The evolution of ecological specialization underlies plant endemism in the Atlantic Forest.

BACKGROUND AND AIMS: The evolution of ecological specialization is favoured under divergent selection imposed by increased environmental heterogeneity, although specialization can limit the geographical range of organisms, thus promoting endemism. The Atlantic Forest (AF) is an ancient montane domain with high plant endemism, containing different environments for plant specialization. Miconia is the most diverse genus of woody flowering plant within the AF domain, including AF-endemic and non-endemic lineages. We hypothesized that Miconia species have faced increased environmental heterogeneity and consequently have been selected towards increased specialization in the AF domain, and this increased specialization has greatly reduced species geographical ranges, ultimately promoting endemism. Hence, we made the following predictions: (1) AF-endemic species should face greater environmental heterogeneity than non-endemic species; (2) AF-endemic species should be more specialized than non-endemic species; (3) specialization should lead to smaller geographical ranges; (4) specialization and small geographical ranges among AF-endemic species should conform to a selection-driven evolutionary scenario rather than to a neutral evolutionary scenario; and (5) small geographical ranges among AF-endemic species should date back to the occupation of the AF domain rather than to more recent time periods. METHODS: We used geographical, environmental and phylogenetic data on a major Miconia clade including AF-endemic and non-endemic species. We calculated Rao's Q to estimate the environmental heterogeneity faced by species. We used georeferenced occurrences to estimate the geographical ranges of species. We applied environmental niche modelling to infer species niche breadth. We inferred the most likely evolutionary scenario for species geographical range and niche breadth via a model-fitting approach. We used ancestral reconstructions to evaluate species geographical range throughout time. KEY RESULTS: Atlantic Forest-endemic species faced 33-60 % more environmental heterogeneity, with the increase being associated with montane landscapes in the AF. The AF-endemic species were 60 % more specialized overall, specifically over highly variable environmental gradients in AF montane landscapes. Specialization strongly predicted small geographical ranges among AF-endemic species and was a major range-limiting factor among endemic lineages. The AF-endemic species have evolved towards specialization and small geographical ranges under a selection-driven regime, probably imposed by the great environmental heterogeneity in AF montane landscapes. The AF-endemic species underwent a major reduction of geographical range immediately after their evolution, indicating a long-standing effect of selective pressures in the AF domain. CONCLUSION: Environmental heterogeneity imposes selective pressures favouring ecological specialization and small geographical ranges among plant lineages in the AF domain. This selection-driven process has probably promoted plant endemism in the AF domain throughout its history.

Beneath a hairy problem: Phylogeny, morphology, and biogeography circumscribe the new Miconia supersection Discolores (Melastomataceae: Miconieae).

Miconia is among the largest plant genera in the Neotropics and a taxonomically complex lineage. Indeed, molecular phylogenetic data shows that none of its traditionally accepted sections are monophyletic, preventing taxonomic advances within the genus. Miconia is the largest plant genus in the Brazilian Atlantic Forest, including three main lineages, the Leandra s.s. clade (ca. 215 spp.), the Miconia sect. Chaenanthera (24 spp.), and the Miconia discolor clade (estimated 77 spp.). Out of these lineages, the Miconia discolor clade is the only currently lacking phylogenetic data, complicating its taxonomy. In this study, we reconstruct the phylogeny of the Miconia discolor clade, using three plastid (atpF-H, psbK-I, and psaI-accD) and two nuclear (ETS and ITS) markers. We sampled 60 out of the 77 species of the group, representing 78% of its diversity. Taxa were selected considering their distribution, morphology, and previous phylogenetic knowledge. We used the newly reconstructed phylogeny to better understand phylogenetic relationships among Atlantic Forest species and morphologically similar taxa, and to propose a new infrageneric classification for the Miconia discolor clade: the Miconia supersection Discolores. We further studied the evolution of seven morphological characters using a Maximum Likelihood approach, and estimated the ancestral range distribution of various lineages in order to understand the biogeographic history of this clade. We found that dichasial inflorescences represent the ancestral condition within Miconia, subsequently giving rise to scorpioid and glomerulate inflorescences in the studied group. We describe Miconia supersect. Discolores, originated in the Amazon region, which is recognized by a dense layer of branched tricomes covering young branches and non-dichasial inflorescences, including three main lineages: (i) Miconia sect. Albicantes, characterized by persistent bracts and arachnoid indument on the abaxial surface of leaves, mainly distributed in the Amazon basin; (ii) Miconia sect. Discolores, characterized by caducous calyx lobes and glomerulate inflorescences, centered in the Atlantic Forest; and (iii) Miconia sect. Multispicatae, characterized by leaves not completely covered with indument, and capitate stigma, mainly distributed in the Atlantic Forest. All three sections and the supersection originated in the Neogene, between the Late Miocene and the Early Pliocene.

