Bio-Prospecting of Crude Leaf Extracts from Thirteen Plants of Brazilian Cerrado Biome on Human Glioma Cell Lines.

(1) Background: Malignant gliomas are aggressive tumors characterized by fast cellular growth and highly invasive properties. Despite all biological and clinical advances in therapy, the standard treatment remains essentially palliative. Therefore, searching for alternative therapies that minimize adverse symptoms and improve glioblastoma patients' outcomes is imperative. Natural products represent an essential source in the discovery of such new drugs. Plants from the cerrado biome have been receiving increased attention due to the presence of secondary metabolites with significant therapeutic potential. (2) Aim: This study provides data on the cytotoxic potential of 13 leaf extracts obtained from plants of 5 families (Anacardiaceae, Annonaceae, Fabaceae, Melastomataceae e Siparunaceae) found in the Brazilian cerrado biome on a panel of 5 glioma cell lines and one normal astrocyte. (3) Methods: The effect of crude extracts on cell viability was evaluated by MTS assay. Mass spectrometry (ESI FT-ICR MS) was performed to identify the secondary metabolites classes presented in the crude extracts and partitions. (4) Results: Our results revealed the cytotoxic potential of Melastomataceae species Miconia cuspidata, Miconia albicans, and Miconia chamissois. Additionally, comparing the four partitions obtained from M. chamissois crude extract indicates that the chloroform partition had the greatest cytotoxic activity against the glioma cell lines. The partitions also showed a mean IC50 close to chemotherapy, temozolomide; nevertheless, lower toxicity against normal astrocytes. Analysis of secondary metabolites classes presented in these crude extracts and partitions indicates the presence of phenolic compounds. (5) Conclusions: These findings highlight M. chamissois chloroform partition as a promising component and may guide the search for the development of additional new anticancer therapies.

Host plant intraspecific variation determines gall traits.

Galls display a multiplicity of traits, including colours, which are driven by pigment accumulation. Their conspicuousness has attracted researchers' attention and several hypotheses have been raised. However, plants themselves vary intra-specifically, including in their pigment concentrations. As galls are a result of host tissue development, colours may be a by-product of the host's own traits, being more conspicuous simply because the sites where galls develop already have the predisposition to accumulate more pigment. Here, we call this the host variation hypothesis. We test this hypothesis using the system of galls induced by Palaeomystella oligophaga on Macairea radula host plant. Using spectrophotometry, we calculated the Anthocyanin Reflectance Index (ARI) of gall projections, which are responsible for their characteristic colours. We tested the influence of occupant identity (galling insect or any natural enemy), gall volume, parenchyma thickness, height from the ground, ARI of leaf, ARI of gall surface and ARI of the respective stem. We corroborated the host variation hypothesis since the anthocyanin content in stems and in galls' projections were positively related. Moreover, anthocyanin in galls' projections was positively related to anthocyanin in the gall surface and negatively related to gall volume and parenchyma thickness. This shows that, besides the host specificities, galls' own traits may also be responsible for pigment accumulation, influencing their colours. In this study, using colour as an example, we show that although galls tend to be considered complex expressions of galling insects' stimuli, their traits may be simply influenced by previous and specific attributes of the host organs.

Identification of a novel α-glucosidase inhibitor from Melastoma dodecandrum Lour. fruits and its effect on regulating postprandial blood glucose.

Melastoma dodecandrum Lour. (MDL) extracts have shown potent α-glucosidase inhibitory activity, suggesting MDL might be a good source of α-glucosidase inhibitors. The aim of the study was to identify compounds in MDL extracts with α-glucosidase inhibitory activities and evaluate their effect on postprandial blood glucose as well as elucidating the underlying mechanisms of inhibition. A total of 34 polyphenols were identified in MDL fruits, among which 10 anthocyanins and three proanthocyanidin derivatives were discovered for the first time. Dosing mice with MDL extracts (100 mg/kg body weight, by gavage) was associated with a significantly decrease in postprandial blood glucose concentrations after oral administration of maltose. The most potent α-glucosidase inhibitor was identified as casuarictin (IC50 of 0.21 µg/mL). Casuarictin bound competitively to α-glucosidase, occupying not only the catalytic site but also forming strong hydrogen bonds with α-glucosidase residues. Therefore, casuarictin derived from MDL fruits might be used as novel α-glucosidase inhibitor in functional foods or other dietary products.

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.

