Models of hepatoprotective activity assessment

Liver diseases are a major health problem worldwide, making it necessary to develop new molecules that help counteract or prevent such diseases. On account of this fact, investigations aiming to obtain natural and/or synthetic compounds possessing hepatoprotective activity have been undertaken. The development of new drugs consists of a variety of steps, ranging from the discovery of the pharmacological effects in cellular and animal models, to finally demonstrate their efficacy and safety in humans. Different models for assessment of the hepatoprotective activity in vitro, ex vivo and in vivo can be found in medical literature. The purpose of this review is to show the features, main advantages and disadvantages of each of the models, the hepatotoxic agents most commonly used (CCl4, acetaminophen, ethanol, dgalactosamine, t-BuOOH, thioacetamide) as well as the biochemical parameters useful to assess liver damage in the different models

Antimicrobial and Antioxidant Activities of Plants from Northeast of Mexico

Traditional medicine has a key role in health care worldwide. Obtaining scientific information about the efficacy and safety of the plants from our region is one of the goals of our research group. In this report, 17 plants were selected and collected in different localities from northeast Mexico. The dried plants were separated into leaves, flowers, fruit, stems, roots and bark. Each part was extracted with methanol, and 39 crude extracts were prepared. The extracts were tested for their antimicrobial activity using three Gram-negative bacterial strains (Pseudomonas aeruginosa, Klebsiella pneumoniae and Acinetobacter baumannii), three Gram-positive bacterial strains (Enterococcus faecalis and two Staphylococcus aureus strains), and seven clinically isolated yeasts (Candida albicans, C. krusei, C. tropicalis, C. parapsilosis and C. glabrata); their antioxidant activity was tested using a DPPH free radical assay. No activity against Gram-negative bacteria was observed with any extract up to the maximum concentration tested, 1000 μg ml−1. We report here for the first time activity of Ceanothus coeruleus against S. aureus (flowers, minimal inhibitory concentration (MIC) 125 μg ml−1), C. glabrata (MICs 31.25 μg ml−1) and C. parapsilosis (MICs between 31.25 and 125 μg ml−1); Chrysanctinia mexicana against C. glabrata (MICs 31.25 μg ml−1); Colubrina greggii against E. faecalis (MICs 250 μg ml−1) and Cordia boissieri against C. glabrata (MIC 125 μg ml−1). Furthermore, this is the first report about antioxidant activity of extracts from Ceanothus coeruleus, Chrysanctinia mexicana, Colubrina greggii and Cyperus alternifolius. Some correlation could exist between antioxidant activity and antiyeast activity against yeasts in the species Ceanothus coeruleus, Schinus molle, Colubrina greggii and Cordia boissieri

Review of plants with hepatoprotective activity evaluated in Mexico

Liver diseases represent a major health problem around the world. in Mexico these are the 5th leading cause of death in the economically active population. in Mexico, it is estimated that about 60% of the population uses some medicine from plants to treat their illnesses. The purpose of this work was to search for medicinal plants in Mexico that have been evaluated for their hepatoprotective effect in different models. in this review we found only 13 plants evaluated for hepatoprotective activity: Amole tuber, Cochlospermum vitifolium, Heterotheca inuloides, Hibiscus sabdariffa, Leucophyllum frutescens, Prostechea michuacana, Psidium Guajava, Rosmarinus officinalis, Verbena Carolin, Centaurea americana, Juglans mollis, Krameria ramossisima and Turnera diffusa. This study describes the studies conducted in Mexico for each of them and the international literature reports of pharmacological and phytochemical studies

In vitro assessment of hepatoprotective agents against damage induced by acetaminophen and CCl4

Abstract Background: In vitro bioassays are important in the evaluation of plants with possible hepatoprotective effects. The aims of this study were to evaluate the pretreatment of HepG2 cells with hepatoprotective agents against the damage induced by carbon tetrachloride (CCl4) and paracetamol (APAP). Methods: Antioxidative activity was measured using an assay to measure 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging. The in vitro hepatotoxicity of CCl4 and APAP, and the cytotoxic and hepatoprotective properties of silymarin (SLM), silybinin (SLB), and silyphos (SLP) were evaluated by measuring cell viability; activities of aspartate aminotransferase (AST), alanine aminotransferase (ALT), and lactate dehydrogenase (LDH); total antioxidant capacity (TAOxC); and reduced glutathione (GSH), superoxide dismutase (SOD), and lipid peroxidation (malondialdehyde (MDA) levels). Results: Only SLB and SLM showed strong antioxidative activity in the DPPH assay (39.71±0.85 μg/mL and 14.14±0. 65 μg/mL, respectively). CCl4 induced time- and concentration-dependent changes. CCl4 had significant effects on cell viability, enzyme activities, lipid peroxidation, TAOxC, and SOD and GSH levels. These differences remained significant up to an exposure time of 3 h. APAP induced a variety of dose- and time-dependent responses up to 72 h of exposure. SLM, SLB, and SLP were not cytotoxic. Only SLB at a concentration of 100 μg/mL or 150 μg/mL significantly decreased the enzyme activities and MDA level, and prevented depletion of total antioxidants compared with CCl4. Conclusions: CCl4 was more consistent than APAP in inducing cell injury. Only SLB provided hepatoprotection. AST, LDH, and MDA levels were good markers of liver damage. Keywords: Hepatoprotective, HepG2 cell line, Acetaminophen, Carbon tetrachloride, Silybinin, Silyphos, Silymari

