Enhancing the Functional Properties of Tea Tree Oil: In Vitro Antimicrobial Activity and Microencapsulation Strategy.

In the context of addressing antimicrobial drug resistance in periocular infections, Tea Tree Oil (TTO) has emerged as a promising therapeutic option. This study aimed to assess the efficacy of TTO against bacterial strains isolated from ocular infections, with a particular focus on its ability to inhibit biofilm formation. Additionally, we designed and analyzed microcapsules containing TTO to overcome certain unfavorable physicochemical properties and enhance its inherent biological attributes. The quality of TTO was confirmed through rigorous analysis using GC-MS and UV-Vis techniques. Our agar diffusion assay demonstrated the effectiveness of Tea Tree Oil (TTO) against ocular bacterial strains, including Corynebacterium spp., coagulase-negative Staphylococcus spp., and Staphylococcus aureus, as well as a reference strain of Staphylococcus aureus (ATCC 25923). Notably, the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) for all tested microorganisms were found to be 0.2% and 0.4%, respectively, with the exception of Corynebacterium spp., which exhibited resistance to TTO. Furthermore, TTO exhibited a substantial reduction in biofilm biomass, ranging from 30% to 70%, as determined by the MTT method. Through the spray-drying technique, we successfully prepared two TTO-containing formulations with high encapsulation yields (80-85%), microencapsulation efficiency (90-95%), and embedding rates (approximately 40%). These formulations yielded microcapsules with diameters of 6-12 µm, as determined by laser scattering particle size distribution analysis, and exhibited regular, spherical morphologies under scanning electron microscopy. Importantly, UV-Vis analysis post-encapsulation confirmed the presence of TTO within the capsules, with preserved antioxidant and antimicrobial activities. In summary, our findings underscore the substantial therapeutic potential of TTO and its microcapsules for treating ocular infections.

Adaptation and biocultural conservation of traditional agroforestry systems in the Tehuacán Valley: access to resources and livelihoods strategies.

Traditional agroforestry systems (TAFS) are important areas for conserving biodiversity, ecosystems benefits and biocultural heritage, outstandingly local knowledge, management techniques, and domestication processes. These systems have adapted to environmental, social, technological, and cultural changes throughout history. However, contemporary drastic socio-environmental changes as climate variability, economic inequality, migration, among others, have caused a productive crisis, with several consequences as productive land abandonment, threaten the sustainability of TAFS and vulnerating livelihoods. In such context, the question arises of what kind of adaptations are needed to face these changes, and how access to water and land, should be managed to improve adaptation of TAFS? The study analyzes TAFS in the Tehuacán Valley, a region with high biological and cultural diversity and early signs of agriculture in Mexico, where TAFS have remained active until present. The study analyzes the capacity of TAFS to conserve biodiversity and sustain local livelihoods, despite socio-environmental threats. It is based on a political ecology approach, which proposes that socio-ecological systems degradation is linked to unequal access to land and natural resources. Looking for an integral study of adaptations of TAFS to socio-environmental changes, this study combines qualitative and historical research methodology with quantitative methods evaluating plant diversity and spatial analysis. The study findings show that differentiated access to resources, water, land, and forest, is a key factor that limits adaptation of TAFS, impacting livelihood strategies, changing management patterns, and constraining social capacities for coping with socio-environmental changes. TAFS have significantly higher species richness than forests but lower diversity. The main contribution of the study is the methodological approach looking for an integral analysis of natural resources management and biocultural conservation in agroecosystems, and the identification of the unequal access to resources, as a keystone to understand and act for improving adaptive strategies of TAFS to socio-environmental changes.

Merging Porphyrins with Gold Nanorods: Self Assembly Construct to High Fluorescent Polyelectrolyte Microcapsules.

Dual probe porphyrin-gold nanorod polyelectrolyte microcapsules were developed to explore the enhancing effects of a plasmonic interface of self-assembled gold nanoparticles in the fluorescence emission from porphyrins loaded into the capsules' core. An analysis of fluorescence lifetime imaging microscopy (FLIM) data reports a notable 105-106-fold increase in the maximum detected photon rates from diffraction-limited spots and an overall six-fold increase in fluorescence as averaged over the whole microcapsule area. Large emission enhancements were correlated with decreases in fluorescence lifetimes. The microcapsule's design proved effective in achieving high fluorescent hybrids and may shed light on new possibilities for advanced materials imaging applications.

