High polarity extracts obtained from Ilex guayusa Loes. leaves, exhibit antioxidant capacity / Extractos de alta polaridad obtenidos a partir de las hojas de Ilex guayusa Loes. exhiben capacidad antioxidante

Background: Ilex guayusa Loes. belongs to the family Aquifoliaceae. It is an evergreen tree native to the Amazon region. According to traditional uses, it is used as a diaphoretic, narcotic, purgative, among other uses. Objective: To evaluate the antioxidant capacity, quantify phenols and total flavonoids of extracts obtained from Ilex guayusa leaves. Methods: Total ethanolic extract was obtained using Soxhlet-type equipment, with subsequent liquid/liquid fractionation with solvents of different polarities (petroleum ether, dichloromethane, and ethyl acetate); were reacted with 2,2-diphenyl-1-picrylhydrazyl (DPPH•) and 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS•+), determining the inhibitory concentration 50 (IC50) and relative antioxidant activity (%AAR), with subsequent statistical analysis (ANOVA and Tukey's post-hoc). Total phenols and flavonoids were quantified using the Folin-Ciocalteu method and complex formation with AlCl3, respectively. Results: The ethanolic extract of leaves showed the highest antioxidant activity in both the DPPH• and ABTS•+ methods with IC50 values of 4.58 and 3.82 ppm, respectively. Conclusions: According to the results obtained in this study, it was possible to corroborate that the ethanolic extract (EE) obtained from the leaves of I. guayusa showed the highest antioxidant capacity, by the DPPH• and ABTS•+ methods. Additionally, it was possible to relate this capacity to the high flavonoids content present in this extract. Based on the above and accompanied by future studies, the Ilex guayusa species could be proposed as an important source of antioxidant compounds with possible application in medicine and the food industry

Antecedentes:Ilex guayusa Loes. pertenece a la familia Aquifoliaceae. Es un árbol perenne, nativo de la región amazónica. De acuerdo con los usos tradicionales es empleada como diaforético, narcótico, purgativo, entre otros usos. Objetivo: Evaluar la capacidad antioxidante, cuantificar fenoles y flavonoides totales de extractos obtenidos a partir de las hojas de Ilex guayusa. Métodos: El extracto etanólico total se obtuvo mediante un equipo tipo "Soxhlet", con posterior fraccionamiento líquido/líquido con solventes de diferentes polaridades (éter de petróleo, diclorometano y acetato de etilo); se hicieron reaccionar con 2,2-difenil-1-picrilhidracilo (DPPH•) y ácido 2,2'-azino-bis-3-etilbenzotiazolin-6-sulfónico (ABTS•+), determinando la concentración inhibitoria 50 (IC50) y la actividad antioxidante relativa (%AAR), con posterior análisis estadístico (ANOVA y post-hoc de Tukey). Los fenoles y flavonoides totales se cuantificaron con el método de Folin-Ciocalteu y el de formación de complejos con AlCl3, respectivamente. Resultados: El extracto etanólico de las hojas fue el que presentó mayor actividad antioxidante tanto en el método DPPH• como en el ABTS•+ con valores de IC50 de 4,58 y 3,82 ppm, respectivamente. Conclusiones: De acuerdo con los resultados obtenidos en este estudio, se pudo corroborar que el extracto etanólico obtenido de las hojas de I. guayusamostró la mayor capacidad antioxidante, por los métodos DPPH• y ABTS•+. Adicionalmente, se pudo relacionar esta capacidad con el alto contenido de flavonoides presentes en este extracto. Con base en lo anterior y acompañado de futuros estudios, la especie I. guayusa podría proponerse como una importante fuente de compuestos antioxidantes con posible aplicación en los campos de la medicina y la industria alimentaria

