Angiotensin Converting Enzyme-1 inhibitory activity of milk proteins evaluated after in vitro digestion and peptidomic analysis

Milk proteins are relevant sources of bioactive peptides. However, many hurdles still exist regarding the widespread utilization of milk protein-derived bioactive peptides as they may be degraded during gastrointestinal digestion. A crucial issue in this field is the demonstration of a cause-effect relationship, from the ingested intact form to the bioactive form. The aim of this study was to study in vitro digestion, digestibility (IVD, using two different hydrolysis methods) and Angiotensin Converting Enzyme-1 inhibitory activity (ACE-1i) of milk and plant proteins (used as control). Based on ACE-1i effect, a peptidomic and proteomic profile analysis was performed on permeate and retentate samples. In particular, milk and plant protein samples were in vitro digested and the total digest was filtered using a 3KDa membrane. A permeate fraction (<3KDa) and retentate fraction (>3KDa) were obtained. ACE-1i activity was measured as the ability of protein fractions (pre-digested, permeate and retentate) to decrease the hydrolysis of furanacroloyl-Phe-Glu-Glu (FAPGG) synthetic substrate for ACE enzyme. Furthermore, permeate were characterized by LC-nano ESI MS/MS using a shotgun-peptidomic approach, whereas retentate was further trypsin-digested prior the analysis with mass spectrometry using a shotgun-proteomic approach. We found a positive correlation among the IVD methods tested (P<0.05; r=0,85). Milk proteins exhibiting higher values of IVD (>82.5%) with both methods used, compared with plant proteins. Milk proteins after in vitro digestion exhibited a significant increase in ACE-1i (P<0.05) (> 23.91 \ub1 0.64%) compared with plant protein tested (10.40 \ub1 1.07 %). Based on proteomic and peptidomic analysis performed, specific peptides associated with anti-hypertensive and ACE-1i effect have been identified in permeate and retentate of milk proteins. Our results demonstrated that milk and plant proteins are highly digestible and, in particular milk proteins may represent valuable sources of ACE-1i and anti-hypertensive peptides which may confers the ability to decrease blood pressure in vivo

Establishment of inflammatory in vitro intestinal epithelial models for translational animal nutrition

Many naturally available compounds as n3-polyunsaturated fatty acids (EPA: Eicosapentaenoic acidand DHA: Docosahexaenoic acid), conjugated linoleic acid, milk exosomes and plant extract from Macleaya cordata exhibits anti-inflammatory effects. From previous studies, these bioactive compounds demonstrated a multitude of beneficiary effects in both human and animal health and are considered as potential therapeutic agents with pharmaceutical properties. Due to their health benefits, new ways to incorporate them in human diet through poultry and livestock nutrition is extensively studied and therefore, it is first important to determine its anti-inflammatory effects in cell-based inflammatory models. The gastrointestinal tract (GI) is the first site where food is broken down and nutrients are absorbed and therefore the GI cell models are widely preferred for food/feed analysis. In this respect, it becomes of paramount importance to establish inflammatory cell line models of intestinal epithelia. Therefore, in the present study, we demonstrated the inflammatory response of IPEC-J2 cell lines of neonate porcine intestinal epithelium challenged against different stimuli as cell wall lipopolysaccharides (LPS) of Gramnegative bacteria as Escherichia coli and Salmonella, and chemical such as dextran sodium sulphate (DSS), analysed by MTT cell viability assay. The cells were treated with each stimulus in a dose-dependent manner (0.15\u201310% for DSS, 1.56\u2013100\u3bcg/mL for LPS) for 24h and thereafter viability was measured and the concentration at 50% inhibition (IC50) was calculated using regression analysis. The IPEC-J2 cells exhibited an IC50 value of 2.89% for DSS challenge and 12.77\u3bcg/mL for Salmonella LPS. The E. coli did not show any significant inflammatory response even with the challenge of highest dose as 100\u3bcg/mL. These results suggest that the epithelial cells are specific for different biological challenge as bacterial LPS and the DSS chemical proves to be potent inflammatory agent even at small doses and can be effectively used to induce inflammatory response to study anti- nflammatory properties of food/feed additives

Natural dye sensitized TiO2 nanorods assembly of broccoli shape based solar cells

TiO2 nanorods based thin films with rutile phase have been synthesized using template free low temperature hydrothermal method. The scanning electron microscope images showed that the prepared TiO2 samples were made of TiO2 nanorods and the nanorods had arranged by itself to form a broccoli like shape. The X-ray diffraction studies revealed that the prepared TiO2 samples exhibit rutile phase. The grown TiO2 nanorods had been sensitized using the flowers of Sesbania (S) grandiflora, leaves of Camellia (C) sinensis and roots of Rubia (R) tinctorum. Dye sensitized solar cells had been fabricated using the natural dye sensitized TiO2 nanorods based thin film photoelectrode and the open circuit voltage and short circuit current density were found to lie in the range of 0.45–0.6 V and 5.6–6.4 mA/cm2 respectively. The photovoltaic performance of all the fabricated natural dye sensitized TiO2 solar cells indicate that natural dyes have the potential to be used as effective sensitizer in dye sensitized solar cells

Natural dye sensitized TiO 2 nanorods assembly of broccoli shape based solar cells

TiO2 nanorods based thin films with rutile phase have been synthesized using template free low temperature hydrothermal method. The scanning electron microscope images showed that the prepared TiO2 samples were made of TiO2 nanorods and the nanorods had arranged by itself to form a broccoli like shape. The X-ray diffraction studies revealed that the prepared TiO2 samples exhibit rutile phase. The grown TiO2 nanorods had been sensitized using the flowers of Sesbania (S) grandiflora, leaves of Camellia (C) sinensis and roots of Rubia (R) tinctorum. Dye sensitized solar cells had been fabricated using the natural dye sensitized TiO2 nanorods based thin film photoelectrode and the open circuit voltage and short circuit current density were found to lie in the range of 0.45–0.6 V and 5.6–6.4 mA/cm2 respectively. The photovoltaic performance of all the fabricated natural dye sensitized TiO2 solar cells indicate that natural dyes have the potential to be used as effective sensitizer in dye sensitized solar cells