5-Aminolevulinic acid and the hepatic oxidative stress in the early phase of experimental hexachlorobenzene intoxication

This work evaluated the levels of 5-aminolevulinic acid (ALA) in the liver of rats exposed to different doses of HCB (25,50, and 100 mg/kg b.w. for 4 weeks) and correlated them with lipid peroxidation parameters. Levels of ALA were determined by high-pressure liquid chromatography after derivatization with acetylacetone and formaldehyde, followed by fluorescence detection. The methodology was carefully validated, nonetheless hepatic levels of ALA in all animals treated or not were below the detection limit of the method (2.27mg of ALA/g liver). On the other hand, lipid peroxidation, evaluated as thiobarbituric acid reactants production and chemiluminescence was found significantly increased in the livers of all treated rats, in comparison with control values (pEste trabalho avaliou os níveis de ácido delta-aminolevulínico (ALA) em fígado de ratos expostos a diferentes doses de hexaclorobenzeno (HCB) (25, 50 e 100 mg/kg de peso corpóreo) durante 4 semanas e correlacionou com os parâmetros de peroxidação lipídica. Os níveis de ALA foram determinados por cromatografia líquida de alta eficiência após derivatização com acetilacetona e formaldeído, seguida de detecção de fluorescência. A metodologia foi cuidadosamente validada, apesar disso, os níveis hepáticos de ALA em todos os animais tratados ou não foram abaixo do limite de detecção do método (2,27 mg de ALA/ g de fígado). Por outro lado, para a peroxidação lipídica, avaliada como produção de reagentes ao ácido tiobarbitúrico e quimiluminescência, os resultados foram significativamente elevados em todos os animais tratados em comparação com os do grupo controle (

Experimental glaucoma in the dog

O glaucoma experimental foi produzido em animais como coelho e macaco na tentativa de explicar os mecanismos da doença. Modelos de glaucoma espontâneo também foram descritos. No presente trabalho a elevação da pressão intraocular (PIO) foi produzida em 12 cães por hemácia autóloga fixada em glutaraldcído injetada na câmara anterior do olho esquerdo, sob microscópio cirúrgico. O olho direito foi o controle. Tonometria pelo SchiOtz foi realizada a cada 24 horas com o animal em posição sentada. Com intervalos de tempo que variavam de 2 a 20 dias após a injeção os animais foram sacrificados, os olhos enucleados e congelados, medidos os diâmetros sagital e transversal e então fixados em solução dc formol a 10% c os cortes corados pela hematoxilinaeosina para exame histológico. Em todos os animais a PIO foi maior quando comparado com os controles, o mesmo acontecendo com a medida dos diâmetros que foram também maiores. Os achados histológicos foram compatíveis com glaucoma.Experimental glaucoma was produced in rabbits and monkeysas an effort to explain the mechanisms of this disease. Spontaneous animal model of glaucoma has also been used. Many technics were employed to produce chronic intraocular pression (IOP) elevation. Fixed autologous red blood cells were used to produce elevated IOP in rabbits and monkeys. In this paper we present the results of the elevation of the IOP in 12 mongrel dogs injecting autologous red blood cells (RBC) fixed in 5% glutaraldehyde in phosphate buffer pH 7.0. The RBC were injected into the left eye following paracentesis and under surgical microscope. The right eyes were controls. Schiötz tonometry was performed, each 24 hours, with the dog in the sitting position. The calibration table Schiötz tonometry in dogs from PEIFFER JUNIOR et al.13 (1977) was used. The enucleated eyes were freezed and measured the sagittal and transversal diameters. The eyes were fixed in 10% formalin and sections were stained with hematoxilin-eosin for histological examination. The fixed RBC injected into the anterior chamber produced elevation in the IOP with buphthalmus and keratitis. The IOP was increased in all dogs when compared with the controls, the same occured with the eyes diameters. The pathologic findings were suggestive of glaucoma

Avaliação da toxidade oral aguda e subcrônica de extrato etanólico de Pothomorphe umbellata L. Miq. (Parapiroba)

