Global warming makes humans and animals more vulnerable to heat stress. Heat stress can cause multiorgan dysfunction, especially in the intestine, primarily via oxidative stress and
inflammation. Mogroside-rich extract (MGE) is the active ingredient of Siraitia grosvenorii and has significant
antioxidant and anti-inflammatory activity. However, whether MGE can alleviate the intestinal damage caused by heat stress has not been explored. In this study, mice were given 600 mg kg-1 MGE followed by exposure to high temperature (40 °C for 2 h per day), and the structures and molecular changes in the ileum were examined. Our findings showed that
body weight was decreased by heat stress, while the activity of serum
superoxide dismutase (SOD) was increased. We further found that heat stress impaired the intestinal barrier by reducing the number of goblet cells and
mRNA levels of the
tight junction proteins zona occludens
protein 1 (ZO-1),
Occludin (OCLD) and recombinant
mucin 2 (MUC2
mucin), but it increased the
mRNA level of
trefoil factor 3 (TFF3). Interestingly, MGE treatment reversed these changes. Furthermore, heat stress increased the activity of SOD in the intestine, downregulated the expression of the oxidative stress-related genes
glutathione peroxidase 1 (GPX1), SOD2 and nuclear factor erythroid 2-related factor 2 (NRF2), and upregulated the expression of
catalase (CAT). Moreover, heat stress increased
tumor necrosis factor-α (TNF-α) levels in the intestine and upregulated the expression of the
inflammation-related genes
interleukin 10 (IL-10), TNF-α,
Interferon-γ (IFN-γ),
toll like receptor 4 (TLR4) and
nuclear factor-kappa B (
NF-kB). However, MGE treatment effectively reduced TNF-α levels and restored the normal activity of SOD and normal
mRNA levels for both oxidative stress-related and
inflammation-related genes. In summary, our results showed that MGE can protect against heat stress-induced intestinal damage by ameliorating
inflammation and oxidative stress.