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.

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.

Frugivory and seed dispersal in a hyperdiverse plant clade and its role as a keystone resource for the Neotropical fauna.

BACKGROUND AND AIMS: Much of our understanding of the ecology and evolution of seed dispersal in the Neotropics is founded on studies involving the animal-dispersed, hyperdiverse plant clade Miconia (Melastomataceae). Nonetheless, no formal attempt has been made to establish its relevance as a model system or indeed provide evidence of the role of frugivores as Miconia seed dispersers. METHODS: We built three Miconia databases (fruit phenology/diaspore traits, fruit-frugivore interactions and effects on seed germination after gut passage) to determine how Miconia fruiting phenology and fruit traits for >350 species interact with and shape patterns of frugivore selection. In addition, we conducted a meta-analysis evaluating the effects of animal gut passage/seed handling on Miconia germination. KEY RESULTS: Miconia produce numerous small berries that enclose numerous tiny seeds within water- and sugar-rich pulps. In addition, coexisting species provide sequential, year long availability of fruits within communities, with many species producing fruits in periods of resource scarcity. From 2396 pairwise interactions, we identified 646 animal frugivore species in five classes, 22 orders and 60 families, including birds, mammals, reptiles, fish and ants that consume Miconia fruits. Endozoochory is the main dispersal mechanism, but gut passage effects on germination were specific to animal clades; birds, monkeys and ants reduced seed germination percentages, while opossums increased it. CONCLUSIONS: The sequential fruiting phenologies and wide taxonomic and functional diversity of animal vectors associated with Miconia fruits underscore the likely keystone role that this plant clade plays in the Neotropics. By producing fruits morphologically and chemically accessible to a variety of animals, Miconia species ensure short- and long-distance seed dispersal and constitute reliable resources that sustain entire frugivore assemblages.

Miconia albicans and Curcuma longa herbal medicines positively modulate joint pain, function and inflammation in patients with osteoarthritis: a clinical study.

This study aims to evaluate the analgesic and modulating effect of Curcuma longa and Miconia albicans herbal medicines in knee's osteoarthritis (OA) treatment. This longitudinal study evaluated 24 patients with OA. The patients were divided into three groups: ibuprofen (1200 mg/day), C. longa (1000 mg/day) and M. albicans (1000 mg/day). The medications were applied orally for 30 days. The synovial fluid of the knee joint was collect at the first (day 0) and the last medical (day 30) consultation. The groups treated with herbal medicines presented the same results when compared to Ibuprofen. The comparison of the means of Total WOMAC for M. albicans before and after treatment presented a statistically significant difference (mean day 0 = 57.19; mean day 30 = 31.02) as well as variation of Total WOMAC for C. longa (mean day 0 = 54.79; mean day 30 = 37.08). The WOMAC Total and the VASP were compared, it was found that there was a significant decrease in the means in the C. longa and M. albicans groups, as well as in the Ibuprofen group after treatment. The study demonstrated that the treatment of knee OA with C. longa or M. albicans positively interferes with patients pain and functionality, decreased WOMAC and VASP scores, leading to functional improvement of these patients. This is the first clinical study demonstrating the analgesic and anti-inflammatory effect on knee osteoarthritis from M. albicans comparable to Ibuprofen drug.

High-Resolution PTP1B Inhibition Profiling Combined with HPLC-HRMS-SPE-NMR for Identification of PTP1B Inhibitors from Miconia albicans.

