The most widely used vaccines were messenger RNA (mRNA), viral vector, and inactivated virus with two‐dose schedules. In Brazil, the CoronaVac (Sinovac) was the first vaccine approved for emergency ...use, and the third dose was administered, preferably, with the BNT162b2 vaccine. We evaluated antibody levels after 6 months of the booster dose with BNT162B2 in previous recipients of CoronaVac and whether a subsequent severe acute respiratory syndrome coronavirus 2 (SARS‐COV‐2) infection enhances the antibody response. We analyze the humoral response (spike S IgM for the SARS‐CoV‐2 and IgG for the S and nucleocapsid N proteins) in samples collected before the third dose and 6 months after the third dose. The presence of antibodies was measured by using Abbott Architect i2000SR. The IgM and IgG antispikes were stimulated mainly 30 days after the third dose (30d/3D), with a decline over time. The IgG anti‐N was stimulated predominantly in 90d/3D and 180d/3D. The N IgG levels were 50 and 35 times higher in the positive polymerase chain reaction (PCR) group in 90d/3D and 180d/3D, respectively. The S IgG titers were 1.5 times elevated in the positive PCR group, in 180d/3D. The BNT162b2 boosted the S IgG levels, decreasing after 60 days. The booster shot induced IgM and IgG antibodies against spike protein. Infection after vaccination increased antibodies against protein N.
Theranostics combines therapeutic and imaging diagnostic techniques that are extremely dependent on the action of imaging agent, transporter of therapeutic molecules, and specific target ligand, in ...which fluorescent probes can act as diagnostic agents. In particular, naphthoimidazoles are potential bioactive heterocycle compounds to be used in several biomedical applications. With this aim, a group of seven naphth1,2-
imidazole compounds were synthesized from β-lapachone. Their optical properties and their cytotoxic activity against cancer cells and their compounds were evaluated and confirmed promising values for molar absorptivity coefficients (on the order of 10
to 10
), intense fluorescence emissions in the blue region, and large Stokes shifts (20-103 nm). Furthermore, the probes were also selective for analyzed cancer cells (leukemic cells (HL-60). The naphth1,2-
imidazoles showed IC
between 8.71 and 29.92 μM against HL-60 cells. For HCT-116 cells, values for IC
between 21.12 and 62.11 μM were observed. The selective cytotoxicity towards cancer cells and the fluorescence of the synthesized naphth1,2-
imidazoles are promising responses that make possible the application of these components in antitumor theranostic systems.
We investigated the impact of the fourth dose with ChAdOx1 nCoV‐19 (AstraZeneca) in the humoral immune response to SARS‐CoV‐2 during a 9‐month follow‐up period in which Omicron was the predominant ...variant in Brazil. IgG for the SARS‐CoV‐2 spike protein (S) and nucleocapsid (N) proteins were analyzed in samples collected before and after the fourth dose. All participants were tested monthly for SARS‐CoV‐2 infection by RT‐qPCR. The antibody response induced by the fourth dose of the coronavirus disease 2019 vaccine was evaluated and compared with the response induced by the second and third doses. The additional antibody response to the viral S protein after the fourth dose was smaller than those after the third vaccine dose. In contrast, an increase in the N IgG levels could be observed after the fourth dose compared to other vaccine doses. In the comparison of the antibody response before and after the fourth dose, an increase in both S‐and‐N IgG was noted, mainly in the positive qPCR group. We did not observe a significant decline in IgG levels after the fourth dose, as observed after the second and third doses, therefore, a sustained humoral response to both S and N proteins seems to be achieved.
The present study evaluated the use of a pressurized method to extract phycobiliproteins from the cyanobacterium
Arthrospira platensis
using sodium phosphate buffer as an extracting solution. ...Phycobiliprotein extracts were characterized and their antioxidant and anticancer activities (on different cancer cell lines) were determined. A high extraction yield was obtained when high pressure was used, without any alteration of the molecules’ biofunctionality. Maximum phycocyanin and allophycocyanin concentrations obtained (at 100 bar after 360 min) were 4.44 g L
−1
and 1.63 g L
−1
, respectively. The purity indexes of extract were 3.59 (A
615
/A
280
) for phycocyanin and 1.72 (A
652
/A
280
) for allophycocyanin. The purified phycobiliprotein extract showed high antioxidant activity, with 98% in the reduction of 2,2-diphenyl-1-picryl-hydrazil (DPPH) radicals and 100% in the chelation of ferrous ions, and it presented in vitro anticancer activity for HL60 leukemic cells.