Traditional Fermented Beverages of Mexico: A Biocultural Unseen Foodscape.

Mexico is one of the main regions of the world where the domestication of numerous edible plant species originated. Its cuisine is considered an Intangible Cultural Heritage of Humanity and ferments are important components but have been poorly studied. Traditional fermented foods are still diverse, but some are endangered, requiring actions to promote their preservation. Our study aimed to (1) systematize information on the diversity and cultural history of traditional Mexican fermented beverages (TMFB), (2) document their spatial distribution, and (3) identify the main research trends and topics needed for their conservation and recovery. We reviewed information and constructed a database with biocultural information about TMFB prepared and consumed in Mexico, and we analyzed the information through network approaches and mapped it. We identified 16 TMFB and 143 plant species involved in their production, species of Cactaceae, Asparagaceae, and Poaceae being the most common substrates. Microbiological research has been directed to the potential biotechnological applications of Lactobacillus, Bacillus, and Saccharomyces. We identified a major gap of research on uncommon beverages and poor attention on the cultural and technological aspects. TMFB are dynamic and heterogenous foodscapes that are valuable biocultural reservoirs. Policies should include their promotion for conservation. The main needs of research and policies are discussed.

The Role of Porphyrinoid Photosensitizers for Skin Wound Healing.

Microorganisms, usually bacteria and fungi, grow and spread in skin wounds, causing infections. These infections trigger the immune system and cause inflammation and tissue damage within the skin or wound, slowing down the healing process. The use of photodynamic therapy (PDT) to eradicate microorganisms has been regarded as a promising alternative to anti-infective therapies, such as those based on antibiotics, and more recently, is being considered for skin wound-healing, namely for infected wounds. Among the several molecules exploited as photosensitizers (PS), porphyrinoids exhibit suitable features for achieving those goals efficiently. The capability that these macrocycles display to generate reactive oxygen species (ROS) gives a significant contribution to the regenerative process. ROS are responsible for avoiding the development of infections by inactivating microorganisms such as bacteria but also by promoting cell proliferation through the activation of stem cells which regulates inflammatory factors and collagen remodeling. The PS can act solo or combined with several materials, such as polymers, hydrogels, nanotubes, or metal-organic frameworks (MOF), keeping both the microbial photoinactivation and healing/regenerative processes' effectiveness. This review highlights the developments on the combination of PDT approach and skin wound healing using natural and synthetic porphyrinoids, such as porphyrins, chlorins and phthalocyanines, as PS, as well as the prodrug 5-aminolevulinic acid (5-ALA), the natural precursor of protoporphyrin-IX (PP-IX).

Recovery and evaluation of cellulose from agroindustrial residues of corn, grape, pomegranate, strawberry-tree fruit and fava.

Considering the expected increasing demand for cellulose fibers in the near future and that its major source is wood pulp, alternative sources such as vegetable wastes from agricultural activities and agro-food industries are currently being sought to prevent deforestation. In the present study, cellulose was successfully isolated from six agroindustrial residues: corncob, corn husk, grape stalk, pomegranate peel, marc of strawberry-tree fruit and fava pod. Cellulose fibers were characterized by Fourier-transform infrared spectroscopy, thermogravimetric analysis, stereomicroscopy and scanning electron microscopy (SEM). Despite the evident morphological differences among the extracted celluloses, results revealed similar compositional and thermal properties with the wood-derived commercial microcrystalline cellulose used as a control. Trace amounts of lignin or hemicellulose were detected in all cellulose samples, with the exception of corncob cellulose, that exhibited the greatest extraction yield (26%) and morphological similarities to wood-derived microcrystalline cellulose, visible through SEM. Furthermore, corncob cellulose was found to have thermal properties (TOnset of 307.17 °C, TD of 330.31 °C, and ΔH of 306.04 kJ/kg) suitable for biomedical applications.

An Insight into the Role of Non-Porphyrinoid Photosensitizers for Skin Wound Healing.