Feno-morfología de dos especies de páramo de Miconia (Melastomataceae): optimización de la floración y fructificación para mejorar la dispersión / Pheno-morphology of two paramo species of Miconia (Melastomataceae): optimization of flowering and fructification to enhance dispersal

Introducción: El Páramo es uno de los ecosistemas más afectados por actividades humanas, lo que aumenta la necesidad de estudios fenológicos como base para el manejo y la conservación. Objetivo: Describir la feno-morfología de Miconia ligustrina y Miconia elaeoides. Métodos: De septiembre 2019 a febrero 2020, y de abril 2021 hasta agosto del mismo año, se monitoreó la fenología de 12 individuos de cada especie. Adicionalmente, se vincularon datos fenológicos de ejemplares de herbario, para corroborar los resultados obtenidos. En los dos conjuntos de datos, se describió su distribución usando estadística circular, además, se obtuvieron registros de precipitación y temperatura del área. Adicionalmente, se describió la morfometría de cada especie. Resultados: El pico de floración de M. lingustrina es en abril, y la fructificación se concentra entre junio y julio; M. elaoides, florece de forma masiva en enero, con la máxima producción de frutos en mayo. Hubo correlación entre fenología y lluvias: la floración se da en época seca y la fructificación en la época lluviosa. Las especies difieren en morfología, pero, como en otras especies de Miconia, las flores y frutos son pequeños (aprox. 5 mm). Conclusión: La floración se presenta en la época seca y la fructificación en la época lluviosa, cuando las tasas de fotosíntesis son bajas y la frugivoría incrementa. Este patrón fenológico favorece la dispersión óptima de semillas.

Introduction: Paramos are among the ecosystems that are most affected by anthropic activities, increasing the need for phenological studies as a basis for management and conservation. Objective: To describe the pheno-morphology of Miconia ligustrina and Miconia elaeoides. Methods: From September 2019 to February 2020, and from April 2021 to August of the same year, the phenology of 12 individuals of each species was monitored. Additionally, phenological data of herbariums were linked to corroborate obtained results. In the two data sets, distribution of data was described using circular statistics; in addition, we recorded the precipitation and temperature in the area. Additionally, we described the morphometry of each species. Results: The flowering peak of M. ligustrina is in April, and fruiting concentrates between June and July; in M. elaeoides, flowering is massive in January, and the highest fruit production in May. The phenology was correlated with rainfall: flowering takes place in the dry season and fruiting in the rainy season. The species differ morphologically, but, as in other Miconia species, the flowers and fruits are small (approx. 5 mm). Conclusions: Flowering occurs in the dry season and fructification in the rainy season, when the photosynthetic rate is low and frugivory increases. This phenological pattern favors optimal seed dispersal.

Acute toxicity and regenerative dose finding of an extract of Miconia ferruginata DC. in a mouse model of Duchenne muscular dystrophy.

Duchenne muscular dystrophy (DMD) is a severe disease with no cure caused by a genetic abnormality, promoting progressive muscle degeneration. Corticosteroids are used drugs in treatment associated with adverse effects. The extract of Miconia ferruginata (Melastomataceae) (MF) has demonstrated potent antioxidant and anti-inflammatory potential in vitro. This study used a DMD model (mdx) to determine the toxic dose of this plant and found a possible non-toxic dose with therapeutic effects. The mdx groups received an intraperitoneal injection of 0 (control group), 50, 100, 200, 300, and 2000 mg kg-1 of the aqueous leaf extract following a single-dose acute toxicity protocol and were observed for 14 days. The range of toxicity of the extract and LD50 were determined. Histopathological analysis, the quantification of fibrosis, and immunohistochemical analysis of the tissues were performed. The results demonstrated that 2000 mg kg-1 was highly toxic, inducing histopathological changes in the tissues evaluated, with 100% mortality in 48 hours. The other doses caused no behavioral changes or signs of toxicity. The MF extract led reduction in histopathological changes, fibrosis, and inflammation, a reduction in HSP70 and an increase in MCL-1 proteins. Doses of 50-200 mg kg-1 demonstrated regenerative tissue and anti-inflammatory potential.

Phytochemical Evaluation and Anti-Inflammatory Potential of Miconia albicans (Sw.) Triana Extracts.

