Brazilian Journal of Science

Effect of different osteogenic media and saline solutions on the osteogenesis protocol using MC3T3-E1 subclones

2025-01-02T20:28:32-03:00

Adequate laboratory protocols may improve the study of bone tissue and its metabolism. Thus, the use of effective techniques for staining bone cells in vitroand evaluating their function is significant. The cell line used for this purpose was MC3T3-E1, which contains preosteoblasts with mineralization potential. Several osteogenic media are used in the culture of these cells, and a variety of saline solutions are used for washing cultures in mineralization staining protocols and in situ alkaline phosphatase detection. Thus, the objective of the present study was to evaluate the effects of different osteogenic media in the culture of MC3T3-E1 cells, subclones 4 and 14, in addition to washing with Dulbecco’s phosphate saline solution (DPBS) and Hanks’ balanced salt solution (HBSS) in an alizarin red staining assay and situ alkaline phosphatase labeling via the Fast Red method. The cells were seeded at a density of 1x10⁴ cells/well for 7 and 10 days for the Fast Red assay and 12, 14, and 17 days for the staining of mineralization nodules. The data were statistically analyzed and significance was set for p < 0.05. Data obtained showed that the presence of dexamethasone significantly enhanced ALP detection in subclone 14 osteoblastic cells after 7 and 10 days as well as in subclone 4 cells washed with DPBS after 7 and 10 days when compared to control. Washing with Hanks’ solution significantly increased the quantification of ALP at 10 days and of mineralized nodules in 4 subclone cells after 17 days. Moreover, alizarin red staining improved, resulting in a more intense red color, in the group that was washed with Hanks’ solution for both subclones in all experimental periods. Thus, it is suggested that washing with Hanks’ salt solution is better for in vitro staining of calcium nodules when using the alizarin red method.

Comparative analysis of the antibacterial activity of Silver nanoparticles synthesized from leaf extracts of Ocimum sanctum, Coriandrum sativum, Hemidesmus indicus, and Tinospora cordifolia

2025-01-02T20:28:30-03:00

The synthesis of metal nanoparticles using biological resources, such as plant leaves, offers a green, cost-effective, and eco-friendly approach. In this study, 1 mM Silver nitrate solution was mixed with freshly prepared aqueous leaf extracts of each medicinal plant like, “Tulsi (Ocimum sanctum), Coriander (Coriandrum sativum), Anantmul (Hemidesmus indicus) and Giloy (Tinospora cordifolia)” in 1:4 ratios. The mixtures were then incubated at 75 °C for 25 min, forming Silver nanoparticles giving a deep brown color to the solution with Silver in a reduced colloidal form. Laser diffraction and UV-Vis spectroscopy further confirmed the synthesis, with the absorption peak for the nanoparticles observed between 419-438 nm. The antibacterial activity of the synthesized nanoparticles was tested against Gram-positive pathogens, including Staphylococcus aureus and Staphylococcus argenteus, as well as Gram-negative bacteria like Escherichia coli and Salmonella typhi. Comparative analysis showed that nanoparticles synthesized from Tulsi, Coriander, and Giloy extracts demonstrated superior antibacterial efficacy, highlighting their potential for use in biomedical and industrial applications such as wound healing, medical devices, and water purification.

Physical analysis from scientific data in Pero Vaz de Caminha’s letter

2025-01-02T20:28:25-03:00

The scientific data presented in the letter by Pero Vaz de Caminha, the scribe of Pedro Álvares Cabral's fleet, were physically analyzed when they landed in Brazil in 1500. Initially, it was clarified that the temperature difference between the Equator and the poles, along with the Coriolis force, determined the maritime routes at the beginning of the Age of Discovery, between the 14th and 17th centuries. Our data analysis used modern technological tools such as dynamic internet maps, GPS, and satellite bathymetry data. From this scientific analysis, several conclusions contradict current historical truths. The main conclusions are that the true Mount Pascoal is today known as Mount Serra Verde, located near the city of João Câmara, that the landing site was at the mouth of the Punaú River, at Zumbir Beach, and that the fleet landed at Marco beach and not Porto Seguro, Bahia state. All of these locations are on the northern coast of Rio Grande do Norte state.

Molecular docking, dynamics, and drug-likeness studies of alprazolam derivatives as a potent anxiolytic drug against GABAA receptors

2025-01-02T20:28:28-03:00

GABAA receptors exhibit permeability to the chloride ion-gated channel, and an increase in excitability disrupts the ion gradients, hence contributing to the development of anxiety-related disorders. This study aims to repurpose potent inhibitors of alprazolam analogs, which were obtained from the PubChem database. These ligands are being investigated for their binding ability to the GABAA receptor. We employed molecular docking through Autodock vina V.4.2 software. The Swiss ADME server was utilized to assess the drug-likeness of the ligands. MDS was conducted using the iMODS platform. Compounds A3, A8, and A9 exhibited a notable binding score range of -8.0 to -8.4 kcal/mol^-1 with GABAA protein. The drug-likeness analysis revealed that 3 ligands had compliance with Lipinski's RO5. Moreover, the A8 compound can traverse the BBB. In contrast, the A3 and A9 ligands remain localized in the GI region. The MDS of the GABAA receptor with the A8 molecule exhibited higher stability than alprazolam. The current investigation unveiled a highly effective antagonist of GABAA receptors, specifically A8 - 8-chloro-1,4-dimethyl-6-phenyl-4H- [1,2,4] triazolo [4,3-a] [1,4] benzodiazepine. This compound holds potential for future wet-lab experiments, perhaps leading to its utilization in therapeutic applications as an anxiolytic medication.