Review of Zuoguiwan on Animal Models and Evaluation in Prevention and Treatment of Osteoporosis / 中国实验方剂学杂志

Zuoguiwan is a classic prescription for replenishing vital essence, tonifying kidney-Yin and nourishing the bone marrow. Zuoguiwan is one of the effective prescriptions for the prevention and treatment of osteoporosis (OP), which reflects the thought of Reinforcing Yang from Yin. The OP animal model simulates the pathological state and pathogenesis of OP in human, which is an important means to research the pathogenesis of OP and verify the effect of drugs. In this paper, two kinds of animal models and characteristics of Zuoguiwan in the prevention and treatment of osteoporosis were discussed in details. They are the primary osteoporosis animal models, including ovariectomized animal models and spontaneous elderly osteoporosis animal models, and the secondary osteoporosis models, including glucocorticoid-induced animal models, cyclophosphamide-induced animal models and subtotal nephrectomy animal models. The evaluation methods of Zuoguiwan in preventing and treating OP, including bone absorption markers and bone formation markers analyzed by enzyme-linked immunosorbent assay (ELISA), bone mineral density detected with dual-energy X-ray, the number of trabeculae, trabecular segregation, trabecular thickness, bone volume/tissue volume ratio and bone surface/volume ratio analyzed using micro-CT, bone pathological morphology observed by hematoxylin-eosin staining, bone biomechanical properties, such as the maximum load force based on biomechanical test. In order to provide scientific reference for the basic and clinical research of Zuoguiwan, the OP animal models and the pharmacodynamic effect of Zuoguiwan are evaluated comprehensively with five different and objective evaluation methods. However, the animal model of OP needs to be further optimized to highlight the pathogenesis and syndrome characteristics of Zuoguiwan in the treatment of OP.

Research progress on therapeutic targets of active components in Chinese herbs for treatment of nonalcoholic fatty liver disease / 中国中药杂志

Nonalcoholic fatty liver disease(NAFLD) is a kind of metabolic liver injury, which is closely associated with insulin resistance and genetic susceptibility. Traditional Chinese herbs used in the treatment of nonalcoholic fatty liver disease are widely investigated in recent years. A series of recent studies show that the effects of the active components in traditional Chinese herbs on NAFLD are associated with activating AMPK signaling pathway, improving insulin resistance, modulating the activity and expression of peroxisome proliferator-activated receptor γ, antioxidant and anti-inflammatory activities and regulating intestinal flora. In this review, the potential therapeutic targets of the active components from traditional Chinese herbs for NAFLD would be summarized to provide a new thought for further research and clinical treatment of nonalcoholic fatty liver disease.

Ginsenoside Rb1 upregulates expressions of GLUTs to promote glucose consumption in adiopcytes / 中国中药杂志

Previous studies have shown that ginsenoside Rb1 (Rb1), one of active components in ginseng, can activate insulin signaling pathway and promote translocation of glucose transporters (GLUTs) to increase glucose uptake in adipocytes. However, the effect of Rb1 on the expressions of GLUTs remains unknown. In this study, the effects of Rb1 on GLUT1 and GLUT4 were observed in 3T3-L1 adipocytes and epididymal adipose tissue of db/db obese diabetic mice. Male db/db mice were treated with Rb1 by intraperitoneal injection at the dosage of 20 mg x kg(-1) for 14 d. Rb1 reduced HOMA-IR significantly (P < 0.05, n = 5), and FBG and FINS sowed declining trend after treatment with Rb1. Rb1 recovered the expressions of GLUT1 and GLUT4 and phosphorylation of AKT in adipose tissue of db/db mice. In vitro, glucose consumption in 3T3-L1 adipocytes treated with 10 micromol x L(-1) Rb1 for 24 h was elevated (P < 0.05, n=3), and mRNA of GLUT1 and GLUT4 were up-regulated (P < 0.05, n=3) and proteins of GLUT1 and GLUT4 were also increased. AKT was activated in adipocytes treated with Rb1 for 3 h. It can be concluded that ginsenoside Rb1 can up-regulate the expression of GLUTs in adipose tissue, in addition to activate insulin signalling pathway, which may partially account for its insulin sensitizing activity and regulating effect of glucose metabolism.

