Probiotics can act as a natural barrier against several pathogens, such Helicobacter pylori, a bacterium linked to stomach cancer. The aim of the present study was to isolate and identify lactic acid bacteria (LAB) from pulque and aguamiel, and evaluate their probiotic potential and antimicrobial effect on Escherichia coli, Staphylococcus aureus, and Helicobacter pylori. Ten isolates were selected and evaluated for in vitro resistance to antibiotics and gastrointestinal conditions, and antimicrobial activity against E. coli and S. aureus and the effect on H. pylori strains. 16S rRNA identification was performed. Ten potential probiotic isolates were confirmed as belonging to the genera Lactobacillus and Pediococcus. All the strains were susceptible to clinical antibiotics, except to vancomycin. Sixty percent of the isolates exhibited antimicrobial activity against E. coli and S. aureus. The growth of H. pylori ATCC 43504 was suppressed by all the LAB, and the urease activity from all the H. pylori strains was inhibited, which may decrease its chances for survival in the stomach. The results suggest that LAB isolated from pulque and aguamiel could be an option to establish a harmless relationship between the host and H. pylori, helping in their eradication therapy.

Nowadays, the food and health industries are generating new products with antioxidant potential; among them are those rich in phenolic compounds that have a beneficial impact on human health. Therefore, the aim of this research was to obtain different types of mixtures from Portulaca oleraceae (P), Chenopodium album (C), Opuntia oligacantha Förster var. Ulapa (O), and Amaranthus tricolor (A) and evaluate the content of total phenols, total flavonoids, and antioxidant potential in order to select the mixture with the highest content of phenolic compounds. An experimental simplex–centroid mixture design with 15 experimental treatments was used; the data were analyzed and adjusted to a quadratic model that allowed for the prediction of the content of phenols, flavonoids, and antioxidant activity using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-Azino-bis (3-ethylbenz-thiazoline-6-sulfonic acid) (ABTS) of different experimental mixtures. The results show that the individual components of C and P had the highest content of phenols and antioxidant potential. It was observed that the binary mixtures P-C and P-A presented values of total phenols greater than 11 mg of gallic acid equivalents g⁻¹ DW and values of flavonoids greater than 13 mg of quercetin equivalents g⁻¹ DW. These values were higher than those found in the individual components. The P-C mixture with an antioxidant potential of 66.0 ± 0.07 Trolox equivalents g⁻¹ DW could be used as an additive in food or to obtain a functional food that improves the intake of antioxidant compounds in the population.

The main aim of this study was to determine and compare the antimicrobial effect of hibiscus acid and a commercial 0.12% (w/v) chlorhexidine mouthrinse against Streptococcus mutans, Streptococcus sanguinis, Capnocytophaga gingivalis, and Staphylococcus aureus, and to determine the effect on bacterial cell membrane permeability and the toxicity of hibiscus acid in a mouse model. Hibiscus acid was obtained from acetone extract of Hibiscus sabdariffa calyces. Chlorhexidine (0.12% w/v) mouthrinse was purchased from a local pharmacy. The antimicrobial activity of hibiscus acid and mouthrinse were determined using the gel diffusion technique. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the solutions were determined using the broth dilution method. The effect on bacterial cell membrane permeability of hibiscus acid and mouthrinse was determined by crystal violet assay. The toxicity of hibiscus acid was investigated in a mouse model (registration number: UAEH2019-A1-S-8288). Hibiscus acid and mouthrinse showed antibacterial activity against all oral pathogenic bacteria. However, hibiscus acid showed a lower antibacterial effect compared with chlorhexidine mouthrinse. The MIC and MBC for hibiscus acid were 3 and 5 mg/mL, respectively, and was between 30 and 50 μg/mL for mouthrinse. The crystal violet test results indicate that hibiscus acid and mouthrinse alter the permeability of the bacterial membrane. Finally, hibiscus acid did not show toxicity in mouse studies.