Existe uma grande preocupação quanto ao uso seguro de extratos vegetais e, por esta razão, a necessidade de estudos toxicológicos pré-clínicos e clínicos destes extratos. O objetivo deste trabalho foi o de avaliar a toxicidade aguda e subcrônica do extrato hidroalcoólico liofilizado de Pothomorphe umbellata L. Miq., administrado por via oral para animais de laboratório. O potencial mutagênico do extrato foi também avaliado pelo teste do micronúcleo. Os resultados dos estudos a curto e médio prazo demonstraram que o extrato não apresenta propriedades tóxicas.There is a high degree of concern regarding the secure use of plant extracts and, for this very reason, preclinical and clinic toxicological evaluation of these extracts are needed. With the aim to assure the quality and the safety of the extract and due to the scarcity of literature information about Pariparoba extract toxicity, our purpose was to investigate the acute and subchronic toxicity of the standardized ethanolic dried root extract of Pothomorphe umbellata L. Miq. This extract was administered orally to adult swiss mice and wistar rats and the mutagenic potencial of the extract was also evaluated. The extract showed to be non toxic

Evaluation of extraction conditions of 4-nerolidylchatecol from Pothomorphe umbellata (L). Miq. using factorial design

Foi avaliada a influência dos fatores (1) tempo: 10 e 40 minutos; (2) tamanho de partícula: 840 e 420 mm; (3) hidromódulo: 1:50 e 1:100 e (4) temperatura: 40 e 60 °C na extração do 4-nerolidilcatecol, (4-NC) mediante planejamento fatorial "2(4)" em que quatro variáveis foram estudadas em dois níveis (máximo e mínimo). O método de extração foi maceração e a quantificação do 4-nerolidilcatecol foi realizada por cromatografia liquida de alta eficiência (CLAE) com detetor eletroquímico. Os resultados da análise fatorial indicam que o fator principal que favorece a extração do princípio ativo é o tamanho de partícula [efeito (2): 12,2086]. Diminuindo o tamanho de partícula aumenta três vezes a quantidade de 4-nerolidilcatecol extraída, enquanto o tempo de maceração [efeito (1): -0,64198], hidromódulo [efeito (3): 1,069804] e temperatura [efeito (4): -0,64198] não influenciam de forma significativa a extração. As interações de dois fatores: (2:3) tamanho:hidromódulo: 1,181142; (2:1) tamanho:tempo: 0,9435065 e (2:4) tamanho:temperatura: 0,0817575 mostraram que apesar do fator tamanho(2) ter favorecido o processo, quando combinado com os demais fatores, não aumenta a eficiência da extração. A metodologia de otimização mediante análise fatorial aplicada ao processo de extração do 4-nerolidilcatecol demonstra a importância do estudo das interações e não de cada fator isolado.The influence of factors: (1) time, 10 and 40 minutes, (2) particle size, 840 and 420 mm; (3) hydromodule, 1:50 and 1:100, and (4) temperature, 40 and 60 °C, in the extraction of 4-nerolidylcathecol (4-NC) from the roots of P. umbellata using factorial design "2(4)" was studied in two levels (maximal and minimal). The extraction method was maceration and the measurement of 4-NC was by HPLC with electrochemical detection. The results of the factorial analysis indicated that the main factor that increases the extraction of the active principle is particle size [effect (2): 12.2086]. The reduction of the particle size (mesh 60) increases threefold the amount of 4-nerolidylchatecol in the extract, while the time of maceration [effect (1): -0.64198], hydromodule [effect (3): 1.069804] and temperature [effect (4): -0.64198] practically do not influence the extraction. Interaction between two factors (2:3) size-hydromodule 1.181142, (2:1) size-time 0.9435065 and (2:4) size-temperature 0.0817575, showed that although the main factor size (2) increases the efficiency of the process, when one of the other three factors was taken together the amount of 4-NC extracted was not significantly increased. The technique of optimization using factorial analysis to investigate the extraction of 4-nerolylilchatecol showed to be useful to notice the interactions between factors and not only the effect of each isolated factor

Simultaneous determination of chlorogenic acid, caffeic acid and caffeine in hydroalcoholic and aqueous extracts of Ilex paraguariensis by HPLC and correlation with antioxidant capacity of the extracts by DPPH· reduction

