Evaluation of antioxidant, photoprotective and antinociceptive activities of Marcetia macrophylla extract: potential for formulation of sunscreens / Avaliação da atividade antioxidante, photoprotetora e antinociceptiva de Marcetia macrophylla: potencial formulação fotoprotetora

The antioxidant, photoprotective and antinociceptive Marcetia macrophylla active extract was investigated as an active ingredient in a sunscreen cream formulation. Thus, the M. macrophylla extract showed IC50 of 3.43 mg/ml of the antioxidant (DPPH∙ scavenging test) and Sun Protection Factor of 20.25 (SPF/UV-B, at 250 µg/ml) and UV-A of 78.09% (photobleaching trans-resveratrol test). The antinociceptive activity was superior to all standards tested using the in vivo acetic acid-induced writhing test (99.14% at the dose of 200 mg/kg) and the high-performance liquid chromatography coupled with diode array detector and mass spectroscopy multi-stage (HPLC-DAD-MS/MS) enabled the structural characterization of the quercetin-3-O-hexoside, quercetin-3-O-pentoside and quercetin-3-O-desoxihexoside. The pharmaceutical formulation containing the Marcetia macrophylla crude active extract was prepared and the physicochemical tests (organoleptic characteristics, pH analysis and centrifugation), the in vitro UVB (sun protection factor, SPF) and UVA (β-carotene) using the spectroscopic method were investigated. The formulation showed satisfactory results concerning the physicochemical parameters evaluated and active against the UV test. Thus, M. macrophylla showed biological activities with potential use in pharmaceutical preparations.

O extrato bruto de Marcetia macrophylla mostrou atividade antioxidante, fotoprotetora e antinociceptiva, sendo em seguida investigado como ingrediente ativo em uma formulação fotoprotetora. Assim, o extrato de M. macrophylla apresentou atividade antioxidante com IC50 de 3,43 mg/mL (teste de sequestro do DPPH∙) e Fator de Proteção Solar de 20,25 (FPS/UV-B, 250 µg/mL) e UV-A de 78,09% (teste de fotobranqueamento do trans-resveratrol). A atividade antinociceptiva usando o teste in vivo de contorções abdominais induzidas por ácido acético foi superior a todos os padrões testados (99,14% na dose de 200 mg/Kg). A análise por cromatografia líquida de alta eficiência acoplada a detector de fotodiodos e espectroscopia de massas multi-estágio (CLAE-DAD-EM/EM) possibilitou a caracterização dos flavonoides quercetina-3-O-hexosídeo, quercetina-3-O-pentosídeo e quercetina-3-O-desoxihexosídeo. A formulação farmacêutica contendo o extrato ativo bruto de Marcetia macrophylla foi preparada e os testes físico-químicos (características organolépticas, análise de pH e centrifugação), o UVB in vitro (fator de proteção solar, FPS) e UVA (β-caroteno) foram investigados. A formulação apresentou resultados satisfatórios frente aos parâmetros físico-químicos avaliados e ativos contra UV. Assim, M. macrophylla apresentou atividades biológicas com potencial uso em preparações fitofarmacêuticas.

Anticarcinogenic activity of methanol extract of Melastoma malabathricum leaves is attributed to the presence of phenolics compounds and the activation of endogenous antioxidant system / Actividad anticancerígena del extracto metanólico de hojas de Melastoma malabathricum atribuida a la presencia de compuestos fenólicos y a la activación del sistema antioxidante endógeno

Melastoma malabathricum (M. malabathricum) extracts have been reported to exert various pharmacological activities including antioxidants, anti-inflammatory and antiproliferative activities. The objective of the present study was to determine the anticarcinogenic activity of its methanol extract (MEMM) against the azoxymethane (AOM)-induced early colon carcinogenesis in rats. Rats were randomly assigned to five groups (n=6) namely normal control, negative control, and treatment (50, 250 or 500 mg/kg of MEMM) groups. Colon tissues were harvested for histopathological analysis and endogenous antioxidant system determination. MEMM was also subjected to HPLC analysis. Findings showed that MEMM significantly (p<0.05) reversed the AOM-induced carcinogenicity by: i) reducing the formation of aberrant crypt foci (ACF) in colon tissues, and; ii) enhancing the endogenous antioxidant activity (catalase, superoxide dismutase and glutathione peroxidase). Moreover, various phenolics has been identified in MEMM. In conclusion, MEMM exerts the in vivo anticarcinogenic activity via the activation of endogenous antioxidant system and synergistic action of phenolics.

