Chemical Fingerprinting and Biological Evaluation of the Endemic Chilean Fruit Greigia sphacelata (Ruiz and Pav.) Regel (Bromeliaceae) by UHPLC-PDA-Orbitrap-Mass Spectrometry

Greigia sphacelata (Ruiz and Pav.) Regel (Bromeliaceae) is a Chilean endemic plant popularly known as "quiscal" and produces an edible fruit consumed by the local Mapuche communities named as "chupón". In this study, several metabolites including phenolic acids, organic acids, sugar derivatives, catechins, proanthocyanidins, fatty acids, iridoids, coumarins, benzophenone, flavonoids, and terpenes were identified in G. sphacelata fruits using ultrahigh performance liquid chromatography-photodiode array detection coupled with a Orbitrap mass spectrometry (UHPLC-PDA-Orbitrap-MS) analysis for the first time. The fruits showed moderate antioxidant capacities (i.e., 487.11 ± 26.22 μmol TE/g dry weight) in the stable radical DPPH assay, 169.08 ± 9.81 TE/g dry weight in the ferric reducing power assay, 190.32 ± 6.23 TE/g dry weight in the ABTS assay, and 76.46 ± 3.18% inhibition in the superoxide anion scavenging assay. The cholinesterase inhibitory potential was evaluated against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). From the findings, promising results were observed for pulp and seeds. Our findings suggest that G. sphacelata fruits are a rich source of diverse secondary metabolites with antioxidant capacities. In addition, the inhibitory effects against AChE and BChE suggest that natural products or food supplements derived from G. sphacelata fruits are of interest for their neuroprotective potential.

Phytochemical analysis and biological activities of in vitro cultured Nidularium procerum, a bromeliad vulnerable to extinction

This study reports the first phytochemical and biological characterization in treatment of adrenocortical carcinoma cells (H295R) of extracts from Nidularium procerum, an endemic bromeliad of Atlantic Forest vulnerable to extinction. Extracts of dry leaves obtained from in vitro-grown plants were recovered by different extraction methods, viz., hexanoic, ethanolic, and hot and cold aqueous. Chromatography-based metabolite profiling and chemical reaction methods revealed the presence of flavonoids, steroids, lipids, vitamins, among other antioxidant and antitumor biomolecules. Eicosanoic and tricosanoic acids, α-Tocopherol (vitamin E) and scutellarein were, for the first time, described in the Nidularium group. Ethanolic and aqueous extracts contained the highest phenolic content (107.3 mg of GAE.100 g-1) and 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) radical scavenging activity, respectively. The immunomodulatory and antitumoral activities of aqueous extracts were assessed using specific tests of murine macrophages modulation (RAW 264.7) and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay against adrenocortical carcinoma cell line, respectively. The aqueous extract improved cell adhesion and phagocytic activities and phagolysossomal formation of murine macrophages. This constitutes new data on the Bromeliaceae family, which should be better exploited to the production of new phytomedicines for pharmacological uses.

Hydrogenotrophic methanogenesis is the dominant methanogenic pathway in neotropical tank bromeliad wetlands

Several thousands of tank bromeliads per hectare of neotropical forest create a unique wetland ecosystem that emits substantial amounts of CH₄ . Tank bromeliads growing in the forest canopy (functional type-II tank bromeliads) were found to emit more CH₄ than tank bromeliads growing on the forest floor (functional type-I tank bromeliads) but the reasons for this difference and the underlying microbial CH₄ -cycling processes have not been studied. Therefore, we characterized archaeal communities in bromeliad tanks of the two different functional types in a neotropical montane forest of southern Ecuador using terminal-restriction fragment length polymorphism (T-RFLP) and performed tank-slurry incubations to measure CH₄ production potential, stable carbon isotope fractionation and pathway of CH₄ formation. The archaeal community composition was dominated by methanogens and differed between bromeliad functional types. Hydrogenotrophic Methanomicrobiales were the dominant methanogens and hydrogenotrophic methanogenesis was the dominant methanogenic pathway among all bromeliads. The relative abundance of aceticlastic Methanosaetaceae and the relative contribution of aceticlastic methanogenesis increased in type-I tank bromeliads probably due to more oxic conditions in type-I than in type-II bromeliads leading to the previously observed lower in situ CH₄ emissions from type-I tank bromeliads but to higher CH₄ production potentials in type-I tank bromeliad slurries.

