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.

In this study, the chemical composition, antimicrobial, and antioxidant activities of orange essential oil (AN), its folded orange oils (5×, 10×, 20×) and d-limonene (LN) were investigated. The results observed in the chemical composition showed a decrease in the major component LN, in contrast to other minor components, which increased their concentration, such as decanal, linalool, and α-terpineol. The antimicrobial activity was determined for foodborne pathogens using the disk diffusion method followed by the minimum inhibitory concentration and minimum bactericidal concentration. Results showed that folded orange oils (5×, 10×, 20×) had better antimicrobial activity than AN and LN. The antioxidant activity was carried out by 2,2ʹ-azinobis-3-ethylbenzthiazoline-6-sulphonate and 1,1-diphenyl-2-picrylhydrazyl methods; folded orange oil 20× presented significantly better results (p ≤ 0.05) than other oils studied. Using folded oils from AN could be a natural alternative in food processing as ingredients with antimicrobial and antioxidant effect.Perfil químico, actividad antimicrobiana y antioxidante del aceite esencial de naranja y sus aceites concentrados RESUMEN En este estudio, se investigó la composición química, actividad antimicrobiana y antioxidante del aceite esencial de naranja (AN), sus concentrados (5×, 10×, 20×) y d-limoneno (LN). Los resultados en la composición química mostraron una disminución del componente mayoritario d-limoneno, contrario a otros componentes minoritarios que aumentaron su concentración como es el decanal, linalol y α-terpinol. La actividad antimicrobiana fue determinada para bacterias de importancia en alimentos por el método de difusión en disco seguido de la concentración mínima inhibitoria (CMI) y concentración mínima bactericida (CMB). Los resultados mostraron que los aceites concentrados (5×, 10×, 20×) presentaron significativamente mayor actividad antimicrobiana que el AN y LN. La actividad antioxidante se realizó por los métodos de ABTS y DPPH obteniendo que la fracción 20×, presentó actividad antioxidante significativamente mayor (p ≤ 0,05) que los demás aceites estudiados. Los aceites concentrados del aceite esencial de naranja podrían ser una alternativa en la aplicación en alimentos como ingredientes con efecto antimicrobiano y antioxidante ARTICLE HISTORY

Diabetes mellitus is a public health problem worldwide. For this reason, ethanolic extract of Miconia sp. from Oaxaca, Mexico, was selected in search of an alternative against this disease. The effect of Miconia sp. on mRNA expression of PPARγ on cell line 3T3-L1, its effect on alpha amylase and alpha glucosidase, lipid accumulation during adipogenesis, and cell viability on VERO cells were evaluated. The mRNA levels of PPARγ increased on 1.393 ± 0.008 folds, lipid accumulation was increased by 29.55% with Miconia sp. extract and 34.57% with rosiglitazone, and α-amylase and α-glycosidase were inhibited with IC50 values from 28.23 ± 2.15 μg/mL and 1.95 ± 0.15 μg/mL, respectively; the IC50 on antiproliferative activity on VERO cells was 314.54 ± 45.40 μg/mL. In case of α-amylase and α-glycosidase assays, IC50 (inhibitory concentration 50) refers to necessary extract amounts to inhibit 50% of enzymatic activity. On the other hand, on antiproliferative activity, IC50 (inhibitory concentration 50) refers to necessary extract amounts to inhibit 50% of cell proliferation. It was concluded that the compounds present in Miconia sp. ethanolic extract increase mRNA expression of PPARγ, inhibit α-amylase and α-glucosidase, and increase lipid accumulation. It constitutes an alternative as adjuvant in diabetes mellitus treatment; therefore, we recommend continuing identifying the compounds responsible for its promising in vivo antidiabetic activity.

Diabetes mellitus (DM) is considered the epidemic of the 21st century. Traditional medicine uses plants to treat DM; many of these have hypoglycemic effects in both animal models and diabetic patients. Our objective was to evaluate the hypoglycemic activity of Tilia americana, Borago officinalis, Chenopodium nuttalliae, and Piper sanctum on diabetic rats. The methanolic extracts of the plants under study were obtained by Soxhlet extraction. Toxicity was evaluated on Artemia salina; the antioxidant potential was evaluated using the DPPH technique. Hypoglycemic capacity at doses of 250 and 500 mg/kg was tested on Wistar rats with diabetes induced by alloxan (120 mg/kg). The toxicity on A. salina was null for the extracts of B. officinalis and P. sanctum, moderate for T. americana, and highly toxic for C. nuttalliae. The relevant extract of T. americana var. mexicana showed antioxidant activity. Three plants of the studied plants showed hypoglycemic activity: Tilia Americana (p=0.0142), Borago officinalis (p=0.0112), and Piper sanctum (p=0.0078); P. sanctum was the one that showed the greatest reduction in glucose levels at a lower dose.

Borage (Borago officinalis) is a plant with nutritional value that is also used in traditional medicine to treat gastrointestinal disease. This study investigated the amoebicidal activity of a methanol extract of borage. The 50% inhibitory concentration (IC₅₀) of the extract for Entamoeba histolytica was 33 μg/mL. The 50% lethal dose of the extract for brine shrimp was greater than 1,000 μg/mL. The IC₅₀ of the extract for Vero cells was 203.9 μg/mL. These results support the use of borage to prevent diseases associated with E. histolytica infection.