Discovery of Sanggenon G as a natural cell-permeable small-molecular weight inhibitor of X-linked inhibitor of apoptosis protein (XIAP)

Chemistry, bioactivities, structure-activity relationship, biosynthesis and metabolism of prenylated flavonoids in Moraceae plants

Plants from Moraceae are globally popular as they represent a valuable resource with wide applications in food, health-care products, and other fields. Prenylated flavonoids are important active components in Moraceae. These compounds share a flavonoid skeleton with prenylated side chain, mostly in the form of single or multiple isoprenyl substituents and benzodimethylfuran structures. So far, nearly 400 prenylated flavonoids have been found in Moraceae, especially a large number of Diels-Alder adducts, which are characteristic components of this family. Due to their distinctive structures, diverse pharmacological properties and interesting synthesis processes, these compounds have attracted considerable attention from scientists. Herein, we review the advances in the structural characteristics, bioactivities, structure-activity relationships, biosynthesis strategies and in vivo metabolism of prenylated flavonoids in Moraceae plants, aiming at strengthening research efforts and utilization toward the great untapped potential of these unique constituents in human health.

A High-Throughput Fluorescence Polarization-Based Assay for the SH2 Domain of STAT4

The signal transducer and activation of transcription (STAT) proteins are a family of Src homology 2 (SH2) domain-containing transcription factors. The family member STAT4 is a mediator of IL-12 signalling and has been implicated in the pathogenesis of multiple autoimmune diseases. The activity of STAT4 requires binding of phosphotyrosine-containing motifs to its SH2 domain. Selective inhibitors of the STAT4 SH2 domain have not been published to date. Here, we present a fluorescence polarization-based assay for the identification of inhibitors of the STAT4 SH2 domain. The assay is based on the interaction between the STAT4 SH2 domain and the fluorophore-labelled peptide 5-carboxyfluorescein-GpYLPQNID (K_d = 34 ± 4 nM). The assay is stable with respect to DMSO concentrations of up to 10% and incubation times of at least 8 h. The Z'-value of 0.85 ± 0.01 indicates that the assay is suited for use in high-throughput screening campaigns aimed at identifying new therapeutic modalities for the treatment of autoimmune diseases.

Ribosomal protein L5 mediated inhibition of c-Myc is critically involved in sanggenon G induced apoptosis in non-small lung cancer cells

Though Sanggenon G (SanG) from root bark of Morus alba was known to exhibit anti-oxidant and anti-depressant effects, its underlying mechanisms still remain unclear. Herein SanG reduced the viability of A549 and H1299 non-small lung cancer cells (NSCLCs). Also, SanG increased sub-G1 population via inhibition of cyclin D1, cyclin E, CDK2, CDK4 and Bcl-2, cleavages of poly (ADP-ribose) polymerase (PARP) and caspase-3 in A549 and H1299 cells. Of note, SanG effectively inhibited c-Myc expression by activating ribosomal protein L5 (RPL5) and reducing c-Myc stability even in the presence of cycloheximide and 20% serum in A549 cells. Furthermore, SanG enhanced the apoptotic effect with doxorubicin in A549 cells. Taken together, our results for the first time provide novel evidence that SanG suppresses proliferation and induces apoptosis via caspase-3 activation and RPL5 mediated inhibition of c-Myc with combinational potential with doxorubicin.

α-Amylase Modulation: Discovery of Inhibitors Using a Multi-Pharmacophore Approach for Virtual Screening

Better control of postprandial hyperglycemia can be achieved by delaying the absorption of glucose resulting from carbohydrate digestion. Because α-amylase initiates the hydrolysis of polysaccharides, the design of α-amylase inhibitors can lead to the development of new treatments for metabolic disorders such as type II diabetes and obesity. In this study, a rational computer-aided approach was developed to identify novel α-amylase inhibitors. Three-dimensional pharmacophores were developed based on the binding mode analysis of six different families of compounds that bind to this enzyme. In a stepwise virtual screening workflow, seven molecules were selected from a library of 1.4 million. Five out of seven biologically tested compounds showed α-amylase inhibition, and the two most potent compounds inhibited α-amylase with IC₅₀ values of 17 and 27 μm. The scaffold benzylideneacetohydrazide was shared by four of the discovered inhibitors, emerging as a novel drug-like non-carbohydrate fragment and constituting a promising lead scaffold for α-amylase inhibition.

Improvement in antiproliferative activity of Angelica gigas Nakai by solid dispersion formation via hot-melt extrusion and induction of cell cycle arrest and apoptosis in HeLa cells

Angelica gigas Nakai (AGN) is one of the most popular herbal medicines and widely used as a functional food product. In this study, AGN was firstly processed by a low-temperature turbo mill and a hot melting extruder to reduce particle size and form solid dispersion (SD). Anticancer activity against HeLa cells was then examined. AGN-SD based on Soluplus was formed via hot-melt extrusion (HME) and showed the strongest cytotoxic effect on HeLa cells. In addition, the possible mechanism of cell death induced by AGN-SD on HeLa cells was also investigated. AGN-SD decreased cell viability, induced apoptosis, increased the production of reactive oxygen species, regulated the expression of Bcl-2 and Bax, and induced G2/M phase arrest in HeLa cells. This study suggested that AGN-SD based on Soluplus and the method to improve antiproliferative effect by SD formation via HME may be suitable for application in the pharmaceutical industry.