Chronic hepatitis C virus (HCV) infection is a leading cause of chronic liver disease. The introduction of direct acting antiviral agents (DAAs) for its treatment represents a major advance in terms of sustained virologic response (SVR) rates and adverse effect profiles. Mechanistically, DAAs inhibit specific HCV non-structural proteins (NS) that are vital for its replication. Boceprevir, telaprevir, simeprevir, asunaprevir, grazoprevir and paritaprevir are NS3/4A inhibitors. Ombitasvir, ledipasvir, daclatasvir, elbasvir and velpatasvir are NS5A inhibitors. Sofosbuvir and dasabuvir are NS5B inhibitors. Currently, a combination of two or more DAAs is the corner stone for the treatment of HCV infection. However, the success of DAA therapy is facing several challenges, including the potential of drug-drug interactions and resistant variance. Moreover, the shortage of relevant clinical pharmacological data and drug interaction regarding DAA is a clinical concern. The present review discusses the clinical pharmacology of DAAs with special emphasis on drug-drug interaction.

Traditional cancer treatments have posed numerous obstacles, including toxicity, multiple drug resistance, and financial cost. On the contrary, bioactive phytochemicals used in complementary alternative medicine have recently increased attention due to their potential to modulate a wide range of molecular mechanisms with a less toxic effect. Therefore, we investigated the potential regulatory mechanisms of andrographolide to treat colorectal cancer (CRC) using a network pharmacology approach. Target genes of andrographolide were retrieved from public databases (PharmMapper, Swiss target prediction, Targetnet, STITCH, and SuperPred), while targets related to CRC were retrieved from disease databases (Genecards and DisGeNet) and expression datasets (GSE32323 and GSE8671) were retrieved from gene expression omnibus (GEO). Protein-protein interaction networks (PPI) were generated using STRING and Cytoscape, and hub genes were identified by topology analysis and MCODE. Annotation of target proteins was performed using Gene Ontology (GO) database DAVID and signaling pathway enrichment analysis using the Kyoto Encyclopedia and Genome Database (KEGG). Survival and molecular docking analysis for the hub genes revealed three genes (PDGFRA, PTGS2, and MMP9) were involved in the overall survival of CRC patients, and the top three genes with the lowest binding energy include PDGFRA, MET, and MAPK1. MET gene upregulation and PDGFRA and PTGS2 gene downregulation are associated with the survival of CRC patients, as revealed by box plots and correlation analysis. In conclusion, this study has provided the first scientific evidence to support the use of andrographolide to inhibit cellular proliferation, migration, and growth, and induce apoptosis by targeting the hub genes (PDGFRA, PTGS2, MMP9, MAPK1, and MET) involved in CRC migration and invasion.

Hypoxia or hypoxia/reoxygenation impairs nitric oxide (NO)-mediated relaxation through the increase in superoxide generation in monkey coronary arteries. Soluble guanylate cyclase (sGC), the target enzyme of NO, has been shown to change from the NO-sensitive reduced form to the NO-insensitive oxidized/heme-free form under substantial oxidative stress, so the present study investigated whether hypoxia or hypoxia/reoxygenation influences sGC redox equilibrium. In isolated monkey coronary arteries without endothelium, the relaxation caused by the sGC stimulator BAY 41-2272 (Emax: 93.3% ± 2.2%) was somewhat impaired under hypoxia (Emax: 86.3% ± 2.6%) or hypoxia/reoxygenation (Emax: 86.1% ± 3.2%), whereas that by the sGC activator BAY 60-2770 (Emax: 86.0% ± 3.2%) was significantly augmented under hypoxia (Emax: 94.4% ± 1.3%) or hypoxia/reoxygenation (Emax: 95.5% ± 1.1%). In addition, cGMP formation in response to BAY 41-2272 and BAY 60-2770 was inhibited and stimulated, respectively, under hypoxia or hypoxia/reoxygenation. The effects of hypoxia or hypoxia/reoxygenation on BAY 41-2272– and BAY 60-2770–induced vasorelaxation were completely canceled by the treatment with the superoxide dismutase mimetic tempol. These findings suggest that sGC redox equilibrium in the coronary artery is shifted towards the NO-insensitive form under hypoxia or hypoxia/reoxygenation and that superoxide seems to play an important role in this shift.