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.

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.

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.

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.

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.

Effects of an accidental dry-season fire on the reproductive phenology of two Neotropical savanna shrubs / Efeitos de um incêndio acidental de estação seca sobre a fenologia reprodutiva de dois arbustos savânicos neotropicais

Abstract Fire is a recurrent disturbance in savanna vegetation and savanna species are adapted to it. Even so, fire may affect various aspects of plant ecology, including phenology. We studied the effects of a spatially heterogeneous fire on the reproductive phenology of two dominant woody plant species, Miconia albicans (Melastomataceae) and Schefflera vinosa (Araliaceae), in a savanna area in South-eastern Brazil. The study site was partially burnt by a dry-season accidental fire in August 2006, and we monitored the phenolology of 30 burnt and 30 unburnt individuals of each species between September 2007 and September 2008. We used restricted randomizations to assess phenological differences between the burnt and unburnt individuals. Fire had negative effects on the phenology of M. albicans, with a smaller production of reproductive structures in general and of floral buds, total fruits, and ripe fruits in burnt plants. All unburnt but only 16% of the burnt M. albicans plants produced ripe fruits during the study. Fire effects on S. vinosa were smaller, but there was a greater production of floral buds and fruits (but not ripe fruits) by burnt plants; approximately 90% of the individuals of S. vinosa produced ripe fruits during the study, regardless of having been burnt or not. The differences between the two species may be related to S. vinosa's faster growth and absence from the seed bank at the study site, whereas M. albicans grows more slowly and is dominant in the seed bank.

Resumo O fogo é uma perturbação recorrente em vegetação savânica e as espécies do cerrado são adaptadas a ele. Mesmo assim, o fogo pode afetar aspectos da ecologia vegetal, incluindo a fenologia. Nós estudamos os efeitos de um incêndio espacialmente heterogêneo sobre a fenologia reprodutiva de duas espécies lenhosas dominantes, Miconia albicans (Melastomataceae) e Schefflera vinosa (Araliaceae), em uma área de cerrado no Sudeste do Brasil. A área de estudo foi parcialmente queimada por um incêndio acidental na estação seca (agosto) de 2006. Nós acompanhamos a fenologia reprodutiva de 30 indivíduos queimados e 30 não-queimados de cada espécie, de setembro de 2007 a setembro de 2008, usando aleatorizações restritas para comparar os dois grupos. Em M. albicans, a produção de estruturas reprodutivas como um todo e de botões florais, frutos e frutos maduros foi maior em indivíduos queimados do que nos não-queimados. Todos os indivíduos não-queimados, mas apenas 16% dos queimados, produziram frutos maduros durante o estudo. Já em S. vinosa, a produção de botões florais e de frutos (mas não de frutos maduros) foi maior em indivíduos queimados; aproximadamente 90% dos indivíduos de S. vinosa produziram frutos maduros durante o estudo, independentemente de terem sido queimados ou não. As diferenças entre as duas espécies podem estar relacionadas com o fato de S. vinosa crescer mais rápido e estar ausente do banco de sementes, ao contrário de M. albicans, de crescimento mais lento e dominante no banco de sementes.

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.

Effects of an accidental dry-season fire on the reproductive phenology of two Neotropical savanna shrubs

Abstract Fire is a recurrent disturbance in savanna vegetation and savanna species are adapted to it. Even so, fire may affect various aspects of plant ecology, including phenology. We studied the effects of a spatially heterogeneous fire on the reproductive phenology of two dominant woody plant species, Miconia albicans (Melastomataceae) and Schefflera vinosa (Araliaceae), in a savanna area in South-eastern Brazil. The study site was partially burnt by a dry-season accidental fire in August 2006, and we monitored the phenolology of 30 burnt and 30 unburnt individuals of each species between September 2007 and September 2008. We used restricted randomizations to assess phenological differences between the burnt and unburnt individuals. Fire had negative effects on the phenology of M. albicans, with a smaller production of reproductive structures in general and of floral buds, total fruits, and ripe fruits in burnt plants. All unburnt but only 16% of the burnt M. albicans plants produced ripe fruits during the study. Fire effects on S. vinosa were smaller, but there was a greater production of floral buds and fruits (but not ripe fruits) by burnt plants; approximately 90% of the individuals of S. vinosa produced ripe fruits during the study, regardless of having been burnt or not. The differences between the two species may be related to S. vinosas faster growth and absence from the seed bank at the study site, whereas M. albicans grows more slowly and is dominant in the seed bank.

