Human Embryonic Kidney HEK293 Cells Research Articles

Development and antioxidant evaluation of mango leaf (Mangifera indica L.) extract loaded silk fibroin nanoparticles

The main antioxidant polyphenol compounds in the mango (Mangifera indica L.) leaf extract are susceptible to environmental degradations. Thus, in biomedical applications, the mango leaf extract is commonly encapsulated in a carrier. However, most studies employed the synthetic carrier materials that could affect the human health, and the complicated formulation procedure that could hinder the scalability. Therefore, this work, for the first time, explored the use of silk fibroin (an FDA-approved biomaterial), in nanoparticles platform, to encapsulate and deliver the mango leaf extract, utilizing the simple coacervation preparation method. Initially, the mango leaf ethanolic extract was obtained through maceration, resulting in a total phenolic content of 76.39 ± 0.14 mg GAE/g DPW and a notably high antioxidant activity (IC50 = 6.872 ± 0.512 μg/mL). Subsequently, silk fibroin nanoparticles loaded with the extract were developed by the coacervation technique. Depending on the fibroin content, these nanoparticles exhibited an appropriate size range of 500–800 nm with narrow size distributions, a spherical shape with smooth surfaces, a dominant silk-II crystalline structure, a drug entrapment efficiency exceeding 70%, and retained the main biomarker mangiferin. Moreover, the phenolic-compounds release profiles from the particles followed the three-step process, the first burst-release step, the second sustained-release step, and the third degradation step. The particles were also non-toxic to the erythrocytes and the human embryonic kidney HEK-293 cell line. Lastly, the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay demonstrated that the antioxidant activity of the mango leaf extract was preserved within the extract-loaded nanoparticles. The results suggested that the silk fibroin nanoparticles could be a potential platform to effectively encapsulate and deliver the mango leaf extract for biomedical purposes.

Propafenone-induced connexin-43 protein accumulation and intracellular dynamics

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): China Scholarship Council Background Connexin-43 (Cx43) plays a pivotal role in intercellular communication through gap junctions. It is instrumental in propagating electrical signals and allowing ions to flow between neighboring cardiomyocytes. This synchronized electrical activity allows the heart to work as a functional syncytium. Any disruption or malfunction of Cx43 can lead to arrhythmias and other cardiac issues. Understanding the functions and regulation of Cx43 is vital in both basic research and clinical contexts. Propafenone, a class Ic antiarrhythmic drug, has shown promise in rhythm control; however, its precise impact on cardiac cellular physiology, particularly regarding Cx43, remains incompletely understood. Purpose To investigate propafenone’s effect on Cx43 expression, physiology, and underlying mechanisms in cell systems. Methods Used cell lines include human embryonic kidney HEK293 cells transfected with Cx43; differentiated murine embryonic carcinoma EPI7 cells with an epithelioid morphology and visceral endoderm-like END2 cells, endogenously expressing high amounts of functional Cx43. Cx43 protein expression levels were determined by Western blot analysis, whereas immunofluorescence (IF) imaged by a Total Internal Reflection Fluorescence (TIRF) microscope was used to assess the subcellular localization of Cx43 proteins. Dye injections were used to gain insight into the effects of propafenone on Cx43 metabolic coupling. Results and Conclusion Full length Cx43 protein levels were increased after treatment with propafenone and IF microscopy showed an intracellular accumulation of Cx43 protein, both on ectopically and endogenously expressed Cx43. Propafenone did not alter Cx43 half-life, in contrast to the lysosomal inhibitor chloroquine. Finally, gap-junctional coupling was decreased by chronic propafenone treatment. We conclude that the class 1c antiarrhythmic drug propanone increases Cx43 protein expression, resulting in its intracellular accumulation, as a side effect.

