ML334

Ammonia is an important component of PM2.5 and PM10, and is also a major harmful gas in intensive and large-scale pig houses, which poses a potential threat to the health of farmers and animals. Intestinal tract is the largest immune organ in the body and is also an important target organ for ammonia exposure. However, the potential toxicity mechanism of ammonia exposure to the intestine remains unclear. L-selenomethionine is an important source of organic selenium with the advantages of high bioavailability, safety and high efficiency. In order to explore the mechanism of ammonia enterotoxicity and the mitigation effect of L-selenomethionine on ammonia enterotoxicity, multi-dimensional ammonia toxicity models and L-selenomethionine intervention models were established in vivo and in vitro. The results showed that ammonia exposure up-regulated the levels of iron, ROS, MDA, and LPO in the small intestinal tissue and the IPEC-J2 cell, down-regulated the activities of antioxidant enzymes and the content of GSH, inhibited the Nrf2 pathway, significantly altered the expression of ferroptosis (TFR-1, FPN-1, FTH1, SLC7A11, GPX4, ACSL4) and intestine tight junctions (Claudin-1, Occludin, ZO-1) genes. Compared with the ammonia exposure group, L-selenomethionine group could significantly improve the changes of these ferroptosis indicators by affecting ROS and iron levels through Nrf2 pathway. Our results indicated that L-selenomethionine inhibited small intestinal epithelial cells ferroptosis caused by ammonia exposure through regulating ROS-mediated iron metabolism.

Rehmannia glutinosa is widely recognized as a prominent medicinal herb employed by practitioners across various generations for the purpose of fortifying kidney yin. Within Rehmannia glutinosa, the compound known as catalpol (CAT) holds significant importance as a bioactive constituent. However, the protective effects of CAT on kidneys, including ameliorative effects on chronic kidney disease — most prominently renal anemia and renal fibrosis — have not been clearly defined. In this study, the kidney injury model of NRK-52E cells and C57BL/6N male mice was prepared by exposure to aristolochic acid I (AA-I), and it was discovered that CAT could ameliorate oxidative stress injury, inflammatory injury, apoptosis, renal anemia, renal fibrosis, and other renal injuries both in vivo and in vitro. Further treatment of NRK-52E cells with Nrf2 inhibitors (ML385) and activators (ML334), as well as NF-κB inhibitors (PDTC), validated CAT’s ability to target Nrf2 activation. Furthermore, the expression of phosphorylated NF-κB p65, IL-6, and Cleaved-Caspase3 protein was inhibited. CAT also inhibited NF-κB, and then inhibited the expression of IL-6, p-STAS3, TGF-β1 protein. Therefore, CAT can regulate Nrf2/NF-κB signaling pathway, significantly correct renal anemia and renal fibrosis, and is conducive to the preservation of renal structure and function, thus achieving a protective effect on the kidneys.