Mori Cortex Radicis Attenuates High Fat Diet-Induced Cognitive Impairment via an IRS/Akt Signaling Pathway

Present study was conducted to investigate ameliorating effects of Mori Cortex radicis on cognitive impair and neuronal defects in HFD-induced (High Fat Diet-Induced) obese mice. To induce obesity, C57BL/6 mice were fed an HFD for 8 weeks, and then mice were fed the HFD plus Mori Cortex radicis extract (MCR) (100 or 200 mg/kg/day) for 6 weeks. Prior to sacrifice, body weights were measured, and Y-maze test and oral glucose tolerance test were performed. Serum lipid metabolic biomarkers (TG, LDL, and HDL/total cholesterol ratio) and antioxidant enzymes (glutathione, superoxide dismutase, and catalase), malondialdehyde (MDA), and acetylcholinesterase (AChE) levels were measured in brain tissues. The expressions of proteins related to insulin signaling (p-IRS, PI3K, p-Akt, and GLUT4) and neuronal protection (p-Tau, Bcl-2, and Bax) were examined. MCR suppressed weight gain, improved serum lipid metabolic biomarker and glucose tolerance, inhibited AChE levels and MDA production, and restored antioxidant enzyme levels in brain tissue. In addition, MCR induced neuronal protective effects by inhibiting p-Tau expression and increasing Bcl-2/Bax ratio, which was attributed to insulin-induced increases in the expressions p-IRS, PI3K, p-Akt, and GLUT4. These indicate MCR may reduce HFD-induced insulin dysfunction and neuronal damage and suggest MCR be considered a functional material for the prevention of T2DM-associated neuronal disease.

Antioxidant, Anti-inflammatory, and Antiproliferative Activity of Mori Cortex Radicis Extracts

Mori Cortex Radicis (MCR) is a well-known Korean and Chinese folk medicine with anti-obesity, anti-inflammatory, anti-asthmatic, and hypoglycemic activities. This study was aimed to evaluate the total phenolic and flavonoid contents, as well as intracellular antioxidant and anti-inflammatory effects of water and 70% (v/v) ethanol extracts of MCR. The antioxidant activities of MCR extracts were determined with diphenyl-2-picrylhydrazyl and 2,2′-azinobis[3-ethylbenzothiazoline-6-sulfonic] scavenging activity assays. The suppressive activities of MCR extracts on the production of nitric oxide (NO*) and the expression of cytokines, c-Fos, activated p38-Mitogen-activated protein kinase (MAPK), and Nuclear factor Kappa B (NF-κB) and splenocytes proliferation in lipopolysaccharide-treated macrophages were determined. Furthermore, this study demonstrated the effects of MCR on reactive oxygen species production in murine macrophages. Mori Cortex Radicis restored deoxyribonucleic acid damages at higher concentrations of the extracts and significantly suppressed free radicals and NO* production. In this study, MCR significantly restored inflammatory responses and intracellular antioxidant activities in murine macrophages (RAW 264.7), which anticipated that MCR could be used as a natural anti-inflammatory agent.

HPLC-PDA Analysis and Anti-inflammatory Effects of Mori Cortex Radicis

Mori Cortex Radicis (MCR, Moraceae) is used traditionally in the treatment of jaundice, hematemesis, edema, and pollakisuria in Korea. In this study, the anti-inflammatory effects of MCR extract were investigated using RAW 264.7 cells. The simultaneous analysis of five components present (neochlorogenic acid, chlorogenic acid, cryptochlorogenic acid, caffeic acid, and p-coumaric acid) in the MCR extract was performed using high-performance liquid chromatography (HPLC) coupled with photodiode array (PDA) detection. We determined the effects of MCR extract and its components on the production of nitric oxide (NO), prostaglandin E2 (PGE2), and mRNA expression of cyclooxygenase-2 (COX-2) in RAW 264.7 cells. MCR extract suppressed the production of NO and PGE2 in RAW 264.7 cells in a dose-dependent manner. None of the five components of the MCR extract had any influence on the production of NO. However, caffeic acid and p-coumaric acid inhibited the production of PGE2 and mRNA expression of COX-2 in RAW 264.7 cells. Our results suggest that MCR extract may offer potential as a therapeutic agent for the treatment of inflammation. The method we have established will help to improve the quality control of MCR extracts.