The plant Miconia albicans (Sw.) Triana has been popularly used in Brazil to treat chronic inflammatory disturbances, such as osteoarthritis. This disease affects 250 million people worldwide, and is associated with intense pain and loss of articular function. There is a lack of information about the phytochemistry and bioactivity of M. albicans. Therefore, this study determined the chemical composition of some extracts and evaluated their cytotoxicity, along with their antioxidant and anti-inflammatory, activities using in vitro models. Aqueous and ethanolic extracts were prepared. Afterwards, a liquid-liquid partition was developed using chloroform, ethyl acetate, and n-butanol. The extracts were characterized by LC-MS, and their biological activities were evaluated on epithelial cells (Vero), tumoral hepatic cells (Hep-G2), and THP-1 macrophages. LC-MS analyses identified several flavonoids in all fractions, such as quercetin, myricetin, and their glycosides. The crude extracts and n-butanol fractions did not present cytotoxicity to the cells. The non-toxic fractions presented significant antioxidant activity when evaluated in terms of DPPH scavenging activity, lipid peroxidation, and ROS inhibition. THP-1 macrophages treated with the n-butanol fraction (250 µg/mL) released fewer pro-inflammatory cytokines, even in the presence of LPS. In the future, it will be necessary to identify the phytochemicals that are responsible for anti-inflammatory effects for the discovery of new drugs. In vivo studies on M. albicans extracts are still required to confirm their possible mechanisms of action.

Amazonian Melastomataceae blueberries: Determination of phenolic content, nutritional composition, and antioxidant and anti-glycation activities.

Berries come from hundreds of different species of plants spread around the world. Blackberries, blueberries and raspberries, for instance, are popular berries that have attracted attention for providing several benefits to human health. Wild berries from the Melastomataceae family are commonly encountered in the Amazon, although these small blue fruits are poorly consumed. Although domesticated fruits give better monetary profits, the consumption of wild fruits is a desirable option to afford income and/or food to communities at the same time as keep the Amazon region preserved. Aiming the divulgation of the nutritional potential of these plants, this paper describes the study of six species of Amazonian blueberries, five of them from the Clidemia genus and one from the Tococa genus, in regard to their nutritional and chemical composition and antioxidant activity (AA). The levels of moisture, ash, protein, lipids, carbohydrates, and the total caloric values obtained for the Amazonian blueberries were comparable to other common edible berries. Although the six species are similar in terms of nutritional composition, their anthocyanin profiles and contents are quite peculiar. Two non-methylated anthocyanins, cyanidin and delphinidin, which bound to a variable number of sugars, characterized the berries of the genera Clidemia and Tococa. Clidemia japurensis, Clidemia hirta and Tococa bullifera were rich in tri-glycosylated anthocyanins, although differences are notable between them. Clidemia pustulata and Clidemia capitellata were characterized by the prevalence of mono-glycosylated anthocyanins, and Clidemia rubra showed a unique profile with mono- and di-glycosylated homologous as the main anthocyanins. In addition to their different chemical profiles, the concentrations of anthocyanins and other phenolic compounds varied a lot among the six species studied. The species C. rubra had the highest total concentration of phenolic acids and flavonoids. Therefore, this study showed that the blueberries analyzed have potential to be better explored, which we suggest doing in a sustainable way, aiming at the preservation of the Amazon's biodiversity.

Structural Characterization and Assessment of Anti-Inflammatory Activities of Polyphenols and Depsidone Derivatives from Melastoma malabathricum subsp. normale.

The roots of Melastoma malabathricum subsp. normale (D. Don) Karst. Mey have been used in traditional ethnic medicine systems in China to treat inflammation-triggered ailments, such as trauma, toothache, and fever. Therefore, the aim of this study is to screen for compounds with anti-inflammatory activity in the title plant. The extract of M. malabathricum subsp. normale roots was separated using various chromatographic methods, such as silica gel, ODS C18, MCI gel, and Sephadex LH-20 column chromatography, as well as semi-preparative HPLC. One new complex tannin, named whiskey tannin D (1), and an undescribed tetracyclic depsidone derivative, named guanxidone B (2), along with nine known polyphenols (2-10) and three known depsidone derivatives (12-14) were obtained from this plant. The structures of all compounds were elucidated by extensive NMR and CD experiments in conjunction with HR-ESI-MS data. All these compounds were isolated from this plant for the first time. Moreover, compounds 1-4, 8, and 10-14 were obtained for the first time from the genus Melastoma, and compounds 1, 2, and 11-14 have not been reported from the family Melastomataceae. This is the first report of complex tannin and depsidone derivatives from M. malabathricum subsp. normale, indicating their chemotaxonomic significance to this plant. Compounds 1-12 were investigated for their anti-inflammatory activities on the production of the nitric oxide (NO) in lipopolysaccharide (LPS)-stimulated RAW264.7 cells, and compounds 1, 11, and 12 showed anti-inflammatory activities with IC50 values of 6.46 ± 0.23 µM, 8.02 ± 0.35 µM, and 9.82 ± 0.43 µM, respectively. The structure-activity relationship showed that the catechin at glucose C-1 in ellagitannin was the key to its anti-inflammatory activity, while CH3O- at C-16 of aromatic ring A in depsidone derivatives had little effect on its anti-inflammatory activity. The study of structure-activity relationships is helpful to quickly discover new anti-inflammatory drugs. The successful isolation and structure identification of these compounds, especially complex tannin 1, not only provide materials for the screening of anti-inflammatory compounds, but also provide a basis for the study of chemical taxonomy of the genus Melastoma.

