Investigation of selenium and selenium species in Cardamine violifolia using in vitro digestion coupled with a Caco-2 cell monolayer model.

Inadequate Se intake can enhance vulnerability to certain health risks, with supplementation lessening these risks. This study investigated the bioavailability of Se and Se species in five Se compounds and in Se-rich Cardamine violifolia using in vitro digestion coupled with a Caco-2 cell monolayer model, which enabled the study of Se transport and uptake. Translocation results showed that SeCys2 and MeSeCys had high translocation rates in C. violifolia leaves (CVLs). The uptake rate of organic Se increased with time, and MeSeCys exhibited a higher uptake rate than that for SeCys2 and SeMet. The translocation mechanisms of SeMet, Se(IV), and Se(VI) were passive transport, whereas those of SeCys2 and MeSeCys were active transport. The bioavailability of organic Se was higher than that of inorganic Se, with a total Se bioavailability in CVLs of 49.11 %. This study would provide a theoretical basis for the application of C. violifolia in the functional food.

Effects of Different Drying Methods on the Selenium Bioaccessibility and Antioxidant Activity of Cardamine violifolia.

Understanding the effects of drying on the selenium (Se) content and Se bioaccessibility of Se-rich plants is critical to dietary supplementation of Se. The effects of five common drying methods (far-infrared drying (FIRD), vacuum drying (VD), microwave vacuum drying (MVD), hot air drying (HD), and freeze vacuum drying (FD)) on the content and bioaccessibility of Se and Se species in Cardamine violifolia leaves (CVLs) were studied. The content of SeCys2 in fresh CVLs was the highest (5060.50 µg/g of dry weight (DW)); after FIRD, it had the lowest selenium loss, with a loss rate of less than 19%. Among all of the drying processes, FD and VD samples had the lowest Se retention and bioaccessibility. FIRD, VD, and FD samples have similar effects on antioxidant activity.

Selenium-enriched peptides isolated from Cardamine violifolia are potent in suppressing proliferation and enhancing apoptosis of HepG2 cells.

Selenium (Se)-enriched peptides were isolated from Cardamine violifolia by enzymatic hydrolysis and ultrafiltration. S3 (molecular weight [MW] distribution of 3-5 kDa) exhibited the strongest inhibitory effect on HepG2 cells and was thus screened using the 3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyltetrazolium bromide assay; it was found to have a high organic Se content. Its amino acid sequence was determined using HPLC-MS/MS. We then examined its ability to inhibit tumor cell proliferation and found that it arrested tumor cells in the S phase; moreover, it could induce cancer cell apoptosis. Following S3 treatment, we observed a decrease in mitochondrial membrane potential and an increase in cell calcium content. Upon S3 treatment at 60 µg/ml, the relative activities of caspase-3 and caspase-9 increased by 1.48 times and 2.17 times, and the contents of PI3K and AKT decreased from 2.05 ng/L and 1.95 ng/L to 0.71 ng/L and 0.50 ng/L, respectively, when compared with the control group. Transcriptomic analysis revealed significant changes in the PI3K-AKT pathway following S3 treatment. This study thus established a foundation for additional development of Se-enriched peptides from C. violifolia as a functional food. PRACTICAL APPLICATION: Cardamine violifolia is a Se-tolerant cruciferous plant that can metabolically transform inorganic Se into organic Se that exists in the form of a selenoprotein. Se-enriched peptide obtained by extraction and enzymolysis of selenoprotein, as an organic combination of organic Se and peptide, possess valuable biological activities. In this paper, the effect of Se-enriched peptides of C. violifolia on tumor cells was studied via cell experiments, and its mechanism was preliminarily discussed, which should provide a theoretical basis for developing functional foods containing C. violifolia.

Antioxidant Activity of Selenium-Enriched Peptides from the Protein Hydrolysate of Cardamine violifolia.

Cardamine violifolia is a selenium (Se)-enriched plant found in China. In this study, the Se-enriched peptides of C. violifolia (CP) were isolated using a 1 kDa ultrafiltration membrane after enzymatic hydrolysis by alkaline and neutral proteases. The peptides were separated by DEAE-Sepharose FF anion-exchange chromatography and purified using preparative high-performance liquid chromatography (prep-HPLC). The component with the highest antioxidant activity, CPR13, was identified by comparing the 1,1-diphenyl-2-picrylhydrazyl (DPPH•), hydroxyl (•OH), 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS+ •), and superoxide ( O 2 - · ) radical scavenging ability of each fraction. At a concentration of 0.1 mg/mL, the DPPH•, •OH, O 2 - · , and ABTS+ • scavenging activities of CPR13 were 89.2%, 26.3%, 40.6%, and 42.9%, respectively. Amino acid sequences were obtained by liquid chromatography combined with mass spectrometry as follows: GRVGSSSC, GRAGGSYM, GHPNFKLNCSGG, GTKSCKA, ASSNARDMI, TAGGCYIPI, and KNCALQ. The seleno-amino acids were identified as selenomethionine, methylselenocysteine, and selenocysteine. Correlation analysis among organic Se content, peptide content, and antioxidant activity revealed that organic Se plays a greater role in free radical scavenging than peptides, and that the organic Se content of the Se-enriched peptides was positively correlated with their antioxidant ability (P < 0.05). It indicated that CP has a great potential as natural functional materials for dietary supplement.

Simultaneous extraction of hydrophobic and hydrophilic bioactive compounds from ginger (Zingiber officinale Roscoe).

Ginger is a commonly used spice around the world. Its bioactive compounds contain hydrophobic gingerols and hydrophilic polysaccharides. Huge physiochemical differences between these compounds and the thermal instability of gingerols impede fast and effective extraction of them using conventional methods. In this research, ionic liquid-based ultrasonic-assisted extraction (ILUAE) was applied to simultaneously extract gingerols and polysaccharides from ginger. Parameters influencing the recovery of gingerols were ionic liquid type, ionic liquid concentration, solid/liquid ratio, ultrasonic power, extraction temperature and extraction time. Compared with traditional methods, LUAE significantly increased the yield of total gingerols and shortened the extraction time. Meanwhile, ginger polysaccharides recovery reached up to 92.82% with ILUAE. Our results indicated that ILUAE has a remarkable capacity to extract gingerols and ginger polysaccharides in one step. Therefore, ILUAE represents a promising technology for simultaneous extraction of hydrophilic and hydrophobic bioactive compounds from plant materials.

Chemical components of cold pressed kernel oils from different Torreya grandis cultivars.

The chemical compositions of cold pressed kernel oils of seven Torreya grandis cultivars from China were analyzed in this study. The contents of the chemical components of T. grandis kernels and kernel oils varied to different extents with the cultivar. The T. grandis kernels contained relatively high oil and protein content (45.80-53.16% and 10.34-14.29%, respectively). The kernel oils were rich in unsaturated fatty acids including linoleic (39.39-47.77%), oleic (30.47-37.54%) and eicosatrienoic acid (6.78-8.37%). The kernel oils contained some abundant bioactive substances such as tocopherols (0.64-1.77mg/g) consisting of α-, ß-, γ- and δ-isomers; sterols including ß-sitosterol (0.90-1.29mg/g), campesterol (0.06-0.32mg/g) and stigmasterol (0.04-0.18mg/g) in addition to polyphenols (9.22-22.16µgGAE/g). The results revealed that the T. grandis kernel oils possessed the potentially important nutrition and health benefits and could be used as oils in the human diet or functional ingredients in the food industry.