New piperazine derivatives helvamides B–C from the marine-derived fungus Penicillium velutinum ZK-14 uncovered by OSMAC (One Strain Many Compounds) strategy

Four extracts of the marine-derived fungus Penicillium velutinum J.F.H. Beyma were obtained via metal ions stress conditions based on the OSMAC (One Strain Many Compounds) strategy. Using a combination of modern approaches such as LC/UV, LC/MS and bioactivity data analysis, as well as in silico calculations, influence metal stress factors to change metabolite profiles Penicillium velutinum were analyzed. From the ethyl acetate extract of the P. velutinum were isolated two new piperazine derivatives helvamides B (1) and C (2) together with known saroclazin A (3) (4S,5R,7S)-4,11-dihydroxy-guaia-1(2),9(10)-dien (4). Their structures were established based on spectroscopic methods. The absolute configuration of helvamide B (1) as 2R,5R was determined by a combination of the X-ray analysis and by time-dependent density functional theory (TD-DFT) calculations of electronic circular dichroism (ECD) spectra. The cytotoxic activity of the isolated compounds against human prostate cancer PC-3 and human embryonic kidney HEK-293 cells and growth inhibition activity against yeast-like fungi Candida albicans were assayed.Graphical

Toward Photosynthetic Mammalian Cells through Artificial Endosymbiosis.

Photosynthesis in plants occurs within specialized organelles known as chloroplasts, which are postulated to have originated through endosymbiosis with cyanobacteria. In nature, instances are also observed wherein specific invertebrates engage in symbiotic relationships with photosynthetic bacteria, allowing them to subsist as photoautotrophic organisms over extended durations. Consequently, the concept of engineering artificial endosymbiosis between mammalian cells and cyanobacteria represents a promising avenue for enabling photosynthesis in mammals. The study embarked with the identification of Synechocystis PCC 6803 as a suitable candidate for establishing a long-term endosymbiotic relationship with macrophages. The cyanobacteria internalized by macrophages exhibited the capacity to rescue ATP deficiencies within their host cells under conditions of illumination. Following this discovery, a membrane-coating strategy is developed for the intracellular delivery of cyanobacteria into non-macrophage mammalian cells. This pioneering technique led to the identification of human embryonic kidney cells HEK293 as optimal hosts for achieving sustained endosymbiosis with Synechocystis PCC 6803. The study offers valuable insights that may serve as a reference for the eventual achievement of artificial photosynthesis in mammals.

Antiplatelet activity and toxicity profile of novel phosphonium salts derived from Michael reaction

In this work, five novel phosphonium salts derived from the Michael reaction were screened for their antiplatelet activity. Our findings revealed that compounds 2a, 2b, 2c, and 2d significantly inhibit platelet aggregation triggered by ADP or collagen (P < 0.001). Notably, compound 2c inhibited the arachidonic acid pathway (P < 0.001). Moreover, the selected compounds reduce CD62-P expression and inhibit GPIIb/IIIa activation. The interactions of the active compounds with their targets, ADP and collagen receptors, P2Y12 and GPVI respectively were investigated in silico using molecular docking studies. The results revealed a strong affinity of the active compounds for P2Y12 and GPVI. Additionally, cytotoxicity assays on platelets, erythrocytes, and human embryonic kidney HEK293 cells showed that compounds 2a, 2c and 2d were non-toxic even at high concentrations. In summary, our study shows that phosphonium salts can have strong antiplatelet power and suggests that compounds 2a, 2c and 2d could be promising antiplatelet agents for the management of cardiovascular diseases.

Insights into the characterization and therapeutic potential of Tasar silkworm pupal oil

Oil extracted from various species of silkworm pupae emerged as an alternative source of edible oil with great therapeutic value. However, the Tasar silkworm, is mainly known for producing more textured silk than the applications of its pupal oil. The current study aimed to extract characterize and investigate edible and therapeutic properties of Tasar Pupal Oil (TPO).TPO was extracted by Soxhlet extraction method. Characterization of TPO was conducted by GC/MS and FTIR. The Total phenolic content of TPO was evaluated by Folin-Ciocalteu assay. The safety evaluation of TPO was checked on healthy HEK293 (human embryonic kidney cells) using MTT assay. Whereas, therapeutic properties of TPO were analyzed through DPPH, FRAP, SRB assay and agar-well diffusion method. GC/MS study revealed that α-linolenic acid (ALA) (38%) was the major component of TPO followed by n-hexadecanoic acid (25.64%), and other minor compounds were detected in small amounts. The functional groups of TPO shown by FTIR analysis correspond with similar peaks of edible oils. The TPO was reported to be low in phenolic content. The DPPH and FRAP radical scavenging assays demonstrate that TPO exhibits significant antioxidant capabilities. Further, TPO revealed a substantial dose-dependent anticancer activity against colon cancer cells, with a GI50 value of ≤20 μg/ml. Interestingly, TPO was safe and non-toxic on HEK293 cells. Further, TPO exhibited antibacterial activity against S. typhi and S. mutans at various dilutions. Our findings clearly reveal the potentiality of TPO by displaying the characteristics of edible oil and therapeutic properties including antioxidant, anticancer, and antibacterial.

