Eugênio Gonçalves de Araújo

Reactive oxygen species (ROS) overproduction contributes to endothelial dysfunction in Type 2 diabetes mellitus (T2DM). Pequi (Caryocar brasiliense, Camb), a native Brazilian fruit, is rich in polyphenolic antioxidants. We investigated whether its ethanolic bark extract modulates ROS levels and promotes proliferation in human coronary artery endothelial cells from patients with diabetes (D-HCAECs). Cells were treated with pequi extract under normoxic, hypoxic, or H₂O₂-induced oxidative stress conditions. Cytosolic and mitochondrial ROS levels, cell proliferation, and the expression of antioxidant proteins (Nrf2, HO-1, SOD1, SOD2, catalase, and GPx1) were assessed. Pequi significantly reduced cytosolic ROS under normoxia and both cytosolic and mitochondrial ROS under stress. It also upregulated antioxidant enzymes through the Nrf2 pathway and enhanced D-HCAEC proliferation under all tested conditions. These results suggest that pequi’s antioxidant effects may be mediated by the increased expression of endogenous enzymes, leading to improved redox balance and endothelial function in diabetic coronary vasculature.

Platelet-Rich Plasma (PRP) directly and indirectly modifies the composition of synovial fluid in horses. This study evaluated the early effects of intra-articular PRP on the synovial fluid of horses with experimentally induced synovitis. Twelve horses were divided into two groups: a control group that received no treatment, and a treatment group that received intra-articular PRP. Five time points were established: T0, T3, T6, T24, and T48. At T0, all horses received an intra-articular injection of lipopolysaccharide from Escherichia coli. At T3, synovial fluid samples were collected from all horses, and the treatment group received PRP via the same joint access. Additional synovial fluid samples were collected at T6, T24, and T48 for evaluation. The PRP preparation protocol used in this study resulted in an adequate platelet concentration that did not affect the physicochemical and cytological characteristics of the synovial fluidor the concentrations of IL-1RA, MMP-9, and MMP-2 in horses with induced synovitis.

The aim of the present study is to describe the skin morphology and morphometry of the giant anteater (M. tridactyla), based on comparative analysis applied to skin segments from central metacarpal torus (palmar pad), dorsal thorax, ventral cervical, ventral abdomen, medial carpal and nasal regions. In order to do so, eight adult specimens of M. tridactyla were used for macroscopic studies and four for microscopic assessments. Microscopy was used to assess fur general features that were macroscopically assessed through visual analysis. Fragments (2.0cm²) were collected from the selected regions for microscopic studies. Samples were fixed on McDowell solution, processed through routine histology techniques and subjected to semi-serial cuts (5 μm). The cuts were stained in HE, Alcian blue and periodic acid Schiff. General morphology of different skin layers was described, as well as their architecture and composition; mesoscopy of the epidermis, dermis and stratum corneum was also carried out. There was difference in skin morphometry between males and females, and between different skin regions in the same animal, based on the statistical evaluation of the recorded values. All epidermis layers were assessed for the selected regions. Dermis encompassed surface and deep layers; it presented sweat and sebaceous glands, as well as hair follicles. Findings also allowed reporting that epidermis components are easily identified given its thickness, and the large amount of sweat glands in it – it contrasts its physiological features.

Seminal studies stated that bean proteins are efficient neuronal tracers with affinity for brain tissue. A low molecular weight peptide fraction (<3kDa) from Phaseolus vulgaris (PV3) was previously reported to be antioxidant, non-cytotoxic, and capable of reducing reactive oxygen species and increasing nitric oxide in cells. We evaluated the effects of PV3 (5, 50, 100, 500, and 5000 µg/kg) on behavior and the molecular routes potentially involved. Acute and chronic PV3 treatments were performed before testing Wistar rats: i) in the elevated plus-maze (EPM) to assess the anxiolytic-like effect; ii) in the open field (OF) to evaluate locomotion and exploration; and iii) for depression-like behavior in forced swimming (FS). Catecholaminergic involvement was tested using the tyrosine hydroxylases (TH) enzyme inhibitor, α-methyl-DL-tyrosine (AMPT). Brain areas of chronically treated groups were dissected to assess: i) lipid peroxidation (LPO); ii) carbonylated proteins (CP); iii) superoxide dismutase (SOD) and catalase (CAT) enzymatic activities. Neuronal nitric oxide synthases (nNOS) and argininosuccinate synthase (ASS) protein expression was evaluated by western blotting. Acute treatment with PV3 increased the frequency and time spent in the EPM open arms, suggesting anxiolysis. PV3 increased crossing episodes in the OF. These PV3 effects on anxiety and locomotion were absent in the chronically treated group. Acute and chronic PV3 treatments reduced the immobility time in the FS test, suggesting an antidepressant effect. TH inhibition by AMPT reverted acute PV3 effects. PV3 decreased LPO and CP levels and SOD and CAT activities, whereas nNOS and ASS were reduced in few brain areas. In conclusion, PV3 displayed central antioxidant actions that are concomitant to catecholaminergic-dependent anxiolytic and antidepressant effects.