Triterpenoids from leaves of Ilex guayusa / 中国中药杂志

The chemical constituents from the leaves of Ilex guayusa were investigated. Sixteen triterpenoids were isolated from the 95% ethanol extract of dried leaves of I. guayusa by silica gel, Sephadex LH-20, and ODS column chromatographies and semi-prepa-rative HPLC. Those triterpenoids were identified by NMR, HR-MS, and literature analysis: 3β-hydroxy-11α,12α-epoxy-24-nor-urs-4(23)-ene-28,13β-olide(1), 3β-hydroxy-24-nor-4(23),12-oleanadien-28-methyl ester(2), oleanolic acid(3), 3β,28-dihydroxy-12-oleanene(4), 2α,3β-dihydroxy-11α,12α-epoxy-24-'nor-olean-4(23)-ene-28,13β-olide(5), ursolic acid(6), 3β,23-dihydroxy ursolic acid(7), 3β,28-dihydroxy-12-ursene(8), 3β-28-nor-urs-12-ene-3,17-diol(9), 3β-hydroxyurs-11-ene-28,13β-olide(10), 13β,28-epoxy-3β-hydroxy-11-ursene(11), 3β-hydroxy-28,28-dimethoxy-12-ursene(12), 3β-hydroxy-24-nor-urs-4(23),12-dien-28-oic acid(13), 3β-hydroxy-24-nor-urs-4(23),12-dien-28-methyl ester(14), 2α,3β-dihydroxy-11α,12α-epoxy-24-nor-urs-4(23)-ene-28,13β-olide(15) and 2α,3β-dihydroxy-11α,12α-epoxy-24-nor-urs-4(23),20(30)-dien-28,13β-olide(16). Compounds 1-2 were new compounds, and compounds 4-5, 7 and 9-16 were isolated from I. guayusa for the first time.

The use of medicinal plants by rural populations of the Pastaza province in the Ecuadorian Amazon / Uso de plantas medicinais por populações rurais da província de Pastaza, na Amazônia equatoriana

Mera, Santa Clara and Pastaza municipalities are located in the Ecuadorian Amazon region. The objective of the study was to identify plant species used in traditional medicine by small farmers of these localities, and to classify these plants according to locality, farmer ethnicity and purposes of use. It was also investigated whether the use of medicinal plants differs between the ethnic groups. Data were collected by applying a questionnaire and personal interview with 213 farmers belonging to two ethnicities (Kichwa and mestizo), and to different municipalities (Mera, Santa Clara and Pastaza). Generated data were analyzed using contingency tables and frequency and the most representative species were determined by proportion analysis comparison. A total of 34 families and 52 species of medicinal plants were identified. The most used species was Ilex guayusa which was cited 48 times. Santa Clara municipality and Kichwa farmers used the highest number of species. These species belonged to the Lamiaceae and Solanacease family, and the plants were used for treating stomach pain, cold and inflammations. There were significant differences (Chi square test p < 0.05) between localities and ethnicities (Kichwa and mestizo). There were differences in the use of medicinal plant species among members of the Kichwa ethnicity and mestizo farmers, depending on locality, being Ilex guayusa the most used species.

A pesquisa foi desenvolvida em três municípios da Província de Pastaza, (Mera, Santa Clara e Pastaza), na Amazônia equatoriana. O objetivo do estudo foi identificar espécies vegetais utilizadas na medicina tradicional pelos agricultores nestas localidades e classificar as espécies segundo a localidade, etnia do produtor e as aflições nas que eram utilizadas. Alem disso, na pesquisa analisaram-se as diferença de uso das plantas entre as etnias Kichwa e Mestiça. A metodologia do trabalho consistiu na aplicação de questionários e entrevistas pessoais com 213 agricultores das diferentes etnias. Utilizaram-se as tabelas de contingência por freqüência de uso com os dados gerados, para determinar as espécies mais representativas e em cada grupo realizou-se comparação por análise de proporções. Os principais resultados mostraram a existência de 52 espécies de plantas medicinais pertencente a 34 famílias. A espécie mais utilizada foi Ilex guayusa com 48 registros. Os produtores Kichwa do município Santa Clara registraram o maior número de espécies pertencente às famílias Lamiaceae e Solanacease e as plantas foram utilizadas para tratamento de dor de estômago, gripe e inflamações. A prova de "chi quadrado" mostrou diferenças (p < 0,05) entre os municípios e as etnias. Conclui-se que existe diferença no uso de plantas medicinais entre as localidades e os grupos étnicos estudados. A espécie Ilex guayusa foi a planta medicinal mais usada pelos agricultores independentemente da localidade e a etnia.