RESUMO
ETHNOPHARMACOLOGICAL RELEVANCE: Plantago australis is a perennial plant widely distributed in Latin America, and its seeds and leaves are used in folk medicine to treat many diseases and conditions. Among its various chemical compounds, verbascoside is one of the most present, and has several pharmacological activities described, but there is not much information about its toxicity. AIMS OF THE STUDY: The aims of this study were to optimize the extraction of verbascoside from P. australis leaves with ultrasound methods, to develop a validated HPLC method to quantify verbascoside, and to evaluate the toxicological safety of the extract and verbascoside using in vitro and in vivo assays. MATERIALS AND METHODS: Dried leaves of P. australis were submitted to different extraction methods (percolation and ultrasound). The optimization of the ultrasound extraction was carried out by complete factorial design (22) and response surface methodology (RSM), followed by HPLC analysis for marker compounds. HPLC analysis was performed to verify the presence of the marker compounds aucubin, baicalein, oleanolic acid, ursolic acid and verbascoside. Mutagenicity was assessed by Salmonella/microsome mutagenicity assay. Cytotoxicity and genotoxicity were evaluated in V79 cells by reduction of tetrazolium salt (MTT) and neutral red uptake (NRU) assays, and alkaline comet assay, respectively. Verbascoside phototoxicity was assessed in 3T3 cells by the NRU phototoxicity assay. Wistar rats were used to perform the acute and sub-chronic toxicity tests. RESULTS: Among the marker compounds, only verbascoside was found in the hydroethanolic extract of P. australis leaves (PAHE); its highest concentration was obtained with the ultrasound-assisted extraction (UAE) method, optimized in 40â¯min and 25⯰C, and the method validation was successfully applied. Neither PAHE nor verbascoside showed mutagenic or genotoxic activities. Cytotoxicity assays demonstrated that both PAHE and verbascoside reduced cell viability only at the highest concentrations, and verbascoside had no phototoxic properties. The in vivo toxicity evaluation of PAHE suggested that the LD50 is higher than 5000â¯mg/Kg, indicating that this extract is safe for use. In addition, no signs of toxicity were found in subchronic exposure. CONCLUSION: The HPLC method to quantify verbascoside was validated, and the extraction of verbascoside from P. australis leaves through ultrasound method was optimized, yielding an extract with 6% verbascoside. Our results suggest the toxicological safety of PAHE and verbascoside, corroborating the use of P. australis in folk medicine, and also indicate verbascoside as a potential ingredient in topical formulations.
Assuntos
Glucosídeos/toxicidade , Fenóis/toxicidade , Extratos Vegetais/toxicidade , Plantago , Células 3T3 , Animais , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Cricetulus , Camundongos , Folhas de Planta , Ratos Wistar , Salmonella typhimurium/efeitos dos fármacos , Salmonella typhimurium/genética , Testes de Toxicidade Aguda , Testes de Toxicidade SubcrônicaRESUMO
BACKGROUND: Chagas disease is caused by the protozoan parasite Trypanosoma cruzi. This illness is found mainly in 21 Latin American countries and an estimated 8 million people are infected worldwide. The unsatisfactory chemotherapy provokes severe toxicity and resistant strains. Medicinal plants constitute a promising source of new drugs and remedies against all kinds of disorders, mainly infectious diseases arousing interest worldwide. OBJECTIVE: The aim of this study is the isolation, structural identification and evaluation of the trypanocidal activity of samples present in the Excoecaria lucida Sw. leaves. METHODS: Total extract (TE) of E. lucida Sw. leaves was obtained by ethanol extract therefore fractionated sequentially with hexane, ethyl acetate and n-butanol, to obtain three phases: Hex, EA and But, respectively. Ellagic acid (EL1) was purified from both EA and But phases, while EL2; a 1:1 stigmasterol-3-O-ß-D-glucopyranoside plus sitosterol-3-O-ß-D-glucopyranoside mixture was obtained from the Hex phase. Activity assays were performed using bloodstream and intracellular forms of T. cruzi and cytotoxicity assays using L929 fibroblasts. RESULTS: The EL1 and EL2 samples were more active against bloodstream trypomastigote forms with EC50 of 53.0±3.6 and 58.2±29.0 µg/mL, respectively; at 100 µg/mL. These samples also showed 70% of inhibition of L929 cells infection. Toxicity assays demonstrated that after 96 h of treatment only the fractions Hex and EA presented detectable cytotoxicity. CONCLUSION: Ellagic acid, stigmasterol-3-O-ß-D-glucopyranoside and sitosterol-3-O-ß-Dglucopyranoside are reported for the first time in E. lucida Sw. leaves as well as their biological activity studies supporting further investigations for Chagas disease treatment.