The concept behind photodynamic therapy (PDT) is being successfully applied in different biomedical contexts such as cancer diseases, inactivation of microorganisms and, more recently, to improve wound healing and tissue regeneration. The effectiveness of PDT in skin treatments is associated with the role of reactive oxygen species (ROS) produced by a photosensitizer (PS), which acts as a "double agent". The release of ROS must be high enough to prevent microbial growth and, simultaneously, to accelerate the immune system response by recruiting important regenerative agents to the wound site. The growing interest in this subject is reflected by the increasing number of studies concerning the optimization of relevant experimental parameters for wound healing via PDT, namely, light features, the structure and concentration of the PS, and the wound type and location. Considering the importance of developing PSs with suitable features for this emergent topic concerning skin wound healing, in this review, a special focus on the achievements attained for each PS class, namely, of the non-porphyrinoid type, is given.

Synthesis and biological evaluation of a bioinspired, tissue-adhesive gellan gum-based hydrogel designed for minimally invasive delivery and retention of chondrogenic cells.

A dopamine-modified, bioinspired gellan gum hydrogel (STM-148B) with improved physicochemical and biological characteristics, suitable for minimally invasive cell delivery and retention in the context of cartilage repair, is herein presented. STM-148B's putative game-changing design characteristics include a highly biocompatible, animal-free and chemically defined composition, reproducibility of manufacture and ease of formulation. STM-148B undergoes rapid ionic crossinking by physiologically relevant mono and divalent cations to form stable 3D hydrogels that possess excellent tissue adhesiveness, such that additional fixation aids are rendered superfluous. STM-148B hydrogels maintain viability of mammalian cells and further promote up-regulation of the expression of healthy chondrogenic extracellular matrix markers upon stimulation. STM-148B is currently undergoing pre-clinical safety and efficacy assessment as a medical device for cell delivery and retention focussing on regeneration of hyaline-like cartilage and may represent a valuable addition to the armamentarium of tissue-engineering therapies for treatment of focal cartilage lesions.

Traditional management of microorganisms in fermented beverages from cactus fruits in Mexico: an ethnobiological approach.

BACKGROUND: Fermentation is an ancient technique for preserving and improving the qualities of food and beverages throughout the world. Microbial communities, not seen by the producers of fermented goods, are the actors involved in the fermentation process and are selected upon through different management processes in order to achieve a final product with culturally accepted features. This study documented the preparation of "colonche" which is a type of traditionally fermented beverages made with the fruits from several cactus species in two main producing regions of Mexico, the Altiplano and the Tehuacán Valley. We documented the selection processes of the cactus species used and the practices that could influence microbial community composition, as well as, how the producers reach the desirable sensorial attributes of the beverages. METHODS: We conducted 53 semi-structured interviews and participatory observations with colonche producers in 7 communities of the Altiplano and the Tehuacán Valley in order to characterize the practices and processes involved in the elaboration of the beverage. Opuntia and columnar cacti species used in colonche production were collected during fieldwork and identified. Selected sensorial attributes of Opuntia colonches were characterized by a ranking table and visualized by principal component analysis in order to distinguish differences of this beverage in the Altiplano localities. RESULTS: Thirteen cactus species are used for colonche production in both regions studied. In the Altiplano, the most commonly used fruit is Opuntia streptacantha because it contributes to the preferred attributes of the beverage in this region. Selection of substrates by producers depends on their preference and the availability of fruits of O. streptacantha and other species. Fermentation is mainly conducted in clay pots which is perceived to be the best type of vessel contributing to the preferred sensorial properties of colonche. The two main differences in colonche preparation between the villages are the practice of boiling the fruit juice and the use of pulque (fermented sap of Agave species) as inoculum. The most contrasting sensorial attributes selected between localities are the alcohol content and sweetness, which might be in accordance with the practices used for obtaining the final product. Colonche is produced mainly for direct consumption and secondarily used as a commercialized good to be sold for economic gains contributing to the general subsistence of households. The preparation methods are passed on by close relatives, mainly women. CONCLUSIONS: Traditional producers of colonche use several techniques in order to reach specific sensorial attributes of the final product. The production of colonche has been upheld for generations but fermentation practices are divided into two categories; (1) the use of an inoculum (either from pulque, or from colonche saved from the previous year), and (2) the use of "spontaneous" fermentation. The differing practices documented reflect the contrasts in the preferred sensorial attributes between regions. Colonche is a beverage that contributes to regional pride, cultural identity and is appreciated because of its gastronomic value. Here, we argue that there is a clear relationship of human knowledge in the management of microbiota composition in order to produce this beverage. In-depth documentation of the microbiota composition and dynamics in colonche will contribute to the preservation of this valuable biocultural heritage.

