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Exponential model for population growth (exponential model) is a foundation to evaluate population dynamics in Population Ecology field. Here, we used a didactic experiment to teach exponential model for an undergraduate course of Population Ecology. We built nine populations of weevils with three different initial population sizes: eight, 16, and 32 individuals with three replicates each. We provided equal food resource availability, and counted their population sizes weekly for 12 weeks. We estimated the intrinsic growth rate (i.e., r parameter), by trials and errors with an exponential model build in an Excel spreadsheet. The population growth rate (i.e., dN/dt parameter) was estimated using r values. Replicates with eight and 16 individuals reached the highest values of r and dN/dt, while replicates with 32 individuals reached the lowest values. Beyond of exponential model, two density dependency issues acting in populations were observed. First, in the lowest initial population sizes we observed the effect of demographic stochasticity acting in both r and dN/dt in one of the three populations. Second, we observed the intraspecific competition reducing r values in largest initial populations. Therefore, we highlight the importance of didactic experiment into learning exponential model in Population Ecology course, both for teaching and learning practices.    

Hookworms are intestinal parasites that cause major public health problems, especially in developing countries. To differentiate eggs from different hookworm species, it is necessary to use molecular methodologies, since the eggs are morphologically similar. Here, we performed the molecular identification of single hookworm eggs from six Brazilian states. Of the 634 eggs individually analyzed, 98.1% (622/634) represented Necator americanus , and surprisingly, 1.9% (12/634 eggs from the same patient) represented Ancylostoma caninum . DNA analysis of the A. caninum -positive stool sample revealed no contamination with animal feces. This is the first report of the presence of A. caninum eggs in human feces, which may have a direct implication for the epidemiology of hookworm infection caused by this species. This suggests the need for special attention regarding prophylaxis, as different reservoirs, previously not described, may have great relevance for the spread of A. caninum .

Oral squamous cell carcinoma (OSCC) represents 90% of oral malignant neoplasms. The search for specific biomarkers for OSCC is a very active field of research contributing to establishing early diagnostic methods and unraveling underlying pathogenic mechanisms. In this work we investigated the salivary metabolites and the metabolic pathways of OSCC aiming find possible biomarkers. Salivary metabolites samples from 27 OSCC patients and 41 control individuals were compared through a gas chromatography coupled to a mass spectrometer (GC-MS) technique. Our results allowed identification of pathways of the malate-aspartate shuttle, the beta-alanine metabolism, and the Warburg effect. The possible salivary biomarkers were identified using the area under receiver-operating curve (AUC) criterion. Twenty-four metabolites were identified with AUC > 0.8. Using the threshold of AUC = 0.9 we find malic acid, maltose, protocatechuic acid, lactose, 2-ketoadipic, and catechol metabolites expressed. We notice that this is the first report of salivary metabolome in South American oral cancer patients, to the best of our knowledge. Our findings regarding these metabolic changes are important in discovering salivary biomarkers of OSCC patients. However, additional work needs to be performed considering larger populations to validate our results.

Background: Eugenia involucrata DC., a Cerrado native plant, is recognized for its medicinal properties. However, its bioactive compounds remain inadequately explored. Objectives: This study investigated bioactive compounds from a standardized liquid extract from E. involucrata leaves that can act with antioxidant, cytogenotoxic, cytoprotective, and genoprotective effects. Methods: The phenolic compounds in the standardized liquid extract from E. involucrata leaves were screened by HPLC-DAD. The capture of the free radicals DPPH, ABTS+, and the metal reduction power FRAP determined the antioxidant potential. Cytotoxicity was evaluated in RAW 264.7 macrophages (MTT assay), and (anti)cytotoxic and (anti)genotoxic effects were assessed in human lymphocytes using the Trypan blue exclusion method and comet assay, respectively. Results: The extracts present key phenolic compounds, such as ellagic acid, myricitrin, and epicatechin gallate. The standardized extract demonstrated antioxidant capacity, evidenced by its ability to reduce iron and scavenge free radicals. The liquid extract from E. involucrata leaves exhibited cytotoxic effects on RAW 264.7 macrophages at higher concentrations, while demonstrating (anti)cytotoxic activity on human lymphocytes from all tested concentrations. The highest concentration tested of the standardized liquid extract from E. involucrata leaves (250 µg/mL) showed genotoxicity against human lymphocytes compared to the negative control. In contrast, the lowest concentration (62.5 µg/mL) exhibited an antigenotoxic effect on human lymphocytes, reducing the genotoxicity of doxorubicin by approximately 27%. Conclusions: The bioactive compounds in the standardized liquid extract from E. involucrata leaves exhibited antioxidant and antigenotoxic properties, suggesting potential value for nutraceutical and pharmaceutical applications, particularly those related to oxidative stress associated withaging and disease progression.