Interaction and antibacterial activity of ciprofloxacin with choline based ionic liquid and CTAB: A comparative spectroscopic study

In this study, the complexation of potential chemo-therapeutic antibacterial drug, ciprofloxacin (CIP) with varying concentrations of surface active compounds (SACs) i.e., (N-(2-hydroxyethyl)-N,N-dimethyl-1-dodecanaminium bromide (12Cho.Br) and cetyltrimethylammonium bromide (CTAB) has been studied. Multispectroscopic techniques were exploited to carry out the study. The higher binding constant (Kb) value for CIP-CTAB than CIP-12Cho.Br obtained from fluorescence data revealed stronger binding of CTAB than 12Cho.Br, owing to the stronger hydrophobic-hydrophobic interaction betweeen CIP and CTAB compared to CIP and 12Cho.Br. The time resolve fluorescence decay shows changes in average lifetime (τavg) with the increasing concentration of 12Cho.Br and CTAB. The changes in τavg suggests that complex formation is taking place between CIP and 12Cho.Br / CTAB. Further, the formation of micelles by 12Cho.Br / CTAB and the effect of alkyl chain length was studied by dynamic light scattering (DLS) and zeta potential to confirm the drug complexation with 12Cho.Br and CTAB. The antibacterial activity has been performed for CIP and 12Cho.Br and CTAB. It was observed that in presence of lower concentrations of 12Cho.Br/ CTAB, the activity of the drug increased. The activity was also found cationic alkyl chain length dependent. Moreover, in-vitro cytotoxicity of CIP and its combinations with 12Cho.Br and CTAB was performed using MTT assay on HEK293 (Human embryonic kidney cells).

Biooriented Synthesis of Ibuprofen-Clubbed Novel Bis-Schiff Base Derivatives as Potential Hits for Malignant Glioma: In Vitro Anticancer Activity and In Silico Approach.

This research work is based on the synthesis of bis-Schiff base derivatives of the commercially available ibuprofen drug in outstanding yields through multistep reactions. Structures of the synthesized compounds were confirmed by the help of modern spectroscopic techniques including high-resolution electrospray ionization mass spectrometry (HR-ESI-MS), 1H NMR, and 13C NMR. The synthesized compounds were evaluated for their anticancer activity using a normal human embryonic kidney HEK293 cell and U87-malignant glioma (ATCC-HTB-14) as a cancer cell line. All of the synthesized compounds among the series exhibited excellent to less antiproliferative activity having IC50 values ranging from 5.75 ± 0.43 to 150.45 ± 0.20 μM. Among them, compound 5e (IC50 = 5.75 ± 0.43 μM) was found as the most potent antiprolifarative agent, while 5f, 5b, 5a, 5n, 5r, 5s, 5g, 5q, 5i, and 5j exhibited good activity with IC50 values from 24.17 ± 0.46 to 43.71 ± 0.07 μM. These findings suggest that these cells (HEK293) are less cytotoxic to the activities of compounds and increase the cancer cell death in brain, while the lower cytotoxicity of the potent compounds in noncancerous cells suggests that these derivatives will provide promising treatment for patients suffering from brain cancer. The results of the docking study exposed a promising affinity of the active compounds toward casein kinase-2 enzyme, which shows green signal for cancer treatment.

Synthesis and biological evaluation of novel salicylidene uracils: Cytotoxic activity on human cancer cell lines and inhibitory action on enzymatic activity.

