Consumption of Amaranth Induces the Accumulation of the Antioxidant Protein Paraoxonase/Arylesterase 1 and Modulates Dipeptidyl Peptidase IV Activity in Plasma of Streptozotocin-Induced Hyperglycemic Rats

Abstract

Background/Aim: Amaranth is a source of several bioactive compounds, among which peptides with inhibitory activity upon dipeptidyl peptidase IV (DPP-IV) have been reported. However, there is no information about the action of amaranth DPP-IV-inhibitory peptides using in vivo models. The aim of this work was to evaluate the effect of amaranth consumption on plasma and kidney DPP-IV activity as well the changes in plasma proteome profile of streptozotocin (STZ)-induced hyperglycemic rats. Methods: Rats were fed for 12 weeks with a diet containing 20% popped amaranth grain. Kidneys and blood samples were collected for lipid profile, DPP-IV activity and expression, and proteomic analysis. Results: Total cholesterol and DPP-IV activity in plasma was increased in hyperglycemic rats, but this effect was reverted by amaranth consumption. Triacylglycerols were increased in the hyperglycemic group fed amaranth, and the highest levels of high-density lipoproteins were also observed in this group. These data correlated with the accumulation of apolipoprotein A-II in plasma. Accumulation of the antioxidant protein paraoxonase/arylesterase 1 in STZ-induced hyperglycemic rats was observed when amaranth was supplied in the diet. Conclusion: This study provides new insights into the molecular mechanisms by which amaranth exerts its beneficial health action in a hyperglycemic state.

A Review of Recent Studies on the Antioxidant Activities of a Third-Millennium Food: Amaranthus spp.

“…The authors also suggested monitoring the level of triacylglycerol carefully, as the same was increased after amaranth supplementation. These findings indicate that amaranth has beneficial effects on reducing cholesterol (Table 3) [87].…”

Amaranth as a Source of Antihypertensive Peptides

“…Amaranth also presents a high percentage of insoluble fiber (78%) and minerals such as copper, manganese, iron, zinc, magnesium, calcium, phosphorus, and potassium. The content of these minerals is higher than that found in rice and corn (Stone and Lorenz, 1984;Bressani, 1994;Alvarez-Jubete et al, 2010;Rastogi and Shukla, 2013;Lamothe et al, 2015;D'Amico and Schoenlechner, 2017;Velarde-Salcedo et al, 2018). The polyphenolic fraction that contains considerable amounts of rutin, isoquercetin, and nicotiflorine is also important (Venskutonis and Kraujalis, 2013;D'Amico and Schoenlechner, 2017).…”

“…According to Quiroga et al (2007Quiroga et al ( , 2009; 11S-glob and P-glob would be two 11S-glob isoforms formed by polypeptides encoded by two different legumin gene subfamilies. Velarde-Salcedo et al (2018) have recently suggested that amaranth glutelins could be polymerized globulins.…”

Characteristics of Food Protein-Derived Antidiabetic Bioactive Peptides: A Literature Update

“…Nonetheless, findings from the few animal studies regarding the effects of the intact proteins, enzyme digestion proteins (hydrolysate), and peptides with diabetic models are promising. Most of the extract of proteins (non-hydrolysate proteins) with proven anti-diabetes effects in vivo are derived from medicinal plants such as H. rosa Sinensis leaves [50], Rhazya stricta root [176], Terminalia arjuna [51,177], Pueraria tuberosa [178], Amaranth grain [179], and Grapeseed [180], with one animal source exception of sea urchin gonads [56]. All of these demonstrated inhibitory activity against DPP-IV enzymes, corresponding to an increase in the secretion of GLP-1.…”