Rhodomeroterpene alleviates macrophage infiltration and the inflammatory response in renal tissue to improve acute kidney injury.

Inflammation is broadly recognized as an important factor in the pathogenesis of acute kidney injury (AKI), but pharmacological approaches to alleviate inflammation in AKI have not been proved successful in clinical trials. Macrophage infiltration into renal tissue promotes inflammatory responses that contribute to the pathogenesis of AKI. Suppression of renal tissue inflammatory responses is postulated to improve renal injury of patients and animals. Rhodomeroterpene (RMT) is a novel meroterpenoid isolated from the Rhododendron genus that was shown to exert anti-inflammatory action in vivo or in vitro in this study. We investigated the treatment effects of RMT on LPS-induced sepsis and two different AKI models. The results showed that pretreatment with RMT (30 mg kg-1  d-1 , ip, for 3 days) significantly inhibited acute inflammatory responses in LPS-induced septic mice. In both renal ischemia-reperfusion injury (I/R) and sepsis-induced AKI models, RMT (30 mg kg-1  d-1 , ip, for 3 days) ameliorated renal function and injury and alleviated inflammation by reducing the infiltration of immune cells, including macrophages and neutrophils. Furthermore, our study demonstrated that RMT inhibits inflammatory responses in macrophages. The anti-inflammatory effects of RMT may be due to the inactivation of the IKK/NF-κB and PI3K/PDK1/Akt inflammatory signaling pathways in macrophages. Collectively, our findings indicate that RMT ameliorates renal injury and alleviates the renal inflammatory state in different AKI models, suggesting that RMT may be a potential agent for the treatment of AKI.

Sarsasapogenin improves adipose tissue inflammation and ameliorates insulin resistance in high-fat diet-fed C57BL/6J mice.

Insulin resistance is a major cause of type 2 diabetes and metabolic syndrome. Macrophage infiltration into obese adipose tissue promotes inflammatory responses that contribute to the pathogenesis of insulin resistance. Suppression of adipose tissue inflammatory responses is postulated to increase insulin sensitivity in obese patients and animals. Sarsasapogenin (ZGY) is one of the metabolites of timosaponin AIII in the gut, which has been shown to exert anti-inflammatory action. In this study, we investigated the effects of ZGY treatment on obesity-induced insulin resistance in mice. We showed that pretreatment with ZGY (80 mg·kg-1·d-1, ig, for 18 days) significantly inhibited acute adipose tissue inflammatory responses in LPS-treated mice. In high-fat diet (HFD)-fed obese mice, oral administration of ZGY (80 mg·kg-1·d-1, for 6 weeks) ameliorated insulin resistance and alleviated inflammation in adipose tissues by reducing the infiltration of macrophages. Furthermore, we demonstrated that ZGY not only directly inhibited inflammatory responses in macrophages and adipocytes, but also interrupts the crosstalk between macrophages and adipocytes in vitro, improving adipocyte insulin resistance. The insulin-sensitizing and anti-inflammatory effects of ZGY may result from inactivation of the IKK /NF-κB and JNK inflammatory signaling pathways in adipocytes. Collectively, our findings suggest that ZGY ameliorates insulin resistance and alleviates the adipose inflammatory state in HFD mice, suggesting that ZGY may be a potential agent for the treatment of insulin resistance and obesity-related metabolic diseases.