Evaluation of anti-inflammatory activity of Pseudananas macrodontes (Morr.) Harms (Bromeliaceae) fruit extract in rats

Several species of the family Bromeliaceae are characterized by the production of proteases in unusual amounts, especially in fruits. Bromelain, an extract rich in cysteine endopeptidases obtained from Ananas comosus L., and a few other proteases have been used as anti-inflammatory agents for some years, but bromelain is still mainly being used as alternative and/or complementary therapy to the treatment with glucocorticoids, nonsteroidal antirheumatics, and immunomodulators. In this study, the anti-inflammatory action of a partially purified extract from Pseudananas macrodontes (Morr.) Harms fruits (PPE(Pm)) is presented, whose main components are cysteine endopeptidases. The effect of PPE(Pm) was assessed in carrageenan-induced and serotonin-induced rat paw edema, as well as in the cotton pellet granuloma model. Doses with equal proteolytic activity of PPE(Pm) and bromelain produced significantly similar anti-inflammatory responses in the acute inflammatory models assayed, supporting the hypothesis that proteolytic activity could be responsible for the anti-inflammatory action. On the contrary, comparable anti-inflammatory effects of PPE(Pm) and bromelain in the chronic inflammatory assay required a much lower proteolytic activity content of PPE(Pm), which could be due to a differential affinity for the protein target involved in this process.

Gastroprotective effect of an ethanolic extract from Neoglaziovia variegata (Arruda) Mez (Bromeliaceae) in rats and mice

This study investigates the gastroprotective effect of a crude ethanolic extract of Neoglaziovia variegata (Arruda) Mez (Bromeliaceae), designated Nv-EtOH, in experimental models of gastric ulcer. In the ethanol-induced gastric ulcer model, Nv-EtOH showed gastroprotection at doses of 200 and 400 mg/kg body weight (BW) (57.0% and 79.7%, respectively). Nv-EtOH also significantly reduced the formation of gastric lesions induced by ethanol/HCl (31.6% and 63.5%), ibuprofen (70.0% and 74.3%), or ischemia/reperfusion in rats (65.0% and 87.0%) at 200 and 400 mg/kg BW when compared with the vehicle group. In the antioxidant activity assessment, Nv-EtOH (400 mg/kg BW) increased the catalase activity and sulfhydryl groups (SH) levels, respectively. Moreover, gastroprotection against ethanol damage was decreased after ibuprofen pretreatment. Nv-EtOH (400 mg/kg BW) promoted a significant increase in the content of gastric wall mucus. The Nv-EtOH effect was significantly reduced in mice pretreated with N(G)-nitro-L-arginine (L-NOARG) or glibenclamide, inhibitors of nitric oxide synthase and K(ATP) channel activation, respectively, suggesting the involvement of these mechanisms in the Nv-EtOH-induced gastroprotective effect. Nv-EtOH decreased the total acidity, but did not modify other gastric juice parameters. Nv-EtOH was also effective in promoting the healing process in chronic gastric ulcer induced by acetic acid in rats.

Aquatic microbial habitats within a neotropical rainforest: bromeliads and pH-associated trends in bacterial diversity and composition

Tank-forming bromeliads, suspended in the rainforest canopy, possess foliage arranged in compact rosettes capable of long-term retention of rainwater. This large and unique aquatic habitat is inhabited by microorganisms involved in the important decomposition of impounded material. Moreover, these communities are likely influenced by environmental factors such as pH, oxygen, and light. Bacterial community composition and diversity was determined for the tanks of several bromeliad species (Aechmea and Werauhia) from northern Costa Rica, which span a range of parameters, including tank morphology and pH. These were compared with a nearby forest soil sample, an artificial tank (amber bottle), and a commercially available species (Aechmea). Bacterial community diversity, as measured by 16S rRNA analysis and tRFLP, showed a significant positive correlation with tank pH. A majority of 16S rRNA bacterial phylotypes found in association with acidic bromeliad tanks of pH < 5.1 were affiliated with the Alphaproteobacteria, Acidobacteria, Planctomycetes, and Bacteroidetes, and were similar to those found in acidic peat bogs, yet distinct from the underlying soil community. In contrast, bromeliads with tank pH > 5.3, including the commercial bromeliad with the highest pH (6.7), were dominated by Betaproteobacteria, Firmicutes, and Bacteroidetes. To empirically determine the effect of pH on bacterial community, the tank pH of a specimen of Aechmea was depressed, in the field, from 6.5 to 4.5, for 62 days. The resulting community changed predictably with decreased abundance of Betaproteobacteria and Firmicutes and a concomitant increase in Alphaproteobacteria and Acidobacteria. Collectively, these results suggest that bromeliad tanks provide important habitats for a diverse microbial community, distinct from the surrounding environment, which are influenced greatly by acid-base conditions. Additionally, total organic carbon (∼46%) and nitrogen (∼2%) of bromeliad-impounded sediment was elevated relative to soil and gene surveys confirmed the presence of both chitinases and nitrogenases, suggesting that bromeliad tanks may provide important habitats for microbes involved in the biological cycling of carbon and nitrogen in tropical forests.