Protein tyrosine phosphatase 1B (PTP1B) is an intracellular enzyme responsible for deactivation of the insulin receptor, and consequently acts as a negative regulator of insulin signal transduction. In recent years, PTP1B has become an important target for controlling insulin resistance and type 2 diabetes. In the present study, the ethyl acetate extract of leaves of Miconia albicans (IC50 = 4.92 µg/mL) was assessed by high-resolution PTP1B inhibition profiling combined with HPLC-HRMS-SPE-NMR for identification of antidiabetic compounds. This disclosed eleven PTP1B inhibitors, including five polyphenolics: 1-O-(E)-caffeoyl-4,6-di-O-galloyl-ß-d-glucopyranose (2), myricetin 3-O-α-l-rhamnopyranoside (3), quercetin 3-O-(2″-galloyl)-α-l-rhamnopyranoside (5), mearnsetin 3-O-α-l-rhamnopyranoside (6), and kaempferol 3-O-α-l-arabinopyranoside (8) as well as eight triterpenoids: maslinic acid (13), 3-epi-sumaresinolic acid (14), sumaresinolic acid (15), 3-O-cis-p-coumaroyl maslinic acid (16), 3-O-trans-p-coumaroyl maslinic acid (17), 3-O-trans-p-coumaroyl 2α-hydroxydulcioic acid (18), oleanolic acid (19), and ursolic acid (20). These results support the use of M. albicans as a traditional medicine with antidiabetic properties and its potential as a source of PTP1B inhibitors.

Bicolored display of Miconia albicans fruits: Evaluating visual and physiological functions of fruit colors.

PREMISE OF THE STUDY: Most bird-dispersed fruits are green when unripe and become colored and conspicuous when ripe, signaling that fruits are ready to be consumed and dispersed. The color pattern for fruits of Miconia albicans (Melastomataceae), however, is the opposite, with reddish unripe and green ripe fruits. We (1) verified the maintenance over time of its bicolored display, (2) tested the communicative function of unripe fruits, (3) tested the photoprotective role of anthocyanins in unripe fruits, and (4) verified whether green ripe fruits can assimilate carbon. METHODS: Using a paired experiment, we tested whether detection of ripe fruits was higher on infructescences with unripe and ripe fruits compared with infructescences with only ripe fruits. We also measured and compared gas exchange, chlorophyll a fluorescence, and heat dissipation of covered (to prevent anthocyanin synthesis) and uncovered ripe and unripe fruits. KEY RESULTS: Although the bicolored display was maintained over time, unripe fruits had no influence on bird detection and removal of ripe fruits. Ripe and unripe fruits did not assimilate CO2, but they respired instead. CONCLUSIONS: Since the communicative function of unripe fruits was not confirmed, seed dispersers are unlikely to select the display with bicolored fruits. Because of the absence of photosynthetic activity in ripe and unripe fruits and enhanced photoprotective mechanisms in ripe fruits rather than in unripe fruits, we could not confirm the photoprotective role of anthocyanins in unripe fruits. As an alternative hypothesis, we suggest that the bicolored fruit display could be an adaptation to diversify seed dispersal vectors instead of restricting dispersal to birds and that anthocyanins in unripe fruits may have a defense role against pathogens.

Health functions and related molecular mechanisms of Miconia genus: A systematic review.

