Exposing the Hepatotoxicity of Medicinal Plants: A Review of Copalchi Stem Bark (Hintonia latiflora) / Exponiendo la hepatotoxicidad de las plantas medicinales: una revisión de palo amargo (Hintonia latiflora)

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.

Atividade farmacológica da monocrotalina isolada de plantas do gênero Crotalaria / Pharmacological activity of monocrotalina isolated from plants of the genus Crotalaria

Crotalaria retusa é uma planta encontrada no Nordeste brasileiro, pertence ao gênero Crotalaria e à família Leguminosae, e possuem mais de seissentas espécies no mundo e mais de quarenta no Brasil. As variedades tóxicas mais conhecidas são C. spectabilis, C. crispata, C. retusa, C. dura e C. globifera. Plantas do gênero Crotalaria são de interesse porque são usadas na medicina popular. Esses gêneros são ricos em alcaloides pirrolizidínicos (AP), que são as principais toxinas e apresentam efeitos pneumotóxicos, nefrotóxicos, cardiotóxicos, fetotóxicos, carcinogênicos, inflamação, hemorragia e fibrose. A monocrotalina é o principal alcaloide pirrolizidínico encontrado nessas plantas e é ativamente oxidada in vivo pelo citocromo P450 no fígado, formando intermediários altamente reativos tipo pirrólicos que são responsáveis pela ligação cruzada do DNA-DNA e DNA-proteína. O presente trabalho teve como objetivo fazer um levantamento bibliográfico via internet, utilizando bancos de dados, programas de pesquisa científica e pesquisa em livros relacionados, acerca da atividade farmacológica e do mecanismo de ação da monocrotalina extraída de plantas do gênero Crotalaria, ressaltando desde os aspectos botânicos da planta, estrutura química dos alcaloides pirrolizidínicos, exemplos experimentais de toxicidade e provável mecanismo de ação.

Crotalia retusa is a plant found in Brazilian Northeast and belongs to the genus Crotalaria and the family Leguminosae, which comprises more than 600 species throughout the world and more than forty in Brazil. The most known toxic species are C. spectabilis, C. crispata, C. retusa, C. dura and C. globifera. Plants of the Crotalaria genus are of great interest because they are used by humans for folk medicine. These plants are rich in pyrrolizidine alkaloids (PA), which are the main toxins that cause effects such as pneumotoxic, nefrotoxic, cardiotoxic, fetotoxic, carcinogenic, inflammation, hemorrhage and fibrosis. Monocrotaline is the main pirrolizidinic alkaloid found in plants and is actively oxidated in vivo by the cytochrome P450 in the liver, yielding highly reactive pyrrolic type intermediates, which are responsible for DNA-DNA and DNA-protein cross-links reaction. The aim of this work is to make a bibliographic survey via internet, using databases, scientific research programs and related books, about pharmacological activity and mechanism of action of monocrotaline extracted from plants of Crotalaria genus, emphasizing plant botanical aspects, chemical structure of pirrolizidinic alkaloid, experimental examples of toxicity and probable action mechanism.