Assuntos
Extratos Vegetais/farmacologia , Tripanossomicidas/farmacologia , 1-Butanol/química , Acetatos/química , Animais , Ácido Elágico/isolamento & purificação , Ácido Elágico/farmacologia , Ácido Elágico/toxicidade , Euphorbiaceae/química , Fibroblastos/efeitos dos fármacos , Fibroblastos/microbiologia , Glucosídeos/isolamento & purificação , Glucosídeos/farmacologia , Glucosídeos/toxicidade , Hexanos/química , Camundongos , Extratos Vegetais/isolamento & purificação , Extratos Vegetais/toxicidade , Folhas de Planta/química , Sitosteroides/isolamento & purificação , Sitosteroides/farmacologia , Sitosteroides/toxicidade , Estigmasterol/análogos & derivados , Estigmasterol/isolamento & purificação , Estigmasterol/farmacologia , Estigmasterol/toxicidade , Tripanossomicidas/isolamento & purificação , Tripanossomicidas/toxicidade , Trypanosoma cruzi/efeitos dos fármacosRESUMO
p-Synephrine is an adrenergic amine found in Citrus aurantium L. fruits and has been used for weight loss in dietary supplements. There are commercial products containing this substance associated to caffeine, salicin, and ephedrine. The aim of this study was to evaluate the acute toxicity of this mixture in mice of both sexes. The significative results observed after acute oral administration to male and female mice of 300, 350, and 400 mg/kg total of p-synephrine, ephedrine, salicin, plus caffeine in a 10:4:6:80 w/w ratio included a reduction in locomotor activity and ptosis in all treated groups for both sexes. Seizures were also observed in male (400 mg/kg) and female groups (350 and 400 mg/kg). Gasping and tearing were observed in males. Salivation (400 mg/kg), agitation (350 and 400 mg/kg), and piloerection (all treated groups) were significantly observed only in females. Deaths occurred in males at 350 and 400 mg/kg treated groups and the necropsy showed cardiopulmonary hemorrhage. A reduction in locomotor activity was confirmed through the spontaneous locomotor activity test, in which the number of crossings considerably decreased (P < .01) in all treated groups. The rotarod test showed a decrease in motor coordination at 400 mg/kg. Body temperature decreased significantly (P < .01) in all treated groups compared to controls. The results suggested clear signs of toxicity of p-synephrine, ephedrine, salicin, and caffeine association; this toxicity augments the attentiveness on commercial products containing this mixture, given the expressive number of adverse events related to its utilization.