12α-hydroxy-N-demethyl-sauroxine, a lycodane type alkaloid from Phlegmariurus saururus.

12α-hydroxy-N-demethyl-sauroxine (1), another new Lycopodium alkaloid from the Lycodane group, was isolated from Phlegmariurus saururus (Lam.) B. Øllg. (Lycopodiaceae). Elucidation of the chemical structure and relative stereochemistry were stated by spectroscopic data and chemical correlation. In addition, the inhibitory activity on acetylcholinesterase for 1 was determined as well as for N-methyllycodine (2), a derivative with the same nucleus, previously identified in P. saururus (IC50 = 33.8 ± 0.8 µM and 547.5 ± 0.5 µM, respectively) and N-demethylsauroxine (3) whose inhibition in the actual conditions was better than the previously informed.

Supercritical CO2 technology: The next standard sterilization technique?

Sterilization of implantable medical devices is of most importance to avoid surgery related complications such as infection and rejection. Advances in biotechnology fields, such as tissue engineering, have led to the development of more sophisticated and complex biomedical devices that are often composed of natural biomaterials. This complexity poses a challenge to current sterilization techniques which frequently damage materials upon sterilization. The need for an effective alternative has driven research on supercritical carbon dioxide (scCO2) technology. This technology is characterized by using low temperatures and for being inert and non-toxic. The herein presented paper reviews the most relevant studies over the last 15 years which cover the use of scCO2 for sterilization and in which effective terminal sterilization is reported. The major topics discussed here are: microorganisms effectively sterilized by scCO2, inactivation mechanisms, operating parameters, materials sterilized by scCO2 and major requirements for validation of such technique according to medical devices' standards.

An alkaloid extract obtained from Phlegmariurus Saururus induces neuroprotection after status epilepticus.

BACKGROUND: The brain is exposed to many excitotoxic insults that can lead to neuronal damage. Among these, Epilepsy is a neurological disease that affects a large percentage of world population and is commonly associated with cognitive disorders and excitotoxic neuronal death. Most experimental strategies are focused on preventing Status Epilepticus (SE), but once it has already occurred, the key question is whether it is possible to save neurons. PURPOSE: The aim of this study was to determine if a purified alkaloid extract (AE) obtained from Phlegmariurus saururus, a genus of Lycophyte plants (sometimes known as firmossesor fir club mosses) could induce neuroprotection following SE. METHODS: In vitro and in vivo techniques were applied for this purpose. Protein levels were measured by western blotting procedures. Neuronal death analysis was performed by calcein-ethidium staining and the presence of the NeuN protein as a marker for presence or absence of cells (in vitro experiments) and by Fluoro Jade B staining for the in vivo experiments. RESULTS: The effect of AE in the hippocampal neurons culture was the first determination, where we found an increase in neuronal survival and in the level of pErk and TrkB activation, 24 h after the addition of AE. In a well-established in vitro model of SE, we found that 24 h after being added to the hippocampal neuron-astrocyte co-culture, the AE induces a significant increase in neuronal survival. In addition to this, in the in vivo Li-pilocarpine model of SE, the AE induced a remarkable neuroprotection in areas such as the entorhinal cortex and hippocampal CA1 area. CONCLUSION: These results make the AE an excellent candidate for potential clinical use in neurological disorders where memory impairment and neuronal death occurs.

Sauroxine reduces memory retention in rats and impairs hippocampal long-term potentiation generation.

