Chemical Composition, Antibacterial and Antifungal Potential of an Extract From the Leaves of Guapira Graciliflora Mart. Against Oral Microorganisms of Dental Interest

Abstract Objective: To perform an in vitro analysis of antibacterial and antifungal potential of an alcoholic extract from the leaves of Guapira Graciliflora Mart. against oral microorganisms and determine its chemical composition. Material and Methods: A hydroalcoholic extract of the leaves form G. graciliflora was obtained through maceration, vacuum concentration and freeze-drying. Antibacterial and antifungal activities were evaluated against Streptococcus mutans, Streptococcus salivarius, Streptococcus oralis, Streptococcus parasanguinis, Streptococcus mitis and strains of Candida albicans using broth microdilution method. Phytochemical analysis determined the total phenolic compounds, protein concentration and total of sugars present in the extract. Results: G. Graciliflora demonstrated antifungal activity against the LM 11 and LM 410 clinical isolates of C. albicans (MIC 0.5 mg/mL and 2 mg/mL, respectively). The other microorganisms tested were resistant to the extract. The phytochemical analysis revealed 3% proteins, 13% total sugars and 17% phenolic compounds. Conclusion: G. Graciliflora has antifungal activity against clinical strains of C. albicans and exhibits proteins, sugars and phenolic compounds in its chemical composition.

Antifungal Activity, Phytochemical Characterization and Thermal Profile of Anadenanthera colubrina (Vell. ) Brenan

Objective: To investigate the antifungal potential of A. colubrina, and its phytochemical characteristics, thermal profile and toxicity. Material and Methods: To assess potential antifungal activity, the technique of microdilution was used with the determination of the Minimum Inhibitory Concentration and Minimum Fungicidal Concentration, using standard species of Candida and recent clinical isolates of Candida albicans. Analyses of action of the extract were performed on the wall and cell morphology of C. albicans, of the interactive effect between the plant extract and nystatin on C. albicans through the checkerboard method, and of growth kinetics. The phytochemical screening was determined by spectrophotometry. The thermal profile was traced with the determination of thermogravimetric curves (TG) and differential scanning calorimetry (DSC). The toxicity was evaluated by the method of hemolysis. Results: The extract of A. colubrina showed a fungistatic potential against all bacteria tested and it acted by modifying the cellular morphology of C. albicans. There was a synergism between nystatin and the plant extract (FIC=0.375), and 53.18% of total polyphenols were determined. The TG curve showed the occurrence of three steps of thermal decomposition. None of the tested concentrations became the effective cytotoxic concentration. Conclusion: Further studies should be conducted to understand the efficacy and the mechanisms of action involved in the antifungal activity of the plant extract of A. colubrina in order to produce a new drug for the treatment of oral candidiasis.