Se ha informado que los extractos de Melastoma malabathricum (M. malabathricum) ejercen diversas actividades farmacológicas, incluidas actividades antioxidantes, antiinflamatorias y antiproliferativas. El objetivo del presente estudio fue determinar la actividad anticancerígena de su extracto de metanol (MEMM) contra la carcinogénesis de colon temprana inducida por azoximetano (AOM) en ratas. Las ratas se asignaron al azar a cinco grupos (n=6), a saber, los grupos de control normal, control negativo y tratamiento (50, 250 o 500 mg/kg de MEMM). Tejidos de colon fueron recolectados para análisis histopatológico y determinación del sistema antioxidante endógeno. MEMM también se sometió a análisis de HPLC. Los hallazgos mostraron que MEMM invirtió significativamente (p<0.05) la carcinogenicidad inducida por AOM al: i) reducir la formación de focos de criptas aberrantes (ACF) en los tejidos del colon, y; ii) potenciar la actividad antioxidante endógena (catalasa, superóxido dismutasa y glutatión peroxidasa). Además, se han identificado varios fenólicos en MEMM. En conclusión, MEMM ejerce la actividad anticancerígena in vivo mediante la activación del sistema antioxidante endógeno y la acción sinérgica de los fenólicos.

Phytochemical composition and biological activities of extracts from ten species of the family Melastomataceae Juss / Composição fitoquímica e atividades biológicas de extratos de dez espécies da família Melastomataceae Juss

Plants possess a renewable source of metabolites with enormous chemical structural diversity, which may have potential therapeutic relevance. Furthermore, this chemical diversity favors the possibility of finding new and different chemical constituents with antimicrobial, antioxidant and anti-tumor activities. This work analyzed preliminary phytochemical profiles and evaluated the antimicrobial, antioxidant and cytotoxic activities of hexane extracts of leaves of ten species of the family Melastomataceae. Phytochemical screening was performed using staining methods while total phenols and flavonoids were quantified by spectrophotometry. Antimicrobial activity was evaluated using the disk diffusion method. Antioxidant activity was determined by the 2,2-diphenyl-1-picrylhydrazil (DPPH) method. Toxicity was recorded using the lethality test with Artemia salina Leach (1819). Cytotoxic activity of the extracts was assessed in vitro with acute monocytic leukemia cells (THP-1). Phytochemical analysis detected the presence of tannins, terpenes, steroids, polyphenols and flavonoids and the absence of alkaloids. Clidemia capitellata (Bonpl.) D. Don had the greatest amount of polyphenols (205.95 mg/g ± 4.14) while Clidemia hirta (L.) D. Don had the highest content of total flavonoids (143.99 mg/g ± 4.18). The hexane extracts did not show antimicrobial activity nor toxicity against Artemia salina. The extract of Tibouchina francavillana Cogn. was the most active in sequestering the DPPH radical. The extracts showed cytotoxicity in THP-1 cells with the appearance of apoptotic bodies and cell death. The extracts of Miconia amoena, Clidemia sericea and Clidemia capitellata are non-toxic against Artemia salina and induce the formation of apoptotic bodies and cell death of the THP-1 lineage.

Os vegetais apresentam uma fonte renovável de metabólitos com enorme diversidade química estrutural, os quais podem apresentar potencial relevante na terapêutica, aumentando as possibilidades de encontrar novos e diferentes constituintes químicos com atividades antimicrobiana, antioxidante e antitumoral. Este trabalho analisou o perfil fitoquímico preliminar e as atividades antimicrobiana, antioxidante, citotóxica dos extratos em hexano das folhas de dez espécies da família Melastomataceae. A triagem fitoquímica foi executada utilizando métodos de coloração e quantificação de fenóis e flavonoides totais por espectrofotometria. A atividade antimicrobiana foi realizada pelo método de difusão em disco. A atividade antioxidante foi determinada pelo método 2,2-difenil1-picrilhidrazila (DPPH). A toxicidade foi registrada utilizando o ensaio de letalidade com Artemia salina Leach (1819). A atividade citotóxica dos extratos foi realizada in vitro com células leucêmicas monocítica aguda (THP-1). A análise fitoquímica detectou a presença de taninos, terpenos, esteroides, polifenóis, flavonoides e ausência de alcaloides. A maior quantificação de polifenóis foi da Clidemia capitellata (Bonpl.) D. Don (205,95 mg/g ± 4,14) e o extrato de Clidemia hirta (L.) D. Don apresentou maior teor de flavonoides totais (143,99 mg/g ± 4,18). Os extratos hexânicos não demostraram atividade antimicrobiana e nem toxicidade frente à Artemia salina. O extrato de Tibouchina francavillana Cogn. foi o mais ativo no sequestro do radical DPPH. Os extratos apresentaram citotoxicidade em células THP-1, com visualização de corpos apoptóticos e morte celular. Os extratos de Miconia amoena, Clidemia sericea e Clidemia capitellata são atóxicos contra Artemia salina e induzem a formação de corpos apoptóticos e morte celular da linhagem THP-1.

