ABSTRACT
Pharmacologically active natural products have played a significant role in the history of drug development. They have acted as sources of therapeutic drugs for various diseases such as cancer and infectious diseases. However, most natural products suffer from poor water solubility and low bioavailability, limiting their clinical applications. The rapid development of nanotechnology has opened up new directions for applying natural products and numerous studies have explored the biomedical applications of nanomaterials loaded with natural products. This review covers the recent research on applying plant-derived natural products (PDNPs) nanomaterials, including nanomedicines loaded with flavonoids, non-flavonoid polyphenols, alkaloids, and quinones, especially their use in treating various diseases. Furthermore, some drugs derived from natural products can be toxic to the body, so the toxicity of them is discussed. This comprehensive review includes fundamental discoveries and exploratory advances in natural product-loaded nanomaterials that may be helpful for future clinical development.
Subject(s)
Biological Products , Nanoparticles , Drug Delivery Systems , Nanotechnology , NanomedicineABSTRACT
TiO2-SiO2 composites were synthesized using cetyl trimethyl ammonium bromide (CTAB) as the structure directing template. Self-assembly hexadecyltrimethyl- ammonium bromide TiO2-SiO2/(CTAB) were soaked into silver nitrate (AgNO3) aqueous solution. The Ag-TiO2-SiO2(Ag-TS) composite were prepared via a precipitation of AgBr in soaking process and its decomposition at calcination stage. Structural characterization of the materials was carried out by various techniques including X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), N2 adsorption-desorption and ultraviolet visible spectroscopy (UV-Vis). Characterization results revealed that Ag particles were incorporated into hierarchical TiO2-SiO2 without significantly affecting the structures of the supports. Further heating-treatment at 723 K was more favorable for enhancing the stability of the Ag-TS composite. The cyclohexene oxide was the major product in the epoxidation using H2O2 as the oxidant over the Ag-TS catalysts. Besides, the optimum catalytic activity and stability of Ag-TS catalysts were obtained under operational conditions of calcined at 723 K for 2 h, reaction time of 120 min, reaction temperature of 353 K, catalyst amount of 80 mg, aqueous H2O2 (30 wt.%) as oxidant and chloroform as solvent. High catalytic activity with conversion rate up to 99.2% of cyclohexene oxide could be obtainable in water-bathing. The catalyst was found to be stable and could be reused three times without significant loss of catalytic activity under the optimized reaction conditions.
Subject(s)
Cyclohexenes/chemistry , Silicon Dioxide/chemistry , Silver/chemistry , Titanium/chemistry , Adsorption , Bromides/chemistry , Catalysis , Hydrogen Peroxide/chemistry , Microscopy, Electron, Scanning , Microscopy, Electron, Transmission , X-Ray DiffractionABSTRACT
The NF-kappaB pathway regulates the expression of over 150 target genes, e.g., cytokines, chemokines, leukocyte adhesion molecules and inducible effector enzymes. Consequently, it plays a crucial role in innate and adaptive immune responses, inflammatory response, stress responses, apoptosis and so on. IkappaB kinase (IKK) is the key of this pathway, and it owns a special structure which consists of catalytic subunit and regulatory subunit. Naturally, the activation of IKK needs the interaction of the two subunits and phosphorylation by its upstream kinases. Actually, there are two methods of activation of the NF-kappaB pathway, and both of the methods need the IKK complex. Given to the crucial role of IKK, researchers have isolated and synthesized amounts of IKK inhibitors, and these provide a great convenience to develop novel anti-inflammatory and anti-tumor drugs.
Subject(s)
I-kappa B Kinase/antagonists & inhibitors , I-kappa B Kinase/metabolism , NF-kappa B/metabolism , Animals , Anti-Inflammatory Agents/pharmacology , Antineoplastic Agents/pharmacology , Enzyme Activation , Enzyme Inhibitors/metabolism , Enzyme Inhibitors/pharmacology , Humans , I-kappa B Kinase/chemistry , I-kappa B Kinase/physiology , Phosphorylation , Signal TransductionABSTRACT
To enhance penicillin acylase (PA) performance, it was immobilized in mesocellular silica foams (MCFs) depended on macromolecular crowding and applied to catalysis in non-aqueous medium. Ficoll 70, dextran 10,000, dextran 40,000 and bovine serum albumin were co-assembled with PA. It was observed that specific activity of PA assembled in MCFs with dextran 10,000 in 80% cyclohexane (v/v) was 233.2 U/mg, 200% as that of PA assembled in MCFs in 80% cyclohexane and 323.5% as that of free PA in full aqueous medium. As content of alkane increased, activity of PA in MCFs with macromolecules varied slightly. In addition, PA co-immobilized with dextran 10 in MCFs retained 58.2% of its initial activity after heating at 50 degrees C for 4 h, 1.2 times higher than that of PA immobilized alone in MCFs. The results showed that macromolecular crowding was favorable for immobilization of PA and its catalysis in suitable aqueous-organic medium.
