Cadmium stimulates mouse skin fibroblast apoptosis by affecting intracellular homeostasis.

CONTEXT: Cadmium (Cd2+) is an important industrial and environmental pollutant and has been shown to induce apoptosis in a variety of cell types and tissues. OBJECTIVE: To assess the specific effects of low-dose Cd2+ on the skin. This organ is easily exposed to Cd2+, but how it damages cells is not fully understood. MATERIALS AND METHODS: Mouse skin fibroblasts were treated with low doses of Cd2+ (0.4, 0.8 or 1.6 µM) for 12-48 h, and we observed cell morphological alterations, measured DNA damage and quantified cell viability changes. RESULTS: Cd2+-treated fibroblasts exhibited morphological changes and evidence of DNA damage, as well as higher numbers of apoptotic and necrotic cells. There were increased caspase -3, -8 and -9 activities when fibroblasts were treated with 0.4, 0.8 and 1.6 µM CdCl2 for 24 h. Higher intracellular calcium (Ca2+) and reactive oxygen species (ROS) levels, and enhanced efflux of extracellular Ca2+ and potassium (K+). The mitochondrial membrane potential was lowered in treated cells, and the cell cycle arrested in the G0/G1 phase. Bax and Fas gene expression increased and Bcl-2 gene expression decreased. DISCUSSION: The results demonstrate that Cd2+ exerts typical apoptotic effects in mouse skin fibroblasts. It strongly inhibited proliferation and induced apoptosis in a dose- and duration-dependent manner. Ca2+ homeostasis was disturbed by oxidative stress, mitochondrial dysfunction and caspase-mediated apoptosis. CONCLUSION: K+ efflux and Bax, Bcl-2 and Fas gene expression regulation play important roles in Cd2+-induced dysfunction by disrupting intracellular homeostasis in mouse skin fibroblasts.

Iodine values, peroxide values and acid values of Bohai algae oil compared with other oils during the cooking.

Objective: Bohai algae oil contains polyunsaturated fatty acids, such as EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid), which are the very important polyunsaturated fatty acids for the human body. In Traditional Chinese Cooking, all cooking methods cannot do without oils. However, the heat of cooking may always lead to formation of large amounts of decomposition products that affect the sensory, nutritional and functional quality of the oils to be unhealthy and the products being cooked, especially the food or edible oil rich in polyunsaturated fatty acids. Therefore, the objective of this study was to research the effect and change of heating on the quality characteristics of Bohai algae oil comparison with soybean oil and olive oil. Method: Quality characteristics such as the iodine values (IVs), peroxide values (POVs) and acid values (AVs) of Bohai algae oil, soybean oil and olive oil were measured, cooking conditions as factors of the study. Result: The POVs percentage changes of Bohai algae oil were larger than the IVs and AVs percentage changes. Bohai algae oil was better heated in a microwave oven at microwave P-20 within 3min, microwave P-60 and P-H1 within 2min, or in induction cooker at 1500w within 1min, or on electric stove (direct heated) within 2min. Conclusion: Bohai algae oil was suitable used for low-temperature and short-time cooking or for salad. This study has important significance for promoting the commercial value and extensive application of Bohai algae oil in daily cooking. It plays a theoretical significance role in Bohai algae oil's better processing and traditional chinese cooking. It can improve product quality to further expand the food processing research scope of Bohai algae oil and increase the richness, diversity and universality of edible methods of Bohai algae oil.

Purification and characterization of bromelain from pineapple (Ananas comosus L.) peel waste.

Bromelain is widely used in food industry and pharmaceutical products due to its strong antioxidant properties. Therefore, the extraction of bromelain from pineapple peel may improve the profitability and sustainability of pineapple industry. The aim of this work is to show the purification, stability, and kinetics of bromelain from pineapple peel. By studying the stability of purified bromelain (PB), we found that the activity of PB was inhibited by Fe3+ , Al3+ , methanol, ethanol, and n-butyl alcohol, while it was increased in the presence of Ca2+ , ethylenediamine tetra acetic acid, glucose, D-xylose, maltose, potassium sodium tartrate, sodium citrate, citric acid, and sodium nitrite. These stability tests will expand the application and space acquisition of bromelain. The kinetics study indicated that the thermal inactivation of PB was conforming to the first-order reaction and the half-life (t1/2 ) of PB under different temperature conditions (45, 55, 65, and 75 °C) was 81.54, 31.12, 10.28, and 5.23 min, respectively. Therefore, the inactivation time of PB can be predicted at different temperatures for food heating processing. PRACTICAL APPLICATION: The potential of utilizing pineapple peel for bromelain extraction might improve the profitability and sustainability of the pineapple industry.