A series of salicylidene uracil (1-18) derived from 5-aminouracil and substituted salicylaldehydes were analyzed for cytotoxic activity and enzyme inhibitory potency. Nine out of eighteen derivatives (6-8, 10, 12-15, 18) are novel molecules synthesized for the first time in this work, and other derivatives were previously synthesized by our group. The compounds were characterized by Proton nuclear magnetic resonance, carbon nuclear magnetic resonance, fourier transform infrared spectroscopy, and elemental analysis. All compounds were tested for their in vitro cytotoxicity against PC-3 (human prostate adenocarcinoma), A549 (human alveolar adenocarcinoma), and SHSY-5Y (human neuroblastoma) cancer cell lines and the nontumorigenic HEK293 (human embryonic kidney cells) cell line. The 3,5-di-tert-butylsalicylaldehyde derived compound (8) was toxic to PC-3 human prostate adenocarcinoma cells, showing a promising IC50 value at 7.05 ± 0.76 μM. The present study also aimed to evaluate the inhibitory effects of the compounds against several key enzymes, namely carbonic anhydrase I and II (CA I and CA II), acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and glutathione reductase (GR), which are implicated in various global disorders, such as Alzheimer's disease, epilepsy, cancer, malaria, diabetes, and glaucoma. The inhibitory profiles of the tested compounds were assessed by determining their Ki values, which ranged from 2.96 to 9.24 nM for AChE, 3.78 to 12.57 nM for BChE, 8.42 to 25.74 nM for CA I, 7.24 to 19.74 nM for CA II, and 0.541 to 1.124 μM for GR. Molecular docking studies were also performed for all compounds. Most derivatives exhibited much more effective inhibitory action compared with clinically used standards. Thus, our findings indicate that the salicylidene derivatives presented in this study are promising drug candidates that need further evaluation.

Gingko biloba L.’nın Fitokimyasal Bileşimi, Antioksidan ve Anti-Kanser Aktiviteleri Üzerine Bir Araştırma

The study aims to investigate the phytochemical composition, antioxidant potential, and anti-cancer activities of Ginkgo biloba L. leaf methanol extract. In this study, the phytochemical compounds, total phenolic and flavonoid contents of G. biloba leaf methanol extract were investigated. Additionally, antioxidant and anti-cancer activities [against HT-29 (human colon cancer line), HeLa (human cervical cancer line), and HEK-293 (human embryonic kidney cell line)] were assayed. The main phytochemical compounds were identified as gallic (0.94±0.01 mg/g), p-hydroxy benzoic (0.71±0.01 mg/g), and protocatechuic (0.60±0.02 mg/g) acids in G. biloba leaf methanol extract by HPLC. The total phenolic and total flavonoid contents were measured as 71.20±0.42 µg GAE/mg extract and 13.24±0.35 µg QE/mg extract, respectively. The high antioxidant activity was found in ABTS•+ assay (89.04±0.71%) while moderate antioxidant activity was observed in DPPH• (43.31±0.75%), metal chelating (49.04±0.49%), CUPRAC (absorbance: 0.85±0.01), and phosphomolybdenum (absorbance: 1.16±0.02) assays at 400 µg/mL. The IC50 values of G. biloba leaf methanol extract on HT-29, HeLa, and HEK-293 cell lines were recorded as 406.70±1.55, 84.86±0.98, and &gt;800 µg/mL, respectively. The present study features a new addition to the antioxidant and anti-cancer properties of the therapeutically valuable G. biloba with its phytochemical content.

Redox Properties and in Vivo Magnetic Resonance Imaging of Cyclodextrin-Polynitroxides Contrast Agents.