Seasonal Chemical Evaluation of Miconia chamissois Naudin from Brazilian Savanna.

Miconia chamissois Naudin is a species from the Cerrado, which is being increasingly researched for its therapeutic potential. The aim of this study was to obtain a standardized extract and to evaluate seasonal chemical variations. Seven batches of aqueous extracts from leaves were produced for the standardization. These extracts were evaluated for total solids, polyphenol (TPC) and flavonoid content (TFC), vitexin derivative content, antioxidant activity; thin-layer chromatography (TLC), and high-performance liquid chromatography (HPLC) profiles were generated. For the seasonal study, leaves were collected from five different periods (May 2017 to August 2018). The results were correlated with meteorological data (global radiation, temperature, and rainfall index). Using chromatographic and spectroscopic techniques, apigenin C-glycosides (vitexin/isovitexin) and derivatives, luteolin C-glycosides (orientin/isoorientin) and derivatives, a quercetin glycoside, miconioside B, matteucinol-7-O-ß-apiofuranosyl (1 → 6) -ß-glucopyranoside, and farrerol were identified. Quality parameters, including chemical marker quantification by HPLC, and biological activity, are described. In the extract standardization process, all the evaluated parameters showed low variability. The seasonality study revealed no significant correlations (p < 0.05) between TPC or TFC content and meteorological data. These results showed that it is possible to obtain extracts from M. chamissois at any time of the year without significant differences in composition.

Chemical composition, quality attributes and antioxidant activity of stirred-type yogurt enriched with Melastoma dodecandrum Lour fruit powder.

This study for the first time used Melastoma dodecandrum Lour fruit powder (MDLP) as a novel functional ingredient for improving the quality of stirred-type yogurt (STY). Physicochemical properties, polyphenol content, antioxidant activity, textural analysis, fat globules, microstructure, and sensorial properties of MDLP-fortified STY were evaluated during storage (at 4 °C). The results indicated that MDLP significantly (p < 0.05) improved the total phenolics, flavonoids, anthocyanins, and proanthocyanidins, as well as increased the antioxidant activity of fortified yogurts compared to an STY-control. Interstitially, MDLP altered the structure of STY, making it firmer and more cohesive, increased its viscosity index, and significantly reduced whey and fat globule release compared to the STY-control during cold storage. Among all MDLP concentrations, 1% MDLP-fortified STY showed the best results followed by 0.5%. This study concluded that MDLP can be used as a potential nutritious ingredient and as a natural stabilizer for yogurt and related products.

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.

The Melastoma dodecandrum genome and the evolution of Myrtales.

Melastomataceae has abundant morphological diversity with high economic and ornamental merit in Myrtales. The phylogenetic position of Myrtales is still contested. Here, we report the chromosome-level genome assembly of Melastoma dodecandrum in Melastomataceae. The assembled genome size is 299.81 Mb with a contig N50 value of 3.00 Mb. Genome evolution analysis indicated that M. dodecandrum, Eucalyptus grandis, and Punica granatum were clustered into a clade of Myrtales and formed a sister group with the ancestor of fabids and malvids. We found that M. dodecandrum experienced four whole-genome polyploidization events: the ancient event was shared with most eudicots, one event was shared with Myrtales, and the other two events were unique to M. dodecandrum. Moreover, we identified MADS-box genes and found that the AP1-like genes expanded, and AP3-like genes might have undergone subfunctionalization. The SUAR63-like genes and AG-like genes showed different expression patterns in stamens, which may be associated with heteranthery. In addition, we found that LAZY1-like genes were involved in the negative regulation of stem branching development, which may be related to its creeping features. Our study sheds new light on the evolution of Melastomataceae and Myrtales, which provides a comprehensive genetic resource for future research.

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.