Effect of ginsenoside Rb1 in ameliorating insulin resistance and ectopic fat deposition in obese mice induced by high fat diet / 中国中药杂志

Ginsenoside Rb1 is an active component in ginseng. Previous in vitro experiments showed that ginsenoside Rb1, could inhibit lipolysis and promote glucose transporter in adipocytes. This study focused on the effect of ginsenoside Rb1 in insulin resistance and ectopic fat deposit in obese mice induced by high fat diet and its molecular mechanism. Obese male C57/L mice induced by high fat diet were randomly divided into the diet-induced obesity group (DIO group), the ginsenoside Rb1 group (Rb1 group) and the rosiglitazone group (Rog group), and continuously fed with high fat diet. In addition, male C57/L mice fed with normal diet were selected as the normal group (NC group). Mice in Rb1 group and Rog groups were intraperitoneally injected with ginsenoside Rb1 and rosiglitazone with the dosage of 20 mg x kg(-1) and 10 mg x kg(-1), respectively. NC and DIO groups were intraperitoneally injected with the same amount of saline. Two weeks later, the intraperitoneal glucose tolerance test (IPGTT) was performed. Three days later, the mice were killed, and their serum samples were collected to detect insulin and free fatty acid (FFA). Their livers were weighed to examine the triglyceride content, and a pathological detection was performed. Epididymal adipose tissues were weighed, and PDE3B, HSL and perilipin were detected by Western blotting. The results showed that the treatment with ginsenoside Rb1 for two weeks could improve the glucose tolerance of obese mice. Except for 0-120 min, the areas under the glucose tolerance curve (0-30 min, 0-60 min and 0-90 min) in the Rb1 group were less than that in the DIO group (P < 0.05, n = 5), with a much lower HOMA-IR (P < 0.05, n = 5). The fat level of obese mice was significantly reduced by Rbl (P < 0.05, n = 5), and so were liver weight/weight (P < 0.05, n = 8). The increased serum FFA of obese mice declined after the treatment of Rb1 (P < 0.05, n = 8). Rb1 could partially recover the expression of perilipin in adipose tissues, but without obvious change in the expressions of PDE3B and HSL and the phosphorylated activation. The above findings indicated that ginsenoside Rb1 could reduce the release of FFA and alleviate the ectopic deposit of triglyceride by up-regulating the expression of perilipin in adipose tissue, which may be one of its mechanisms for improving the insulin resistance and abnormal glucose metabolism of organisms.

Ginsenoside Rb_1 facilitates adipocyte differentiation and inhibits lipolysis in 3T3-L1 adipocytes / 中华内分泌代谢杂志

Objective To observe the effect of ginsenoside Rb1,the most abundant ginsenoside in ginseng root,on differentiation and lipolysis of 3T3-L1 cells and to explore its anti-diabetic mechanism.Methods 3T3-L1 preadipoeytes were induced under standard differentiation process in the presence of 0.1,1,10,100?mol/L ginsenoside Rb_1 for 6 days.Oil red O staining,measurement of triglyceride contents and glucose uptake assay were performed.The expressions of mRNA and protein of PPAR?2,C/EBP?,ap2,glucose transporter (Glut) 1,and Glut4 were analysed with quantitative real time-PCR and Western blot.The binding affinity of Rb_1 to PPAR?-LBD was evaluated by Surface Plasmon Resonance (SPR).Lipolysis of adipocytes was examined by the measurement of glycerol released from adipoeytes treated with Rb_1 for 1 h.Results Ginsenoside Rb_1 facilitated differentiation of 3T3-L1 preadipoeytes in a dose-depondent manner.10?mol/L ginsenoside Rb_1 increased lipid accumulation by about 56%.Treatment of differentiating adipocytes with 10?mol/L ginsenoside Rb_1 increased the expressions of PPAR?2 and C/EBP?mRNA and protein,as well as mRNA expression of ap2,one of their target genes.After treatment of differentiating adipoeytes with Rb_1,basal and insulin-mediated glucose transport augmented significantly accompanied by up-regulations of mRNA and protein level of Glut4,but not of Glutl.SPR showed Rb_1 could bind to PPAR?which suggested Rb_1 was a ligand of PPAR?.Ginsenoside Rb_1 inhibited basal lipolysis in adipoeytos in a dose-dependent manner.However,it did not affect isoproterenol-stimulated lipolysis.Conclusion As a PPAR?ligand,ginsenoside Rb_1 promotes adipogenesis,inhibitas basal lipolysis and inereasos basal and insulin-mediated glucose transport in cultured adipoeytes.Therefore,anti-diabetic and insulin-sensitizing activity of ginsenosides is,at least in part,involved in the enhancing effect on PPAR?2 and C/EBP?expressions,hence promoting adipogenesis and glucose uptake,and inhibiting lipolysis in adipocytes.