A Triterpenoid Inhibited Hormone-Induced Adipocyte Differentiation and Alleviated Dexamethasone-Induced Insulin Resistance in 3T3-L1 adipocytes.

6α-Hydroxylup-20(29)-en-3-on-28-oic acid (1), a natural triterpenoid, was found to possess the ability in a dose-dependent manner inhibiting hormone-induced adipocyte differentiation in 3T3-L1 preadipocytes, and restoring glucose consuming ability in dexamethasone (DXM)-induced insulin resistant 3T3-L1 adipocytes. Compound 1 was also found to ameliorate DXM-induced adipocyte dysfunction in lipolysis and adipokine secretion. Mechanistic studies revealed that 1 inhibited adipocyte differentiation in 3T3-L1 preadipocytes via down-regulating hormone-stimulated gene transcription of peroxisome proliferator-activated receptor γ and CCAAT-enhancer-binding protein alpha which are key factors in lipogenesis, and restored DXM-impaired glucose consuming ability in differentiated 3T3-L1 adipocytes via repairing insulin signaling pathway and activating down-stream signaling transduction by phosphorylation of signaling molecules PI3K/p85, Akt2 and AS160, thus leading to increased translocation of glucose transporter type 4 and transportation of glucose.

Alleviating effects of Bushen-Yizhi formula on ibotenic acid-induced cholinergic impairments in rat.

This study explored the curative effect and underlying mechanisms of a traditional Chinese medicine compound prescription, Bushen-Yizhi formula (BSYZ), in ibotenic acid (IBO)-induced rats. Morris water maze and novel object recognition tests showed that BSYZ significantly improved spatial and object memory. Brain immunohistochemistry staining showed that BSYZ significantly up-regulated expression of choline acetyltransferase (ChAT) and nerve growth factor (NGF) in the hippocampus and cortex. The protein tyrosine kinase high-affinity receptor TrkA was slightly increased in the hippocampus and cortex, and significantly enhanced in the nucleus basalis of Meynert (NBM) after BSYZ intervention. The immunoreactivity of the p75 low-affinity receptor in BSYZ-treated rats was significantly strengthened in the cortex. Similar expression trends of nerve growth factor (NGF), TrkA, and p75 mRNA were observed in the hippocampus and cortex. Additionally, BSYZ reversed IBO-induced disorders of acetylcholine (ACh) levels, ChAT, and cholinesterase (ChE) in the cortex, which was consistent with the changes in mRNA levels of ChAT and acetylcholinesterase (AChE). Expression of ChAT and AChE proteins and mRNA in the hippocampus was up-regulated, whereas the apoptosis-relative protein cleaved caspase-3 was decreased after administration of BSYZ. Moreover, changes in cell death were confirmed by histological morphology. Thus, the results indicated that the BSYZ formula could ameliorate memory impairments in IBO-induced rats, and it exerted its therapeutic action probably by modulating cholinergic pathways, NGF signaling, and anti-apoptosis. Overall, it is suggested that the BSYZ formula might be a potential therapeutic approach for the treatment of Alzheimer's disease (AD) and other cholinergic impairment-related diseases.

Effects of Traditional Chinese Medicinal Plants on Anti-insulin Resistance Bioactivity of DXMS-Induced Insulin Resistant HepG2 Cells.

ABSTRACT: Medicinal plants have a long history of use in China to treat diabetic symptoms. Ancient Chinese medical manuscripts and ethnobotanical surveys document plant remedies that continue to be actively used in China for the treatment of diabetic symptoms. Based on a systematic ancient Chinese medical manuscripts review in combination with ethnobotanical survey, 16 medicinal plants for the traditional treatment of diabetic symptoms were identified for the evaluation of anti-insulin resistance bioactivity. The biological activity of 16 medicinal plants was tested on dexamethasone (DXMS)-induced insulin resistant HepG2 cells. The result shows that 11 of the 16 medicinal plants enhanced glucose uptake of DXMS-induced insulin resistant HepG2 cells, thereby demonstrating their ability to increase insulin sensitivity, other five medicinal plants including Astragalus membranaceus were found ineffective. The study shows that ancient Chinese medical manuscripts and ethnobotanical surveys on plants for the prevention and treatment of diabetic symptoms provide a promising knowledge base for drug discovery to mitigate the global diabetes epidemic.