Effects of fermentation conditions on the potential anti-hypertensive peptides released from yogurt fermented byLactobacillus helveticusand Flavourzyme®

Investigation of the Elemental Contents, Functional and Nutraceutical Properties of Kefirs Enriched with Spirulina platensis, an Eco-friendly and Alternative Protein Source

In this study, the effect of the use of S. platensis, which is presented as an eco-friendly and alternative protein source, in the production of kefir, a probiotic dairy product, on various physicochemical properties as well as FAA, ACE inhibitory activity, proteolysis, TPC, DPPH, ABTS+, and mineral values was investigated. It was observed that the addition of S. platensis at different ratios to the kefir samples had a statistically very significant (p < 0.01) effect on all physicochemical analyses; L. mesenteroides count; all amino acids except isoleucine, aspartic acid, and glutamic acid; ACE inhibitory activity, TN, TCAN, TCAN/TN, mM Gly, TPC, DPPH, ABTS+, Na, Mg, K, and Fe. In plain kefir samples, mineral contents were determined by order of K > P > Na > Ca > Mg > Zn >> Fe > Cr > Cr > Mn. Furthermore, a general increase was observed in FAA, ACE inhibitory activity, TPC, DPPH, ABTS+, and mineral values, as well as in the counts of Lactococcus spp. and L. mesenteroides in the samples, depending on the proportion of S. platensis added, compared to plain kefir samples. In this context, it was concluded that the addition of S. platensis to kefir at different rates could meet various components required by the body on a daily basis and result in a nutraceutical product.

The effect of dietary supplementation with blueberry, cyanidin-3-O-β-glucoside, yoghurt and its peptides on gene expression associated with glucose metabolism in skeletal muscle obtained from a high-fat-high-carbohydrate diet induced obesity model

Obesity is a leading global health problem contributing to various chronic diseases, including type II diabetes mellitus (T2DM). The aim of this study was to investigate whether blueberries, yoghurt, and their respective bioactive components, Cyanidin-3-O-β-glucoside (C3G) and peptides alone or in combinations, alter the expression of genes related to glucose metabolism in skeletal muscles from diet-induced obese mice. In extensor digitorum longus (EDL), yoghurt up-regulated the expression of activation of 5’adenosine monophosphate-activated protein kinase (AMPK), insulin receptor substrate-1 (IRS-1), phosphatidylinositol-3 kinase (PI3K) and glucose transporter 4 (GLUT4), and down-regulated the expression of angiotensin II receptor type 1 (AGTR-1). The combination of blueberries and yoghurt down-regulated the mRNA expression of AGTR-1 and Forkhead box protein O1 (FoxO1) in the EDL. Whereas the combination of C3G and peptides down-regulated AGTR-1 and up-regulated GLUT4 mRNA expression in the EDL. In the soleus, blueberries and yoghurt alone, and their combination down-regulated AGTR-1 and up-regulated GLUT4 mRNA expression. In summary blueberries and yoghurt, regulated multiple genes associated with glucose metabolism in skeletal muscles, and therefore may play a role in the management and prevention of T2DM.

Identification and Effects of Skim Milk-Derived Bioactive Antihypertensive Peptides

Bioactive peptides are generated during milk fermentation or enzymatic hydrolysis. Lactobacillus (L) helveticus is commonly used to produce some types of fermented milk products. Fermented milk derived bioactive peptides are known to be beneficial in human health. Anti-hypertensive peptides play a dual role in the regulation of hypertension through the production of the vasoconstrictor angiotensin II and its inactivation of the vasodilator bradykinin. MALDI MS/MS, nano-LC/MS/MS and RP-HPLC were used to isolate peptides showing angiotensin converting enzyme inhibition (ACE-I) from 12% fermented skim milk using a combination of L. helveticus and Flavourzyme®. The fermentation procedure facilitated the identification of 133 anti-hypertensive peptides and 75% short chain amino acids, and the three with the highest ACE-I activity reduced blood pressure in a rat model of hypertension. The freeze- dried extract was supplemented in rodent chow. In this study 14-week-old male spontaneously hypertensive rats were fed for 10 weeks with the identified peptides added to chow and compared to controls supplemented with skim milk powder. Blood pressure (BP) decreased significantly (p < 0.05) from 6 to 10 weeks of FS groups (120/65 mmHg) compared with the NFS control groups, where the BP increased significantly (220/150 mmHg) (p < 0.05). The F6 fraction provided bioactive peptides with stronger antihypertensive properties than other fractions. Skim milk fermented by L. helveticus and Flavourzyme® generates several bioactive peptides which have a blood pressure lowering effect in hypertensive disease.

The protective effects of enriched citrulline fermented milk with Lactobacillus helveticus on the intestinal epithelium integrity against Escherichia coli infection

This study examined the protective effects of citrulline enriched-fermented milk with live Lactobacillus helveticus ASCC 511 (LH511) on intestinal epithelial barrier function and inflammatory response in IPEC-J2 cells caused by pathogenic Escherichia coli. Five percent (v/v) of fermented milk with live LH511 and 4 mM citrulline (5%LHFM_Cit-4mM) significantly stimulated the population of IPEC-J2 cells by 36% as determined by MTT assay. Adhesion level of LH511 was significantly increased by 9.2% when incubated with 5%LHFM_Cit-4mM and 5%LHFM_Cit-4mM reduced the adhesion of enterohemorrhagic (EHEC) and entero-invasive (EIEC) E. coli in IPEC-J2 cells by 35.79% and 42.74%, respectively. Treatment with 5%LHFM_Cit-4mM ameliorated lipopolysaccharide (LPS) from E. coli O55:B5 induced activated inflammatory cytokines expression (TNF-α, IL-6 and IL-8) and concentration (IL-6 and IL-8) and early apoptosis. It restored the transepithelial electrical resistance (TEER) and regulated the expression and distribution of tight junction (TJ) proteins (zonula occluden-1 (ZO-1), occludin and claudin-1), toll-like receptors (TLRs) (TLR2 and TLR4) and negative regulators of TLRs signalling pathway (A20 and IRAK-M). In conclusion, our findings suggested that 5%LHFM_Cit-4mM might have the positive effects on improving and maintaining the intestinal epithelial cell integrity and inflammatory response under both normal and pathogenic LPS-stimulated conditions.