Evaluación de la actividad biológica de productos herbolarios comerciales

Antecedentes: En México los productos herbolarios se comercializan mayormente sin ningún control de calidad, lo cual fue evidenciado recientemente por nuestro grupo de investigación. Objetivo: Evaluar la actividad biológica de diversos productos, considerando el uso tradicional de las plantas que contienen. Material y métodos: Los productos fueron adquiridos comercialmente tanto en hierberías como en centros comerciales. Se obtuvieron extractos hidroalcohólicos por maceración a temperatura ambiente y extractos acuosos por ebullición. Se evaluaron la actividad antioxidante (DPPH) antimicrobiana contra S. aureus, E. coli y C. albicans (microdilución en placa), antihipertensiva (inhibición de la enzima convertidora de angiotensina) e inmunomoduladora de los extractos obtenidos. Resultados: Los productos que contenían Peumus boldus, Turnera diffusa, Eucalyptus globulus, Ginkgo biloba y Agastache mexicana resultaron con buena actividad antioxidante, los demás mostraron actividad antioxidante baja o moderada. P. boldus, E. globulus y Salvia officinalis mostraron buena actividad antimicrobiana; sin embargo, los productos analizados de Allium sativum y Mentha piperita, reconocidos tradicionalmente por sus propiedades antisépticas, no mostraron actividad contra los microorganismos utilizados. Los productos comerciales con A. sativum o con Esquisetum arvense, que se recomiendan como diuréticos, no mostraron efecto en la prueba utilizada. Conclusiones: Los resultados de esta investigación demuestran que distintos productos que dicen contener la misma planta producen diferentes grados de actividad biológica. Se hace necesario un estricto control de calidad de los productos herbolarios que evalúe también la actividad biológica, con el fin de prevenir problemas en la salud de la población que los consume

Biological Activities of Extracts from Aerial Parts of Salvia pachyphylla Epling Ex Munz

Abstract: The antioxidant, antimicrobial, antiproliferative, and enzyme inhibitory properties of five extracts from aerial parts of Salvia pachyphylla Epling ex Munz were examined to assess the prospective of this plant as a source of natural products with therapeutic potential. These properties were analyzed by performing a set of standard assays. The extract obtained with dichloromethane showed the most variety of components, as they yielded promising results in all completed assays. Furthermore,theextractobtainedwithethylacetateexhibitedthegreatestantioxidantactivity,aswell as the best xanthine oxidase inhibitory activity. Remarkably, both extracts obtained with n-hexane or dichloromethane revealed significant antimicrobial activity against the Gram-positive bacteria; additionally, they showed greater antiproliferative activity against three representative cell lines of the most common types of cancers in women worldwide, and against a cell line that exemplifies cancers that typically develop drug resistance. Despite that, other extracts were less active, such as the methanolic or aqueous; their results are promising for the isolation and identification of novel bioactive molecules

Synthesis, Biological Evaluation and Docking Studies of Chalcone and Flavone Analogs as Antioxidants and Acetylcholinesterase Inhibitors

Several oxidative processes are related to a wide range of human chronic and degenerative diseases, like Alzheimer’s disease, which also has been related to cholinergic processes. Therefore, search for new or improved antioxidant molecules with acetylcholinesterase activity is essential to offer alternative chemotherapeutic agents to support current drug therapies. A series of chalcone (2a–2k) and flavone (3a–3k) analogs were synthesized, characterized, and evaluated as acetylcholinesterase (AChE) inhibitors, and antioxidant agents using 1,1-diphenyl-2-picrylhydrazyl (DPPH•), 2-20-azino-bis-(3-ethylbenzothiazoline-6-sulfonate) (ABTS•), and β-carotene/linoleic acid bleaching assay. Compounds more active were 3j and 2k in DPPH with EC50 of 1 × 10−8 and 5.4 × 10−3 µg/mL, respectively; 2g and 3i in ABTS (1.14 × 10−2 and 1.9 × 10−3 µg/mL); 2e, 2f, 3f, 2j, and 3j exceeded the α-tocopherol control in the β-carotene assay (98–99% of antioxidant activity). At acetylcholinesterase inhibition assay, flavones were more active than chalcones; the best results were compounds 2d and 3d (IC50 21.5 and 26.8 µg/mL, respectively), suggesting that the presence of the nitro group enhances the inhibitory activity. The docking of these two structures were made to understand their interactions with the AChE receptor. Although further in vivo testing must be performed, our results represent an important step towards the identification of improved antioxidants and acetylcholinesterase inhibitors

Measurement of the cosmic ray spectrum above 4×10184{\times}10^{18} eV using inclined events detected with the Pierre Auger Observatory

A measurement of the cosmic-ray spectrum for energies exceeding $4{\times}10^{18}$ eV is presented, which is based on the analysis of showers with zenith angles greater than $60^{\circ}$ detected with the Pierre Auger Observatory between 1 January 2004 and 31 December 2013. The measured spectrum confirms a flux suppression at the highest energies. Above $5.3{\times}10^{18}$ eV, the "ankle", the flux can be described by a power law $E^{-\gamma}$ with index $\gamma=2.70 \pm 0.02 \,\text{(stat)} \pm 0.1\,\text{(sys)}$ followed by a smooth suppression region. For the energy ($E_\text{s}$) at which the spectral flux has fallen to one-half of its extrapolated value in the absence of suppression, we find $E_\text{s}=(5.12\pm0.25\,\text{(stat)}^{+1.0}_{-1.2}\,\text{(sys)}){\times}10^{19}$ eV.Comment: Replaced with published version. Added journal reference and DO