In the present paper it was investigated the role of sauroxine, an alkaloid of Phlegmariurus saururus, as a modulator of some types of learning and memory, considering the potential nootropic properties previously reported for the alkaloid extract and the main alkaloid sauroine. Sauroxine was isolated by means of an alkaline extraction, purified by several chromatographic techniques, and assayed in electrophysiological experiments on rat hippocampus slices, tending towards the elicitation of the long-term potentiation (LTP) phenomena. It was also studied the effects of intrahippocampal administration of sauroxine on memory retention in vivo using a Step-down test. Being the bio distribution of a drug an important parameter to be considered, the concentration of sauroxine in rat brain was determined by GLC-MS. Sauroxine blocked LTP generation at both doses used, 3.65 and 3.610-2µM. In the behavioral test, the animals injected with this alkaloid (3.6510-3nmol) exhibited a significant decrease on memory retention compared with control animals. It was also showed that sauroxine reached the brain (3.435µg/g tissue), after an intraperitoneal injection, displaying its ability to cross the blood-brain barrier. Thus, sauroxine demonstrated to exert an inhibition on these mnemonic phenomena. The effect here established for 1 is defeated by other constituents according to the excellent results obtained for P. saururus alkaloid extract as well as for the isolated alkaloid sauroine.

Aphrodisiac activity of Phlegmariurus saururus in copulating and noncopulating male rats.

BACKGROUND: Phlegmariurus saururus is popularly known in Argentina as aphrodisiac. For this reason, it was previously investigated and determined that the decoction of this plant elicits pro-ejaculatory activity and increases the ejaculatory potency in the Fictive Ejaculation Model. HYPOTHESIS/PURPOSE: the decoction of P. saururus facilitates sexual behavior in sexually experienced male rat and induces copulatory behavior in non-copulating male rats. METHODS: The extraction method (decoction) was validated through Selectivity, Accuracy and Precision, by identification of the majority alkaloids, expressed as sauroxine. Male (sexually experienced and noncopulating) and female (receptive) Wistar rats were used to determine sexual behavior. Sildenafil was used as positive control. The following variables were evaluated: Mount Latency, Intromission Latency, Ejaculation Latency, Post Ejaculatory Interval, as well as the Mounts and Intromissions Number. RESULTS: In sexually experienced male rats, P. saururus decoction stimulates sexual arousal and facilitates sexual execution. In noncopulating male rats, this decoction induces copulation with behavioral characteristics similar to sexually experienced animals. CONCLUSION: P. saururus possesses aphrodisiac activity in copulating and noncopulating male rats.

Agroforestry systems of the lowland alluvial valleys of the Tehuacán-Cuicatlán Biosphere Reserve: an evaluation of their biocultural capacity.

BACKGROUND: Agroforestry systems (AFS) are valuable production systems that allow concealing benefits provision with conservation of biodiversity and ecosystem services. We analysed AFS of the zone of alluvial valleys of the Tehuacán-Cuicatlán Valley (TCV), Mexico, the most intensive agricultural systems within a region recognized for harbouring one of the most ancient agricultural experience of the New World. We hypothesized that the biodiversity conservation capacity of AFS would be directly related to traditional agricultural features and inversely related to management intensity. METHODS: Agricultural practices, use frequency of machinery and chemical inputs, and proportion of forest and cultivated areas were described in 15 AFS plots in alluvial valleys of the Salado River in three villages of the region. With the information, we constructed a management intensity index and compared among plots and villages. We documented the reasons why people maintain wild plant species and traditional practices. Perennial plant species were sampled in vegetation of AFS (15 plots) and unmanaged forests (12 plots 500 m(2)) in order to compare richness, diversity and other ecological indicators in AFS and forest. RESULTS: In all studied sites, people combine traditional and intensive agricultural practices. Main agroforestry practices are ground terraces and borders surrounding AFS plots where people maintain vegetation. According to people, the reasons for maintaining shrubs and trees in AFS were in order of importance are: Beauty and shade provision (14% of people), fruit provision (7%), protection against strong wind, and favouring water and soil retention. We recorded 66 species of trees and shrubs in the AFS studied, 81% of them being native species that represent 38% of the perennial plant species recorded in forests sampled. Land tenure and institutions vary among sites but not influenced the actions for maintaining the vegetation cover in AFS. Plant diversity decreased with increasing agricultural intensity. CONCLUSIONS: Maintenance of vegetation cover did not confront markedly with the intensive agricultural practices. It is possible the expansion and enrichment of vegetation in terraces and borders of AFS. Information available on plant species and local techniques is potentially useful for a regional program of biodiversity conservation considering AFS as keystones.

