Shen Zhuang1, Jia Zhong1, Yifei Bian1, Yingsai Fan1, Qiyan Chen1, Ping Liu1, Zhongjie Liu2. 1. Division of Traditional Chinese Veterinary Medicine, College of Veterinary Medicine, China Agricultural University, Beijing, China. 2. Division of Traditional Chinese Veterinary Medicine, College of Veterinary Medicine, China Agricultural University, Beijing, China. Electronic address: liuzhongjiecau@163.com.
Abstract
AIMS: In this study, we explored the underlying mechanisms of protective effects of rhein against intestinal barrier injury in a rat model, induced by intraperitoneal injection of lipopolysaccharide (LPS). MAIN METHODS: Twenty-four male rats were assigned equally to three groups. Rats were given an oral administration of rhein (66.7 mg/kg/day) or not for three continuous days. LPS or saline were injected intraperitoneally in an hour after the last oral administration. The rats were sacrificed at 7 h after LPS or saline administration. Both blood samples and intestinal samples were collected. KEY FINDINGS: Rhein pretreatment markedly inhibited the levels of serum diamine oxidase (DAO), D-lactate (D-lac) and intestinal histological damage, significantly recovered the levels of intestinal DAO, ZO-1 and occludin. Additionally, rhein suppressed LPS-induced intestinal inflammation and oxidative stress, by decreased serum and intestinal, tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6 and nitric oxide levels, up-regulated intestinal catalase, glutathione peroxidase (GSH-Px) activities and HO-1 expression, and down-regulated malondialdehyde (MDA) level in the small intestine. Finally, rhein inhibited JNK, p38 MAPK phosphorylation and activated Nrf2 pathway. SIGNIFICANCE: Rhein could exert the anti-inflammatory and anti-oxidative effects against LPS-induced intestinal barrier injury by suppressing p38 MAPK and JNK and activating Nrf2 pathway.
AIMS: In this study, we explored the underlying mechanisms of protective effects of rhein against intestinal barrier injury in a rat model, induced by intraperitoneal injection of lipopolysaccharide (LPS). MAIN METHODS: Twenty-four male rats were assigned equally to three groups. Rats were given an oral administration of rhein (66.7 mg/kg/day) or not for three continuous days. LPS or saline were injected intraperitoneally in an hour after the last oral administration. The rats were sacrificed at 7 h after LPS or saline administration. Both blood samples and intestinal samples were collected. KEY FINDINGS: Rhein pretreatment markedly inhibited the levels of serum diamine oxidase (DAO), D-lactate (D-lac) and intestinal histological damage, significantly recovered the levels of intestinal DAO, ZO-1 and occludin. Additionally, rhein suppressed LPS-induced intestinal inflammation and oxidative stress, by decreased serum and intestinal, tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6 and nitric oxide levels, up-regulated intestinal catalase, glutathione peroxidase (GSH-Px) activities and HO-1 expression, and down-regulated malondialdehyde (MDA) level in the small intestine. Finally, rhein inhibited JNK, p38 MAPK phosphorylation and activated Nrf2 pathway. SIGNIFICANCE: Rhein could exert the anti-inflammatory and anti-oxidative effects against LPS-induced intestinal barrier injury by suppressing p38 MAPK and JNK and activating Nrf2 pathway.