This paper reports the synthesis, characterization and in vivo application of water-soluble supramolecular contrast agents (Mw: 5-5.6 kDa) for MRI obtained from β-cyclodextrin functionalized with different kinds of nitroxide radicals, both with piperidine structure (CD2 and CD3) and with pyrrolidine structure (CD4 and CD5). As to the stability of the radicals in presence of ascorbic acid, CD4 and CD5 have low second order kinetic constants (≤0.05 M-1 s-1 ) compared to CD2 (3.5 M-1 s-1 ) and CD3 (0.73 M-1 s-1 ). Relaxivity (r1 ) measurements on compounds CD3-CD5 were carried out at different magnetic field strength (0.7, 3, 7 and 9.4 T). At 0.7 T, r1 values comprised between 1.5 mM-1 s-1 and 1.9 mM-1 s-1 were found while a significant reduction was observed at higher fields (r1 ≈0.6-0.9 mM-1 s-1 at 9.4 T). Tests in vitro on HEK293 human embryonic kidney cells, L929 mouse fibroblasts and U87 glioblastoma cells indicated that all compounds were non-cytotoxic at concentrations below 1 μmol mL-1 . MRI in vivo was carried out at 9.4 T on glioma-bearing rats using the compounds CD3-CD5. The experiments showed a good lowering of T1 relaxation in tumor with a retention of the contrast for at least 60 mins confirming improved stability also in vivo conditions.

Cytotoxic and apoptotic effects of chemically synthesized silver nanoparticles loaded with recombinant Staphylococcus LukS-PV toxin.

Chronic myeloid leukemia (CML) accounts for approximately 15% of leukemias. LukS-PV, a Panton-Valentine leucocidin (PVL) component, is secreted by Staphylococcus aureus. Silver nanoparticles have increasingly been used for different purposes, most notably for drug delivery and anticancer agents. In this work, the cytotoxicity effect of recombinant LukS-PV protein, chemically synthesized AgNPs, and recombinant LukS-PV protein-loaded silver nanoparticles was investigated on human Chronic myeloid leukemia K562 cells and human normal embryonic kidney HEK293 cells. Cell apoptosis was investigated by staining with Annexin V/propidium iodide. The recombinant LukS-PV protein-loaded silver nanoparticles exhibited dose-dependent cytotoxicity and induced apoptosis in the K562 cells but had little effect on normal HEK293 cells. After 24h of exposure to recombinant LukS-PV protein-loaded silver nanoparticles (IC50 concentration), flow cytometry showed that 31.17% of K562 cells were apoptotic. These results indicate that recombinant LukS-PV protein-loaded silver nanoparticles maybe are a potential chemotherapeutic agent candidate against K562 cells. Hence, silver nanoparticles could be used as drug carriers for toxin release to cancer cells.

Multimerization of HIF enhances transcription of target genes containing the hypoxia ancillary sequence

Transcriptional activity of the hypoxia inducible factor (HIF) relies on the formation of a heterodimer composed of an oxygen-regulated α-subunit and a stably expressed β-subunit. Heterodimeric HIF activates expression by binding to RCGTG motifs within promoters of hypoxia-activated genes. Some hypoxia targets also possess an adjacent HIF ancillary sequence (HAS) reported to increase transcription but whose function remains obscure. Here, we investigate the contribution of the HAS element to the hypoxia response and its mechanism of action, using the HAS-containing prolyl 4-hydroxylase subunit α1 (P4HA1) as a gene model in NIH/3T3 mouse embryonic fibroblasts and HEK293 human embryonic kidney cells. Our HIF overexpression experiments demonstrate that the HAS motif is essential for full induction by hypoxia and that the presence of the tandem HAS/HIF, as opposed to HIF-only sequences, provides HIF proteins with the capacity to form complexes of stoichiometry beyond the classical heterodimer, likely tetramers, to cooperatively potentiate hypoxia-induced transcription. We also provide evidence of the crucial role played by the Fα helix of the PAS-B domain of the HIF1β subunit to support the interaction between heterodimers. Functional analysis showed that human genes containing the HAS/HIF motifs are better responders to hypoxia, and their promoters are enriched for specific transcription factor binding sites. Gene ontology enrichment revealed a predominance of HAS/HIF in genes primarily related to tissue formation and development. Our findings add an extra level of regulation of the hypoxia/HIF signaling through multimerization of HIF proteins on regulatory elements containing the HAS/HIF motifs.

