Identification and characterization of agnuside, a natural proangiogenic small molecule

HIF-1α in Osteoarthritis: From Pathogenesis to Therapeutic Implications

Osteoarthritis is a common age-related joint degenerative disease. Pain, swelling, brief morning stiffness, and functional limitations are its main characteristics. There are still no well-established strategies to cure osteoarthritis. Therefore, better clarification of mechanisms associated with the onset and progression of osteoarthritis is critical to provide a theoretical basis for the establishment of novel preventive and therapeutic strategies. Chondrocytes exist in a hypoxic environment, and HIF-1α plays a vital role in regulating hypoxic response. HIF-1α responds to cellular oxygenation decreases in tissue regulating survival and growth arrest of chondrocytes. The activation of HIF-1α could regulate autophagy and apoptosis of chondrocytes, decrease inflammatory cytokine synthesis, and regulate the chondrocyte extracellular matrix environment. Moreover, it could maintain the chondrogenic phenotype that regulates glycolysis and the mitochondrial function of osteoarthritis, resulting in a denser collagen matrix that delays cartilage degradation. Thus, HIF-1α is likely to be a crucial therapeutic target for osteoarthritis via regulating chondrocyte inflammation and metabolism. In this review, we summarize the mechanism of hypoxia in the pathogenic mechanisms of osteoarthritis, and focus on a series of therapeutic treatments targeting HIF-1α for osteoarthritis. Further clarification of the regulatory mechanisms of HIF-1α in osteoarthritis may provide more useful clues to developing novel osteoarthritis treatment strategies.

Investigation Driven by Network Pharmacology on Potential Components and Mechanism of DGS, a Natural Vasoprotective Combination, for the Phytotherapy of Coronary Artery Disease

Phytotherapy offers obvious advantages in the intervention of Coronary Artery Disease (CAD), but it is difficult to clarify the working mechanisms of the medicinal materials it uses. DGS is a natural vasoprotective combination that was screened out in our previous research, yet its potential components and mechanisms are unknown. Therefore, in this study, HPLC-MS and network pharmacology were employed to identify the active components and key signaling pathways of DGS. Transgenic zebrafish and HUVECs cell assays were used to evaluate the effectiveness of DGS. A total of 37 potentially active compounds were identified that interacted with 112 potential targets of CAD. Furthermore, PI3K-Akt, MAPK, relaxin, VEGF, and other signal pathways were determined to be the most promising DGS-mediated pathways. NO kit, ELISA, and Western blot results showed that DGS significantly promoted NO and VEGFA secretion via the upregulation of VEGFR2 expression and the phosphorylation of Akt, Erk1/2, and eNOS to cause angiogenesis and vasodilation. The result of dynamics molecular docking indicated that Salvianolic acid C may be a key active component of DGS in the treatment of CAD. In conclusion, this study has shed light on the network molecular mechanism of DGS for the intervention of CAD using a network pharmacology-driven strategy for the first time to aid in the intervention of CAD.

Discovery of VEGFR-2 inhibitors exerting significant anticancer activity against CD44+ and CD133+ cancer stem cells (CSCs): Reversal of TGF-β induced epithelial-mesenchymal transition (EMT) in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a malignancy characterized by neoangiogenesis, which is an augmented production of proangiogenic factors by the tumor and its adjacent infected cells. These dysregulated angiogenic factors are the therapeutic targets in anti-angiogenic drug development. The signaling pathway of vascular endothelial growth factor (VEGF)/VEGFR-2 is crucial for controlling the angiogenic responses in endothelial cells (ECs). In this study, we carried out a rational drug design approach wherein we have identified the novel orally bioavailable compound VS 8 as a potent VEGFR-2 inhibitor, which remarkably suppresses hVEGF and hVEGFR-2 expression in HUVECs and exhibits significant anti-angiogenic effects in CAM assay. Besides, VS 8 significantly induces apoptosis in HCC cell line (Hep G2). Later we examined its effectiveness against CD44+ and CD133+ CSCs. Here, VS 8 was found to be active against CSCs, and adequate for the cessation of the cell cycle at 'G₀/G₁' and 'S' phase in CD44+ and CD133+ CSCs respectively. Factually, transforming growth factor-β (TGF-β) stimulated epithelial-mesenchymal transition (EMT) induces invasion and migration of HCC cells, which results in the metastasis. Therefore, we studied the effect of VS 8 on EMT markers using flow cytometry, which suggested that VS 8 significantly upregulates E-cadherin (epithelial biomarker) and downregulates vimentin (mesenchymal biomarker). Further, VS 8 downregulates the expression of EMT-inducing transcription factors (EMT-TFs), i.e., SNAIL. Altogether, our findings indicate that VS 8 could be a promising drug candidate for cancer therapy.

A Beta/ZSM-22 Zeolites-Based-Mixed Matrix Solid-Phase Dispersion Method for the Simultaneous Extraction and Determination of Eight Compounds with Different Polarities in Viticis Fructus by High-Performance Liquid Chromatography

Viticis Fructus (VF) was named Manjingzi as a commonly used traditional Chinese medicine (TCM) targeting various pains and inflammation for more than 2000 years. To guarantee the quality of Viticis Fructus, a simple, quick and eco-friendly Beta/ZSM-22 zeolites-based-mixed matrix solid-phase dispersion method (B/Z-MMSPD) was established for simultaneous extraction and determination of eight compounds (two phenolic acids, two iridoid glycosides, vanillin and three flavonoids) with different polarities from Viticis Fructus by high performance liquid chromatography coupled with a diode array detector (HPLC-DAD). Beta and ZSM-22 were mixed as the sorbent. Water, tetrahydrofuran and methanol were blended with certain ratio as the eluent. Several parameters including types of sorbents, mass ratio of Beta to ZSM-22, mass ratio of matrix to sorbent, grinding time, types, concentration and volume of eluent were optimized. The recoveries of eight analytes were within the range of 95.0%–105% (RSDs ≤ 4.13%). The limits of detection and limits of quantitation ranged from 0.5 to 5.5 μg/g and from 1.5 to 16 μg/g, respectively. Compared to the traditional extract methods, it was a simple, rapid, efficient and green method. The results demonstrated that a simple, rapid, efficient and green B/Z-MMSPD was developed for the simultaneous extraction and determination of eight target analytes with different polarities for quality control of Viticis Fructus.

Mimicking growth factors: role of small molecule scaffold additives in promoting tissue regeneration and repair

The primary aim of tissue engineering scaffolds is to mimic the in vivo environment and promote tissue growth. In this quest, a number of strategies have been developed such as enhancing cell-material interactions through modulation of scaffold physico-chemical parameters. However, more is required for scaffolds to relate to the cell natural environment. Growth factors (GFs) secreted by cells and extracellular matrix (ECM) are involved in both normal repair and abnormal remodeling. The direct use of GFs on their own or when incorporated within scaffolds represent a number of challenges such as release rate, stability and shelf-life. Small molecules have been proposed as promising alternatives to GFs as they are able to minimize or overcome many shortcomings of GFs, in particular immune response and instability. Despite the promise of small molecules in various TE applications, their direct use is limited by nonspecific adverse effects on non-target tissues and organs. Hence, they have been incorporated within scaffolds to localize their actions and control their release to target sites. However, scanty rationale is available which links the chemical structure of these molecules with their mode of action. We herewith review various small molecules either when used on their own or when incorporated within polymeric carriers/scaffolds for bone, cartilage, neural, adipose and skin tissue regeneration.