The Miconia genus is traditionally used in folk medicine in Brazil and other tropical American countries and is represented by 282 species in this region. It is a multifaceted genus of medicinal plants widely used to treat rheumatoid arthritis (RA), pain, inflammatory diseases, and many more therapeutic applications. In the present study, we systematically identify and discuss the literature on in vivo and in vitro studies focusing on the therapeutic potentials and related molecular mechanisms of the Miconia genus. The review also assessed phytochemicals and their pharmacological properties and considered safety concerns related to the genus. Literature searches to identify studies on the Miconia genus were carried out through four main electronic databases, namely PubMed, Embase, Scopus, and Web of Science limited to Medical Subjects Headings (MeSH) and Descriptores en Ciencias de la Salud (DCS) (Health Sciences Descriptors) to identify studies published up to December 2022. The relevant information about the genus was gathered using the keywords 'Miconia', 'biological activities', 'therapeutic mechanisms', 'animal model, 'cell-line model', 'antinociceptive', 'hyperalgesia', 'anti-inflammatory', and 'inflammation'. The therapeutic potentials and mechanisms of action of 14 species from genus Miconia were examined in 18 in vitro studies and included their anti-inflammatory, anticancer, analgesic, antibacterial, cytotoxic, mutagenic, antioxidant, anti-leishmanial, antinociceptive, schistosomicidal, and anti-osteoarthritis potentials, and in eight in vivo studies, assessing their analgesic, antioxidant, antinociceptive, and anti-osteoarthritis activities. Some of the main related molecular mechanisms identified are the modulation of cytokines such as IL-1ß, IL-6, and TNF-α, as well as the inhibition of inflammatory mediators and prostaglandin synthesis. The limited number of studies showed that commonly available species from the genus Miconia are safe for consumption. Miconia albicans Sw.Triana and Miconia rubiginosa (Bonpl.) DC was the most frequently used species and showed significant efficacy and potential for developing safe drugs to treat pain and inflammation.

Why woody plant modularity through time and space must be integrated in fire research?

Different ecosystems evolved and are maintained by fire, with their vegetation hosting species with a wide diversity of persistence strategies allowing them to insulate their body and resprout new branches after fire disturbance. Changes in fire regime are predicted due to climate change, either by promoting more frequent and/or severe fires or by reducing the number of fire events due to the limitation of fuel load. Predicting the future of fire-driven ecosystems is a complex task as species' survival depends on many factors that vary in space and time. Since plants are constantly experiencing new environments as they grow through meristem development, woody plant modularity, modules morpho-physiological aspects and their integration should be considered when investigating species strategies in fire-prone ecosystems: according to their position and their tissue composition, plants' modules experience fire differently and will contribute differently to other modules and the whole plant survival, with consequences cascading over the overall vegetation structure. Growth modules may hold the key to understanding how fast plants can get protected from fire, ultimately helping us to predict which species will persist across changing fire regimes. We present an empirical example showing how different fire-return intervals translate into distinct pressures on the timing, protection and location of modules, and discuss how these can translate into modifications in the vegetation structure due to climate change.

Native Hyperaccumulator Plants with Differential Phytoremediation Potential in an Artisanal Gold Mine of the Ecuadorian Amazon.

In tropical forests of southern Ecuador, artisanal gold mining releases heavy metals that become xenobiotic with indefinite circulation and eventual bioaccumulation. Restoration and rehabilitation of degraded mining sites represent a major ecological, technological and economic issue. In this study, we estimate the capacity of two native woody plants to accumulate cadmium (Cd), lead (Pb), zinc (Zn) and mercury (Hg), with the goal of developing effective strategies for phytoremediation of mining sites. Individuals of Erato polymnioides and Miconia sp., as well as their rhizospheric soils, were sampled from a natural zone (NZ) of montane cloud forest, used as a control, and a polluted zone (PZ) subjected to active gold mining. Concentrations of the four heavy metals were analyzed using atomic absorption spectrophotometry. Cd, Zn and Hg concentrations were higher in soils of PZ than NZ. Bioaccumulation (BCF) and translocation factors (TF) showed that Miconia sp. has potential for Cd and Zn phytostabilization, E. polymnioides has potential for Cd and Zn phytoextraction, and both species have potential for Hg phytoextraction. Despite the low productivity of these species, their adaptability to the edaphoclimatic conditions of the region and the possibility of using amendments to increase their biomass could compensate for the effectiveness of these species in reclaiming soils contaminated by mining.

Chemical profile, antioxidant and anti-inflammatory properties of Miconia albicans (Sw.) Triana (Melastomataceae) fruits extract.