Hydroethanolic preparations of the botanical species Acmella oleracea L. are used in the north of Brazil for the treatment of various diseases. However, few studies have been conducted to evaluate the toxicity of this species. The objective of this study was to evaluate the acute toxicity of the hydroethanolic extract of A. oleracea L. (EHFAo) flowers in zebrafish by immersion and oral administration. The extract was analyzed by ultra-performance liquid chromatography–mass spectrometry (UPLC–MS). EHFAo was administered orally (44.457, 88.915, 199.94, 281.83, and 448.81 mg/kg) and by immersion (250, 300, 350, 400, and 450 µg/L). Behavioral and histopathological analysis of gills, liver, intestine, and kidney were performed. The presence of (2E,6Z,8E)-N-isobutyl-2,6,8-decatrienamide (spilanthol) in EHFAo was identified by ultra-high-re.solution liquid chromatography–electrospray ionization mass spectrometry (UHPLC–ESI-MS). Treatment with EHFAo caused significant behavioral changes and death. The calculated median lethal dose (LD50) was 148.42 mg/kg, and the calculated median lethal concentration (LC50) was 320 μg/L. In the histopathological study, it was observed that upon oral treatment, the tissue alterations that compromised the normal functioning of the organism occurred with EHFAo doses of 88.915, 199.53, and 281.83 mg/kg, the intestine being the most affected. When the treatment was performed by immersion, the most toxic EHFAo concentrations according to the histopathological evaluation were 300, 350, and 400 μg/L, with the most affected organ being the gills. Finally, EHFAo in this study was shown to be more toxic to the liver, intestine, and kidneys when administered orally and to gills, liver, and kidneys when administered by immersion in water. Therefore, considering the results obtained and the chemical characteristics of the main phytochemical marker of EHFAo, spilanthol, it can be suggested that, depending on the dose, this compound can lead to histopathological damages in the organs highlighted in this study.

This study aimed to evaluate two transportation methods (with moistened foam and without foam) for 10 h on blood parameters of bullfrogs 0, 6, 12, 24, and 48 h after transportation. There was no mortality. The glucose increased at 0 and 12 h after transportation and returned to baseline at 24 h in both transportations. Triglycerides increased at 0 and 6 h in both transportations and were restored 12 h after transport with foam and 24 h in transport without foam. Plasma proteins and globulins increased at 0 h after transportation under both transportations. After 48 h, there was a reduction in transport without foam. Globulins decreased 48 h under both transportations. Albumin increased at 12, 24, and 48 h after both transportations. Transport with foam had high albumin. The albumin/globulin ratio increased 24 and 48 h after both transportations. The number of erythrocytes increased at 0 h and recovered after 6 h in transport with foam and 12 h in transport without foam. Hematocrit and hemoglobin increased at 0 h and recovered at 6 h in both transportations. MCV increased 48 h after transportation with foam. MCHC decreased 12, 24, and 48 h after both transportations. MCH was lower in the transport carried out with foam.

