The use of natural compounds from plants can provide an alternative approach against food-borne pathogens. The mechanisms of action of most plant extracts with antimicrobial activity have been poorly studied. In this work, changes in membrane integrity, membrane potential, internal pH (pH _in ), and ATP synthesis were measured in V ibrio cholerae cells after exposure to extracts of edible and medicinal plants. A preliminary screen of methanolic, ethanolic, and aqueous extracts of medicinal and edible plants was performed. Minimal bactericidal concentrations (MBCs) were measured for extracts showing high antimicrobial activity. Our results indicate that methanolic extracts of basil ( Ocimum basilicum L.), nopal cactus ( Opuntia ficus-indica var. Villanueva L.), sweet acacia ( Acacia farnesiana L.), and white sagebrush ( Artemisia ludoviciana Nutt.) are the most active against V. cholera , with MBCs ranging from 0.5 to 3.0 mg/ml. Using four fluorogenic techniques, we studied the membrane integrity of V. cholerae cells after exposure to these four extracts. Extracts from these plants were able to disrupt the cell membranes of V. cholerae cells, causing increased membrane permeability, a clear decrease in cytoplasmic pH, cell membrane hyperpolarization, and a decrease in cellular ATP concentration in all strains tested. These four plant extracts could be studied as future alternatives to control V. cholerae contamination in foods and the diseases associated with this microorganism.

Biofilm is a complex microbial community highly resistant to antimicrobials. The formation of biofilms in biotic and abiotic surfaces is associated with high rates of morbidity and mortality in hospitalized patients. New alternatives for controlling infections have been proposed focusing on the therapeutic properties of medicinal plants and their antimicrobial effects. In the present study the antimicrobial and antibiofilm activities of 8 methanolic plant extracts were evaluated against clinical isolated microorganisms. Preliminary screening by diffusion well assay showed the antimicrobial activity of Prosopis laevigata, Opuntia ficus-indica, and Gutierrezia microcephala. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined ranging from 0.7 to >15 mg/mL. The specific biofilm formation index (SBF) was evaluated before and after the addition of plant extracts (MBC × 0.75). Opuntia ficus-indica caused the major reduction on SBF in dose‐dependent manner. Cytotoxic activity of plant extracts was determined using brine shrimp lethality test (Artemia salina L.). Lethal Dose concentration (LD₅₀ values) of the plant extracts was calculated. LD₅₀ values for P. laevigata and G. microcephala were 141.6 and 323.3 µg/mL, respectively, while O. ficus-indica showed a slight lethality with 939.2 µg/mL. Phytochemical analyses reveal the presence of flavonoids, tannins, and coumarines.

Concentrated orange oils (5x, 10x, 20x) are ingredients used in different industries as components of flavors and aromas due to their great organoleptic qualities. This research focuses on the search for alternative uses for their application through encapsulation in inclusion complexes with β-cyclodextrin (β–CD). Inclusion complexes of concentrated orange oils (COEO) and β–CD were developed by the co-precipitated method in ratios of 4:96, 12:88, and 16:84 (w/w, COEO: β–CD). The best powder recovery was in the ratio 16:84 for the three oils, with values between 82% and 84.8%. The 20x oil in relation 12:88 showed the highest entrapment efficiency (89.5%) with 102.3 mg/g of β–CD. The FT-IR analysis may suggest an interaction between the oil and the β–CD. The best antioxidant activity was observed in the ratio 12:88 for the three oils. The antifungal activity was determined for all the inclusion complexes, and the 10x fraction showed the highest inhibition at a concentration of 10 mg/mL in ratios 12:88 and 16:84. Antibacterial activity was determined by the minimum inhibitory concentration (MIC) and was found at a concentration of 1.25 mg/mL in ratios 12:88 and 16:84 for 5x and 20x oils.