Antibacterial and antibiofilm activities of Mayan medicinal plants against Methicillin-susceptible and -resistant strains of Staphylococcus aureus.

ETHNOPHARMACOLOGICAL RELEVANCE: Several medicinal plants are used in Mayan Traditional Medicine to treat skin, urinary, respiratory, and gastrointestinal infectious diseases. However, scientific studies that have supported the bioactivity of these Mayan medicinal plants are limited. AIM OF THE STUDY: To assess the in-vitro anti-Staphylococcus aureus growth and biofilm-formation activities of 15 Mayan medicinal plants that were selected based on their traditional uses for the treatment of infectious diseases. MATERIALS AND METHODS: Mayan medicinal plants used traditionally to treat infectious diseases were preselected. For each part of the plants, four extracts were prepared with different solvents (water, n-hexane, ethyl acetate, and methanol). These were tested against two reference strains: a Methicillin-susceptible and -resistant S. aureus, and two clinical isolates, including a susceptible and multidrug-resistant S. aureus using a Resazurin Microtiter Assay. In addition, the plant extracts were evaluated in biofilm-formation inhibition on S. aureus by means of the Crystal Violet method. RESULTS: A total of 120 extracts from 15 Mayan medicinal plant species belonging to 12 different families were selected according their ethnopharmacological uses to treat infectious diseases. Among the selected plant species, 26 extracts obtained from eight medicinal Mayan plants exhibited significant anti-S. aureus against the four strains tested. The most active extracts were the Aq (aqueous) leaf extract of Krugiodendron ferreum (Minimal Inhibitory Concentration [MIC] = 125-250 µg/mL), the MeOH bark extracts of Matayba oppositifolia, Clusia flava, Gymnopodium floribundum, the MeOH leaf extract of Spondias purpurea with MIC values of 250 µg/mL, and the MeOH leaf and Aq bark extracts of K. ferreum (MIC = 250-500 µg/mL). Among the active extracts, 12 exhibited a bactericidal effect on S. aureus strains (Minimal Bactericidal Concentration [MBC] = 250-1000 µg/mL). Forty extracts from 13 plants have an effect on the anti-formation of biofilm, the most active were the MeOH leaf extract of M. oppositifolia (one-half Inhibitory Concentration [IC50] = 10.4 µg/mL) and the MeOH (IC50 = 17.7 µg/mL) and Hex (18.2 µg/mL) leaf extracts from S. purpurea. CONCLUSION: Aqueous and organic extracts from Mayan medicinal plants showed bactericidal and anti-biofilm activities even against drug-resistant S. aureus strains. The present study supports the traditional usage of some plants employed in Mayan medicine for illnesses such as skin, gastrointestinal, and urinary infections and suggest that these plants could be a good source of antibacterial phytochemicals.

Antinociceptive and Antihyperalgesic Activity of a Traditional Maya Herbal Preparation Composed of Pouteria Campechiana, Chrysophyllum Cainito, Citrus Limonum, and Annona Muricata.

Preclinical Research The purpose of this work was to assess the antinociceptive and antihyperalgesic properties of an herbal preparation, composed of four vegetal species: Pouteria campechiana (P. campechiana), Chrysophyllum cainito (C. cainito), Citrus limonum (C. limonum), and Annona muricata (A. muricata), that is commonly used in combination (PCCA) in traditional Mayan medicine for the treatment of diabetes and pain. An ethanolic extract of PCCA was prepared at a ratio of 1:1:1:1 for each plant. The systemic antinociceptive effect of PCCA extract (50-600 mg/kg, p.o.) was dose-dependent in the rat formalin (1%) producing 66% antinociceptive response at 400 mg/kg, p.o. A concentration-dependent antinociceptive effect of the PCCA extract (20-160 mg/paw) was also demonstrated in the rat capsaicin (0.2%) test. The PCCA extract (100-400 mg/kg, p.o.) had antihyperalgesic effects in alloxan diabetic rats. These findings demonstrate the antinociceptive and antihyperalgesic effects of PCCA and supports the use of the plant extracts in Mayan folk medicine. Drug Dev Res 78 : 91-97, 2017. © 2017 Wiley Periodicals, Inc.

Ecological risk assessment for small omnivorous mammals exposed to polycyclic aromatic hydrocarbons: a case study in northeastern Mexico.

An ecological risk assessment (ERA) was performed using the hazard quotient (HQ) method to evaluate the risks of oral exposure to polycyclic aromatic hydrocarbons (PAHs) for medium sized omnivorous mammals. This is the first in a series of three papers. In Mexico there is little experience in performing this kind of assessment for the terrestrial compartment, in particular for birds and mammals exposed to hydrocarbons. The purpose of this paper is to perform an ERA and to establish if the omnivorous mammalian species living in the area are at risk of adverse effects. The studied site is a land that in past years had been used for the disposition of petroleum tank bottom sludges, and scrap metals. Soil and water samples were collected and analyzed, and we obtained a list of the site's wildlife species as well as samples of the specimens, which were analyzed also. HQs were calculated for the hydrocarbons identified as chemicals of potential ecological concern (COPECs) and the omnivorous mammals of the site were evaluated. Toxicity reference values (TRVs) were taken from the appropriate literature, and the doses of exposure were estimated considering the ingestion of water, soil, and diet. Results indicated that potential risks associated to the oral exposure route were less than benchmarks for effects (in all cases HQ<1). The methodology is adequate in terms of the parameters considered in the calculations, but it was concluded that in order to reduce uncertainty, more research is required in Mexico. This should be primarily aimed at obtaining TRVs for mammals, and consider test species with body weights more similar to those found in the local fauna.

Las plantas del Nuevo Mundo y su amplísima utilización en la Medicina tradicional desde los tiempos precolombinos / The plants of the New World and their wide use in traditional Medicine since pre-Columbian times

Nos complace presentar en este número, el primero del Volumen 20, un artículo original que demuestra una actividad larvicida de plantas americanas contra Aedes aegypti (transmisor del dengue), lo que representa una herramienta alternativa de elevado impacto dentro de las medidas para el control y el manejo integrado de vectores.

Registro de plantas tóxicas para ganado en el estado de Veracruz, México / Toxic plantas for cattle registered in the state of Veracruz, Mexico

A través de entrevistas, recolecta de material de herbario y revisión bibliográfica se llevó a cabo un inventario de las plantas tóxicas para el ganado en el estado de Veracruz. Se registró un total de 173 especies correspondientes a diversas familias de angiospermas. Los resultados se presentan a manera de catálogo incluyendo para cada especie sus nombres científico y común, además de su distribución en México, el tipo de vegetación donde se presenta, la parte tóxica de la planta, la toxicidad y las referencias bibliográficas