Antiulcer activity of ethanolic extract of Encholirium spectabile Mart. ex Schult & Schult f. (Bromeliaceae) in rodents

This study evaluated the antiulcer activity of an ethanolic extract of Encholirium spectabile (ES-EtOH) by using different standard experimental models of induced acute gastric ulceration. ES-EtOH (100 mg/kg p.o) protected the gastric mucosa against ulceration that was induced by absolute ethanol (53%), ethanol/HCl (75%), ibuprofen (52 %) and ischemia/reperfusion (43 %). It also restored catalase activity and non-protein sulfhydryl group concentration in the gastric wall of mice that had been treated with ethanol. The pre-treatment of mice with N-nitro-L-arginine (70 mg/kg i.p.) abolished the protective activity of ES-EtOH, which indicates that prostaglandins, antioxidant compounds and nitric oxide synthase activity are involved in the gastroprotective activity of the extract.

Ants mediate foliar structure and nitrogen acquisition in a tank-bromeliad

Aechmea mertensii is a tank-bromeliad that roots on ant-gardens initiated by the ants Camponotus femoratus and Pachycondyla goeldii. Its leaves form compartments acting as phytotelmata that hold rainwater and provide habitats for invertebrates. In this article, we aimed to determine whether the association with either C. femoratus or P. goeldii influenced the vegetative traits of A. mertensii, invertebrate diversity and nutrient assimilation by the leaves. Transmitted light, vegetative traits and phytotelmata contents were compared between the two A. mertensii ant-gardens. Camponotus femoratus colonized partially shaded areas, whereas P. goeldii colonized exposed areas. The bromeliads' rosettes had a large canopy (C. femoratus ant-gardens), or were smaller and amphora shaped (P. goeldii ant-gardens). There were significant differences in leaf anatomy, as shaded leaves were thicker than exposed leaves. The mean volumes of water, fine particulate organic matter and detritus in C. femoratus-associated bromeliads were three to five times higher than in P. goeldii-associated bromeliads. Moreover, the highest invertebrate diversity and leaf delta(15)N values were found in C. femoratus-associated bromeliads. This study enhances our understanding of the dynamics of biodiversity, and shows how ant-plant interactions can have trophic consequences and thus influence the architecture of the interacting plant via a complex feedback loop.

Glucuronoarabinoxylan structure in the walls of Aechmea leaf chlorenchyma cells is related to wall strength

In CAM-plants rising levels of malic acid in the early morning cause elevated turgor pressures in leaf chlorenchyma cells. Under specific conditions this process is lethal for sensitive plants resulting in chlorenchyma cell burst while other species can cope with these high pressures and do not show cell burst under comparable conditions. The non-cellulosic polysaccharide composition of chlorenchyma cell walls was investigated and compared in three cultivars of Aechmea with high sensitivity for chlorenchyma cell burst and three cultivars with low sensitivity. Chlorenchyma layers were cut from the leaf and the non-cellulosic carbohydrate fraction of the cell wall fraction was analyzed by gas-liquid chromatography. Glucuronoarabinoxylans (GAXs) were the major non-cellulosic polysaccharides in Aechmea. The fine structure of these GAXs was strongly related to chlorenchyma wall strength. Chlorenchyma cell walls from cultivars with low sensitivity to cell burst were characterized by an A/X ratio of ca. 0.13 while those from cultivars with high sensitivity showed an A/X ratio of ca. 0.23. Xylose chains from cultivars with high cell burst sensitivity were ca. 40% more substituted with arabinose compared to cultivars with low sensitivity for cell burst. The results indicate a relationship in vivo between glucuronoarabinoxylan fine structure and chlorenchyma cell wall strength in Aechmea. The evidence obtained supports the hypothesis that GAXs with low degrees of substitution cross-link cellulose microfibrils, while GAXs with high degrees of substitution do not. A lower degree of arabinose substitution on the xylose backbone implies stronger cell walls and the possibility of withstanding higher internal turgor pressures without cell bursting.