Assuntos
Fármacos Antiobesidade/toxicidade , Álcoois Benzílicos/toxicidade , Cafeína/toxicidade , Efedrina/toxicidade , Glucosídeos/toxicidade , Sinefrina/toxicidade , Adrenérgicos/toxicidade , Animais , Ataxia/induzido quimicamente , Temperatura Corporal , Estimulantes do Sistema Nervoso Central/toxicidade , Combinação de Medicamentos , Feminino , Masculino , Camundongos , Atividade Motora/efeitos dos fármacosRESUMO
Stevioside is a natural non-caloric sweetener extracted from Stevia rebaudiana (Bertoni) leaves. It has been widely used in many countries, including Japan, Korea, China, Brazil and Paraguay, either as a substitute for sucrose in beverages and foods or as a household sweetener. The aim of this work was to study its genotoxic potentiality in eukaryotic cells. Wistar rats were treated with stevioside solution (4mg/mL) through oral administration (ad libitum) and the DNA-induced damage was evaluated using the single cell gel electrophoresis (comet assay). The results showed that treatment with stevioside generates lesions in peripheral blood, liver, brain and spleen cells in different levels, the largest effect being in liver. Therefore, these undesired effects must be better understood, once the data present here point to possible stevioside mutagenic properties.
Assuntos
Ensaio Cometa/métodos , Diterpenos do Tipo Caurano/toxicidade , Glucosídeos/toxicidade , Edulcorantes/toxicidade , Animais , Dano ao DNA , Ratos , Ratos WistarRESUMO
Stevioside is widely used daily in many countries as a non-caloric sugar substitute. Its sweetening power is higher than that of sucrose by approximately 250-300 times, being extensively employed as a household sweetener, or added to beverages and food products. The purpose of this study was to ascertain stevioside genotoxic and cytotoxic potentiality in different biological systems, as its use continues to increase. Agarose gel electrophoresis and bacterial transformation were employed to observe the occurrence of DNA lesions. In addition to these assays, Escherichia coli strains were incubated with stevioside so that their survival fractions could be obtained. Results show absence of genotoxic activity through electrophoresis and bacterial transformation assays and drop of survival fraction of E. coli strains deficient in rec A and nth genes, suggesting that stevioside (i) is cytotoxic; (ii) could need metabolization to present deleterious effects on cells; (iii) is capable of generating lesions in DNA and pathways as base excision repair, recombination and SOS system would be important to recover these lesions.
Assuntos
Diterpenos do Tipo Caurano/toxicidade , Glucosídeos/toxicidade , Mutagênicos/toxicidade , Edulcorantes/toxicidade , DNA Bacteriano/efeitos dos fármacos , Eletroforese em Gel de Ágar , Escherichia coli/efeitos dos fármacos , Escherichia coli/crescimento & desenvolvimento , Escherichia coli/metabolismo , Plasmídeos/efeitos dos fármacos , Plasmídeos/metabolismo , Transformação BacterianaRESUMO
Trehalases present in body wall, Malpighian tubules, fat body, midgut and haemolymph from Tenebrio molitor (Coleoptera), Musca domestica (Diptera), Spodoptera frugiperda and Diatraea saccharalis (Lepidoptera) were assayed in the presence and absence of toxic beta-glucosides produced by plants or their aglycones. The glucosides used were phlorizin, amygdalin, prunasin and the aglycone mandelonitrile. In addition, T. molitor and S. frugiperda trehalases were assayed with and without esculin. More than 60% of total trehalase activity was found in the midgut of these insects. As a rule, trehalases present in each insect were inhibited by at least two of the glucosides. Prunasin was the best inhibitor in tissues with highest trehalase activity. S. frugiperda beta-glucosidases were not able to hydrolyze esculin. Nevertheless, their larval midguts absorb the intact glucoside that is recovered from the fat body, Malpighian tubules and mainly from haemolymph. Mature larvae fed on a diet containing 3 mM (0.1%) esculin have 0.2 mM esculin in their haemolymph, and weigh 60% of control larvae. In vitro, haemolymph trehalase activity is abolished by 0.5 mM esculin. This inhibition may play a role in the decrease of body weight and in animal survival. S. frugiperda larvae reared in 0.1% amygdalin-containing diet present higher trehalase activity in tissues than the larvae reared in 0.1% esculin-containing diet. Higher trehalase activity should be the reason why the S. frugiperda development is not impaired by 1% dietary amygdalin, in contrast to what is observed when insects are reared in 0.1% esculin. The data suggest that many plant beta-glucosides are toxic because they inhibit trehalase, a key enzyme controlling glucose availability in insects.
