Introduction: Hymenosporum flavum (Hook.) F. Muell. is the sole species within the genus Hymenosporum is known for its antimicrobial activity. The current study aims to examine the prospective activity of H. flavum as a safe supporter of sorafenib (as a reference standard) against hepatocellular carcinoma (HCC). Methods: Isolation and identification of compounds were made by chromatographic and spectroscopic methods. A fingerprint for the plant extract was done using HPLC-MS/MS spectrometric analysis. The total plant extract was examined in vitro for HCC activity. The isolated flavonoids were examined for their cytotoxic activities using molecular docking studies against both RAF-1 and ERK-2, and the promising compounds were further examined in vitro using quantitative reverse transcription-polymerase chain reaction (qRT-PCR). Results: Two new flavonols were isolated from the leaf extract of H. flavum (Hook.) F. Muell., quercetin-3-O-(glucopyranosyl 1→2 ribopyranoside) (1) and kaempferol-3-O-(glucopyranosyl 1→2 ribopyranoside) (2), accompanying other six known flavonoids (3-8), and identified via spectroscopic analysis. Moreover, HPLC- PDA/MS/MS spectrometric analysis revealed the presence of seventy phenolic metabolites. The cytotoxic activity of the plant extract confirmed its potential action on HepG2 cells indicated by the production level of lactate dehydrogenase (LDH) upon treatment compared with the normal cells. The isolated flavonoids were examined for their cytotoxic activity using molecular docking studies against both RAF-1 and ERK-2 as proposed mechanisms of their anticancer activities. Furthermore, compounds 1 and 3, which showed the best in silico results, were further examined in vitro using qRT-PCR. They exhibited promising inhibitory activities against both RAF-1 and ERK-2 gene expression. Moreover, they showed promising cytotoxic activities indicated by the MTT assay. Also, both of them improved the efficiency of sorafenib in targeting both RAF-1 and ERK-2 pathways suggesting synergistic combinations. Conclusion: Our findings showed the potential cytotoxic activity of H. flavum extract on HepG2 cells. Some isolated compounds (1 & 3) exhibited promising inhibitory activities against both RAF-1 and ERK-2 gene expression giving a lead future study for these compounds to be used in pharmaceutical preparations either alone or in combination with sorafenib.

Influenza A virus is a negative RNA stranded virus of the family Orthomyxoviridae, and represents a major public health threat, compounding existing disease conditions. Influenza A virus replicates rapidly within its host and the segmented nature of its genome facilitates re-assortment, whereby whole genes are exchanged between influenza virus subtypes during replication. Antiviral medications are important pharmacological tools in influenza virus prophylaxis and therapy. However, the use of currently available antiviral is impeded by sometimes high levels of resistance in circulating virus strains. Here, we identified novel anti-influenza compounds through screening of chemical compounds synthesized de novo on human lung epithelial cells. Computational and experimental screening of extensive and water soluble compounds identified novel influenza virus inhibitors that can reduce influenza virus infection without detectable toxic effects on host cells. Interestingly, the indicated active compounds inhibit viral replication most likely via interaction with cell receptors and disturb influenza virus entry into host cells. Collectively, screening of new synthesis chemical compounds on influenza A virus replication provides a novel and efficacious anti-influenza compounds that can inhibit viral replication via disturbing virus entry and indicates that these compounds are attractive candidates for evaluation as potential anti-influenza drugs.

Introduction: Cancer is one of the most difficult challenges faced by humanity due to its many associated issues, such as inability to prevent diseases, treatment safety, and high mortality rate. In cancer, a variety of cellular signaling is activated to ensure malignancy transformation, angiogenesis and metastasis. The most efficient signaling pathway in cancer is mitogen-activated protein kinase (MAPK), which controls malignancy and regulates apoptosis. Methods: Four different flavonoid glycosides have been isolated from Pulicaria jaubertii using the phytochemical characterization of hydro-methanol extract. The purified glycosides (PJs) were investigated for their potential repression of cancer development using human lung epithelial cells and hepatocellular carcinoma (HCC) and compared with Sorafenib (SOR), the standard systemic drug for HCC. In PJ-treated cells, the expression profile of K-Ras, B-Raf, and P53 were detected using qRT-PCR, flow cytometry, confocal microscopy and western blot. Steady-state mRNA and levels of transforming growth factor-beta (TGF-β) and interleukin 8 (IL-8) were monitored in the fluids media at different time points following treatment. Results: Our results showed that the qurictine glycosides (PJ-1 and PJ-9) selectively inhibited the mutant K-Ras/B-Raf proteins expression and interaction in both cancer cells; while SOR showed obvious depletion of total Raf-1 protein in cancer cells and normal cells as well. Interestingly, the combination of PJ-1 or PJ-9 with SOR exhibited restoring cell viability of normal cells via controlling Raf-1 and P53 genes expression. Further, these identified PJ agents significantly adjusted the levels of TGF-β and IL-8 in cancer treated cells accompanied by restoring the activation of P53 expression. These findings were confirmed by docking analysis of PJs ligand and the crystal structure of K-Ras, B-Raf, and ERK transcription factor. Conclusion: The current data provide novel and natural multi-kinase inhibitors with competitive regulation of the mutant proteins; K-Ras and B-Raf and sustained MAPK signaling without any detectable toxic effect in normal cells.

