Reduction of Paraquat-induced Oxidative Stress in Rats by Dietary Soy Peptide

Abstract

The effect of a dietary soy protein isolate (SPI), soy peptide (PEP) and the amino acids in soy protein on paraquat (PQ)-induced oxidative stress was investigated in rats. In the first experiment, male Wistar rats were fed on experimental diets containing casein (CAS), SPI and PEP as nitrogen sources with or without 0.025% PQ. The reduced food intake and body weight gain of the rats fed with PQ was mitigated by either the SPI or PEP intake. Both SPI and PEP prevented the elevation of the serum TBARS concentration and tended to prevent the elevation of lung weight induced by PQ. In the second experiment, the rats were fed on diets containing an amino acid mixture resembling casein (CASAA) or soy protein (SPIAA) with or without PQ. The SPIAA intake did not affect the reduction of food intake and body weight gain, nor the elevation of lung weight and TBARS in the serum and liver induced by PQ. These results demonstrate that the intake of either dietary SPI or PEP, but not an amino acid mixture resembling soy protein, had the effect of reducing PQ-induced oxidative stress in rats.

Functional Implications and Ubiquitin-Dependent Degradation of the Peptide Transporter Ptr2 in Saccharomyces cerevisiae

“…In addition to being a source of nitrogen, peptides play beneficial roles in physiological activity. For example, soy peptides, the proteolytic products of soy proteins, can reduce serum lipid levels, scavenge free radicals, and reduce oxidative stress in mammalian cells (6)(7)(8). In yeast, soy peptides improve tolerance to freeze-thaw stress, repress the formation of lipid bodies (9), and accelerate ethanol fermentation (10,11).…”

Bioactive peptides from meat and their influence on human health

“…Moreover, it has been found that substitution of L-His by D-His in a peptide leads to reduction of the antioxidative activity, which proves that configuration of amino acids also has infl uence on antioxidant activity (Chen et al, 1996;Sarmadi and Ismail, 2010). Some researchers have found that certain amino acids exhibit higher antioxidative activity when they are incorporated in dipeptides (Alabovsky et al, 1997;Takenaka et al, 2003;Erdmann et al, 2008;Sarmadi and Ismail, 2010).…”

Beneficial Effects of Bioactive Peptides Derived from Soybean on Human Health and Their Production by Genetic Engineering

“…Hydrolysates of soy proteins contain antioxidant peptides (Chen et al, 1998). These peptides show high activity against the peroxidation of linoleic acid, paraquat-induced oxidative stress in rats, and scavenging effects on peroxynitrite, active oxygen, and free radical species (Takenaka et al, 2003). They may therefore help prevent some free radical-related diseases.…”