The Influence of Coumestrol on Sphingolipid Signaling Pathway and Insulin Resistance Development in Primary Rat Hepatocytes

Abstract

Coumestrol is a phytoestrogen widely known for its anti-diabetic, anti-oxidant, and anti-inflammatory properties. Thus, it gets a lot of attention as a potential agent in the nutritional therapy of diseases such as obesity and type 2 diabetes. In our study, we evaluated whether coumestrol affects insulin resistance development via the sphingolipid signaling pathway in primary rat hepatocytes. The cells were isolated from the male Wistar rat's liver with the use of collagenase perfusion. Next, we incubated the cells with the presence or absence of palmitic acid and/or coumestrol. Additionally, some groups were incubated with insulin. The sphingolipid concentrations were assessed by HPLC whereas the expression of all the proteins was evaluated by Western blot. Coumestrol markedly reduced the accumulation of sphingolipids, namely, ceramide and sphinganine through noticeable inhibition of the ceramide de novo synthesis pathway in insulin-resistant hepatocytes. Moreover, coumestrol augmented the expression of fatty acid transport proteins, especially FATP5 and FAT/CD36, which also were responsible for excessive sphingolipid accumulation. Furthermore, coumestrol altered the sphingolipid salvage pathway, which was observed as the excessive deposition of the sphingosine-1-phosphate and sphingosine. Our study clearly showed that coumestrol ameliorated hepatic insulin resistance in primary rat hepatocytes. Thus, we believe that our study may contribute to the discovery of novel preventive and therapeutic methods for metabolic disorders.

ANGPTL8/Betatrophin Improves Glucose Tolerance in Older Mice and Metabolomic Analysis Reveals Its Role in Insulin Resistance in HepG2 Cells

“… 46 The concentrations of sphingolipids, namely, ceramide and sphinganine were reduced in insulin-resistant primary rat hepatocytes, resulting to the amelioration of hepatic insulin resistance. 47 In the present study, the sphinganine level was significantly higher in ANGPTL8/betatrophin knockout HepG2/IR cells than that in wild type HepG2/IR cells ( p = 0.005), suggesting ANGPTL8/betatrophin knockout may contribute to the development of insulin resistance.…”

A Rheostat of Ceramide and Sphingosine-1-Phosphate as a Determinant of Oxidative Stress-Mediated Kidney Injury

“…Furthermore, a rheostat of ROS-antioxidants can regulate the activity of SphKs ( Section 7.2 ). In support of this, adiponectin [ 284 ] and coumestrol [ 296 ] that function as antioxidants and administration of antioxidants [ 297 ] reduced the ratio of ceramide/S1P, contributing to prevention against oxidative stress-mediated diseases ( Table 4 ). As described earlier, the binding of adiponectin, an antioxidant, to its receptor, AdipoR, further enhances the receptor’s CDase activity [ 12 ].…”

Sex Differences in Cardiovascular Diseases: A Matter of Estrogens, Ceramides, and Sphingosine 1-Phosphate

“…However, as discussed above, the risk associated with ERT outweighs the benefits, thus the modern perspective can be to use plant-based therapies like phytoEs (PhEs) and their derivatives [ 178 ] ( Figure 2 ). These polyphenolic estrogenic compounds of plant origin are classified in four main classes (isoflavones, lignans, coumestans, and stilbenes) and possess E-like activity binding both ERα and ERβ [ 179 ]. And as per previous studies, appear to increase both Cer and S1P in vitro in HepG2 cells and in primary rat hepatocytes [ 179 , 180 , 181 ].…”

“…These polyphenolic estrogenic compounds of plant origin are classified in four main classes (isoflavones, lignans, coumestans, and stilbenes) and possess E-like activity binding both ERα and ERβ [ 179 ]. And as per previous studies, appear to increase both Cer and S1P in vitro in HepG2 cells and in primary rat hepatocytes [ 179 , 180 , 181 ]. Importantly, over the last years, some experimental and clinical data have demonstrated the potential of these E-like molecules to address several conditions associated with menopause, including CVDs [ 182 , 183 ].…”