Resumo O fogo é uma perturbação recorrente em vegetação savânica e as espécies do cerrado são adaptadas a ele. Mesmo assim, o fogo pode afetar aspectos da ecologia vegetal, incluindo a fenologia. Nós estudamos os efeitos de um incêndio espacialmente heterogêneo sobre a fenologia reprodutiva de duas espécies lenhosas dominantes, Miconia albicans (Melastomataceae) e Schefflera vinosa (Araliaceae), em uma área de cerrado no Sudeste do Brasil. A área de estudo foi parcialmente queimada por um incêndio acidental na estação seca (agosto) de 2006. Nós acompanhamos a fenologia reprodutiva de 30 indivíduos queimados e 30 não-queimados de cada espécie, de setembro de 2007 a setembro de 2008, usando aleatorizações restritas para comparar os dois grupos. Em M. albicans, a produção de estruturas reprodutivas como um todo e de botões florais, frutos e frutos maduros foi maior em indivíduos queimados do que nos não-queimados. Todos os indivíduos não-queimados, mas apenas 16% dos queimados, produziram frutos maduros durante o estudo. Já em S. vinosa, a produção de botões florais e de frutos (mas não de frutos maduros) foi maior em indivíduos queimados; aproximadamente 90% dos indivíduos de S. vinosa produziram frutos maduros durante o estudo, independentemente de terem sido queimados ou não. As diferenças entre as duas espécies podem estar relacionadas com o fato de S. vinosa crescer mais rápido e estar ausente do banco de sementes, ao contrário de M. albicans, de crescimento mais lento e dominante no banco de sementes.

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.

Efeito de diferentes temperaturas na germinação de sementes e no crescimento inicial de plântulas de Miconia albicans (Melastomataceae) / Effect of different temperatures on seed germination and seedling formation of Miconia albicans (Melastomataceae)

Miconia albicans (Sw.) Triana é uma espécie nativa do Brasil utilizada na medicina tradicional em comunidades rurais. O objetivo deste estudo foi investigar a temperatura mais adequada para a germinação de sementes e formação de plântulas de M. albicans. Para avaliar o efeito da temperatura sobre a germinação da espécie foram utilizadas 1200 sementes postas a germinar sob temperaturas constantes de 20, 25, 30 e 35 ºC e nas temperaturas alternadas de 20-30 e 25-35 ºC. Foram avaliados a percentagem de germinação (PG), o índice de velocidade de germinação (IVG), o tempo médio de germinação (TMG), e o comprimento das raízes primárias e do caule das plântulas. Os resultados encontrados indicaram PG acima de 63% paras as sementes sob temperaturas de 20, 25, 30 e 20-30 ºC. Para o IVG, foram observados valores entre 2,17 a 2,93 para as sementes sob temperaturas de 20, 25, 30 e 20-30 ºC, indicando maior vigor; em relação ao TMG, a maioria dos tratamentos alcançou resultado acima de 15 dias, indicando que as sementes germinaram lentamente. Levando-se em consideração todos os parâmetros avaliados, a temperatura de 25 ºC propiciou o melhor desempenho para as sementes da espécie.

The Miconia albicans (Sw.) Triana is a species native to Brazil, which has been used by traditional medicine in rural communities. The aim of this study was to investigate the most suitable temperature for seed germination and seedling development for M. albicans. For the evaluation of the effect of temperature on species, a total of 1200 seeds were placed under constant temperatures of 20, 25, 30 and 35 ºC and under alternate temperatures of 20-30 and 25-35 ºC. Germination percentage (GP), germination speed index (GSI), average time of germination (ATG) and average length of primary roots and stems of seedlings were evaluated. The results indicate a GP above 63% for seeds under the constant temperatures of 20, 25, 30 and 20-30 ºC. For GSI, values between 2.17 and 2.93 were observed for seeds under temperatures of 20, 25, 30 and 20-30 ºC, which indicates greater vigor; almost all treatments indicated high ATG, longer than 15 days, which demonstrates that the seeds germinated slowly. Taking into consideration all parameters, the temperature of 25 ºC provided the best performance for the seeds of this species.