ETHNOPHARMACOLOGICAL RELEVANCE: Miconia albicans (Sw.) Triana has been widely used in Brazilian popular medicine for the treatment of several diseases. Aerial parts are used as an infusion to treat arthrosis and arthritis, to relieve rheumatic and stomach pains, and intestinal disorders due to its anti-inflammatory, anti-mutagenic anti-nociceptive, digestive and hepatoprotective properties. AIM OF THE STUDY: This study aimed to characterize the of M. albicans (Sw.) Triana fruits extract (MAFRE) chemical profile and to evaluate its antioxidant, anti-inflammatory and antitumor activities, as well as its toxicity. MATERIALS AND METHODS: Maceration with methanol as liquid extractor was used to prepare MAFRE. M. albicans (Sw.) Triana fruits chemical composition was characterized by UHPLC-QTOF-MS/MS and GC-FID (fatty acid methyl esters composition from lyophilized fruits). MAFRE antioxidant potential was evaluated in vitro using a combination of assays: Folin-Ciocalteu reducing capacity, DPPH• and ABTS radical scavenging ability and ferric reducing antioxidant power (FRAP). In vitro antiproliferative activity was investigated in four human tumor cell lines (U251, 786-0, HT29 and MDA-MB-231) while the effect on the non-tumor cell viability was assessed in the VERO cell line using the on-step MTT assay. In addition, in vivo anti-inflammatory effect was assessed by Croton oil-induced ear edema in mice followed by myeloperoxidase (MPO) activity evaluation. RESULTS: Thirty-five compounds were identified by UHPLC-QTOF-MS/MS. Among it flavonoids derived from quercetin (8), myricetin (1), kaempferol (2), terpenoids (6) and other compounds (18). GC-FID analysis identified and quantified nine fatty acids: palmitic, stearic, arachidic, behenic, elaidic, oleic, eicosenoic, and linoleic acids. The most abundant fatty acids were polyunsaturated fatty acids (5.33 ± 0.17 mg g-1), followed by saturated fatty acids (2.38 ± 0.07 mg g-1) and monounsaturated fatty acids (1.74 ± 0.09 mg g-1). The extract revealed high content of phenolic compounds (43.68 ± 0.50 mg GAE/g of extract), potent antioxidant, and ferrous chelating capacities. Morever, it proved to be non-toxic to the VERO cells, not affecting cells viability (95% of viable cells). No antiproliferative effect against human tumor cell lines were found. Furthermore, MAFRE significantly (p<0.05) reduced ear edema (≈35%) and MPO activity (84.5%) having a statistical effect similar to traditional steroidal and non-steroidal anti-inflammatory drugs. CONCLUSIONS: Taken together, the results evidenced that M. albicans fruit extract has antioxidant properties, a higher concentration of phenolic compounds, flavonoids, fatty acids, and also topical anti-inflammatory activity with low toxicity of extract on VERO cells. Through the ethnomedicinal study, these findings supporting the popular use of M. albicans, but also highlight that not only aerial parts and leaves deserve attention, but the fruits also have anti-inflammatory proprieties and can be a source of phenolic compounds and other substances with potential health benefices.

Antibacterial screening of plants from the Brazilian Atlantic Forest led to the identification of active compounds in Miconia latecrenata (DC.) Naudin.

Antibiotic resistance is a serious global threat to public health. This has promoted the research for new drug targets, and the use of other approaches, such as antimicrobial combined therapy. The present study evaluated the antibacterial activity of 88 extracts from Brazilian Atlantic Forest trees. The organic extract from leaves of Miconia latecrenata (EMl) was the most promising for inhibiting the growth of Staphylococcus aureus (0.3 mg/mL) and Pseudomonas aeruginosa (2.5 mg/mL). After the bioguided fractionation of EMl and metabolite profiling performed by UPLC-DAD-MS/MS, the ethyl acetate (AFMl) and aqueous (WFMl) fractions showed a mixture of phenolic compounds derived from ellagic acid and quercetin. The MIC value of AFMl was two-times lower than EMl for P. aeruginosa, suggesting that these phenolic compounds can perform bioactivity. Furthermore, EMI and AFMl showed synergism with ampicillin and tetracycline for S. aureus and P. aeruginosa, respectively. These findings suggest that extract and fractions of the Miconia latecrenata leaves can be used as therapeutic antibacterial agents.

Evidence for the involvement of IL-1ß and TNF-α in anti-inflammatory effect and antioxidative stress profile of the standardized dried extract from Miconia albicans Sw. (Triana) Leaves (Melastomataceae).