Um novo método de cromatografia líquida de alta eficiência foi desenvolvido para a determinação simultânea de ácido clorogênico, ácido caféico e cafeína no extrato hidroalcoólico e aquoso de Ilex paraguariensis. As curvas de calibração mostraram boa regressão linear nas faixas de concentração 0,49-7,8 µg/mL para o ácido clorogênico, 0,25-3,9 µg/mL para ácido caféico e 0,244-7,8 µg/mL para cafeína. A redução do radical DPPH· foi usada para determinar a capacidade antioxidante dos extratos. Nosso método para a determinação simultânea de ácido caféico, ácido clorogênico e cafeína foi altamente sensível, possuindo limites de detecção e de quantificação menores do que em outros trabalhos que empregaram metodologias semelhantes.A new high performance liquid chromatographic method has been established for simultaneous determination of chlorogenic acid, caffeic acid and caffeine in hydroalcoholic and aqueous extracts of Ilex paraguariensis. Analytical curves showed good linear regression in the concentration ranges 0.49-7.8 µg/mL for chlorogenic acid, 0.25-3.9 µg/mL for caffeic acid and 0.244-7.8 µg/mL for caffeine. Reduction of the DPPH· radical was used to determine the antioxidant capacity of the extracts. Our method for the simultaneous determination of chlorogenic acid, caffeic acid and caffeine was highly sensitive, having lower detection and quantitation limits than other papers that used similar methodology

Validation of ±-tocopherol and 4-nerolidylcathecol quantitative assessment methodologies

O objetivo do nosso trabalho foi desenvolver um método para avaliação da concentração do ±-tocoferol, considerado o antioxidante lipofílico de maior importância, e do 4-nerolidilcatecol (4-NC), uma substância natural com comprovada ação antioxidante in vitro e in vivo, em matriz biológica (homogeneizado de pele). Utilizamos a cromatografia de alta eficiência acoplada a um detector eletroquímico, sendo que o método apresentou linearidade para as concentrações de 0,025 µg/mL a 0,1 µg/mL para o ±-T (tempo de retenção 3, 4 min) e de 0,15 µg/mL a 2,5 µg/mL para o 4-NC (tempo de retenção 2,06 min), dissolvidos em etanol e etanol:água (1:1). A taxa de recuperação do ±-T adicionado nas concentrações de 0,5; 0,1 e 0,025 µg/mL aos homogeneizados de pele foi de 94,03; 111,2 e 80,7%, respectivamente. A taxa de recuperação de 4-NC adicionado nas concentrações de 2,5; 0,625 e 0,156 µg/mL foi de 103,7; 91,7 e 91,7%. Este método analítico foi e está sendo empregado, com sucesso devido à sua precisão e rapidez, em diversas análises do laboratório.Topical administration of antioxidants, such as ±-tocopherol (±-T), provides an efficient manner of enriching the endogenous cutaneous protection system, and it constitutes a successful strategy for diminishing the ultraviolet radiation-mediated oxidative damage. Besides ±-tocopherol the use of other natural occurring compounds with antioxidant activity has been proposed for the same purpose. The aim of this study was to develop a validated analytical method for the determination of a-tocopherol and 4-nerolidylcathecol (4-NC) concentrations in skin homogenates in a pharmaceutical formulations. We employed liquid chromatography with electrochemical detection. Chromatography was performed on a Supelcosil LC-8, 3 mm, 75x4.6 mm column (Supelco, Bellefonte, PA, USA) with a mobile phase of methanol:water (9:1) for 4-NC and (95:5) for a-T, both containing 20 mM LiClO4 and 2 mM KCl. The flow rate was set at 1.0 ml/min. We established validation parameters including sensitivity, precision, accuracy, stability and found a linear relationship between the concentrations ranges of 0.025 µg/mL to 0.1 µg/mL of ±-T and 0.15 mg/mL to 2.5 mg/mL of 4-NC. The recovery of ±-T from skin homogenates was 94.03, 111.2 and 80.7% for the concentrations of 0.5, 0.1 and 0.025 µg/mL respectively. The recovery for the following concentrations of 4-NC: 2.5, 0.625 and 0.156 µg/mL was 103.7, 91.7 and 91.7%. This analytical procedure has been successfully employed in cutaneous permeation studies, antioxidant activity studies and determinations of 4-NC in Pothomorphe umbellata root extracts

