br Antioxidative stress and anti inflammation

Antioxidative stress and anti-inflammation Oxidative stress is a major cause of reduced endothelial NO bioavailability in hypertension, and inflammatory response is thought to play an important role in these processes (Blake and Ridker, 2001, Landmesser et al., 2006). Reactive oxygen species (ROS), in particular superoxide radical, reacts rapidly with NO to form the highly reactive intermediate peroxynitrite, thus substantially limiting NO bioavailability and its protective roles (Cai and Harrison, 2000, Münzel et al., 2008). Peroxynitrite leads to tyrosine nitration of various proteins and, incidentally, tripeptides IQW and IRW but not LKP were found to reduce nitrotyrosine levels in the TNKS 22 of hypertensive rats (Majumder et al., 2015b). Since both the expression of eNOS and ROS scavenging activity were not affected, it remains to be determined if the vasorelaxation effect of LKP maybe through modulation of vascular reactivity at the level of EDHF or endothelin pathways (Jakala et al., 2009, Maes et al., 2004). Ovokinin, an octapeptide (FRADHPFL) derived from ovalbumin, exerted relaxation through prostaglandin I2 but not NO (Fujita, Usui, Kurahashi, & Yoshikawa, 1995). Inflammation is also implicated as an important precursor of endothelial dysfunction (Sattar, 2004). Many chronic diseases are characterized by uncontrolled inflammation (McEver, 1992); inflammatory processes enhance ROS formation, a well-characterized causation factor of endothelial dysfunction (Galle, Quaschning, Seibold, & Wanner, 2003). ROS activates the transcription factor nuclear factor (NF)-κB, leading to vascular inflammation. Endothelial dysfunction due to reduced NO bioavailability on the other hand promotes oxidative stress and inflammation (Schulz et al., 2004). Oxidative stress, inflammation and endothelial dysfunction are interrelated components of an etiological network that has been linked to the development of cardiovascular diseases (Lahera et al., 2007). Peptides IRW and IQW, but not LKP, showed anti-inflammatory effect in cultured endothelial cells and SHRs (Majumder et al., 2013b, Majumder et al., 2013a, Majumder et al., 2015b). Some other peptides, such as SSS, EEE and VPL (Ringseis, Gotze, & Eder, 2009), as well as VPP and IPP (Nakamura, Yamamoto, Sakai, & Takano, 2013), were reported to inhibit leukocyte-endothelial interactions. Recruitment of immune cells such as leukocyte into endothelial cells is a critical step for initiation of inflammation. Therefore, peptides inhibiting leukocyte recruitment activity may help maintain normal endothelial functions in an inflamed environment.
Considerations for future translational studies The role of food peptides in blood pressure regulation is still a subject of ongoing debate considering the lack of consensus in their physiological antihypertensive effects in different human populations (Cicero et al., 2011, Fekete et al., 2013, Geleijnse and Engberink, 2010). It is clear however that, apart from ACE inhibition, food-derived peptides exert their blood pressure-lowering effects via mechanisms that target renin activity, endothelin system function, Ang receptors, calcium channels, arginine-nitric oxide pathway, vascular inflammation and oxidative stress, sympathetic nervous system, and vascular remodeling (Majumder and Wu, 2014, Udenigwe and Mohan, 2014). Although the peptides may not need to be absorbed as they can bind receptors in the gut to trigger signalling processes, many peptides need to be bioavailable in relevant amounts in the vascular system in order to exert their antihypertensive effects. Therefore, some important factors need to be considered to achieve health benefits with the food peptides in hypertensive human subjects:
Acknowledgements Our research programs are supported by the Natural Sciences and Engineering Research Council of Canada (NSERC) through Individual Discovery Grants to CCU and JW.
Introduction Accumulation of contaminants in the food chain is a basic threatening factor for human health. In most countries with parental industries contaminants are identified to a high rate. Contaminated soils and water are also dangerous for agricultural production and human consumption. Although, the first option is definitely preventing contamination but in general, these principles are not followed in industrial areas. Zinc (Zn), which at high pH (7.2 to 7.8), the amount of absorbed Zinc by the plant depends on the available forms of Zinc in soil [1]. Roots, especially in soils which are rich of Zinc often store more amount of Zinc compared to aerial parts. The presence of more than 500mg of Zinc per kg of plants dry matter can cause toxicity to organisms which feed from them [2]. Also, much higher than 300mg per kg cause toxicity in plants especially sensitive species [3]. Phytoremediation is one of the methods of soils bioremediation which in recent decades has received a lot of attentions. In this method, the resistant plants are used for remediation of soils contaminated with organic and inorganic compounds. The advantages which this method has over other methods are simplicity, low cost and the possibility of utilizing in large-scale. In this method, plant selection is of great importance. Plant selection depends on climatic conditions and also the amount of pollution [4].