Assuntos
Inibidores Enzimáticos/toxicidade , Glucosídeos/toxicidade , Insetos/efeitos dos fármacos , Trealase/antagonistas & inibidores , Animais , Inibidores Enzimáticos/isolamento & purificação , Glucosídeos/isolamento & purificação , Insetos/enzimologia , Plantas/química , Trealase/análiseRESUMO
Reversed-phase HPLC fractionation, monitored by brine shrimp bioassay, led to the isolation of a new illudane-type sesquiterpene glucoside, ptaquiloside Z (2), as well as the known bracken carcinogen ptaquiloside (1), from a bioactive aqueous extract of the neotropical bracken fern Pteridium aquilinum var. caudatum (Pteridaceae). The structure of ptaquiloside Z (2) was confirmed by spectroscopic analyses and chemical degradation. Both compounds exhibited similar toxicity (LC50 62.5 micrograms/ml at 24 h and LC50 7.8 micrograms/ml at 48 h) toward brine shrimp.
Assuntos
Glucosídeos/química , Indanos , Plantas Medicinais , Sesquiterpenos/química , Terpenos/química , Animais , Artemia , Cromatografia Líquida de Alta Pressão , Glucosídeos/isolamento & purificação , Glucosídeos/toxicidade , Modelos Moleculares , Conformação Molecular , Intoxicação por Plantas , Sesquiterpenos/isolamento & purificação , Sesquiterpenos/toxicidade , Clima Tropical , VenezuelaRESUMO
Samples of the toxic Brazilian plant, Baccharis coridifolia, which is responsible for numerous cases of livestock poisoning in southern Brazil and Argentina, were collected during the growing season, and the toxicities in calves of the plant materials were correlated with the levels of macrocyclic trichothecenes present. Female plants in flower were considerably more toxic than male plants or plants not in flower. Plants not in flower were of intermediate toxicity. The female plants in flower typically contained 5-10 times the levels of toxins as were found in the male plants. In addition, six new glucosides of the macrocyclic trichothecenes were isolated and characterized. The most prominent glucosides, those of roridins A and E, were found in high levels in the female plants.
Assuntos
Micotoxinas/isolamento & purificação , Extratos Vegetais/isolamento & purificação , Plantas Tóxicas , Tricotecenos/isolamento & purificação , Acetilação , Animais , Animais Domésticos , Antibacterianos/química , Antibacterianos/isolamento & purificação , Antibacterianos/toxicidade , Brasil , Fracionamento Químico , Cromatografia Líquida de Alta Pressão , Cromatografia Gasosa-Espectrometria de Massas , Glucosídeos/química , Glucosídeos/isolamento & purificação , Glucosídeos/toxicidade , Espectroscopia de Ressonância Magnética , Micotoxinas/química , Micotoxinas/toxicidade , Extratos Vegetais/química , Extratos Vegetais/toxicidade , Intoxicação por Plantas/etiologia , Intoxicação por Plantas/veterinária , Plantas Tóxicas/química , Relação Estrutura-Atividade , Tricotecenos/química , Tricotecenos/metabolismo , Tricotecenos/toxicidadeRESUMO
The aims of this study were to characterize clinically and biochemically malnutrition related diabetes mellitus (MRDM) as it presents in Jamaica (J-type or phasic insulin dependent diabetes mellitus) and to examine the food toxin (linamarin)/malnutrition hypothesis as a possible aetiological factor in the onset of MRDM. The study was broadly divided into two major areas: (i) Clinical or patient study and (ii) Animal model study. The patient population consisted of thirty-four, (23 females, 17 males) who attend the Diabetic Outpatient Clinic of the University Hospital of the West Indies. This group consisted of 14 phasic insulin dependent diabetes mellitus (PIDDM) (8 females, 6 males) 10 non-insulin dependent diabetes mellitus (IDDM), (6 females, 4 males). Ten (10) normal (4 females, 6 males) subjects also participated. The diabetic and normal subjects were matched for age, body mass index and duration of diabetes (among diabetics). Comparitive studies were