Arylacetamides are widely used as synthetic intermediates to obtain medicinal substances. This work evaluated in vitro antiproliferative activity of ten 2-Chloro-N-arylacetamides on human normal and ...cancer cells and detailed in vivo toxicological and anticancer investigations. Initially, cytotoxic colorimetric assays were performed using tumor lines, peripheral blood mononuclear cells (PBMC) and erythrocytes. Compounds 2, 3 and 4 were tested for acute toxicity (50, 150 and 300 mg/kg) and for subacute antitumoral capacity in HCT-116 colon carcinoma-bearing xenograft mice for 15 days at 25 mg/kg/day. Most compounds revealed cytotoxic action on tumor lines and PBMC, but activity on human erythrocytes were not detected. Molecular dipole moment, lipophilicity and electronic constant of aryl substituents had effects upon in vitro antiproliferative capacity. More common in vivo acute behavioral signals with compounds 2, 3 and 4 were muscle relaxation, reduction of spontaneous locomotor activity and number of entries in closed arms and increased number of falls andtime spent in open arms, suggesting diazepam-like anxiolytic properties. Decrease of grabbing strength and overall activity were common, but palpebral ptosis and deaths occurred at 300 mg/kg only. Compounds 2 and 3 reduced colon carcinoma growth (21.2 and 27.5%, respectively, p < 0.05) without causing apparent signals of organ-specific toxicity after subacute exposure. The structural chemical simplicity of arylacetamides make them cost-effective alternatives and justifies further improvements to enhance activity, selectivity and the development of pharmaceutical formulations.
Display omitted
•Most molecules revealed cytotoxicity and CI50 values from 4.9 to 50.1 μM.•Steric aspects, lipophilicity and substituents had effects on in vitro antitumoral action.•Single dose studies showed diazepam-like anxiolytic properties of compounds 2 and 4.•In vivo signals of organ-specific toxicity were not detected after subacute exposure.•Compounds 2 and 3 reduced in vivo xenograft human colon carcinoma growth.
The genus Chamaecrista comprises more than 330 species, with only a few studies on their chemical composition and biologic activities. In this study, the phytochemical profile of leaf, stems, and ...fruits extracts of the C. duckeana were examined by UPLC-ESI-HRMS analysis to determine possibly bioactive constituents. The antioxidant activity was carried out through in vitro assay, by the sequestration of the free radical DPPH. To evaluate the cytotoxic activity of the extracts, an MTT assay was used and the IC50 was determined against HL60 and RAJI cell lines. The metabolic profiles of the botanical parts are dominated by flavonoid class, highlighting isoflavonoids such as daidzin and ononin. All these compounds are reported for the first time in C. duckeana. The extracts presented antioxidant potential, and the activity of the stems extract was higher than the standard butylated hydroxytoluene. In the cytotoxic assay, only HL60 line (leukemia) had growth inhibition over 80%. The stems presented more expressive cytotoxicity with IC50 of 137.3 (104.6-180.1) and 106.8 (96.52-118.3) μmol. L-1 for HL60 and RAJI, respectively. In conclusion, the present work provides an in-depth knowledge about the chemical profile of C. duckeana, a species rich in bioactive secondary metabolites with cytotoxic activity
Tamoxifen/montmorillonite as a controlled release oral system Silva, Dayanne Tomaz Casimiro; Arruda, Igor Eduardo Silva; Araújo, José Izak Ribeiro de ...
