RESUMO
Resumen Se estima que el 80% de la población mundial utiliza diversas plantas medicinales para el tratamiento o control de diversas enfermedades, ya sean agudas o crónicas, debido a su accesibilidad y bajo costo, observándose en los últimos años un aumento en el consumo sin una observación médica adecuada. México es considerado como el segundo país más importante del mundo en cuanto al conocimiento de la medicina tradicional, solo después de china. El uso de las plantas medicinales se ha reportado desde tiempos prehispánicos como una opción terapéutica, sin embargo, el único enfoque que se tiene es la parte curativa y no se ha reflexionado en que las plantas poseen metabolitos secundarios (compuestos químicos producidos por las plantas con actividad biológica en los seres vivos) que, además de tener efectos terapéuticos poseen efectos tóxicos en las personas que las consumen, observándose en algunos casos efectos reversibles después de suspender su consumo. El copalchi o palo amargo es una planta medicinal que proviene de la corteza del árbol de Hintonia latiflora (sin. Coutarea latiflora), la cual ha sido utilizada principalmente como tratamiento alternativo para pacientes con diabetes tipo 2, ya que se ha demostrado que tiene efecto hipoglucemiante. Sin embargo, se han reportado casos de hepatotoxicidad aguda con un incremento en las transaminasas hepáticas (ALT y AST) por el consumo continuo de dicha corteza, no obstante el procesamiento de las plantas medicinales utilizando medios físicos (calentar o hervir) puede alterar la actividad farmacológica de los constituyentes orgánicos, los cuales pueden verse también afectados en su concentración dependiendo de los factores ambientales de cultivo, localización del suelo, humedad y temperatura ambiental, así como la temporada de cosecha (tallos, hojas, flores, raíces, semillas). El consumo de esta planta medicinal es por medio de infusiones calientes o en cápsulas con extracto.
Abstract Approximately 80% of the world's population uses various medicinal plants for the treatment or control of various diseases, whether acute or chronic, due to their accessibility and low cost, observing in recent years an increase in consumption without proper medical observation. Mexico is considered the second most important country in the world in terms of traditional medicine knowledge, only after China. The use of medicinal plants has been reported since pre-Hispanic times as a therapeutic option; however, the only focus is on the curative part and it has not been considered that plants have secondary metabolites (chemical compounds produced by plants with biological activity in living beings) that, besides having therapeutic effects, have toxic effects in people who consume them, and in some cases reversible effects are observed after suspending their consumption. Copalchi or palo amargo is a medicinal plant obtained from the bark of the Hintonia latiflora tree (syn. Coutarea latiflora), which has been used mainly as an alternative treatment for patients with type 2 diabetes, since it has been shown to have a hypoglycemic effect. However, cases of acute hepatotoxicity have been reported with an increase in hepatic transaminases (ALT and AST) by the continuous consumption of this bark. However, the processing of medicinal plants using physical means (heating or boiling) can alter the pharmacological activity of the organic constituents, which can also be affected in their concentration depending on the environmental factors of cultivation, soil location, humidity, and environmental temperature, as well as the harvesting season (stems, leaves, flowers, roots, seeds). The consumption of this medicinal plant is by means of hot infusions or in capsules with extract.