Background: A heart attack occurs when coronary artery blockage interrupts the blood supply to the heart such as is seen in cardiovascular disease (CVD). Importantly, autophagy is commonly regarded as a host defense mechanism against microbial invaders. Methods: A total of 50 blood samples were obtained from cardiovascular (CV) patients in addition to 30 samples that were obtained from healthy individuals and served as controls. Macrophages were isolated in vitro and propagated from the blood samples. Autophagosome formation, cytokine secretion, and apolipoprotein B (ApoB) gene expression were monitored in patient samples and their derived macrophages. Results: The results showed that autophagy-related (Atg) LC3 and Atg5 genes were significantly down-regulated in all samples obtained from CV patients. Furthermore, the relative gene expression of ApoB, which plays the major role in lipoprotein metabolism, was significantly increased in CV patients. Interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) levels were increased in these blood samples. Interestingly, targeting of ApoB by small interference RNA (siRNA) reduced the production levels of low-density lipoprotein (LDL), IL-6 and TNF-α in patient-derived macrophages. Further, treatment of patient-derived macrophages with rapamycin, an autophagy inducer agent, successfully regulated the production of LDL, IL-6, TNF-α, and ApoB expression via activation of autophagosome formation. Conclusion: The current data reveal the potential disturbance of autophagy in CV patients that accompanied ApoB over-expression. Furthermore, our findings provide evidence for the protective role of autophagy in accumulation of pro-inflammatory cytokines and intracellular LDL degradation in CV patient-derived macrophages.

Legionella pneumophila (L. pneumophila) is a Gram-negative bacterium that infects the human respiratory tract causing Legionnaires’ disease, a severe form of pneumonia. Recently, rising evidence indicated the ability of Legionella to regulate host defense via its type 4 secretion system including hundreds of effectors that promote intracellular bacterial replication. The host defense against such invaders includes autophagic machinery that is responsible for degradation events of invading pathogens and recycling of cell components. The interplay between host autophagy and Legionella infection has been reported, indicating the role of bacterial effectors in the regulation of autophagy during intracellular replication. Here, we investigated the potential impact of Legionella effector Lpg2936 in the regulation of host autophagy and its role in bacterial replication using mice-derived macrophages and human lung epithelial cells (A549 cells). First, monitoring of autophagic flux following infection revealed a marked reduction of Atg7 and LC3B expression profile and low accumulation levels of autophagy-related LC3-I, LC3-II, and the Atg12–Atg5 protein complex. A novel methyladenine alteration was observed due to irreversible changes of GATC motif to G(6 mA) TC in the promoter region of Atg7 and LC3B indicated by cleaved genomic-DNA using the N6 methyladenine-sensitive restriction enzyme DpnI. Interestingly, RNA interference (RNAi) of Lpg2936 in infected macrophages showed dramatic inhibition of bacterial replication by restoring the expression of autophagy-related proteins. This is accompanied by low production levels of bacterial-associated pro-inflammatory cytokines. Furthermore, a constructed Lpg2936 segment in the GFP expression vector was translocated in the host nucleus and successfully induced methyladenine changes in Atg7 and LC3B promoter region and subsequently regulated autophagy in A549 cells independent of infection. Finally, treatment with methylation inhibitors 5-AZA and (2)-Epigallocatechin-3-gallate (EGCG) was able to restore autophagy-related gene expression and to disrupt bacterial replication in infected macrophages. This cumulative evidence indicates the methylation effect of Legionella effector Lpg2936 on the host autophagy-related molecules Atg7 and LC3B and subsequent reduction in the expression levels of autophagy effectors during intracellular replication of L. pneumophila.