Inhibition of Staphylococcus aureus α-Hemolysin Production Using Nanocurcumin Capped Au@ZnO Nanocomposite.

Nanoparticles of gold with zinc oxide (Au@ZnO NPs) were prepared by laser ablation and then capped with curcumin nanoparticles (Cur-Au@ZnO NPs). The synthesized NPs were characterized using different techniques, including transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FTIR), UV-visible spectroscopy, and X-ray diffraction. In addition, the ability of NPs as a promising antibacterial agent was tested against Staphylococcus aureus through the agar well diffusion method and AO/EtBr staining assay. The results showed that the prepared nanoparticles (Cur-Au@ZnO) served as an antibacterial agent and can destroy the bacterial cells by losing the cell wall integrity and penetrating the cytoplasmic membrane. Moreover, the findings confirmed the role of the formed NPs in attenuation of the adherence and invasion of S. aureus to rat embryonic fibroblast (REF) cells. Furthermore, the activity of Cur-Au@ZnO NPs against the S. aureus α-hemolysin toxin was evaluated using the western blot technique, using human alveolar epithelial cells (A549), and through histopathology examination in a mouse model. In conclusion, the built Cur-Au@ZnO NPs can be used as a potential antibacterial agent and an inhibitor of α-hemolysin toxin secreted by S. aureus. These NPs may offer a new strategy in combating pathogen infections and in the future for biomedical and pharmaceutical applications.

Pt(II)-Thiocarbohydrazone Complex as Cytotoxic Agent and Apoptosis Inducer in Caov-3 and HT-29 Cells through the P53 and Caspase-8 Pathways.

In this study, a platinum(II) complex ([Pt(H2L)(PPh3)] complex) containing a thiocarbohydrazone as the ligand was tested as an anti-proliferative agent against ovarian adenocarcinoma (Caov-3) and human colorectal adenocarcinoma (HT-29) through MTT assays. Apoptotic markers were tested by the AO/PI double staining assay and DNA fragmentation test. Flow cytometry was conducted to measure cell cycle distribution, while the p53 and caspase-8 pathways were tested via immunofluorescence assay. Results demonstrated that the cytotoxic effect of the Pt(II)-thiocarbohydrazone complexes against Caov-3 and HT-29 cells was highly significant, and this effect triggered the activation of the p53 and caspase-8 pathways. Besides, apoptosis stimulated by the Pt(II)-thiocarbohydrazone complex was associated with cell cycle arrest at the G0/G1 phase. These findings suggest that the target complex inhibited the proliferation of Caov-3 and HT-29 cells, resulting in the arrest of the cell cycle and induction of apoptosis via the stimulation of the p53 and caspase-8 pathways. The present data suggests that the Pt(II)-thiocarbohydrazone complex could also be a promising chemotherapeutic agent for other types of cancer cells.

Gold Nanoparticles and Graphene Oxide Flakes Enhance Cancer Cells' Phagocytosis through Granzyme-Perforin-Dependent Biomechanism.

The study aimed to investigate the roles of gold nanoparticles (GNPs) and graphene oxide flakes (GOFs) as phagocytosis enhancers against cancer cells. The nanomaterials were characterized through SEM and UV-VIS absorptions. The GNPs and GOFs increased the macrophages' phagocytosis ability in engulfing, thereby annihilating the cancer cells in both in vitro and in vivo conditions. The GNPs and GOFs augmented serine protease class apoptotic protein, granzyme, passing through the aquaporin class protein, perforin, with mediated delivery through the cell membrane site for the programmed, calibrated, and conditioned cancer cells killing. Additionally, protease inhibitor 3,4-dichloroisocoumarin (DCI) significantly reduced granzyme and perforin activities of macrophages. The results demonstrated that the GOFs and GNPs increased the activation of phagocytic cells as a promising strategy for controlling cancer cells by augmenting the cell mortality through the granzyme-perforin-dependent mechanism.

Linalool-Loaded Glutathione-Modified Gold Nanoparticles Conjugated with CALNN Peptide as Apoptosis Inducer and NF-κB Translocation Inhibitor in SKOV-3 Cell Line.

BACKGROUND: Linalool is a monoterpene compound with various potential therapeutic applications in several medical fields. Previous studies have indicated the activity of linalool against cell lines; however, its high level of toxicity restricts its use. The aim of this study was to design and manufacture compounds with a novel structure that can be used for loading linalool, to reduce its toxicity and improve its reachable ability. METHODS: We synthesized and characterized a new molecule for loading linalool onto gold nanoparticles (GNPs) capped with glutathione and conjugated with a CALNN peptide. Linalool was loaded onto the GNPs via the reaction of the surface groups of both linalool and the GNPs. Moreover, the target peptide could be loaded onto the surface of the GNPs via a chemical reaction. The cytotoxic effects of linalool-GNP (LG) and linalool-GNP-CALNN peptide (LGC) conjugates against ovarian cancer cells were investigated, as were the possible mechanisms underlying the induction of apoptosis. RESULTS: Our findings illustrated the significant antiproliferative effect of LG and LGC on SKOV-3 cells. The cytotoxicity assay demonstrated that LG and LGC were selectively toxic in cancer cells and induced apoptosis by activating caspase-8, the p53 protein, and various proteins involved in apoptosis. The present data demonstrated that LG and LGC have a high therapeutic potential and should be given particular consideration as anticancer drug-delivery systems, as LG and LGC were remarkably more cytotoxic against a cancer cell line than were linalool and GNPs alone. CONCLUSION: We concluded that LG and LGC are promising compounds that can be used for treating ovarian cancer (SKOV-3) cells via the induction of apoptosis through extrinsic and intrinsic pathways.