RESUMO
The copalchi complex, Hintonia latiflora, H. standleyana, and Exostema caribaeum, is widely used in Mexico for treating diabetes and gastrointestinal disorders. The first therapeutic use for H. latiflora bark was registered in the "Florentine Codex" in the sixteenth century. The latest pharmacological and phytochemical studies revealed that the infusion of the leaves have hypoglycemic, antihyperglycemic and gastroprotective activities. For these reasons the monograph of the main copalchi species, H. latiflora, was recently added to the Mexican Herbal Pharmacopoeia. Nevertheless, quality control parameters are focused to the bark but not to the leaves. Moreover, information about other Rubiaceae species is needed. The main goal of this study was to generate molecular and chemical markers for quality control of the copalchi complex raw material. In addition, the resolution of the taxonomical ambiguity between H. latiflora and H. standleyana, as well as the testing of the molecular and chemical markers in different geographical batches, were aims of this study. The molecular markers and chemical profiles of the leaf infusions were generated considering three different populations for H. latiflora and separate individuals of the three species (HL, n = 10; HS, n = 3; EC, n = 4). The molecular markers matK, rbcL, trnH-psbA, rpl32-trnL, and ITS2 were tested for their discriminating capabilities. Chemical profiles of the leaf infusions were obtained by means of HPLC analyses using chlorogenic acid and 4-phenylcoumarins as chemical markers. The concatenated sequence of the molecular markers trnH-psbA, rpl32-trnL, and ITS2 clearly distinguished the three taxa, clarifying the taxonomical ambiguity of the Hintonia genus. Additionally, the chemical profiles allowed the unequivocal identification of each species supporting the molecular results; the geographical origin of the samples did not modify neither the chemical profiles nor the concatenated sequence of H. latiflora, suggesting that it is a robust identity test. The complementary use of molecular and chemical markers will assure the quality of plant material used in traditional medicine for therapeutic purposes, and should be valuable new information for the National Health authorities as a part of the Mexican Herbal Pharmacopoeia.
RESUMO
ETHNOPHARMACOLOGICAL RELEVANCE: Hintonia latiflora is a Mexican medicinal plant with well-documented ethnomedical record comprising more than 400 years; in modern Mexico is used for treating several maladies such as diabetes and gastric ulcers. Although the pharmacological actions of the stem-bark and leaves have been demonstrated, the phenological and geographical effect on the concentration of active principles remains unexplored. AIM OF THE STUDY: The main goals of this study were to analyze the amount of selected 4-phenylcoumarins and chlorogenic acid in the leaves in order to assess the best harvesting period, and consequently their pharmacological efficacy. In addition, the preclinical antidiabetic efficacy of the infusion of the leaves was corroborated using standard pharmacological tests. MATERIALS AND METHODS: The aqueous extracts from the leaves of Hintonia latiflora were prepared by infusion. For phenological and geographical comparison, leaves of Hintonia latiflora were collected in two different regions in Chihuahua and Michoacán. The material was analyzed by UPLC applying an analytical method that developed and validated for this purpose following the ICH guidelines. Investigation of the antidiabetic action was accomplished using an acute hypoglycemic test and oral glucose and sucrose tolerance tests. RESULTS: The validated analytical method was successfully applied for quantifying chlorogenic acid (1) and 4-phenylcoumarins (2-5) in the leaves of 12 different batches (1-12) during one-year period, and seven different batches for each geographical region; the concentration of the metabolites at the phenological cycle was significantly different, their concentration increased during the pre-senescence phase whereas in the leaf renovation stage the highest concentration of 2-5 was reached. The overall analysis of the active compounds concentration between the two populations investigated seems to be less important than the phenological variations. The aqueous extract of the leaves of Hintonia latiflora exerted its antidiabetic effect by different mechanisms showing comparable effect to the organic extract. CONCLUSIONS: The findings of the present investigation reveal that the best harvest season for the leaves of Hintonia latiflora is between the leaves renovation and senescence stages avoiding the flowering period. In addition, no significant differences were found among the two different geographical populations analyzed. The infusions of the leaves, rich in 4-phenylcoumarins and chlorogenic acid, showed comparable antidiabetic action than the organic extract.
