Antibacterial Effect of Ethanolic Extracts of Dodonaea viscosa L. Jacq. and Mammea americana L. against Staphylococci Isolated from Skin Lesions.

Background: The resistance to antibiotics shown by some dermatological pathogenic microorganisms has increased the interest of pharmaceutical and cosmetic industries in developing natural products that possess different biological activities, including antimicrobial effects. Methods: In the present investigation, the antibacterial activity of ethanolic extracts of Dodonaea viscosa aerial part and Mammea americana leaves and seed was evaluated against resistant strains of Staphylococcus isolated from skin lesions and against S. aureus ATCC 25923 (reference strain). Column chromatography (CC) and preparative thin-layer chromatography (PTLC) were used to obtain separate fractions of the seed extract of M. americana. We also determined the antimicrobial resistance of the strains against antibiotics using the agar disc diffusion assay. In addition, phytochemical screening was performed by colorimetric standard techniques. Results: M. americana seed extract showed the highest antibacterial activity with MBC from 2.3 µg/mL to 19.5 µg/mL without differences with gentamicin (p = 0.998). The isolated strain S. epidermidis I showed the highest antimicrobial resistance against the tested antibiotics. PTLC-fractions of M. americana seed extract showed MBC from 3.2 µg/mL to 40.7 µg/mL against S. epidermidis I and S. aureus 25923 (reference), respectively, which suggests a synergistic effect of the secondary metabolites present in the crude ethanolic extract compared to its active PTLC-fractions, where only coumarins and compounds with lactone groups were detected in the phytochemical screening. Conclusion: M. americana seed extract has promising effects that should be considered in further studies as an alternative or adjuvant in treating skin infections caused by staphylococci.

Evaluación antimicrobiana y coagulante de extractos de cinco vegetales de interés etnobotánico / Antimicrobial and coagulating evaluation of extracts of five vegetables of ethnobotanical interest

Resumen Objetivo: Evaluar la actividad antibacteriana de los extractos de Mimosa tenuiflora, Equisetum arvense, Syzygium aromaticum, Lippia graveolens y Aloe vera contra cepas bacterianas de S. mutans (ATCC700611) y S. sobrinus (ATCC33478) comparado con clorhexidina a 1200 µg/mL (0.12%) y la actividad coagulante en sangre humana. Materiales y métodos: Estudio comparativo, abierto, experimental, prospectivo y transversal in vitro. Se realizaron diluciones a 500 y 1000 µg/mL de cinco extractos y se probaron por triplicado contra microorganismos orales por medio de técnica de pozo en agar y en la evaluación de la actividad coagulante se probaron los cinco extractos por triplicado en sangre humana evaluando TP (tiempo de protrombina) y TTPa (tiempo de tromboplastina parcial activado) mediante coagulómetro. Resultados: El extracto de Lippia graveolens a 500 y 1000 µg/mL mostró un promedio de halos de inhibición sobre S. mutans de 26mm con respecto a clorhexidina a 1200 µg/mL que mostró un promedio de 15mm. Contra cepas de S. sobrinus mostraron un promedio de 19mm a 500 µg/mL y 23mm a 1000 µg/mL con respecto a 15mm de clorhexidina. El valor de TP (tiempo de protrombina) de la muestra de sangre fue 12.27 segundos, al aplicarle E. arvense y S. aromaticum ambos a 1000 µg/mL presentaron tiempos de 13.37 segundos. En cuanto al tiempo de tromboplastina parcial activada (TTPa) el valor de la muestra sin extracto fue 32.63 segundos, al aplicar M. tenuiflora a 500 µg/mL se aumentó el tiempo a 39.17 segundos. Conclusiones: Se concluye que Lippia graveolens tiene mejor efecto antibacteriano contra micrrorganismos orales y M. tenuiflora fue el extracto que aumentó por más tiempo el valor de TTPa.

