Equisetum giganteum and Punica granatum Linn associated with denture adhesive: antimicrobial activity against Candida albicans biofilms

Author(s)

Nara Lígia Martins Almeida

• Document type: Master's Dissertation
• Press: Bauru.
• Institution: Universidade de São Paulo (USP). Faculdade de Odontologia de Bauru (FOB/SDB)
• Defense date: 2016-05-03

Examining board members

Vanessa Soares Lara; Eduardo Bagagli; Karin Hermana Neppelenbroek; James Venturini

• Advisor: Vanessa Soares Lara

Abstract

Denture adhesives inhibit inflammation of the underlying mucosal tissue and can receive, in their composition, antimicrobial components, reducing the risk of development of denture stomatitis (DS), a disease related mainly to the colonization of the prosthesis by the fungus Candida albicans. It has been reported the antifungal activity of herbal medicines, which may help in the treatment of DS. Objective: To realize the phytochemical study of potentially active substances of Equisetum giganteum (Eg) (Cola de caballo) and Punica granatum Linne (Pg) (Pomegranate) and evaluate in vitro the incorporation of hydroalcoholic extracts of Eg and Pg to a denture adhesive (COREGA®) influences the development C. albicans biofilm (SC5314) on the surface a polymerized acrylic resin (Lucitone 550). Material and Methods: After identification of compounds of the herbal by HPLC-PAD, the fraction and the concentration were selected by minimum inhibitory concentration (MIC). Biofilms were induced for 3, 6 or 12 hours on the surface of acrylic resin specimens, previously subjected to treatment with the adhesive associated with herbal (AD/Eg or AD/Pg). As controls, samples were treated with adhesive (AD), adhesive/nystatin association (AD/Nt) or not received treatment (PBS). The antimicrobial activity was evaluated by quantifying the biofilm using counting colony forming units per milliliter (CFU/mL) and by reduction percentage of fungal metabolic activity using colorimetric assay XTT (2,3 Bis (2-Methoxy-4-Nitro-5-Sulfophenil) 5 - [(Phenyl-Amino) Carbonyl] 2H - Tetrazolium Hidroxide). The results were expressed as mean ± standard deviation, and subjected to Kruscal-Wallis test for CFU/mL and Mann-Whitney or 2-way analysis of variance (ANOVA) followed by Tukey\'s HSD post-hoc test and Dunnett test for XTT. The mean values obtained by the two methods (CFU/mL and XTT) were submitted to Spearman correlation test (α=0,05). Results: It was possible to identify, by the analysis on HPLC-PAD, compounds derived from kaempferol and quercetin in Eg and ellagitannins derivatives, as punicalin in Pg. The combination of both herbal medicines to the adhesive (AD/Eg or AD/Pg) significantly reduced the biofilm on the surface of the resin, compared to the AD group. Accordingly, there was an increase in the percentage of reduction of the metabolic activity of biofilm at all periods in the presence of herbal medicines. Considering the treated specimens, the initial period (3 hours) showed the best results in relation to inhibition of fungal growth compared with other periods. Conclusion: Possibly, the antimicrobial potential of E. giganteum and P. granatum is associated with compounds such as flavonoids and tannins, respectively. Finally, we suggest that the combination of these herbal medicines to COREGA® prosthetic adhesive may be a temporary, viable and innovative alternative to assist in the treatment and/or prevention of DS, since the maintenance of the inherent properties of this adhesive is proven after further studies. (AU)

• FAPESP's process: 14/07012-7 - Equisetum giganteum and Punica granatum associated with denture adhesive Corega Ultra: antimicrobial and anti-adherent activities against induced biofilms of Candida albicans and cytotoxic potential in human gingival fibroblastos
• Grantee: Nara Ligia Martins Almeida
• Support Opportunities: Scholarships in Brazil - Master