Background and Aim: New substances for neoplasm treatment have to be carefully studied to minimize adverse effects and prevent disease progression stimulation. Jatobá is a typical tree of the Cerrado and Caatinga biome, with antifungal, antimicrobial, larvicide, antioxidant, and antiproliferative properties. This study aimed to investigate the action of the crude extract of Jatobá leaves (EBFJ) on canine osteosarcoma (CO) cells and analyze the expression of biomarkers in neoplasm progression. Materials and Methods: D17 cells were cultured and subjected to treatment with EBFJ at different concentrations (10 μg/ mL; 100 μg/mL; 1000 μg/mL; 2000 μg/mL; and 5000 μg/mL) and exposure times (24 h, 48 h, and 72 h). The tetrazolium reduction assay and the immunocytochemistry technique, with anti-Bcl2, anti-p53, and anti-Ki-67 antibodies, were used to observe the effect of the extract on cell proliferation. Results: Doses of 2000 μg and 5000 μg had cell viability of 300.80% and 361.84%, respectively. The extract did not show significant cytotoxicity of samples with the control group. The confluence of cells, the number of labeled cells, and the expression of Bcl2, Ki-67, and p53 were higher in the groups treated with EBFJ, with a statistical difference from the group without treatment. Conclusion: EBFJ was not cytotoxic and had a proliferative effect on CO D17 cells. The confluence of cells, the number of labeled cells, and the expression of Bcl2, Ki-67, and p53 were higher in the groups treated with the extract.

Reactive oxygen species (ROS) imbalance results in endothelial cell function impairment. Natural phenolic antioxidant compounds have been investigated as therapeutic alternatives. The fruit bark of Brazilian-native pequi (Caryocar brasiliense, Camb.) is rich in polyphenols. The HPLC-MS (High-Performance Liquid Chromatography coupled with Mass Spectrometry) analyses identified gallic acid and catechin in six out of seven ethanolic extract samples prepared in our lab. In this study, we examined the effects of ethanolic pequi extract on ROS levels in human coronary artery endothelial cells (HCAEC) subjected to hypoxia or oxidative stress. We first confirmed the oxidant scavenging capacity of the extract. Then, HCAEC pre-incubated with 10 or 25 μg/mL of extract were subjected to hypoxia for 48 h or 100 μM H₂O₂ for six hours and compared to the normoxia group. Total and mitochondrial ROS levels and cell proliferation were measured. Pequi significantly reduced cytosolic HCAEC ROS levels in all conditions. Mitochondrial ROS were also reduced, except in hypoxia with 10 μg/mL of extract. HCAEC proliferation increased when treated with 25 μg/mL extract under hypoxia and after H₂O₂ addition. Additionally, pequi upregulated oxidative stress defense enzymes superoxide dismutase (SOD-)1, SOD-2, catalase, and glutathione peroxidase. Together, these findings demonstrate that pequi bark extract increases antioxidative enzyme levels, decreases ROS, and favors HACEC proliferation, pointing to a protective effect against oxidative stress.

Resumo A Curcuma longa L., planta conhecida popularmente como açafrão, tem sido amplamente estudada por suas diversas propriedades terapêuticas, incluindo a ação antineoplásica. O extrato etanólico da planta contém diversos compostos fenólicos, com destaque para a curcumina. O osteossarcoma é um tumor ósseo predominante em cães e humanos, caracterizado por apresentar alto potencial metastático e prognóstico desfavorável. Procurou-se investigar os efeitos de diferentes concentrações de curcumina do extrato etanólico de açafrão sobre células de osteossarcoma canino de cultura estabelecida. As células foram cultivadas e submetidas ao tratamento com extrato com diferentes concentrações de curcumina (0, 10 μM, 20 μM, 50 μM, 100 μM e 1000 μM) e tempos de exposição (24h, 48h e 72h) pelo EEA. Inicialmente, foram realizados: técnica de redução do tetrazólio (MTT) e cálculo da IC50. Posteriormente, após o tratamento com o extrato, realizou-se o ensaio de imunocitoquímica para verificar a expressão de p53 mutada e estudar o potencial proliferativo das células malignas; Bcl-2, com intuito de averiguar o estímulo de via antiapoptótica; e o marcador Ki-67, que sinaliza aumento no grau de malignidade. O extrato promoveu proliferação de células de osteossarcoma canino, com incremento de até 3819,74% na concentração de 50μM de curcumina. O composto também alterou a expressão das proteínas p53 mutante e Ki-67 significativamente, mas não alterou a expressão de Bcl-2, mostrando que não induziu a via antiapoptótica mediada por esta. Estes resultados demonstram que o extrato etanólico do açafrão apresenta potencial proliferativo sobre células de osteossarcoma canino, sugerindo a necessidade de conscientização e conhecimento dos reais efeitos de determinados compostos naturais, considerados seguros ao serem utilizados como tratamento de diversas enfermidades.

Curcuma longa L., also known as turmeric, has been widely studied for its various therapeutic properties, including antineoplastic action. The ethanolic extract of the plant contains several phenolic compounds, especially curcumin. Osteosarcoma is a predominant bone tumor in dogs and humans, characterized by high metastatic potential and an unfavorable prognosis. The aim of this study was to investigate the effects of turmeric ethanol extract on canine osteosarcoma cells from established culture. The cells were cultured and treated with different curcumin concentrations (0, 10 μM, 20 μM, 50 μM, 100 μM, and 1000 μM) and exposure times (24h, 48h, and 72h). We first performed tetrazolium reduction technique (MTT) assay and calculated IC50. An immunocytochemistry assay was performed after extract treatment to verify the expression of mutated p53 and therefore study the proliferative potential of malignant cells; Bcl-2 and Ki-67 were used to assess apoptosis and the degree of malignancy, respectively. The extract enhanced the proliferation of canine osteosarcoma cells, reaching 3,819.74% at 50 μM of curcumin. The extract also significantly altered the expression of mutated p53 and Ki-67 proteins but not that of Bcl-2, suggesting that it did not induce this antiapoptotic pathway. Overall, these results are prerequisite to better understanding how natural compounds such as turmeric ethanolic extract affect cell proliferation and could be used to treat various diseases.