Abstract Objective: To evaluate the antimicrobial and coagulating activity from five vegetables of ethnobotanical interest extracts (Mimosa tenuiflora, Equisetum arvense, Syzygium aromaticum, Lippia graveolens and Aloe vera). Materials and methods: It was a Comparative, open, experimental, prospective and cross-sectional study through antimicrobial evaluation of the five extracts against bacterial strains of S. mutans (ATCC700611) and S. sobrinus (ATCC33478) by means of agar well technique and an evaluation of coagulating activity by measuring TP (prothrombin time) and APTT (activated partial thromboplastin time) using a coagulometer and comparing the results with those of a healthy patient. Results: It was found that the antimicrobial activity of the extracts on S. mutans at 500 and 1000ppm is statistically significant in the extracts of E. arvense and L. graveolens (p= 0.0057) and (p= 0.0000) respectively and on strains of S. sobrinus from the extracts of A. vera (p= 0.0011) and L. graveolens (p= 0.0089) in both concentrations, which show an antimicrobial effect superior to chlorhexidine. The PT patient's (prothrombin time) value was 12.27 seconds, no statistical difference was observed with a value of (p<0.05), however, E. arvense and S. aromaticum, both at 1000ppm, presented times of 13.37 seconds and at the activated partial thromboplastin time (PTPA) the value of the patient was 32.63 seconds, highlighting M. tenuiflora at 500 ppm, which presented times of 39.17 seconds. Conclusions: The extracts described above contain chemical compounds that are valuable alternatives against microorganisms and oral treatments, and it is also very important that research suggests materials and medications that are effective in the treatment of patients and that do not represent a health risk.

Hypoglycemic Activity of Tilia americana, Borago officinalis, Chenopodium nuttalliae, and Piper sanctum on Wistar Rats.

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.

Safety of Aqueous Extract of Calea ternifolia Used in Mexican Traditional Medicine.

There is a trend to use medicinal plants for primary medical care or as dietary supplements; however, the safety of many of these plants has not been studied. The objective of this work was to determine the toxic effect of the aqueous extract of Calea ternifolia (C. zacatechichi), known popularly as "dream herb" in vivo and in vitro in order to validate its safety. In vivo, the extract had moderate toxicity on A. salina. In vitro, the extract induced eryptosis of 73% at a concentration of 100 µg·mL-1 and it inhibited CYP3A by 99% at a concentration of 375 µg/mL. After administering 8.5 mg/kg of C. ternifolia to rats, we found a reduction in platelets and leukocytes and an increase in urea and the liver enzymes alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP). Histological analysis showed spongiform changes in the proximal tubules of renal tissue and a lymphoid infiltrate in liver tissue. This plant is used in the treatment of diabetes, and it is commercialized as a dietary supplement in several countries. Our results show renal and hepatic toxicity; therefore, more profound research on the toxicity of this plant is needed.

Evaluation of hypocholesterolemic activity of extracts of Bidens odorata and Brickellia eupatorioides.

We sought to evaluate the hypolipidemic activity of extracts of Bidens odorata and Brickellia eupatorioides using a model of hyperlipidemia induced in rats by Triton WR-1339 (300mg/kg intraperitoneally). The rats were divided into 5 groups of 3 rats each: normal control group, hyperlipidemic control group, hyperlipidemic with 20 mg/kg atorvastatin, hyperlipidemic with 300 mg/kg B. odorata extract, and hyperlipidemic with 300mg/kg B. eupatorioides extract, respectively. After 10 d of treatment by intragastric administration, the extract of B. odorata caused a significant decrease of serum total cholesterol and triglyceride levels without altering the liver enzymes aspartate transaminase and alanine aminotransferase. In addition, the extract had antioxidant potential as shown by the 2,2-diphenyl-1-picrylhydrazyl technique. These findings indicate that B. odorata has potential as a hypolipidemic agent and might be beneficial in treatment of hyperlipidemia and atherosclerosis.

Miconia sp. Increases mRNA Levels of PPAR Gamma and Inhibits Alpha Amylase and Alpha Glucosidase.

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.

Antibacterial and Antibiofilm Activity of Methanolic Plant Extracts against Nosocomial Microorganisms.

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 vitro amoebicidal activity of borage (Borago officinalis) extract on Entamoeba histolytica.

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.