ETHNOPHARMACOLOGICAL RELEVANCE: Miconia albicans (Melastomataceae), commonly known in Brazil as "canela-de-velho", is used in folk medicine for treating rheumatoid arthritis and reducing pain and inflammation. THE AIM OF THE CURRENT WORK WAS: to provide data on physicochemical characterization of the drug plant and dried extract from M. albicans leaves, as well as investigate the anti-inflammatory effect and antioxidant stress profile from the standardized dried extract of this species employing different model systems. MATERIALS AND METHODS: plant material (dried crushed leaves) was extracted by turboextraction using 50% ethanol (v/v). Different pharmacological techniques were performed to establish quality control parameters of the plant drug, and dried extract of M. albicans (DEMA) was chemically characterized by HPLC-PDA to selection of the chemical marker. Total phenolic and flavonoid contents were determined by the Folin-Ciocalteu and AlCl3 colorimetric methods, respectively. Antioxidant potential of the DEMA was investigated by employing different in vitro antioxidant assays, including DPPH and ABTS radical scavenging assays, ferric reducing antioxidant assay, NO scavenging assay, metal ion (Fe2+) chelating activity and antioxidant capacity by inhibition of lipid peroxidation (TBARS). Finally, anti-inflammatory activity of the DEMA was evaluated using two models of acute inflammation: carrageenan induced inflammation and mechanical hyperalgesia. RESULTS AND DISCUSSION: M. albicans leaves, after drying in forced air circulation chamber at ±40 °C for 48 h and crushing in knife mill, presented a moisture content below the maximum allowed for plant drugs (6.4%). The powder of M. albicans was classified as moderately coarse and total ash content was found to be 6.27%. Preliminary phytochemical screening of DEMA revealed the presence of flavonoids, tannins, saponins, leucoanthocyanins and steroids. DEMA had significant higher total phenolic (551.3 mg gallic acid equivalent/g of dried extract) and flavonoid contents (367.19 mg catechin equivalent/g of dried extract). Two major compounds (λ = 340 nm) were identified in DEMA by HPLC-PDA: the flavonoids rutin and quercetin. Rutin content, selected as chemical marker, was determined and found to be 1.16 mg/g dried extract (r = 0.9941). Regarding to antioxidant activity, our results revealed the DEMA exhibited good antioxidant activity on different models. M. albicans treatment also reduced the levels of TNF-α e IL-1ß and consequently inflammatory nociception and edema caused by carrageenan injection. Based on previous studies and our results, is possible to suggest a positive correlation between the flavonoids rutin and quercetin and the antioxidant and anti-inflammatory capacities. CONCLUSION: Together, these data suggest that M. albicans has the possibility of use in conditions such as arthritis or other joint pain, even needing other work to better consolidate this profile.

Leishmanicidal and antimicrobial activity of primin and primin-containing extracts from Miconia willdenowii.

As a part of an ongoing bioprospective project, searching for potential medicinal plants from the Brazilian Atlantic Forest, Miconia willdenowii was selected for its potential leishmanicidal and antimicrobial activities. The crude ethanolic extract of M. willdenowii showed an inhibition of 99.7% of the promastigote forms of Leishmania amazonensis at the concentration of 80 µg/mL. Further investigation of its antimicrobial activity against pathogenic fungi and Gram positive and negative bacteria, revealed a significant antimicrobial activity. A bioguided study with its liquid-liquid partition fractions revealed the hexane fraction (Hex) as the most active against Leishmania, inhibiting 99.2% and 46.9% of the protozoan at concentrations of 40 and 20 µg/mL, respectively. Hex also showed significant antimicrobial activity against Staphylococcus aureus and Candida krusei with IC50 of 15.6 and 62.5 µg/mL, respectively. Purification of Hex led to the isolation of 2-methoxy-6-pentyl-benzoquinone (1, also known as primin) as the active metabolite, probably responsible for the observed antimicrobial and anti-leishmania effects. Primin (1) disclosed leishmanicidal activity (IC50 = 1.25 µM), showing higher potency than the standard drug amphotericin B (IC50 = 5.08 µM), with additional antifungal effects against all tested fungi species. Compound 1 also showed significant activity against S. aureus (IC50 = 8.94 µM), showing a comparable potency with the reference drug chloramphenicol (IC50 = 6.19 µM), but with a potential cytotoxicity towards peripheral human blood mononuclear cells (CC50 = 255.15 µM). Here in, the antimicrobial and anti-L. amazonensis effects of M. willdenowii are reported for the first time, as well as Primin (1) as its probable bioactive metabolite.