Lycopene is a carotenoid with potential use in the treatment of chronic illnesses. Here, different formulations of lycopene were studied: lycopene-rich extract from red guava (LEG), purified lycopene from red guava (LPG) and a self-emulsifying drug delivery system loaded with LPG (nanoLPG). The effects of administering orally various doses of LEG to hypercholesterolemic hamsters were evaluated regarding the liver function of the animals. The cytotoxicity of LPG in Vero cells was analyzed by a crystal violet assay and by fluorescence microscopy. In addition, nanoLPG was employed in stability tests. LPG and nanoLPG were tested for their cytotoxic effect on human keratinocytes and antioxidant capacity on cells in an endothelial dysfunction model in an isolated rat aorta. Finally, the effect of different nanoLPG concentrations on the expression of immune-related genes (IL-10, TNF-α, COX-2 and IFN-γ) from peripheral blood mononuclear cells (PBMC) using real-time PCR was also analyzed. Results suggest that LEG, despite not being able to improve blood markers indicative of liver function in hypercholesterolemic hamsters, reduced hepatic degenerative changes. Additionally, LPG did not show cytotoxicity in Vero cells. In relation to nanoLPG, the effects produced by heat stress evaluated by Dynamics Light Scattering (DLS) and visually were loss of color, texture change and phase separation after 15 days without interfering with the droplet size, so the formulation proved to be efficient in stabilizing the encapsulated lycopene. Although LPG and nanoLPG showed moderate toxicity to keratinocytes, which may be related to cell lineage characteristics, both revealed potent antioxidant activity. LPG and nanoLPG showed vasoprotective effects in aortic preparations. The gene expression assay indicates that, although no significant differences were observed in the expression of IL-10 and TNF-α, the PBMCs treated with nanoLPG showed a reduction in transcriptional levels of IFN-γ and an increased expression of COX-2. Thus, the work adds evidence to the safety of the use of lycopene by humans and shows that tested formulations, mainly nanoLPG due to its stability, stand out as promising and biosafe products for the treatment of diseases that have oxidative stress and inflammation in their etiopathology.

Background: The present study aimed to evaluate the potential synergy between pharmaceutical formulations containing Bixa orellana L. (granulated—CHR OR and injectable nanodispersion—CHR IN) in conjunction with a cannabidiol (CBD)-rich extract of Cannabis sativa L. (CSE) on experimental pain models in Wistar rats. Methods: Chemical analysis was performed using gas chromatography (GC-MS). The pain tests employed were acetic acid-induced writhing (injection i.p. of 0.9% acetic acid), formalin (solution 1%), hot plate (55 ± 0.5 °C), and cold-water tail withdrawal tests. Results: Chemical analyses by chromatography confirmed that the oil from B. orellana is rich in δ-tocotrienol (72.0 ± 1.0%), while the oil from Cannabis sativa highlighted the presence of cannabidiol (CBD). The results from the experimental pain tests indicated that the combined administration of formulations containing Bixa orellana and C. sativa, such as the granulated CHR OR (400 mg/kg, orally) with CSE (40 mg/kg, orally) or the nanodispersion CHR IN (10 mg/kg, intramuscularly) with CSE (40 mg/kg, orally), demonstrated significant results (p < 0.001) in pain reduction. Although the formulations containing Bixa orellana extract showed statistical significance in the tests when used in isolation, their effects were inferior compared to the combined use with CSE or the isolated use of CSE. These findings suggest that combining formulations containing extracts of these plant species may represent a viable therapeutic option, considering the synergistic action in reducing pain under the experimental conditions employed. Conclusions: these results imply that combining the phytocomplexes present in B. orellana and C. sativa may be a promising approach for pain treatment.

Assessment of water resources requires interdisciplinary studies that include multiple ecosystem aspects. This study evaluated the water quality of Juara Lagoon (ES, Brazil) based on physical and chemical variables, cytogenetic responses in Allium cepa and phytoplankton dynamics. Three sampling sites were defined and water samples were collected during two sampling periods. Analyses such as determination of photic zone, conductivity, and concentrations of nutrients and metals were conducted as well as cytotoxic, mutagenic, and genotoxic potentials using A. cepa test. The main attributes of phytoplankton community, such as total richness, total density, density by class, dominance, and diversity, were also evaluated. Results have revealed that Juara Lagoon has signs of artificial eutrophication at two sampling sites due to high levels of total phosphorus and ammonia nitrogen. Cytotoxic, genotoxic, and mutagenic potentials were detected as well as high concentrations of Fe and Mn. Furthermore, 165 phytoplankton taxa were recorded, with highest richness in Chlorophyceae and Cyanophyceae classes. In addition, Cyanophyceae presented as the highest density class. A. cepa test and phytoplankton community evaluation indicated that the ecological quality of Juara Lagoon is compromised.