Fabrication of self-assembled Radix Pseudostellariae protein nanoparticles and the entrapment of curcumin

pH-shifting encapsulation of curcumin in egg white protein isolate for improved dispersity, antioxidant capacity and thermal stability

Curcumin (Cur) has many functions, such as antioxidant and anti-inflammatory. However, its poor solubility and thermal stability at aqueous solutions limit its application in the food industry. In this study, egg white protein isolate (EPI) was complexed with Cur via a pH-shifting method. The effects of ultimate pH (from 5.0 to 7.0) on the physicochemical properties of the complex were studied. Cur could reach 84.4% encapsulation efficiency at pH 6.0. Meanwhile, the EPI complex could remain stable at pH 7.0 after 30 days and protect Cur from thermal degradation, thereby improving the Cur retention rate with the increasing ultimate pH. Compared with those of EPI and free Cur, the antioxidant capacity of the complex was enhanced effectively. The EPI-Cur complex was certified using UV-vis and fluorescence spectra. The fluorescence results indicated that Cur and EPI are combined through a static quenching and with a strong affinity of 1.8 × 10⁵ M^-1 at pH 6.0. In summary, this work provides a biocompatible and straightforward method for the development of nanoparticles based on egg white protein isolates, which can be used as a promising carrier for insoluble nutritional compounds.

Isolation, Identification, and Immunomodulatory Effect of a Peptide from Pseudostellaria heterophylla Protein Hydrolysate

In this study, a bioactive peptide YGPSSYGYG (YG-9) with immunomodulatory activity was isolated and identified from Pseudostellaria heterophylla protein hydrolysate. The highest proliferation index of mouse spleen lymphocytes reached 1.19 in the presence of 50 μg/mL YG-9. YG-9 could activate RAW264.7 cells by promoting the secretions of NO, the pinocytosis activity, and the productions of ROS and TNF-α. Moreover, YG-9 enhanced the expressions of TLR2 and TLR4 in RAW264.7 cells. TNF-α secretions induced by YG-9 were reduced in TLR2 and TLR4 siRNAs knockdown cells, and this suggested that macrophage activation of YG-9 was through TLR2 and TLR4. Furthermore, YG-9 promoted the translocation of NF-κB through the acceleration of IκB-α phosphorylation and degradation. Also, TNF-α secretions promoted by YG-9 were inhibited by NF-κB-specific inhibitors pyrrolidine dithiocarbamate and BAY11-7082. Altogether, these results suggested YG-9 activated RAW264.7 cells via the TLRs/NF-κB/TNF-α signaling pathway.

Purification and characterization of the major protein isolated from Semen Armeniacae Amarum and the properties of its thermally induced nanoparticles

From the aqueous extract of Semen Armeniacae Amarum, a major protein isolate was purified and characterized as a novel member of the 11S globulin family, which is composed of three polypeptides linked by disulfide bond. Furthermore, the feasibility of using the isolated protein for fabricating nanocarriers was investigated. The results indicate that thermal treatment of the globulin induced the rearrangement of the disulfide bond to form homodimers of acid polypeptides during the formation of nanoparticles. The harvested nanoparticles produced by heat-induced assembly are spherical in shape, with an average size of 92 nm and exhibited low cytotoxicity to L-02 and MDCK cell lines. These nanoparticles are capable to encapsulate paclitaxel, estimated the maximum encapsulation efficiency of paclitaxel loaded to the nanoparticles was 92.6% and the maximum release of paclitaxel was 57.4%. This research suggests that the screening of traditional herbal extracts could provide a novel source of protein nanocarriers.

Curcumin Delivery Mediated by Bio-Based Nanoparticles: A Review

Todays, nano-pharmaceutics is emerging as an important field of science to develop and improve efficacy of different drugs. Although nutraceuticals are currently being utilized in the prevention and treatment of various chronic diseases such as cancers, a number of them have displayed issues associated with their solubility, bioavailability, and bio-degradability. In the present review, we focus on curcumin, an important and widely used polyphenol, with diverse pharmacological activities such as anti-inflammatory, anti-carcinogenic, anti-viral, etc. Notwithstanding, it also exhibits poor solubility and bioavailability that may compromise its clinical application to a great extent. Therefore, the manipulation and encapsulation of curcumin into a nanocarrier formulation can overcome these major drawbacks and potentially may lead to a far superior therapeutic efficacy. Among different types of nanocarriers, biological and biopolymer carriers have attracted a significant attention due to their pleiotropic features. Thus, in the present review, the potential protective and therapeutic applications of curcumin, as well as different types of bio-nanocarriers, which can be used to deliver curcumin effectively to the different target sites will be discussed.

Boiling Licorice Produces Self-Assembled Protein Nanoparticles: A Novel Source of Bioactive Nanomaterials

As a popular ingredient for western and traditional Chinese medicine, the root and rhizome of Chinese licorice (Glycyrrhiza uralensis Fisch.) is often administered in the form of a decoction. The protein nanoparticles (NPs) self-assembled during the process of decoction. A major constitutive protein (GLP) was purified and determined to have a molecular weight of 28 kDa with an N-terminal sequence of NPDGL IACYC GQYCW. Over 80% of the purified GLP self-assembled into spherical NPs with diameters of 74.1 ± 0.7 nm and ζ-potential of -24.3 ± 1.7 mV when boiled in Tris-HCl buffer (pH = 7.9, 20 mM) at 100 °C for 60 min. Each nanoparticle was estimated by the SEC-MALLS approach to be composed of approximately 23 protein molecules. The NPs and GLP showed low cellular toxicity upon four types of cells including MDCK, L-02, HepG2, and Caco2 cells, while the NPs promoted proliferation of normal hepatocytes by 67%. The NPs solubilized the insoluble astragaloside IV by encapsulation. The results suggest a great potential for GLP-NPs as a promising prototype of a type of drug vehicle, a novel source of bioactive nanomaterials from herbal proteins, as well as a new mode of function with herbal components.