Journal of drug delivery science and technology,
August 2023, 2023-08-00, Letnik:
85
Journal Article
Recenzirano
Drugs have been incorporated into clay minerals to obtain a controlled-release system. In the present study, tamoxifen citrate (TMX) was loaded in pharmaceutical montmorillonite (VHS) at pH 3.0, 4.0, ...and 5.0 and released in vitro under simulated stomach and intestinal conditions to evaluate the cytotoxic activity of TMX/VHS systems. The systems were characterized using structural (X-ray diffractometry and Fourier transform infrared spectroscopy) and thermal (thermogravimetric analysis and differential calorimetry) techniques. TMX was loaded in VHS via a reaction between 1660 mg L−1 TMX methanol solutions and 0.1 g of VHS at pH 3.0 (VHS/TMX/pH3), 4.0 (VHS/TMX/pH4), and 5.0 (VHS/TMX/pH5) for 12 h at 200 rpm and 25 °C. The release of TMX was evaluated with dispersed amounts of loaded TMX systems in a simulated medium at pH 1.2 and 6.8, and TXM was quantified by high-performance liquid chromatography. Cytotoxicity tests were performed in vitro using the MTT assay for human tumor cell lineages. Characterization results indicated the intercalation of TMX in the clay mineral, and the amounts of TMX were 344.7, 347.1, and 374.4 mg per gram of VHS for the systems prepared at pH 3, 4, and 5, respectively. Releases of 8.40% (VHS/TMX/pH3), 8.68% (VHS/TMX/pH4), and 11.15% (VHS/TMX/pH5) occurred at pH 1.2, whereas at pH 6.8, the release of TMX increased to 21.21% (VHS/TMX/pH3), 24.85% (VHS/TMX/pH4), and 39.27% (VHS/TMX/pH5). The VHS/TMX systems exhibited cytotoxicity with increasing concentrations for all cells, with increased cytotoxic activity with IC50 of 54.57 μg mL−1 (TMX 20.10 μg mL−1) for the VHS/TMX/pH5 for glioblastoma lineages. Therefore, the TMX/VHS systems presented drug release control and, depending on the concentration, could exert cytotoxic activity without causing damage to normal cells, thus reducing adverse effects.
Display omitted
•Hybrids formed from the clay mineral Montmorillonite and the anticancer drug tamoxifen citrate.•The release of the drug from the interior of the clay is influenced by its interaction with the clay surface.•The hybrid with the lowest affinity with the clay surface obtained greater release and better cytotoxic activity.•The hybrid with that had less interaction with the clay surface, showed cytotoxicity without causing damage to normal cells.
The chemical composition and biological activity of a sample of yellow propolis from Mato Grosso do Sul, Brazil (EEP-Y MS), were investigated for the first time and compared with green, brown, and ...red types of Brazilian propolis and with a sample of yellow propolis from Cuba. Overall, EEP-Y MS had different qualitative chemical profiles, as well as different cytotoxic and antimicrobial activities when compared to the other types of propolis assessed in this study and it is a different chemotype of Brazilian propolis. Absence of phenolic compounds and the presence of mixtures of aliphatic compounds in yellow propolis were determined by analysing 1H-NMR spectra and fifteen terpenes were identified by GC-MS. EEP-Y MS showed cytotoxic activity against human tumour strain OVCAR-8 but was not active against Gram-negative or Gram-positive bacteria. Our results confirm the difficulty of establishing a uniform quality standard for propolis from diverse geographical origins. The most appropriate pharmacological applications of yellow types of propolis must be further investigated.
Tithonia diversifolia is a perennial bushy plant found in South America with significant ethnopharmacological importance as an antimalarial, antidiabetic, antibacterial, and anticancer agent. The aim ...of the present study was to determine the cytotoxicity of the ethanolic extract from leaves of T. diversifolia (TdE) on human cancer cell lines (HCT-116, SNB-19, NCIH-460 and MCF-7), as well as the mechanism of action involved in cell death and cellular modulation of oxidative stress. The TdE exhibited significant activity with IC
50
values ranging from 7.12 to 38.41 μg/ml, with HCT-116 being the most sensitive cell line. Subsequent experiments were conducted with HCT-116 cell line. TdE decreased the number of viable cells, followed by induction of apoptotic events, increase in mitochondrial membrane permeabilization, and enhanced G
2
/M phase of the cell cycle. Pro-oxidative effects including elevated acidic vesicular organelle formation, lipid peroxidation, and nitric oxide by-products, as well as reduced levels of intracellular glutathione and reactive oxygen species production were also observed following incubation with TdE, which may lead to DNA damage followed by apoptotic cell death. These results demonstrate the potential of TdE ethanolic leaf extraction for biological activity and enhance the importance of continuing to study natural sources of plants for the development of anticancer agents.
![Naphth[1,2- d ]imidazoles B...](http://api.summon.serialssolutions.com/2.0.0/image/issn/XR4PS5YY4K/1420-3049/small "Naphth[1,2- d ]imidazoles Bioactive from β-Lapachone: Fluorescent Probes and Cytotoxic Agents to Cancer Cells")
PDF