Assuntos
Ácido Clorogênico/farmacologia , Cumarínicos/farmacologia , Extratos Vegetais/farmacologia , Rubiaceae/química , Animais , Ácido Clorogênico/isolamento & purificação , Cromatografia Líquida de Alta Pressão , Cumarínicos/isolamento & purificação , Diabetes Mellitus Experimental/tratamento farmacológico , Hipoglicemiantes/isolamento & purificação , Hipoglicemiantes/farmacologia , Masculino , Medicina Tradicional , México , Camundongos , Camundongos Endogâmicos ICR , Folhas de Planta , Rubiaceae/crescimento & desenvolvimentoRESUMO
An extract of the solid cultures of Sporormiella minimoides (Sporormiaceae) isolated as an endophytic fungus from Hintonia latiflora (Rubiaceae), yielded three polyketides, 3,6-dimethoxy-8-methyl-1H,6H-benzo[de]isochromene-1,9-dione, 3-hydroxy-1,6,10-trimethoxy-8-methyl-1H,3H-benzo[de]isochromen-9-one, and 5-hydroxy-2,7-dimethoxy-8-methylnaphthoquinone, along with three known compounds, corymbiferone, ziganein, and brocaenol B. Their structures were characterized by spectrometric and spectroscopic methods. So as to be consistent the literature reports, 3,6-dimethoxy-8-methyl-1H,6H-benzo[de]isochromene-1,9-dione and 3-hydroxy-1,6,10-trimethoxy-8-methyl-1H,3H-benzo[de]isochromen-9-one were given the trivial names of corymbiferone C and corymbiferan lactone E, respectively. All isolates were tested as potential human calmodulin (hCaM) inhibitors using the fluorescent biosensor hCaM V91C-mBBr, but only 5-hydroxy-2,7-dimethoxy-8-methylnaphthoquinone quenched significantly the extrinsic fluorescence of this biosensor, with a dissociation constant (Kd) value of 1.55 µM. Refined docking analysis predicted that 5-hydroxy-2,7-dimethoxy-8-methylnaphthoquinone could also be bound to hCaM at site I displaying hydrophobic interactions with Phe19 and 68, Met51, 71, and 72, and Ile52 and 63 residues.
Assuntos
Ascomicetos/química , Calmodulina/antagonistas & inibidores , Naftoquinonas/isolamento & purificação , Naftoquinonas/farmacologia , Policetídeos/isolamento & purificação , Policetídeos/farmacologia , Rubiaceae/microbiologia , Compostos Bicíclicos com Pontes , Humanos , Modelos Químicos , Estrutura Molecular , Naftoquinonas/química , Policetídeos/química , Rubiaceae/químicaRESUMO
Bioassay-guided fractionation of the bio-active organic extract obtained from solid-media culture of MEXU 27095, an endophytic fungus isolated from the Mexican medicinal plant Hintonia latiflora (Rubiaceae), led to separation of three tridepsides which were identified as thielavins A, J and K. All three compounds inhibited Saccharomyces cerevisieae α-glucosidase (αGHY) in a concentration-dependent manner with IC50 values of 23.8, 15.8, and 22.1µM, respectively. Their inhibitory action was higher than that of acarbose (IC50=545µM), used as a positive control. Kinetic analysis established that the three compounds acted as non-competitive inhibitors with ki values of 27.8, 66.2 and 55.4µM, respectively (α=1.0, 1.2, 0.7, respectively); acarbose behaved as competitive inhibitor with a ki value of 156.1µM. Thielavin J inhibited the activity of α-glucosidase from Bacillus stearothermophilus (αGHBs) with an IC50 of 30.5µM, being less active than acarbose (IC50=0. 015µM); in this case, compound (2) (ki=20.0µM and α=2.9) and acarbose (ki=0.008µM and α=1.9) behaved as non-competitive inhibitors. Docking analysis predicted that all three thielavins and acarbose bind to homologated αGHBs and to αGHY (PDB: 3A4A) in a pocket close to the catalytic site for maltose and isomaltose, respectively. The α-glucosidase inhibitory properties of thielavin K (3) were corroborated in vivo since it induced a noted antihyperglycemic action during an oral sucrose tolerance test (3.1, 10.0 and 31.6mg/kg) in normal and nicotinamide-streptozotocin diabetic mice. In addition, at a dose of 10mg/kg, it provoked a moderate hypoglycemic activity in diabetic mice.