Tailoring mechanical and in-vitro cytotoxicity behavior of LZ4X(X=0,1,2&3) magnesium alloy for bone implant application

This present research is focused on understanding the mechanical and bio-corrosion behavior of thermo-mechanically processed i.e. rolled Mg–4Li-XZn alloys with a 90% reduction in thickness. A single-phase Mg–4Li alloy was rolled with a 90% reduction in thickness, reducing the grain size to30 μm, incorporating varying amounts of zinc. Zinc addition and thermo-mechanical processing (hot rolling) at 300 °C refine the grains and increase tensile strength, resulting in LZ43 Mg alloy with an ultimate tensile strength (UTS) of 277 ± 8 MPa and an elongation (El) of 14 ± 3%. Kokubo's simulated body fluid (SBF) was used to perform bio-corrosion and electrochemical tests (PDP and PEIS). SEM, XRD, and FTIR were used to characterize corrosion morphology and bio-mineralization products like hydroxyapatite (HAp) compound. The in-invo corrosion conduction in HEK-293 (Human embryonic kidney cell line) proves that cells were less toxic and 95% of cells remained healthy when cultured in LZ43-HR90 Mg alloy condition.

New Anthranilic Acid Hydrazones as Fenamate Isosteres: Synthesis, Characterization, Molecular Docking, Dynamics & in silico ADME, in vitro Anti-inflammatory and Anti-cancer Activity Studies.

In this study, twenty new anthranilic acid hydrazones 6-9 (a-e) were synthesizedand their structures were characterized by Fourier-transform Infrared (FTIR), Nuclear Magnetic Resonance (1H NMR - 13C NMR), and High-resolution Mass Spectroscopy (HRMS). The inhibitory effects of thecompounds against COX-II were evaluated. IC50 values of the compounds were found in the range of >200 - 0.32 µM and compounds 6e, 8d, 8e, 9b, 9c, and 9e were determined to be the most effective inhibitors. Cytotoxic effects of the most potent compounds were investigated against human hepatoblastoma (Hep-G2) and human healthy embryonic kidney (Hek-293) cell lines. Doxorubicin (IC50: 8.68 ± 0.16 µM for Hep-G2, 55.29 ± 0.56 µM for Hek-293) was used as standard.8e is the most active compound, with low IC50against Hep-G2 (4.80 ± 0.04 µM), high against Hek-293 (159.30 ± 3.12), and high selectivity (33.15). Finally, molecular docking and dynamics studies were performed to understand ligand-protein interactions between the most potent compounds and COX II, Epidermal Growth Factor Receptor (EGFR), and Transforming Growth Factor beta II (TGF-βII). The docking scores were calculated in the range of -10.609 - -6.705 kcal/mol for COX-II, -8.652 - -7.743 kcal/mol for EGFR and -10.708 - -8.596 kcal/mol for TGF-βII.

Icariin, a phytoestrogen, exerts rapid estrogenic actions through crosstalk of estrogen receptors in osteoblasts.

Icariin, a flavonoid glycoside derived from Epimedium brevicornum Maxim, exerts bone protective effects via estrogen receptors (ERs). This study aimed to investigate the role of ER-α66, ER-α36, and GPER in bone metabolism in osteoblasts following treatment with icariin. Human osteoblastic MG-63 cells and osteoblast-specific ER-α66 knockout mice were employed. The ERs crosstalk in the estrogenic action of icariin was evaluated in ER-α66-negative human embryonic kidney HEK293 cells. Icariin, like E2, regulated ER-α36 and GPER protein expression in osteoblasts by downregulating them and upregulating ER-α66. ER-α36 and GPER suppressed the actions of icariin and E2 in bone metabolism. However, the in vivo administration of E2 (2 mg/kg/day) or icariin (300 mg/kg/day) restored bone conditions in KO osteoblasts. ER-α36 and GPER expression increased significantly and rapidly activated and translocated in KO osteoblasts after treatment with E2 or icariin. ER-α36 overexpression in KO osteoblasts further promoted the OPG/RANKL ratio induced by E2 or icariin treatment. This study showed icariin and E2 elicit rapid estrogenic responses in bone through recruiting ER-α66, ER-α36, and GPER. Notably, in osteoblasts lacking ER-α66, ER-α36, and GPER mediate the estrogenic effects of icariin and E2, while in intact osteoblasts, ER-α36 and GPER act as negative regulators of ER-α66.

