The Involvement of Serotonin in the Hypoglycemic Effects Produced by Administration of the Aqueous Extract of Xylaria nigripes with Steroid-Induced Insulin-Resistant Rats

Abstract

Xylaria nigripes (XN) is a medicinal fungus with a high-economic value. The aim of this study was to explore the hypoglycemic effects and mechanisms of the XN aqueous extract in steroid-induced insulin-resistant (SIIR) rats. Significant hypoglycemic effects were observed 60 min after administration of XN aqueous extract. In normal Wistar, hypoglycemic effects were 21% (the plasma glucose level decreased from 128.6 ± 12.5 to 100.9 ± 10.7 mg/dL). In SIIR, hypoglycemic effects were 26% (the plasma glucose level decreased from 177.6 ± 12.5 to 133.3 ± 29.7 mg/dL) rats refer to their baseline. The signaling proteins for insulin-receptor substrate-1 and glucose transporter-4 increased 0.51-fold and 1.12-fold, respectively, as determined by Western blotting; the increase in the proteins was 13% and 9%, respectively, as determined by immunohistochemistry. The serotonin antagonist, α-p-chlorophenylalanine, effectively blocked the hypoglycemic effects and increased the signaling protein levels. After XN administration, none of the animals showed significant changes in plasma-free fatty acids in 60 min. In summary, the XN extract may have hypoglycemic effects in normal Wistar and SIIR rats that may have a serotonin-related hypoglycemic effect and enhance insulin sensitivity in the SIIR rats.

Hypoglycemic and Antihyperglycemic Activities of Nine Medicinal Herbs Used as Antidiabetic in the Region of Lubumbashi (DR Congo)

“…All tested plants exhibited antihyperglycemic properties, with inhibition factors ranging from 25.8% to 62.3%. Published antidiabetic studies of herbal drugs on in vivo OGTT models have monitored various measurements of hyperglycemia reduction (Dias et al ., ; Chen et al ., ), making difficult the comparison of efficiencies. Indeed published studies differ in animal models, duration of observation, dose of glucose, reference drug, type of plant extract; also investigated herbs probably differ in their mechanisms of action (Patel et al ., ).…”

Improving insulin resistance with Antrodia cinnamomea mycelium powder to induce a hypoglycemic effect in dexamethasone‑induced insulin‑resistant rats

“…Previous studies have indicated that AC stimulates AMPK to enhance GLUT-4 translocation and activates the peroxisome proliferator activated receptor α (PPARα) to decrease plasma FFA levels, which may complement the insulin signaling pathway to result in a hypoglycemic effect and improvement in insulin resistance (18,20,32,34). In our previous studies, we also used the SIIR animal model to test the hypoglycemic effect of the Xylaria nigripes (Xn) fungus and the Gardenia jasminoides (GJ) plant (26,35). However, Xn was found to exert a serotonin-associated hypoglycemic effect, and PPAR activation was key to the hypoglycemic effect of GJ.…”

Hypoglycemic Effect of Electroacupuncture Combined with Antrodia cinnamomea in Dexamethasone-Induced Insulin-Resistant Rats

“…This study was performed according to previously published research methods. 17 The SIIR rats were injected intraperitoneally (i.p.) with 1 mg/kg of dexamethasone daily for 5 days.…”