DHA induces apoptosis of human malignant breast cancer tissues by the TLR-4/PPAR-α pathways.

Docosahexaenoic acid (DHA) oil is an important polyunsaturated fatty acid for the human body. Evidence has demonstrated that DHA is beneficial for inhibiting mammary carcinogenesis. However, the mechanisms of DHA mediating apoptosis induction have not been fully elucidated. Thus, in the present study, the activity levels of total-superoxide dismutase (t-SOD), catalase (CAT), glutathione-peroxidase (GSH-PX) and the concentration of malondialdehyde (MDA) were determined in DHA oil-treated human malignant breast tissues. The results revealed that compared with control, DHA significantly increased the main antioxidant enzymes levels, including t-SOD, CAT, and GSH-PX, but decreased the MDA concentration in the DHA oil treated breast cancer tissues. Furthermore, DHA significantly increased the ratio of cyclic (c)AMP/cGMP levels and promoted the expression of Toll-like receptor 4 (TLR-4) and peroxisome proliferator activated receptor (PPAR)-α, thus DHA induced breast cancer cell apoptosis. We hypothesized that the levels of TLR-4 and PPAR-α are involved in the antitumorigenesis properties of DHA in breast cancer. The results of the present study hold significance for the further clinical development of DHA oil in breast cancer treatment.

Optimization of the preparation of pectin from Aloe using a Box-Behnken design.

The extraction condition of pectin from Aloe vera barbadensis Mill was optimized by a Box-Behnken design. The effect of parameters of extraction water proportion (EWP), extraction pH (EpH), extraction temperature (ETe), extraction time (ETi), alcohol precipitation pH (APpH)and alcohol precipitation temperature (APTe) on the extraction yield of pectin was investigated by a software of Design Export 8.0.5b. The maximum extraction yield was obtained with the EWP of 20:1, EpH of 1.5, ETe of 90°C, ETi of 120min, APpH of 3.0 and APTe of 50°C, which was consistent with the experimental value. We also found out that the pectin content decreased gradually during storage and sucrose concentration had a significant impact on the viscosity of pectin.

Expression and function of heregulin-alpha and its receptors in the mouse mammary gland.

Heregulin-alpha (HRGalpha) is a cytokine secreted by the mammary mesenchyme, adjacent to lobuloalveolar structures. To understand the role of HRGalpha and its receptors in mammary glands, and the underlying mechanisms, we performed this study to determine the expression and localization of HRGalpha and its receptors ErbB2 and ErbB3. We also determined the role of HRGalpha in the development of mammary glands, beta-casein expression and secretion, Rab3A protein expression and the phosphorylation of HRGalpha signaling molecules using confocal laser scanning microscopy, tissue culture, capillary electrophoresis, Western blotting and enzyme-linked immunosorbent assays. We found that a peak was on pregnancy day 15. Changes of ErbB2 and ErbB3 expression were positively and linearly correlated with HRGalpha, indicating that HRGalpha positively regulates ErbB2 and ErbB3 expression. During pregnancy, HRGalpha enhanced the phosphorylation of STAT5, p42/p44, p38, PKC and Rab3A protein expression, stimulated the proliferation and differentiation of the ductal epithelial cells of mammary glands, and increased and maintained the expression and secretion of beta-casein. During lactation, HRGalpha enhanced the phosphorylation of STAT5 and p38, inhibited the phosphorylation of PKC and Rab3A protein expression, maintained the morphology of the mammary glands and increased the secretion of lactoprotein to reduce the expression of beta-casein in mammary epithelial cells. During involution, HRGalpha induced the phosphorylation of STAT3 and Rab3A protein expression, and inhibited the phosphorylation of PKC to stimulate the degeneration of mammary epithelial cells. It also inhibited the secretion of beta-casein, resulting in increased levels of beta-casein in mammary epithelial cells.