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This study evaluated the effect of experimental solutions containing plant extracts on bacterial species and enamel caries prevention. Microcosm biofilm was produced from human saliva mixed with McBain saliva (0.2% sucrose) on bovine enamel for 5 days (3 days under anaerobiosis and 2 days under aerobiosis) at 37°C. From the 2nd day, the following treatments were applied (1 × 60 s/day): Vochysia tucanorum (10 mg/mL); Myrcia bella (5 mg/mL); Matricaria chamomilla (80 mg/mL); Malva sylvestris, fluoride, and xylitol (Malvatricin Plus®); 0.12% chlorhexidine (CHX, PerioGard®); and PBS (negative control). The medium pH was measured. Quantitative polymerase chain reaction was performed for the detection of Streptococcus mutans and Lactobacillus spp. Enamel demineralization was measured by spectral-domain optical coherence tomography. The data were compared by means of the Kruskal-Wallis/Dunn, two-way ANOVA/Bonferroni, and ANOVA/Tukey tests (p < 0.05). The pH decreased after sucrose exposure; only CHX reestablished pH >5.5 by the last day. CHX also eliminated Lactobacillusspp., but the other treatments did not differ significantly from PBS. Malvatricin Plus® and CHX eliminated S. mutans, but the other treatments did not differ from PBS. Similar results were seen concerning the reduction of lesion depth and reflectivity. The experimental natural-extract solutions were ineffective against cariogenic bacteria and in preventing the development of enamel caries.

This study aimed to evaluate the effect of the addition of xylooligosaccharide (XOS, 1.25 g/100 mL) on the pH, physicochemical composition, functional properties, volatile profile, rheological properties, and sensory acceptance of strawberry-flavored whey beverage. The addition of XOS resulted in whey beverages with better functional characteristics (greater antioxidant activity, ACE inhibitory activity, and ⍺-amylase and ⍺-glucosidase inhibition), rheological properties (higher viscosity), volatiles profile, and sensory acceptance (aroma, texture and overall liking), besides providing adequate concentrations of the prebiotic in the product (1.25 g/mL). XOS is an interesting ingredient to improve the functional potential of strawberry-flavored whey beverages.

Water and nitrogen availability are two major environmental factors that can impair plant growth, and when combined, their effects on plant performance can be either intensified or reduced. The objective of this study was to analyze the influence of nitrogen availability on the responses of Amaranthus cruentus’s metabolism to water stress. The plants were cultivated in plastic pots filled with vermiculite, kept under greenhouse conditions, and were watered three times a week with 70% of a full strength nitrogen-free Long Ashton solution, containing 1.97 or 9.88 kg N ha−1 as ammonium nitrate. Photosynthetic parameters were evaluated in planta, and leaves were harvested for chemical analysis of photosynthetic pigments, proline, and phenolic contents. Higher nitrogen supply increased the shoot dry matter, photosynthetic pigments, photosynthesis, stomatal conductance, transpiration, total leaf nitrogen, proline, nitrate, and ammonium but reduced the concentration of flavonoids and total phenols. Six days of water stress did not affect dry matter, photosynthetic pigments, leaf nitrogen, ammonium, or specialized metabolites but increased the proline under high nitrogen and negatively affected stomatal conductance, transpiration, photosynthesis, relative water content, instantaneous water use efficiency, and leaf nitrate. The negative effect was more pronounced under high nitrogen supply. The results show that the addition of a high amount of nitrogen made the physiological processes of plants more sensitive to water stress, indicating that the plant response to water restriction depends on the interaction between the different environmental stressors to which the plants are subjected.

Made available in DSpace on 2020-12-12T02:25:06Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-08-01 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Objective: This study evaluated the antibiofilm and anti-caries effects of an experimental mouth rinse containing aqueous extract of Matricaria chamomilla L. Methods: Microcosm biofilm was produced on bovine enamel, from pooled human saliva mixed with McBain saliva, under 0.2 % sucrose exposure, for 5 days. The biofilm was daily treated using (1 mL/1 min): Vochysia tucanorum Mart. (2.5 mg/mL); Myrcia bella Cambess. (1.25 mg/mL); Matricaria chamomilla L. (20 mg/mL); Malva sylvestris (Malvatricin® Plus–Daudt); 0.12 % Chlorhexidine (PerioGard®-Palmolive, Positive control) and PBS (Negative control). The % dead bacteria, biofilm thickness, EPS biovolume, lactic acid concentration, the CFU counting (total microorganisms, Lactobacillus sp., total streptococci and Streptococcus mutans/S. sobrinus) were determined. Enamel demineralization was measured by TMR. Results: All mouth rinses induced bacterial death compared to PBS (p < 0.0001). The biofilm thickness varied from 12 ± 2 μm (chlorhexidine) to 18 ± 2 μm (V. tucanorum) (ANOVA/Tukey, p < 0.0001). The EPS biovolume varied from 7(4)% (chlorhexidine) to 30(20)% (PBS) (Kruskal-Wallis/Dunn, p < 0.0001). The lactic acid production was reduced by M. sylvestris (1.1 ± 0.2 g/L) and chlorhexidine (0.6 ± 0.2 g/L) compared to PBS (2.6 ± 1.3 g/L) (ANOVA, p < 0.0001). Malva sylvestris and chlorhexidine showed significant low CFU for total microorganisms, Lactobacillus sp. and total streptococci. Only chlorhexidine significantly reduced S. mutans/S. sobrinus. CFUs for total streptococci and Lactobacillus sp, were also significantly reduced by M. chamomilla L. Malva sylvestris (63.4 % of mineral loss reduction), chlorhexidine (47.4 %) and M. chamomilla L. (39.4 %) significantly reduced enamel demineralization compared to PBS (ANOVA/Tukey, p < 0.0001). Conclusion: M. chamomilla L. has lower antibiofilm action, but comparable anti-caries effect to those found for chlorhexidine, under this model. Clinical relevance: This study shows that the antibiofilm and anti-caries potential may vary between the commercial and experimental mouth rinses containing natural agents, with promising results for those containing Matricaria chamomilla L. and Malva Sylvestris. Department of Biological Sciences Bauru School of Dentistry University of São Paulo Department of Biological Sciences School of Science The São Paulo State University (UNESP) Department of Biological Sciences School of Science The São Paulo State University (UNESP)