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.

Bioassays of nutrient limitation in a tropical rain forest soil.

Six speices of shrubs and one large herb with contrasting life history patterns were used as bioassays of nutrient availability in a Costa Rican lowland rain forest soil. Growth responses of the herb (Phytolacca rivinoides, Phytolaccaceae) confirmed soil measurements indicating high availability of N and potentially limiting levels of P, K, Mg and Ca. Growth responses of the shrub species (Miconia spp., Melastomataceae and Piper spp., Piperaceae) to a complete nutrient fertilizer were generally less than that of Phytolacca. Lack of a strong shrub response to +P fertilization is probably due to mycorrhizal associations and slower growth rates of woody species. In general, increased growth did not occur at the expense of phenolic production in the leaves. The results emphasize that assessment of specific nutrient limitations to plant growth vary depending on species selected for the bioassay, even among species from the same community.

Photosynthetic responses of Miconia species to canopy openings in a lowland tropical rainforest.

We examined the photosynthetic acclimation of three tropical species of Miconia to canopy openings in a Costa Rican rainforest. The response of photosynthesis to canopy opening was very similar in Miconia affinis, M. gracilis, and M. nervosa, despite differences in growth form (trees and shrubs) and local distributions of plants (understory and gap). Four months after the canopy was opened by a treefall, photosynthetic capacity in all three species had approximately doubled from closed canopy levels. There were no obvious signs of high light damage after treefall but acclimation to the gap environment was not immediate. Two weeks after treefall, Amax, stomatal conductance, apprarent quantum efficiency, and dark respiration rates had not changed significantly from understory values. The production of new leaves appears to be an important component of light acclimation in these species. The only variables to differ significantly among species were stomatal conductance at Amax and the light level at which assimilation was saturated. M. affinis had a higher stomatal conductance which may reduce its water use efficiency in gap environments. Photosynthesis in the more shade-tolerant M. gracilis saturated at lower light levels than in the other two species. Individual plant light environments were assessed after treefall with canopy photography but they explained only a small fraction of plant variation in most measures of photosynthesis and growth. In conclusion, we speculate that species differences in local distribution and in light requirements for reproduction may be more strongly related to species differences in carbon allocation than in carbon assimilation.

Ditylenchus drepanocercus Rediscovered in the Neotropics Causing Angular Leaf Spots on Miconia calvescens.

During searches for pathogens to be used as classical biocontrol agents for Miconia calvescens (velvet tree), a devastating plant invader of Hawaii and French Polynesia, damaging angular leaf spots were found repeatedly. The etiological agent of this disease was identified as the nematode Ditylenchus drepanocercus. This nematode has a distinctive falciform appendage at the apex of the tail on both sexes, which allows easy identification. The nematodes were found in the lacunar parenchyma. Infected tissues have abnormally large cells (7 to 13 times the normal size). The lamina at infected areas is chlorotic, slightly thicker, and becomes necrotic with time. The best method of inoculation for this nematode was spraying plants with a suspension containing individuals of various stages on previously wounded leaves. Incubation period was determined to be 20 days.

Flavanones from Miconia prasina.

A glycosidic flavanone miconioside C (1) has been isolated from the methanolic extract of the stems of Miconia prasina, together with 7-O-ß-D-apiofuranosyl-(1→6)-ß-D-glucopyranosylmatteucinol (2), miconioside B (3), matteucinol (4), farrerol (5) and desmethoxymatteucinol (6). Their structures were mainly established by extensive NMR studies (1H NMR, 13C NMR, DEPT, 1H-1H COSY, HSQC, HMBC) and mass spectrometry. The compounds 1- 3 were evaluated for in vitro binding assays using cannabinoid receptors (CB1 and CB2).