Novel of nano delivery system for Linalool loaded on gold nanoparticles conjugated with CALNN peptide for application in drug uptake and induction of cell death on breast cancer cell line.

Linalool is a monoterpene alcohol which occurs naturally in several aromatic plants. The aims of this study are to load Linalool on gold nanoparticles, conjugate the complex with CALNN peptide, and investigate them for in-vitro anticancer activities against breast cancer (MCF-7) cell line. Linalool was obtained with 98% purity while gold nanoparticles and CALNN peptide were chemically synthesized. The formation of LIN-GNPs and LIN-GNPs-CALNN was observed through a color change. These compounds were confirmed and characterized using SEM, DLS, AFM, UV-VIS spectrophotometer, XRD, and FTIR. The free radical scavenging potential of each compound was confirmed based on its stable antioxidant effects using different parameters. Blood compatibility on red blood cells was confirmed by hemolytic and in vitro cytotoxicity assays. The in-vitro anticancer activity of each compound towardMCF-7 cell line was investigated using various parameters. From the results, Linalool, GNPs, LIN-GNPs, and LIN-GNPs-CALNN were found to exert cell growth arrest against MCF-7 cell line. The anti-proliferative effect of these compounds was due to cell death and induction of apoptosis confirmed using acridine orange-Ethidium bromide dual staining, DAPI staining, and electrophoresis analysis of DNA fragmentation. High fluorescent signals specific for the cellular uptake of LIN-GNPs and LIN-GNPs-CALNN into the cytoplasm of the cell line were confirmed. To study the toxicity of LIN-GNPs-CALNN in animal models, the hematological, histopathological, and body weight changes were estimated after 4 weeks of intraperitoneal injection of the compounds into the animal models. Our results demonstrate that Linalool, GNPs, Linalool-GNPs, and Linalool-GNPs-CALNN peptide had no side effects and could be clinically used for future therapeutic purposes.

Iraqi propolis increases degradation of IL-1ß and NLRC4 by autophagy following Pseudomonas aeruginosa infection.

Autophagy is a cellular process for maintaining cellular homeostasis. This process can be induced by different factors, such as immune stimuli and pathogen-associated molecules. Autophagy has an important role in the control of IL-1ß secretion by macrophages and other cell types. In present study, we describe a novel role for Iraqi propolis affecting autophagy in controlling the secretion of IL-1ß in bone-marrow macrophages (BMDMs). After infection with Pseudomonas aeruginosa in the presence of propolis, the degradation of IL-1ß was induced, and the activity of inflammasome was reduced. Iraqi propolis-induced autophagy in in vitro and in vivo models decreased the levels of IL-1ß and caspase-1. Results indicated that IL-1ß pathway production is regulated by autophagy via two different novel mechanisms, namely, regulation of the activation of NLRC4 inflammasome and IL-1ß targeting for lysosomal degradation.

RKIP: much more than Raf kinase inhibitory protein.

From its discovery as a phosphatidylethanolamine-binding protein in bovine brain to its designation as a physiological inhibitor of Raf kinase protein, RKIP has emerged as a critical molecule for maintaining subdued, well-orchestrated cellular responses to stimuli. The disruption of RKIP in a wide range of pathologies, including cancer, Alzheimer's disease, and pancreatitis, makes it an exciting target for individualized therapy and disease-specific interventions. This review attempts to highlight recent advances in the RKIP field underscoring its potential role as a master modulator of many pivotal intracellular signaling cascades that control cellular growth, motility, apoptosis, genomic integrity, and therapeutic resistance. Specific biological and functional niches are highlighted to focus future research towards an enhanced understanding of the multiple roles of RKIP in health and disease.

RAF kinase inhibitory protein (RKIP) modulates cell cycle kinetics and motility.

RKIP-1 is a metastasis suppressor that is frequently downregulated in aggressive cancers. However, the consequences of RKIP loss in primary or immortalized cells have not yet been explored. Using HEK-293 RKIP depleted (termed HEK-499) and Flp-In T-Rex-293 RKIP inducible cell lines combined with whole transcriptome analysis, we show that RKIP-1 silencing accelerates DNA synthesis and G1/S transition entry by inducing the expression of cdc6, MCM 2, 4, 6, 7, cdc45L, cyclin D2, cyclin E2, cyclin D1, SKP2 and the downregulation of p21(cip1). Moreover, RKIP depletion accelerates the time from nuclear envelop breakdown (NEB) to anaphase markedly, while the upregulation of RKIP shortened the NEB to anaphase time. We show that RKIP depletion induces the expression of NEK6, a molecule known to enhance G2/M transition, and down-regulates G2/M checkpoint molecules like Aurora B, cyclin G1 and sertuin that slow the G2/M transition time. These subtle changes in the kinetics of the cell cycle culminate in a higher proliferation rate of HEK-499 compared to control cells. Finally, we show that RKIP depletion enhances cellular motility by inducing the expression/stabilization of ß-catenin, vimentin, MET and PAK1. Overall, our data suggest that modulation of the cell cycle checkpoints and motility by RKIP may be fundamental to its metastasis suppressive function in cancer and that RKIP role in a cell is more intricate and diverse than previously thought.