Mass spectrometry studies of lycodine-type Lycopodium alkaloids: sauroxine and N-demethylsauroxine.

RATIONALE: Sauroxine and N-demethylsauroxine are lycodine-type Lycopodium alkaloids. In recent years, Lycopodium alkaloids have gained significant interest due to their unique skeletal characteristics as well as due to their acetylcholinesterase activity. It is known that drugs that inhibit acetylcholinesterase can be used to treat the early stages of Alzheimer's disease. METHODS: Sauroxine and N-demethylsauroxine were isolated from the aerial parts of Huperzia saururus (Lam.) Trevis. Electron ionization mass spectrometry (EI-MS) (low resolution) and collision-induced dissociation tandem mass spectrometry (CID-MS/MS) fragmentation was conducted using an ion trap, GCQ Plus mass spectrometer with MS/MS. Electron ionization high-resolution mass spectrometry (EI-HRMS) was performed in a magnetic sector mass spectrometer (Micromass VG). RESULTS: Using GC/EI-CID-MS/MS we obtained different fragmentation routes that connect all the ionic populations. In addition, the use of EI-HRMS allowed us to measure the exact masses of all the fragment ions, and, with all this information gathered, we tried to establish a fragmentation scheme concordant with the ascendant and descendant species. CONCLUSIONS: The mass spectrometry studies presented in this work complete our mass studies of Lycopodium alkaloids. The mass spectrometry work presented has been very useful to confirm the structures as well as to support the biogenetic relationships between the lycodine-type Lycopodium alkaloids: sauroxine and N-demethylsauroxine.

A new semisynthetic derivative of sauroine induces LTP in hippocampal slices and improves learning performance in the Morris Water Maze.

Two semisynthetic acetyl derivatives of the alkaloid sauroine from Huperzia saururus, monoacetyl sauroine, and diacetyl sauroine (DAS) were obtained and their chemical structures were analyzed by NMR. While monoacetyl sauroine is the typical product of acetylation, DAS is an unexpected derivative related to the keto-enol formation of sauroine. Recordings of field excitatory post-synaptic potentials from the CA1 region of rat hippocampal slices showed that only DAS acutely applied induced chemical long-term potentiation (LTP) in a dose-dependent manner with an EC50 of 1.15 ± 0.09 µM. This effect was blocked by 10 µM D(-)-2-amino-5-phosphonopentanoic acid (AP5), suggesting dependence on the NMDA receptor. DAS significantly increased NMDA receptor-dependent excitatory post-synaptic currents without affecting α-amino-3-hydroxy-5-methylisoxazole-4-propionate receptor-dependent currents. Repetitive administration of DAS improved visuo-spatial learning in the Morris Water Maze. In slices from rats tested in the Morris Water Maze, LTP resulting from electrical synaptic stimulation was 2.5 times larger than in controls. Concentration of DAS measured in the brain after repetitive administration was 29.5 µM. We conclude that slices perfused with DAS display a robust NMDA receptor-dependent chemical LTP. During chronic treatment, DAS enhances learning abilities through a metaplastic mechanism as revealed by the augmentation of LTP in slices. DAS, therefore, may be a promising compound as a nootropic therapeutic drug. A semisynthetic derivative of sauroine, diacetyl sauroine (DAS), induces chemical long-term potentiation in rat hippocampal slices increasing the NMDA receptor-dependent current. 2 mg/kg prior to each session in a Morris Water Maze (MWM) improves behavior performance. In slices prepared from the tested rats the electrical stimulation-dependent long-term potentiation (LTP) was greatly enhanced. Therefore, DAS may have potency as a nootropic drug against the memory decline.

Plant management and biodiversity conservation in Náhuatl homegardens of the Tehuacán Valley, Mexico.