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.

Structural Characterization and Assessment of Anti-Inflammatory and Anti-Tyrosinase Activities of Polyphenols from Melastoma normale.

Polyphenols, widely distributed in the genus Melastoma plants, possess extensive cellular protective effects such as anti-inflammatory, anti-tyrosinase, and anti-obesity, which makes it a potential anti-inflammatory drug or enzyme inhibitor. Therefore, the aim of this study is to screen for the anti-inflammatory and enzyme inhibitory activities of compounds from title plant. Using silica gel, MCI, ODS C18, and Sephadex LH-20 column chromatography, as well as semipreparative HPLC, the extract of Melastoma normale roots was separated. Four new ellagitannins, Whiskey tannin C (1), 1-O-(4-methoxygalloyl)-6-O-galloyl-2,3-O-(S)-hexahydroxydiphenoyl-ß-d-glucose (2), 1-O-galloyl-6-O-(3-methoxygalloyl)-2,3-O-(S)-hexahydroxydiphenoyl-ß-d-glucose (3), and 1-O-galloyl-6-O-vanilloyl-2,3-O-(S)-hexahydroxydiphenoyl-ß-d-glucose (4), along with eight known polyphenols were firstly obtained from this plant. The structures of all isolates were elucidated by HRMS, NMR, and CD analyses. Using lipopolysaccharide (LPS)-stimulated RAW2 64.7 cells, we investigated the anti-inflammatory activities of compounds 1-4, unfortunately, none of them exhibit inhibit nitric oxide (NO) production, their IC50 values are all > 50 µM. Anti-tyrosinase activity assays was done by tyrosinase inhibition activity screening model. Compound 1 showed weak tyrosinase inhibitory activity with IC50 values of 426.02 ± 11.31 µM. Compounds 2-4 displayed moderate tyrosinase inhibitory activities with IC50 values in the range of 124.74 ± 3.12-241.41 ± 6.23 µM. The structure-activity relationships indicate that hydroxylation at C-3', C-4', and C-3 in the flavones were key to their anti-tyrosinase activities. The successful isolation and structure identification of ellagitannin provide materials for the screening of anti-inflammatory drugs and enzyme inhibitors, and also contribute to the development and utilization of M. normale.

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.

Phytochemical composition and biological activities of extracts from ten species of the family 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.

Chemopreventive effects of Melastoma malabathricum L. extract in mammary tumor model via inhibition of oxidative stress and inflammatory cytokines.

The objective of this study was to evaluate the anticancer effects of Melstoma malabathricum L. (MM) MDA-MB-231 human breast cancer and in vivo mammary tumor model and decipher the potential mechanism. The phyto-constituents in the extract have been identified by liquid chromatography-mass spectrometry (LC-MS). The anti-cancer activity of MM extract was tested on MDA-MB-231 human breast cancer cells. Chemical carcinogen 7,12-dimethylbenz(a)anthracene (DMBA) was used for the induction of breast cancer in rodents. Burden, volume, tumor incidence, pro-inflammatory cytokines, antioxidant parameters and mitochondrial parameters were estimated. Histological analysis was determined in mammary gland, vagina, uterus, heart, liver, lung and renal tissues. LC-MS showed the 21 phyto-constituents present in the extract of MM. MM extract showed the potent cytotoxicity against MDA-MB-231 cells and exhibited the IC50 value (14.6 µM). MM extract significantly decreased the body weight and altered the organ weight such as ovary, uterus, liver, spleen, lungs, renal, adrenal and brain tissue. MM extract significantly down-regulated the tumor incidence, tumor burden and average tumor weight at dose dependently manner. MM extract significantly altered the antioxidants activity in term of augmented the level of superoxide dismutase (SOD), catalase (CAT) and suppressed the level of malonaldehyde (MDA); pro-inflammatory cytokines levels such as reduced the level of tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß), interleukin-6 (IL-6) in the serum, hepatic and mammary gland tissue in DMBA induced mammary gland tumor rats. MM extract significantly (P < 0.001) enhanced the activity of mitochondrial parameters include Isocitrate dehydrogenase (ICDH), succinate dehydrogenase (SDH), Malate dehydrogenase (MDH) and alpha-keto glutaraldehyde dehydrogenase (α-KGDH). The histopathological finding exhibited that MM extract has a marked reduced effect on mammary glands, mammary gland, vagina, uterus, heart, liver, lung and renal.These data provide the scientific evidence that MM extract might be used as a traditional medicine to cure the breast cancer.