal Kinetics (BK) and fungicidal (FC) were determined from the extracts of Enterococcus faecalis, Staphylococcus aureus, Pseudomonas aeruginosa and Candida albicans (ATCC and clinical isolates). The t-Student test or Mann-Whitney test was applied with 5% significance (p <0.05). Each assay was performed in duplicate and chlorhexidine digluconate at 0.12% and nystatin 100,000 I.U. were used as positive controls. The cytotoxic potential of the extracts was assessed by cell viability from fibroblasts from the 3T3 cell line. Analysis by TLC suggested the presence of phenolic acids, tannins, saponins, alkaloids, flavonoids, ellagic acid, quercetin, kaempferol, coumarins and carbohydrates. All extracts showed bacteriostatic and fungistatic action. S. paniculatum demonstrated a higher mean performance than the positive control and was statistically significant up till the dilution 1:16 (31.25 mg / mL) of P. aeruginosa ATCC. S. mombin had a mean performance superior to chlorhexidine and was statistically significant at the dilutions 1: 512 (0.97 mg / mL) and 1: 256 (1.95 mg / mL) of E. faecalis ATCC and P. aeruginosa ATCC, respectively. Lycium barbarum showed a mean performance higher than the positive control and was statistically significant at the 1:4 dilution (125 mg / mL) and 1:16 (31.25 mg/mL) of Enterococcus faecalis ATCC and P. aeruginosa ATCC, respectively. S. paniculatum presented bactericidal and fungicidal action on E. faecalis (ATCC and OE) and C. albicans (ATCC and OE) and non-stick effect on all microorganisms tested until the dilution 1: 512 (0.97 mg/mL), except for S. aureus ATCC (1:8) and P. aeruginosa ATCC (1: 2). S. mombin showed bactericidal action against E. faecalis (ATCC and OE) and C. albicans (ATCC and OE) and non-stick action on all tested bacteria, especially P. aeruginosa ATCC and E. faecalis (ATTC and OE) until the dilution 1: 512 (0.97 mg/mL). Lycium barbarum showed no bactericidal and fungicidal action, but showed non-stick effect until the 1:32 dilution (15.65 mg/mL) of P. aeruginosa ATCC. The extracts showed cytotoxicity in cell culture at the concentrations tested (100 mg / mL, 31.25 mg / mL, 15.65 mg / mL, 7.81 mg / mL, 6.67 mg / mL, 1.95 mg / mL and 0.97 mg / mL) indicating the need for tests that indicate how much more the tested products are effective against the determined targets than the human cell. It can be concluded that S. paniculatum, Spondias mombin and Lycium barbarum showed significant antimicrobial action, justified by the pharmacological findings, thus stimulating the need for further research of target-specific, bioactive natural substances in the treatment of persistent or refractory oral infections.