Biological properties and phytochemical characterization from Miconia chamissois Naudin aqueous extract / Propiedades biológicas y caracterización fitoquímica del extracto acuoso de Miconia chamissois Naudin

The objective of this study was to evaluate biological and phytochemical properties of the aqueous extract from the leaves of Miconia chamissois Naudin (AEMC). Phytochemical properties were assessed by analyzing the chromatographic profile and the polyphenol content of AEMC. Biological properties evaluation was conducted based on cytotoxicity assay and by evaluating the antioxidant, antimicrobial, and enzymatic inhibition activities. Results indicated the presence of phytochemicals in AEMC such as flavonoids and polyphenols, including rutin, isoquercitrin and vitexin derivatives. AEMC showed antioxidant activity, which may be attributed to the high polyphenolic content. Moreover, AEMC demonstrated in vitro enzyme inhibition activity against tyrosinase and alpha-amylase, as well as showed low cytotoxicity. On the other hand, AEMC exhibited weak antimicrobial activity against S. aureusand C. albicans. Thus, AEMC is a promising alternative in search of potential drugs for the treatment of diseases induced by oxidative stress and inflammation, conditions due to hyperpigmentation processes, such as melisma, as well as for diabetes.

El objetivo de este estudio fue detectar las propiedades biológicas y fitoquímicos del extracto acuoso de las hojas de Miconia chamissois Naudin (AEMC). Las propiedades fitoquímicas se evaluaron analizando el perfil cromatográfico y el contenido de polifenoles de AEMC. La evaluación de las propiedades biológicas se realizó en base al ensayo de citotoxicidad y evaluando las actividades de inhibición antioxidante, antimicrobiana y enzimática. Los resultados indicaron la presencia de fitoquímicos en AEMC, como flavonoides y polifenoles, que incluyen derivados de rutina, isoquercitrina y vitexina. AEMC mostró una actividad antioxidante considerable, que puede atribuirse al alto contenido polifenólico. Además, AEMC exhibió actividad de inhibición enzimática in vitro contra tirosinasa y alfa-amilasa, así como mostró baja citotoxicidad. Por otro lado, AEMC demostró actividad antimicrobiana débil contra S. aureusy C. albicans. Por lo tanto, AEMC es una alternativa prometedora en busca de posibles drogas para el tratamiento de enfermedades inducidas por el estrés oxidativo y la inflamación, afecciones debidas a procesos de hiperpigmentación, como el melasma, así como para la diabetes.

Actividad ictiotóxica de extractos de dos especies colombianas del género Meriania Swartz (melastomataceae) / Ichtyotoxic activity of two colombian species extracts fromthe genus Meriania Swartz (melastomataceae)

Introducción: la familia melastomataceae es la séptima más grande del reino vegetal y ha sido utilizada en la medicina tradicional para el tratamiento de algunas enfermedades. En Colombia se encuentra representada por alrededor de 62 géneros, de los cuales Meriania ha sido poco estudiado, sin presentar reportes en la literatura de sus propiedades químicas y biológicas; por lo que el estudio de sus propiedades ictiotóxicas, constituye un acercamiento en la búsqueda de sustancias activas que permitan avanzar en el conocimiento del género y en la búsqueda de compuestos promisorios con aplicaciones biológicas. Objetivo: evaluar la actividad ictiotóxica de extractos de diferente polaridad de Meriania speciosa (Bonpl.) Naudiny Merianiaquintuplinervis Naudin. Métodos: los extractos de diferente polaridad (n-hexano, acetona 70 por ciento, metanol, acetato de etilo, n-butanol y agua) de ambas especies fueron evaluados frente a peces guppy (Poecilia reticulata Peters),sometidos durante 24 h a la acción de los extractos para la cuantificación del porcentaje de actividad ictiotóxica en una escala semicuantitativa, el test de observación de FinnSandberg-Irwin y como prueba anexa se obtuvieron cortes histopatológicos, con el fin de identificar posibles lesiones generadas por los extractos vegetales. Resultados: de acuerdo con los porcentajes de actividad ictiotóxica obtenidos en este estudio, las sustancias evaluadas se clasifican como no activas, sin embargo, los resultados aportados por el test de observación indican que las sustancias afectan el sistema nervioso y generan daño hepático en el pez. Conclusiones: los extractos vegetales de las especies de Meriania estudiadas presentan comportamientos diferentes, ya que M. speciosa ejerce un efecto psicoactivo en los peces, alterándose su sistema nervioso central, mientras que M. quintuplinervis está más relacionada con un nivel de toxicidad moderado, además de provocar un efecto vasodilatador comprobado en el hígado de P. reticulata(AU)

