Effects of ultrasonic pre-treatment on physicochemical properties of proteins extracted from cold-pressed sesame cake.

Sesame is an oil crop with high nutritional value. Protein is one of the main ingredients of sesame, however research on protein of cold-pressed sesame cake is limited. This study aimed to investigate the effects of ultrasonic pre-treatment (UPT) on physicochemical properties of proteins (yield, solubility, amino acid composition, surface properties, structural and thermal stability) extracted from the cold-pressed sesame cake, after removing lignans by ultrasonic-assisted extraction. By comparison, the extraction yield of protein was significantly (p ＜ 0.05) increased from 22.24% (without UPT) to 25.95% (with UPT), while the purity (54.08% without UPT, 55.43% with UPT), total amount of essential amino acids (22.48% without UPT, 23.10% with UPT) and non-essential amino acids (37.48% without UPT, 36.54% with UPT) were not significantly influenced. Besides, UPT slightly reduced the solubility, foaming capacity and stability (FC and FS) of protein. In addition, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR) and thermal stability (TG) analysis demonstrated that UPT could disorder and loose protein molecular structure, resulting in the change of morphology, secondary structure and thermal stability. In conclusion, this study provides a way for the separation and future application of sesame cake protein. UPT is a good option to remove the lignans from sesame cake proteins.

Protective effect of low molecular-weight seleno-aminopolysaccharides against H2O2-induecd oxidative stress in intestinal epithelial cells.

Organoselemium compounds possess strong antioxidant activity as well as protecting cells from DNA damage, mitochondrial injury, lipid peroxidation, protein denaturation and cell death. Herein, we used an in vitro oxidative model to further investigate the antioxidant effects of a novel organoselemium compound, low molecular-weight seleno-aminopolysaccharides (LSA) in intestinal porcine epithelial cells (IPEC-1), and the molecular mechanisms of these effects. Analysis by MTT assay showed that LSA could significantly increase the viability of IPEC-1 cells compared to cells exposed to H2O2. We found that the levels of different antioxidant enzymes could dramatically increase in LSA pretreatment group compared to H2O2 treatment group. Furthermore, LSA significantly increased the gene expression of antioxidant enzymes and phase 2 detoxifying enzymes in IPEC-1 cells, as measured by qRT-PCR. In addition, LSA up-regulated the expression level of intracellular transcription factor NF-E2-related factor 2 (Nrf2) and inhibited the level of kelch-like ECH-associated protein 1 (Keap1) with western blot analysis. Collectively, the present study suggested that LSA has the protective effect of IPEC-1 cells against H2O2-induecd oxidative stress, and its mechanism may be related to activation of Keap1/Nrf2 signaling pathway in intestinal epithelial cells.

Taraxacum mongolicum extract exhibits a protective effect on hepatocytes and an antiviral effect against hepatitis B virus in animal and human cells.

In order to validate the antiviral effect against hepatitis B virus (HBV) of Taraxacum mongolicum (T. mongolicum), the protective effect on hepatocytes, and antiviral properties against duck hepatitis B virus (DHBV) and HBV of T. mongolicum extract (TME) were evaluated in chemically-injured neonatal rat hepatocytes, DHBV-infected duck fetal hepatocytes and HBV-transfected HepG2.2.15 cells, respectively. The results demonstrated that TME at 50-100 µg/ml improved D-galactosamine (D-GalN), thioacetamide (TAA) and tert-butyl hydroperoxide (t-BHP)-injured rat hepatocytes, and produced protection rates of 42.2, 34.6 and 43.8% at 100 µg/ml, respectively. Furthermore, TME at 1-100 µg/ml markedly inhibited DHBV DNA replication. Additionally, TME at 25-100 µg/ml reduced HBsAg and HBeAg levels and produced inhibition rates of 91.39 and 91.72% at 100 µg/ml, respectively. TME markedly inhibited HBV DNA replication at 25-100 µg/ml. The results demonstrate the potent antiviral effect of T. mongolicum against HBV effect. The protective of TME effect on hepatocytes may be achieved by its ability to ameliorate oxidative stress. The antiviral properties of TME may contribute to blocking protein synthesis steps and DNA replication. Furthermore, major components of TME were quantificationally analyzed. These data provide scientific evidence supporting the traditional use of TME in the treatment of hepatitis.

Blood anticoagulation and antiplatelet activity of green tea (-)-epigallocatechin (EGC) in mice.

EGC was prepared from green tea polyphenols through column chromatography of a polyamide (3.6 × 40 cm). Three dosages of EGC (0.25, 0.5, 1.0 g kg(-1) d(-1)) were ingested respectively by ICR mice via gavage. Compared with the control group, group EGC0.5 (dosage, 0. 5 g kg(-1) d(-1)) and group EGC1.0 (dosage, 1.0 g kg(-1) d(-1)) presented significant inhibition on platelet aggregation in mice accompanied by 18.4 and 25.6% of inhibition ratio, respectively. The bleeding times (BT) of mice in group EGC0.5 and group EGC1.0 were significantly prolonged (P < 0.01) as well as blood clotting time (BCT) in group EGC1.0 (P < 0.05). All three dosages of EGC prolonged activated partial thromboplastin time (APTT) significantly (P < 0.01), but had no prominent effect on prothrombin time (PT) and fibrinogen level which indicated that the anticoagulation of EGC could not be attributed to the level decrease of coagulation factor such as fibrinogen. The results demonstrated that EGC had prominent antiplatelet activity and blood anticoagulation in a dose-dependent manner.