BACKGROUND: The Tehuacán Valley is one of the areas of Mesoamerica with the oldest history of plant management. Homegardens are among the most ancient management systems that currently provide economic benefits to people and are reservoirs of native biodiversity. Previous studies estimated that 30% of the plant richness of homegardens of the region are native plant species from wild populations. We studied in Náhuatl communities the proportion of native plant species maintained in homegardens, hypothesizing to find a proportion similar to that estimated at regional level, mainly plant resources maintained for edible, medicinal and ornamental purposes. METHODS: We analysed the composition of plant species of homegardens and their similarity with surrounding Cloud Forest (CF), Tropical Rainforest (TRF), Tropical Dry forest (TDF), and Thorn-Scrub Forest (TSF). We determined density, frequency and biomass of plant species composing homegardens and forests through vegetation sampling of a total of 30 homegardens and nine plots of forests, and documented ethnobotanical information on use, management, and economic benefits from plants maintained in homegardens. RESULTS: A total of 281 plant species was recorded with 12 use categories, 115 ornamental, 92 edible, and 50 medicinal plant species. We recorded 49.8 ± 23.2 (average ± S.D.) woody plant species (shrubs and trees) per homegarden. In total, 34% species are native to the Tehuacán Valley and nearly 16% are components of the surrounding forests. A total of 176 species were cultivated through seeds, vegetative propagules or transplanted entire individual plants, 71 tolerated, and 23 enhanced. The highest species richness and diversity were recorded in homegardens from the CF zone (199 species), followed by those from the TRF (157) and those from the TDF (141) zones. CONCLUSION: Homegardens provide a high diversity of resources for subsistence of local households and significantly contribute to conservation of native biodiversity. The highest diversity was recorded in homegardens where the neighbouring forests had the least diversity, suggesting that management of homegardens aims at compensating scarcity of naturally available plant resources. Cultivated species were markedly more abundant than plants under other management forms. Diversity harboured and management techniques make homegardens keystones in strategies for regional biodiversity conservation.

Study of the interaction of Huperzia saururus Lycopodium alkaloids with the acetylcholinesterase enzyme.

In the present study, we describe and compare the binding modes of three Lycopodium alkaloids (sauroine, 6-hydroxylycopodine and sauroxine; isolated from Huperzia saururus) and huperzine A with the enzyme acetylcholinesterase. Refinement and rescoring of the docking poses (obtained with different programs) with an all atom force field helped to improve the quality of the protein-ligand complexes. Molecular dynamics simulations were performed to investigate the complexes and the alkaloid's binding modes. The combination of the latter two methodologies indicated that binding in the active site is favored for the active compounds. On the other hand, similar binding energies in both the active and the peripheral sites were obtained for sauroine, thus explaining its experimentally determined lack of activity. MM-GBSA predicted the order of binding energies in agreement with the experimental IC50 values.

Amino acid content and acetylcholinesterase inhibition of Huperzia saururus infusion and decoction.

UNLABELLED: CONTEXT. Huperzia saururus (Lam.) Trevis. (Lycopodiaceae), an autochthonous plant species in Argentina, is used as a memory improver in traditional medicine. It was studied for this reason and the purified alkaloid extract did show significant activity on learning and memory. The species is mostly consumed in the form of infusions and decoctions. OBJECTIVES: To evaluate the activity of the H. saururus infusion and decoction as inhibitors of acetylcholinesterase (AChE) and to determine the amino acid content in both extracts. MATERIAL AND METHODS: Infusion and decoction were purified by ionic exchange chromatography and analyzed by high-performance liquid chromatography HPLC-UV, and the AChE inhibition of these extracts was evaluated by using the Ellman method. RESULTS: Both infusion and decoction exerted strong AChE inhibitory activities (IC50=7.2 ± 0.4 and 22.7 ± 5.6 µg/mL, respectively). Among nine amino acids, arginine (Arg) was identified in a concentration greater than 9 mg/100 g of dried aerial parts in both extracts. DISCUSSION AND CONCLUSION: This high content of Arg could be considered a contributing factor to the activity on memory previously demonstrated for the H. saururus alkaloid extract, since Arg is implicated indirectly in mnemonic processes as a precursor in nitric oxide synthesis. Thus, the central effect of H. saururus could involve two different mechanisms, the cholinergic mechanism and the nitric oxide pathway.