The Study of the Cytotoxicity, Proliferative and Microbiological Activity of the Medicated Chewing Gum with Ascorbic Acid and Lysozyme Hydrochloride Using Different Culture of Cells.

Medicated chewing gum with lysozyme hydrochloride and ascorbic acid as active pharmaceutical ingredients was developed for application in dentistry. The aim of this research was to study the cytotoxicity, proliferative, and microbiological activities of the active ingredients in different types of cell cultures. The preclinical study of active pharmaceutical ingredients and their combinations was carried out using culture lines such as HepG2 (human hepatocarcinoma cells), Hek293 (human embryonic kidney cells), and MAEC (mouse aortic endothelial cells). MTT assays were used to analyse cytotoxicity and proliferative activity, while the state of antioxidant protection was assessed by the content of sulfhydryl groups and catalase activity. The determination of lipid peroxidation products was based on the level of TBA-active products. As a microbiological model for studying the effect of the developed dental medicine on the ability of the oral cavity microorganisms to form biofilms, the following strains were used: Streptococcus mutans, Staphylococcus aureus, Staphylococcus epidermidis, Lactobacillus plantarum, and Candida albicans. The optical density of the formed biofilm was evaluated by the intensity of the experimental sample's colour on a StatFax 303 Plus photometer at a wavelength of 630 nm. The combination of ascorbic acid and lysozyme hydrochloride in the established concentrations (20 mg and 10 mg per 1 gum, respectively) resulted in a slight stimulation of cell proliferation without any toxic effects and increased antioxidant protection, preventing the development of oxidative stress. It was found that, in contrast to the separately used active substances, the combination of lysozyme hydrochloride and ascorbic acid inhibits the biofilm formation of all studied microorganisms and shows the ability to destroy diurnal biofilms of L. plantarum and fungi of the genus Candida, indicating potentiation and summation of the active pharmaceutical ingredients' composition effects in the developed dental medicine. Due to the observed positive pharmacological and microbiological action, the combination of lysozyme hydrochloride and ascorbic acid in the medicated chewing gum serves as a promising tool for the prevention and treatment of infectious and inflammatory diseases of the periodontium and mucous membranes and the prevention of caries.

Spectroscopic, X-ray crystallographic and preliminary biological screening study of unsymmetrical diphosphinoamine (PNP’) and monodentate aminophosphine (PNH) ligands coordinated to Pt(II)

An efficient and simple synthetic route to a new class of unsymmetrical diphosphinoamine {PNP'=(o-Tol)2P'N(R1)P(R2)2} and monophosphinoamine {(o-Tol)2P(R1)NH} ligands are presented, which allowed the manipulation of the R1 substituents on the amine as well as the cyclic R2 substituents on the phosphorus atom. The unsymmetrical (o-Tol)2P'N(R1)P(R2)2 ligands {R1 = p-MePh (A), o-MePh (B), p-ClPh (C) or p-FPh (D)} and their coordination to a Pt(II) metal center as [Pt{κ2-(P,P')(PNP')}Cl2] (3N; N = A, C, D) type of complexes are presented. In addition, monophosphinoamine ligands {(o-Tol)2P(R1)NH} are described, yielding the cisplatin analogue cis-[Pt((o-Tol)2P(p-MePh)NH)2Cl2] (2A), and trans-[Pt((o-Tol)2P(o-MePh)NH)2Cl2] (2B). Five single crystal X-ray studies are reported (2A, 2B, 3A, 3C, 3D), together with a detailed 31P NMR spectroscopy study. The electrostatic and steric repulsions on the ortho-CH3 on these types of ligands induces restricted rotation as seen by solution NMR spectra of all free ligands. The presence of two stable conformers (syn,syn,anti) and (syn,syn,syn) for the free PNP' ligands is illustrated, both in solution and solid state (31P MAS NMR). Moreover, in the synthesis, a scrambling/disproportionation of the unsymmetrical PNP' ligand is observed, yielding some 20% of the corresponding symmetrical PNP nucleophiles. However, the (syn,syn,anti)-conformer disappear upon coordination to the Pt(II), as required by the cis-[Pt(PNP')Cl2] complexes. The two Pt-PN complexes cis-[Pt((o-Tol)2P(p-MePh)NH)2Cl2] (2A) and trans-[Pt((o-Tol)2P(o-MePh)NH)2Cl2] (2B) were evaluated for biological activity to ascertain whether the stereo chemistry on these would show more activity as analogous cisplatin and derivatives. Additionally, 2A and 2B were also screened for antimicrobial activity. Significant microbial inhibition against Gram-positive Staphylococcus aureus and two Fungi Cryptococcus neoformans and Candida albicans was found for complex trans-[Pt(p-MePh-PNH)2Cl2] (2A), while the cytotoxicity evaluation of 2A against HEK293 human embryonic kidney cells displayed a moderate activity CC50 of 18.1 μM.

