José Luis Aragón-Gastélum

Climate change is altering environmental conditions, which can, in turn, change the geographic distribution and flowering patterns of plant species, affecting both the plants themselves and their pollinators. The responses of melliferous plant species to climate change in southeastern Mexico are poorly understood, which hinders an accurate assessment of their vulnerability and the resulting ecological impacts. As understanding the mechanisms that influence the distribution and susceptibility of these species is essential, the present study examined how climate change affects their potential distribution areas and spatial distribution patterns. This information will serve as reference data for the implementation of conservation strategies and inform the selection of species for reforestation. Ecological niche models were used to estimate the potential distributions of 92 melliferous species under both current environmental conditions and two climate change scenarios projected for the 2041–2060 period (SSP245 and SSP585). Changes in distribution patterns were then assessed by evaluating the range size of each species and analyzing the spatio–temporal trends in species richness. The results revealed that suitable habitats shifted for approximately 80% of melliferous species, with more significant habitat loss observed under the SSP585 scenario than under SSP245. Although a significant decrease in melliferous plant species richness was expected in future scenarios, richness was slightly higher (by 10% for SSP245 and 5% for SSP585) than that observed under current environmental conditions. Under SSP245 conditions, species richness areas expanded to encompass almost the entire region, although this contrasted drastically with the SSP585 scenario, where areas with the highest concentration of species richness contracted significantly and areas with low species richness expanded. These projections are of potential use for conservationists and environmental management authorities, providing crucial insights into the future distributions of several melliferous plant species in the region, the potential impacts of climate change on their habitats, and the vulnerability of threatened species to changing climatic conditions.

The mangrove ecosystem is reported to have a large diversity of species that develop in environments with high salinity levels. Plant species from mangroves are used in traditional medicine and are potential sources of chemicals entities with therapeutic applications. The present work aims to assess and document the influence of salinity on the antioxidant activity exerted by extracts of mangrove species through spectroscopic and chemical analysis. The highest salinity is recorded in Río Verde (RV) in Petén Neyac (PN), an LPBR site. The leaves of Laguncularia racemosa (from RV and PN) recorded the highest extraction yield (35.29 ± 0.45%). Phytochemical analysis indicated the presence of several families of secondary metabolites in the leaves of Rhizophora mangle, Avicennia germinans, and L. racemosa collected in PN and RV, and the chromatographic profile confirms the complexity of the extracts, especially in L. racemosa-RV. The highest content of chlorophylls, carotenoids, and simple phenols was recorded in R. mangle (in RV and PN); flavonoids were high in A. germinans (RV), and the highest antioxidant activity was recorded in L. racemosa (RV) using the DPPH model (EC₅₀: 39.74 ± 0.91 μg/mL; E_max: 67.82 ± 1.00%). According to HPLC, gallic acid (GA), and quercetin (Q) are important metabolites in L. racemosa. FTIR spectra can identify several chemical groups and fingerprint regions in complex mixtures, such as methanolic extracts of the species under study. In this context, this is the first report on chemical changes resulting from species collected at sites with different degrees of salinity. GA is the main metabolite affected by salinity and participates in the antioxidant activity exerted by the original extract, which could explain the physiological adaptations of L. racemosa and its traditional uses. L. racemosa (RV) is ideal for a bioguided phytochemical study that would yield valuable knowledge about its medicinal properties, support ecological conservation, and drive innovation across multiple industries. Further analytical studies are needed to corroborate the impact of salinity on the biosynthesis of secondary metabolites.

The objective of this study was to describe the diversity, composition, and structure of the woody vegetation in a section of LDF in Lerma, Campeche. Between August and September 2018, 10 plots of 10 × 10 m2 (1 000 m2 in total) were delimited, measuring all woody individuals with diameter at breast height (DBH = 1.30 cm). The structure of the site was described based on the relative values of density, frequency, and dominance (IVI), as well as the distribution of diameter classes. Diversity was estimated with the Shannon-Wiener index (H'), while equity was measured by the Pielou index. 40 woody species were recorded, belonging to 35 genera and 19 families. The H' index had a value of 2.92, and the Pielou index was 0.79, the density was 8 950 ind ha-1. Gymnopodium floribundum (204 individuals) and Lonchocarpus xuul (129) were the most abundant species. Bursera simaruba and Lysiloma latisiliquum showed higher diameter values (36 and 28.6 cm DBH, respectively). The families Rubiaceae (eight species), Fabaceae (five species), Ebenaceae and Polygonaceae (three species each) were the most representative. The species with the highest IVI were Gymnopodium floribundum (48.24%), Lonchocarpus xuul (29.12%), Bursera simaruba (26.11%) and Lysiloma latisiliquum (24.98%), these species being the most important in the structure of the LDF in the site. The distribution of the diameter classes suggests that the section of the LDF in Lerma Campeche is in an adequate state of regeneration.