Phenolic compounds from Rosemary (Rosmarinus officinalis L.) attenuate oxidative stress and reduce blood cholesterol concentrations in diet-induced hypercholesterolemic rats

Abstract\ud \ud \ud \ud Background\ud \ud Phenolic compounds combine antioxidant and hypocholesterolemic activities and, consequently, are expected to prevent or minimize cardiometabolic risk.\ud \ud \ud \ud Methods\ud \ud To evaluate the effect of an aqueous extract (AQ) and non-esterified phenolic fraction (NEPF) from rosemary on oxidative stress in diet-induced hypercholesterolemia, 48 male 4-week old Wistar rats were divided into 6 groups: 1 chow diet group (C) and 5 hypercholesterolemic diet groups, with 1 receiving water (HC), 2 receiving AQ at concentrations of 7 and 140 mg/kg body weight (AQ70 and AQ140, respectively), and 2 receiving NEPF at concentrations of 7 and 14 mg/kg body weight (NEPF7 and NEPF14, respectively) by gavage for 4 weeks.\ud \ud \ud \ud Results\ud \ud In vitro, both AQ and NEPF had remarkable antioxidant activity in the 2,2-diphenyl-1-picrylhydrazyl (DPPH●) assay, which was similar to BHT. In vivo, the group that received AQ at 70 mg/kg body weight had lower serum total cholesterol (−39.8%), non-HDL-c (−44.4%) and thiobarbituric acid reactive substance (TBARS) levels (−37.7%) compared with the HC group. NEPF (7 and 14 mg/kg) reduced the tissue TBARS levels and increased the activity of tissular antioxidant enzymes (superoxide dismutase, catalase and glutathione peroxidase). Neither AQ nor NEPF was able to ameliorate the alterations in the hypercholesterolemic diet-induced fatty acid composition in the liver.\ud \ud \ud \ud Conclusions\ud \ud These data suggest that phenolic compounds from rosemary ameliorate the antioxidant defense in different tissues and attenuate oxidative stress in diet-induced hypercholesterolemic rats, whereas the serum lipid profile was improved only in rats that received the aqueous extract.This investigation was supported by grants 08/51333-1 (Afonso MS) and 08/54319-0 (Mancini-Filho, J) from the Fundação de Amparo a Pesquisa do Estado de São Paulo (FAPESP), Brazil. We would like to thank Gabriela Castilho for helping with the language revision. All authors read and approved the final manuscript

Proteasome inhibition and ROS generation by 4-nerolidylcatechol induces melanoma cell death

Induction of apoptotic cell death in response to chemotherapy and other external stimuli has proved extremely difficult in melanoma, leading to tumor progression, metastasis formation and resistance to therapy. A promising approach for cancer chemotherapy is the inhibition of proteasomal activity, as the half-life of the majority of cellular proteins is under proteasomal control and inhibitors have been shown to induce cell death programs in a wide variety of tumor cell types. 4-Nerolidylcatechol (4-NC) is a potent antioxidant whose cytotoxic potential has already been demonstrated in melanoma tumor cell lines. Furthermore, 4-NC was able to induce the accumulation of ubiquitinated proteins, including classic targets of this process such as Mcl-1. As shown for other proteasomal inhibitors in melanoma, the cytotoxic action of 4-NC is time-dependent upon the pro-apoptotic protein Noxa, which is able to bind and neutralize Mcl-1. We demonstrate the role of 4-NC as a potent inducer of ROS and p53. The use of an artificial skin model containing melanoma also provided evidence that 4-NC prevented melanoma proliferation in a 3D model that more closely resembles normal human skin.FAPESP [2006/50479-7, 2006/60930-8, 2008/58817-4, 2009/54816-6 2010/50157-5]FAPESPCNPqCNPqINCT_if (CNPq)INCT-if CNPqCAPESCAPESPRP-USPPRPUS