Circadian Oscillation Pattern of Endoplasmic Reticulum Quality Control (ERQC) Components in Human Embryonic Kidney HEK293 Cells.

The circadian clock regulates the "push-pull" of the molecular signaling mechanisms that arrange the rhythmic organization of the physiology to maintain cellular homeostasis. In mammals, molecular clock genes tightly arrange cellular rhythmicity. It has been shown that this circadian clock optimizes various biological processes, including the cell cycle and autophagy. Hence, we explored the dynamic crosstalks between the circadian rhythm and endoplasmic reticulum (ER)-quality control (ERQC) mechanisms. ER-associated degradation (ERAD) is one of the most important parts of the ERQC system and is an elaborate surveillance system that eliminates misfolded proteins. It regulates the steady-state levels of several physiologically crucial proteins, such as 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR) and the metastasis suppressor KAI1/CD82. However, the circadian oscillation of ERQC members and their roles in cellular rhythmicity requires further investigation. In the present study, we provided a thorough investigation of the circadian rhythmicity of the fifteen crucial ERQC members, including gp78, Hrd1, p97/VCP, SVIP, Derlin1, Ufd1, Npl4, EDEM1, OS9, XTP3B, Sel1L, Ufd2, YOD1, VCIP135 and FAM8A1 in HEK293 cells. We found that mRNA and protein accumulation of the ubiquitin conjugation, binding and processing factors, retrotranslocation-dislocation, substrate recognition and targeting components of ERQC exhibit oscillation under the control of the circadian clock. Moreover, we found that Hrd1 and gp78 have a possible regulatory function on Bmal1 turnover. The findings of the current study indicated that the expression level of ERQC components is fine-tuned by the circadian clock and major ERAD E3 ligases, Hrd1 and gp78, may influence the regulation of circadian oscillation by modulation of Bmal1 stability.

Screening and characterisation of a novel efficient tumour cell-targeting peptide derived from insulin-like growth factor binding proteins

Targeted delivery of antitumor drugs is particularly important in tumour treatment. Tumour-targeted peptide is a very effective drug carrier for tumour therapy. Here, we screened and characterised a highly efficient targeted peptide named IHP5, which was derived from insulin-like growth factor binding proteins (IGFBPs). IHP5 exhibited preferential binding to the tested tumour cell lines. The delivery efficiency of IHP5 was higher in various tested tumour cells than in normal cells, especially in the human cervical cancer cell line HeLa, which was 11.7-fold higher than in normal human embryonic kidney cells HEK293. Moreover, the penetration efficiency of IHP5 was 13 times higher than that of the classical cell penetrating peptide TAT in HeLa cells. Detail analysis revealed that IHP5 endocytosis was possibly correlated with acetylated heparan sulphate proteoglycans including phosphatidylinositol proteoglycan 3 (GPC3), phosphatidylinositol proteoglycan 5 (GPC5) and syndecan 2 (SDC2). Subsequently, the introduction of IHP5 enhanced the inhibitory effect of trichosanthin (TCS) on tumour cells, resulting in at least 19-fold increase in tumour cells without enhanced cytotoxicity in normal cells HEK293. These results suggested that IHP5, as a novel tumour cell-targeting penetrating peptide with the ability to target tumour cells, has great potential in drug delivery applications.