Coccoloba uvifera is a Mayan medicinal plant, and these leaves are used as antidiarrheal and diuretic agents. In the present work, we develop in-vitro, ex-vivo, in-vivo, and in-silico strategies to evaluate several aqueous extracts of C. uvifera leaves. In vitro tests showed that decoction extract (CuDe) presented the best yield and chlorophyll, phenol, and flavonoid content; however, CuDe showed low antioxidant activity (DPPH model). All aqueous extracts exert spasmolytic and vasorelaxant activity in a concentration-dependent manner (ex vivo), and in vivo tests showed that CuDe exerts the best antiperistaltic and diuretic effects. The in-silico analysis suggests that C. uvifera triterpenes act as a ligand of GPCR, and β-sitosterol could act as an antagonist of muscarinic acetylcholine receptor subtype 3 (m3AChR). In the context of aqueous extracts of C. uvifera, β-sitosterol and their heterosides were identified by FTIR and ¹H-NMR spectroscopy. The concerted binding of β-sitosterol and other triterpenes within the m3AChR binding site may be relevant for the induction of relaxant effects at the gastrointestinal smooth muscle level. In this context, C. uvifera is a high-value plant species that requires analytical and pharmacological studies to confirm traditional medicinal use.

Publicado em 18 de dezembro de 2023. A produção de conhecimento é um processo fundamental para o avanço da sociedade, da ciência e da tecnologia, que envolve a geração, aquisição, organização e disseminação de informações e ideias que contribuem para a compreensão e o desenvolvimento de novos conceitos, teorias, tecnologias e práticas. É um processo dinâmico e contínuo, que se alimenta da interação entre diferentes áreas do conhecimento, da colaboração entre pesquisadores e profissionais e da aplicação prática do conhecimento adquirido. Ela também envolve a comunicação e disseminação de informações por meio de publicações acadêmicas, conferências, mídias sociais, palestras, entre outros meios. A disseminação do conhecimento é essencial para que as descobertas e ideias sejam compartilhadas e utilizadas por outros pesquisadores, profissionais e o público em geral. A pesquisa é uma das principais formas de produção de conhecimento. Ela envolve a realização de estudos, experimentos e investigações para responder a perguntas, testar hipóteses e descobrir novos fenômenos, e contribui para o avanço do conhecimento em diversas áreas, incluindo ciências biológicas. As ciências biológicas desempenham um papel fundamental na produção de ciência em diversas áreas do conhecimento, incluindo medicina, biotecnologia, ecologia, genética, zoologia, botânica, entre outras. Através do estudo dos seres vivos, suas características, processos e interações com o meio ambiente, a biologia contribui para o avanço do conhecimento científico e tecnológico e constrói diariamente novos paradigmas. Nesta obra, “Las ciencias biológicas y la construcción de nuevos paradigmas de conocimiento 3”, são apresentados trabalhos originais que englobam a intersecção entre teoria, prática e metodologia científica. São apresentados, ao longo de quatro capítulos, trabalhos científicos que abordam diferentes áreas da biologia, inclusive a educação básica. A Atena Editora possui um corpo editorial com professores das melhores universidades do Brasil, e apresenta obras atualizadas, com qualidade, que podem ser utilizadas por profissionais e estudantes, como a obra que ora apresentamos. Esperamos que você tenha uma agradável leitura! Daniela Reis Joaquim de Freitas

Introduction: Multidrug-resistant (MDR) pathogenic bacteria in seafood, especially shrimp and octopus, are significant public health concerns and are able to be transmitted to humans in foodstuffs, particularly when they are of animal origin. The present study was conducted to measure the antimicrobial susceptibility patterns and prevalence of Salmonella isolates obtained from octopus and shrimp in San Francisco de Campeche, Mexico. Methods: Two hundred shrimp and octopus samples (one hundred each) were collected from the municipal market, and each sample consisted of 100 g. The present study used conventional methods to identify and isolate Salmonella, with the disk-diffusion method used to screen all isolates for sensitivity to 12 antibiotics. Results: The prevalence of Salmonella was found to be 56% and 45% in shrimp and octopus, respectively. The high levels of Salmonella observed in the municipal market sampled by the present study reveal poor sanitary conditions in the processing and transport of the products of interest and those handling them at the point of sale. All the Salmonella strains were resistant to at least three antimicrobial classes. All shrimp isolates (100%) presented susceptibility to chloramphenicol and the majority (88%) presented sensitivity to ciprofloxacin, while the strains isolated in the octopus individuals sampled presented sensitivity to both the foregoing antibiotics (74% and 90%, respectively). Conclusion: Based on the high prevalence in the samples analyzed, our results suggest that shrimp and octopus could be involved in Salmonella infections in the population.

Enterolobium cyclocarpum and Piscidia piscipula are two important tree Fabaceae species distributed from the Yucatan Peninsula, Mexico. Our aims were focused on the E. cyclocarpum and P. piscipula seeds for: (1) to examine the seed permeability and imbibition rate, (2) to evaluate the effect of seed pre-germinative treatments, and (3) to characterize the structures involved on the presence of physical dormancy (PY). We used fresh seeds to determine seed permeability and imbibition rate, seed viability by means of tetrazolium test, furthermore, we applied mechanical scarification and boiler shocks for 5 s, 10 s and 15 s treatments. Morphological characterization of the seed coat was by Scanning Electron Microscope (SEM). Seed viability in E. cyclocarpum and P. piscipula were 100% and 96%, respectively. Seed permeability and imbibition rate in E. cyclocarpum were low. The highest germination in E. cyclocarpum was in the mechanical scarification (92%), while in P. piscipula, this parameter was in the 10 s boiling water treatment (76.0%). The presence of PY was confirmed in both species because they showed low seed permeability, and imbibition rate; furthermore, exhibited macrosclereids cells. The present research seeks to promote the sustainable use of E. cyclocarpum and P. piscipula.