Ginsenoside Ro Ameliorates High-Fat Diet-Induced Obesity and Insulin Resistance in Mice via Activation of the G Protein-Coupled Bile Acid Receptor 5 Pathway.

Obesity, a well known risk factor in multiple metabolic diseases, is dramatically increasing worldwide. Ginsenosides extracted from ginseng have been reported against obesity and the associated metabolic disorders. As a subtype of ginsenoside, ginsenoside Ro is a critical constituent of ginseng. However, its specific effects on obesity remain unknown. G protein-coupled bile acid receptor 5 (TGR5) (also known as GPBAR1) is a bile acid membrane receptor, widely expressed in human tissues contributing to various metabolic processes to confer the regulations of glucose and lipid homeostasis. TGR5 has displayed potential as a therapeutic target for the treatment of metabolic disorders. Here, we explore the antiobesity effect of ginsenoside Ro with TGR5 activation screened by a library of natural products. Our results showed that the ginsenoside Ro (90mg/kg) treatment ameliorated body weight and lipid accumulation in multiple metabolic organs of high-fat diet-induced obese (DIO) mice without affecting food intake and improved oral glucose tolerance tests, intraperitoneal insulin tolerance tests, and fasting serum glucose. We also found that triglyceride and total cholesterol in serum and liver were significantly decreased after ginsenoside Ro treatment. Then we used Tgr5 knockout mice to explore the role of Tgr5 in the antiobesity effect of ginsenoside Ro. Our results further demonstrated that ginsenoside Ro promoted glucagon-like peptide 1 (GLP-1) secretion and energy expenditure in wild-type DIO mice. However, the stimulation of ginsenoside Ro on GLP-1 secretion and energy expenditure were restrained in the Tgr5 knockout mice. In conclusion, our findings demonstrated that ginsenoside Ro ameliorates obesity and insulin resistance in DIO mice via activating TGR5, indicating a potential therapeutic role of ginsenoside Ro to treat obesity and its associated metabolic diseases. SIGNIFICANCE STATEMENT: Obesity is dramatically increasing worldwide, and it contributes to multiple metabolic diseases. G protein-coupled bile acid receptor 5 (TGR5) is a potential therapeutic target for the treatment of metabolic disorders. Ginsenoside Ro, as an oleanane-type ginsenoside, ameliorates obesity and insulin resistance, promotes glucagon-like peptide 1 secretion, and increases energy expenditure via activating TGR5. Ginsenoside Ro could be a potential leading compound for treating obesity and its associated metabolic diseases.

[In vivo study of Chuankezhi metabolism in rat].

To study the metabolic products of main compounds of Chuankezhi injection in rat, 12 Sprague Dawley rats were classed into 2 groups, a blank control group and an intermuscular administration group, respectively. Rat feces and urine samples were collected from 0−24 h and 24−48 h after administration. All the samples were ultrasonically treated with methanol and then analyzed using LC-LTQ Orbitrap MSn. By comparison with the total ion chromatogram of samples from the blank control group, the metabolites in the samples of drug-treated group were screened. These metabolites were further analyzed by multistage product ion scanning and comparison of retention time with reference substances. As a result, a total of 12 flavonoid metabolites were tentatively identified from the rat feces and no metabolite was discovered in the rat urine. Epimedin C and icariin were detected in the rat blood samples after 30 min of administration, but their metabolites and other original flavones were not detected. Furthermore, no original flavones and their metabolites were detected in rat blood samples after 2 and 4 h of administration. The potential metabolism paths were further characterized and the principal in vivo transformation of flavones from Chuankezhi injection were deglycosylation, dehydration, methylation, oxidation and isomerization in rats.

[Simultaneous determination of 4 prenylflavonoids of Chuankezhi injection in rat plasma by LC-MS/MS].

A quantitative method for epimedin A, B, C and icariin in rat plasma was established using LC-MS/MS after intermuscular administration of Chuankezhi injection to rat. Chromatographic separation was performed on an Agilent Eclipse XDB-C(18) column (150 mm × 2.1 mm, 5.0 µm) at 40 ℃. Mobile phase consisted of acetonitrile-0.1% formic acid in water（35∶65）, and the flow rate was 0.22 m L·min(-1). The LC effluent was detected and analyzed using an ESI-triple quadrupole tandem mass spectrometer under the multiple reaction monitoring (MRM) in the negative ion mode. The plasma samples were treated with solid phase extraction prior to LC-MS/MS analysis. As a result, all of the four analytes displayed a good linearity over the concentration of 1-1 000 ng·mL(-1). The RSDs of intra-day and inter-day assays were less than 5.99% and 10.16%, respectively. The relative recovery of each analyte was between 88.1%-101.1% with RSD < 7.9% and the absolute recovery was between 72.0%-86.6%（RSD < 6.3%）. In conclusion, the established method shows good specificity, sensitivity and efficiency for quantifying the four flavonoid glycosides contained in rat plasma.

[Pharmacokinetics of epimedin A, B, C and icariin of Chuankezhi injection in rat].

To study pharmacokinetic characteristics of epimedin A, B, C and icariin after intermuscular administration of Chuankezhi injection to rat. The established RRLC-MS/MS method was applied for simultaneous determination of four analytes in rat plasma and calculating their pharmacokinetic parameters. As a result, each analyte showed a good linear relationship in the concentration range of 1-1 000 µg•L⁻¹.The intra-day precise was 96.9%-107.5% with RSD<5.99%, inter-day precise was 92.3%-105.0% with RSD<10.16%. The relative recovery of four analytes was 88.1%-101.1% with RSD<7.9% and their absolute recovery was 72.0%-86.6% with RSD<6.3%. After intermuscular administration of Chuankezhi injection, the plasma concentration of four flavonoid glycosides rapidly arose to peaks at about 10 min, and then quickly declined in rat. Tmax of epimedin A, B, C and icariin was 0.21, 0.19, 0.16 and 0.49 h, respectively, and their mean elimination half-life(t1/2z) was 0.60, 0.62, 0.47 and 0.49 h. The established method was validated to be sensitive, rapid and specific for determination of the four analytes. Serum concentration of 4 species of epimedium flavonoids in Chuankezhi injection was low, and their absorption and elimination seem quickly, displaying similar pharmacokinetic characteristics in this study.

[The relationship between the quality and the leaf shape of Magnolia officinalis produced in Hubei enshi].

OBJECTIVE: To reveal the relationship between the quality and the leaf shape of Magnolia officinalis produced in Hubei Enshi. METHODS: Determined the content of magnolol and honokiol by HPLC with methanol-water (78:22) and the detective wavelength was 294 nm. RESULTS: The content of magnolol and honokiol in the leaf of Magnolia officinalis was usually higher if the leaf apex was convex and the leaves were short. In certain years, the content of magnolol and honokiol in Cortex Magnoliae officinalis was positively correlated with the bark thickness. CONCLUSION: The leaf shape of Magnolia officinalis produced in Hubei Enshi is directly related to the phenolic content of leaf itself. But it has nothing to do with the content of magnolol and honokiol in Cortex Magnoliae officinalis.