Effects of dietary supplementation with glutamate and aspartate on diquat-induced oxidative stress in piglets

Abstract

This study aimed to investigate the protective effects of dietary glutamate and aspartate supplementations on diquat-induced oxidative stress in piglets. Diquat injection significantly reduced growth performance, including body weight, average daily weight gain, and feed intake (P<0.05). Meanwhile, diquat administration induced oxidative stress evidenced by the decreased serum nitric oxide (NO) and elevated malondialdeyhde (MDA) concentration (P<0.05). Furthermore, diquat-induced oxidative stress disrupted intestinal absorption system and decreased serum threonine, serine, and glycine levels. Dietary supplementation with glutamate improved final body weight, antioxidant system, and expressions of amino acids transporters and enhanced serum glutamate concentration compared with diquat group (P<0.05). While aspartate failed to alleviate diquat-induced oxidative stress, growth depression, and dysfunction of nutrients absorption except for liver relative weight. In conclusion, dietary supplementation with glutamate confers beneficial effects on diquat-induced oxidative stress in piglets, while aspartate exhibits little effects.

Fig 1. Feed intake (A) and serum SOD, T-AOC, NO, and MDA levels (B, C, D, and E) in four groups after exposure to diquat.

* means feed intake in control is significantly higher than that in other three groups and # means feed intake in control is markedly higher than that in diquat and aspartate groups (P<0.05), but has no difference compared with glutamate group (P>0.05).

Fig 2. Histological evaluation of intestinal tissues (HE×250) after exposure to diquat.

Fig 3. Intestinal relative mRNA abundances in four groups after exposure to diquat.