Introduction: Melastomataceae is the seventh largest family in the plant kingdom and has been widely used in traditional medicine for the treatment of some diseases. In Colombia it is represented by around 62 genera, of which Meriania has been understudied, without presenting reports in the literature of its chemical and biological properties; so the study of their ichtyotoxic properties constitutes an approach in the search for active substances that advance knowledge of genus and in finding promising compounds with biological applications. Objetive: To evaluate the ichtyotoxic activity of extracts of different polarity of Meriania speciosa (Bonpl.) and Meriania quintuplinervis Naudin. Methods: The extracts of different polarity (n-hexane, acetone 70 percent, methanol, ethyl acetate, n-butanol and water) of both species were evaluated against guppy (Poeciliareticulata Peters), subjected for 24 h to action extracts for quantification of the percentage of ichtyotoxic activity in a semiquantitative scale and the observation Finn Sandberg-Irwintest and histopathological sections were obtained, in order to identify potential injuries from plant extracts. Results: According to ichtyotoxic activity rates obtained in this study, the evaluated substances are classified as inactive; however, the test results indicate that the substances affect the nervous system and produce liver damage in fishes. Conclusions: The plant extracts of the Meriania species studied have different behaviors, as M. speciosahas a psychoactive effect on fishes, mainly altering the central nervous system, while M. quintuplinervisis more related to a moderate level of toxicity as well as causing a vasodilator effect found in the liver of P. reticulata(AU)

Effect of light and temperature on seed germination in Tibouchina mutabilis (Vell.) Cogn. (Melastomataceae) / Efeito da luz e da temperatura na germinação de sementes de Tibouchina mutabilis (Vell.) Cogn. (Melastomataceae)

The effect of light and temperature on Tibouchina mutabilis seed germination was analyzed by isothermic incubations in the range of 10 to 40 ºC, with 5 ºC intervals under both continuous white light (32.85 µmolm-2s-1) and darkness and alternating temperatures (15-20; 15-25; 15-30; 15-35; 20-25; 20-30; 20-35; 25-30; 25-35 and 30-35 ºC) under both photoperiod of 12 hours and continuous darkness. The seeds of T. mutabilis need light to trigger the germination and no germination was observed in darkness. The range of optimum temperatures for germination was between 25 to 30 ºC and the 20-25 ºC alternating temperatures. These results indicate that T. mutabilis behaves as a pioneer species and daily alternating temperatures did not change the light sensitivity of seeds.

A influência da luz e da temperatura na germinação de sementes de Tibouchina mutabilis foi avaliada sob incubações isotérmicas de 10 a 40 ºC sob luz branca contínua (32,85 µmolm-2s-1), com intervalos de 5 ºC e temperaturas alternadas (15-20; 15-25; 15-30; 15-35; 20-25; 20-30; 20-35; 25-30; 25-35 e 30-35 ºC) sob fotoperíodo de 12 horas de luz branca. As sementes de T. mutabilis requerem luz para germinar, sendo nula a germinação no escuro em todas as temperaturas testadas. A faixa ótima de temperatura para a germinação foi de 25 a 30 ºC e a alternância de temperaturas de 20-25 ºC. Estes resultados indicam que T. mutabilis apresenta comportamento de uma espécie pioneira e que as alternâncias diárias de temperatura não alteraram a sensibilidade da semente à luz.

In vitro inhibition of acetylcholinesterase by crude plant extracts from Colombian flora

The methanol extracts from five different plant families (Asteraceae, Euphorbiaceae, Melastomataceae, Rubiaceae, and Solanaceae) collected at Regional Natural Park Ucumarí (Colombia), were screened for their acetylcholinesterase inhibitory activity through the modified Ellman's spectrophotometric method. The best inhibitory activities on this study were shown by the extracts of Solanum leucocarpum Dunal (IC50 = 204.59 mg/l) and Witheringia coccoloboides (Damm) (IC50 = 220.68 mg/l), both plants belonging to the Solanaceae family.