performed on insulin receptor binding, hormonal profile, glucose tolerance, blood status, renal, hepatic and pancreatic function. The results show a significantly decreased white and red blood cell binding to insulin (P<0.05), extensive kidney damage (P<0.05) and increased pancreatic echogenicity in PIDDM. These findings support a separate identity of the latter syndrome from Types 1 and 11 diabetes mellitus. In the animal model study, the dogs (male and female) were maintained on a diet of cornmeal cooked with chicken, fortified with Purina laboratory chow and water ad libitum. Malnutrition was induced by restricting the diet to a very small quantity of cornmeal only for a period of 7-10 days. The recovered dogs were re-fed the normal diet with added milk and multi-vitamin supplement. Linamarin dosage of 20 mg per kg body weight induced abnormally high glucose levels, and in two cases the hyperglycaemia was sustained for several days. There was an associated decrease in binding of insulin to erythrocytes and mononuclear leucocytes, as well as prevailng hypoinsulinaemia in the limarin-induced hyperglycaemic conditions. This animal study presents a possible aetiological model for malnutrition related diabetes mellitus (Summary)
Assuntos
Humanos , Animais , Adulto , Cães , Feminino , Diabetes Mellitus Tipo 1/etiologia , Glucosídeos/toxicidade , Manihot/toxicidade , Nitrilas/toxicidade , Distúrbios Nutricionais/complicações , Desnutrição Proteico-Calórica/complicações , Diabetes Mellitus Tipo 1/metabolismo , Diabetes Mellitus Tipo 2/etiologia , Modelos Animais de Doenças , Jamaica/epidemiologia , Desnutrição Proteico-Calórica/metabolismoRESUMO
The aims of this study were to characterize clinically and biochemically malnutrition related diabetes mellitus (MRDM) as it presents in Jamaica (J-type or phasic insulin dependent diabetes mellitus) and to examine the food toxin (linamarin)/malnutrition hypothesis as a possible aetiological factor in the onset of MRDM. The study was broadly divided into two major areas: (i) Clinical or patient study and (ii) Animal model study. The patient population consisted of thirty-four, (23 females, 17 males) who attend the Diabetic Outpatient Clinic of the University Hospital of the West Indies. This group consisted of 14 phasic insulin dependent diabetes mellitus (PIDDM) (8 females, 6 males) 10 non-insulin dependent diabetes mellitus (IDDM), (6 females, 4 males). Ten (10) normal (4 females, 6 males) subjects also participated. The diabetic and normal subjects were matched for age, body mass index and duration of diabetes (among diabetics). Comparitive studies were performed on insulin receptor binding, hormonal profile, glucose tolerance, blood status, renal, hepatic and pancreatic function. The results show a significantly decreased white and red blood cell binding to insulin (P<0.05), extensive kidney damage (P<0.05) and increased pancreatic echogenicity in PIDDM. These findings support a separate identity of the latter syndrome from Types 1 and 11 diabetes mellitus. In the animal model study, the dogs (male and female) were maintained on a diet of cornmeal cooked with chicken, fortified with Purina laboratory chow and water ad libitum. Malnutrition was induced by restricting the diet to a very small quantity of cornmeal only for a period of 7-10 days. The recovered dogs were re-fed the normal diet with added milk and multi-vitamin supplement. Linamarin dosage of 20 mg per kg body weight induced abnormally high glucose levels, and in two cases the hyperglycaemia was sustained for several days. There was an associated decrease in binding of insulin to erythrocytes and mononuclear leucocytes, as well as prevailng hypoinsulinaemia in the limarin-induced hyperglycaemic conditions. This animal study presents a possible aetiological model for malnutrition related diabetes mellitus (Summary)