Supranutritional selenium level minimizes high concentrate diet-induced epithelial injury by alleviating oxidative stress and apoptosis in colon of goat

Abstract

Background High concentrate (HC) diet-induced oxidative stress causes gut epithelial damages associated with apoptosis. Selenium (Se) being an integral component of glutathione peroxidase (GSH-Px) plays an important role in antioxidant defense system. Therefore, increasing dietary Se level would alleviate HC diet-induced injuries in gut mucosa. The present study investigated eighteen cross-bred goats, randomly divided into three groups (n = 6/group) fed either low concentrate (LC, roughage: concentrate ratio 65:35), high concentrate (HC, 35:65) or HC plus Se (HC-SY) diets for 10 weeks. Se was supplemented at the dose rate of 0.5 mg Se kg− 1 diet in the form of selenium yeast. The background Se level in HC and LC diets were 0.15 and 0.035 mg.kg− 1 diet, respectively. The Se at the dose of 0.115 mg.kg− 1 diet was added in LC diet to make its concentration equivalent to HC diet and with the supplementation of 0.5 mg Se kg− 1, the goats in group HC-SY received total Se by 0.65 mg.kg− 1 diet. Results The molar concentrations of individual and total short chain fatty acids (TSCFA) significantly increased (P < 0.05) with simultaneous decrease in pH of colonic fluid in goats of HC and HC-SY groups compared with LC goats. HC diet induced loss of epithelial integrity, inflammation and loss of goblet cells in colonic mucosa associated with higher lipopolysaccharide (LPS) concentrations in colonic fluid whereas, the addition of SY in HC diet alleviated such damaging changes. Compared with LC, the HC diet elevated malondialdehyde (MDA) level with concurrent decrease in GSH-Px and superoxide dismutase (SOD) activities, while SY supplementation attenuated these changes and improved antioxidant status in colonic epithelium. Moreover, epithelial injury and oxidative stress in colon of HC goats were associated with increased apoptosis as evidenced by downregulation of bcl2 and upregulation of bax, caspases 3 and 8 mRNA expressions compared with LC goats. On contrary, addition of SY in HC (HC-SY) diet alleviated these changes by modulating expression of apoptotic genes in colonic epithelium. Conclusions Our data suggest that supranutritional level of Se attenuates HC diet-induced oxidative stress and apoptosis and thereby minimizes the epithelial injury in colon of goats.

Ameliorative effects of supranutritional selenium on TLR‐4‐NF‐kB‐TNF‐α‐mediated hepatic oxidative injury and inflammation in goats fed high concentrate diet

“…Though LPS levels raised in both HC and HCSe goats, but LPS levels were significantly lower by 22 .35% and 37.68% in colon and serum of HCSe goats, respectively. Similar findings have been reported by previous studies in goats (Samo et al, 2020 ). However, the exact mechanism of lowering LPS levels by Se supplementation is not known.…”

“…The increase in acetate concentration and acetate propionate ratio by 49.21% and 20.35 along with reduced pH suggest that fermentation process was negatively affected in HC compared with LC goats (Huhtanen et al, 1993 ). However, Se addition improved fermentation in HCSe compared with HC goats, which is consistent with findings of Samo et al ( 2020 ).…”

“…Though the elevation of peripheral blood LPS levels may be caused by leakage from both rumen and hindgut epithelia, yet it is generally believed that the hind gut, because of being composed of monolayered epithelium and easily compromised by abnormal luminal environment, is a major site of translocation (Li et al, 2012 ). Several studies have shown increased starch flow and elevated amylase activity in digesta accompanied with severe epithelial injuries in cecum and colon of ruminants fed HC diets (Samo et al, 2020 ; Tao et al, 2017 ; Wang, Peng, et al, 2021 ; Wang, Salem, et al, 2021 ). Though LPS levels raised in both HC and HCSe goats, but LPS levels were significantly lower by 22 .35% and 37.68% in colon and serum of HCSe goats, respectively.…”

“…In particular, the dietary extra‐Se addition in stressful conditions have been shown to exert protective effects. The surplus Se levels ranging from 0.6 to 0.7 mg kg −1 diet mitigated concentrate diet‐induced oxidative injury and apoptosis in colonic epithelium of goat (Samo et al, 2020 ) and reduced stress during and after calving in cattle by enhancing immune response through attenuation of APPs, including SAA, Hp, and albumin (Gong & Xiao, 2021 ; Hall et al, 2014 ). The oversupply of Se in feed increased blood antioxidant status and improved immune health in sheep and pigs under heat stress (Chen et al, 2020 ; Liu, Chen, et al, 2021 ) and alleviated metabolic impairment by recovering the gene expression profile in swine liver exposed to chronic heat stress (Liu, Tang, et al, 2021 ).…”

Dietary supplementation of thiamine enhances colonic integrity and modulates mucosal inflammation injury in goats challenged by lipopolysaccharide and low pH

“…Samo et al (2020) revealed that long-term HC diet feeding can induce epithelial injury and apoptosis in the colon. In the present study (42) , Bax mRNA levels were significantly decreased, whereas the Bcl-2 mRNA level and the Bcl2/bax ratio were significantly increased in HCT goats compare to that in the HC goats. Moreover, the results of enzyme activity analysis in colonic mucosa showed that the HCT group had a markedly decrease in caspase-3, caspase-8 enzyme activity compared with the only HC diet feeding, which suggests that thiamine contributes to the attenuation of the HC diet-induced apoptosis through regulation of the Bax/Bcl-2 ratio and the caspase pathway.…”