Extract of Silphium perfoliatum L. improve lipid accumulation in NAFLD mice by regulating AMPK/FXR signaling pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: Globally, the incidence rate and number of patients with nonalcoholic fatty liver disease are increasing, which has become one of the greatest threats to human health. However, there is still no effective therapy and medicine so far. Silphium perfoliatum L. is a perennial herb native to North America, which is used to improve physical fitness and treat liver and spleen related diseases in the traditional medicinal herbs of Indian tribes. This herb is rich in chlorogenic acids, which have the functions of reducing blood lipids, losing weight and protecting liver. However, the effect of these compounds on nonalcoholic fatty liver disease remains unclear. AIM OF THE STUDY: Clarify the therapeutic effects and mechanism of the extract (CY-10) rich in chlorogenic acid and its analogues from Silphium perfoliatum L. on non-alcoholic fatty liver disease, and to determine the active compounds. MATERIALS AND METHODS: A free fatty acid-induced steatosis model of HepG2 cells was established to evaluate the in vitro activity of CY-10 in promoting lipid metabolism. Further, a high-fat diet-induced NAFLD model in C57BL/6 mice was established to detect the effects of CY-10 on various physiological and biochemical indexes in mice, and to elucidate the in vivo effects of the extract on regulating lipid metabolism, anti-inflammation and hepatoprotection, and nontarget lipid metabolomics was performed to analyze differential metabolites of fatty acids in the liver. Subsequently, western blotting and immunohistochemistry were used to analyze the target of the extract and elucidate its mechanism of action. Finally, the active compounds in CY-10 were elucidated through in vitro activity screening. RESULTS: The results indicated that CY-10 significantly attenuated lipid droplet deposition in HepG2 cells. The results of in vivo experiments showed that CY-10 significantly reduce HFD-induced mouse body weight and organ index, improve biochemical indexes, oxidation levels and inflammatory responses in the liver and serum, thereby protecting the liver tissue. It can promote the metabolism of unsaturated fatty acids in the liver and reduce the generation of saturated fatty acids. Furthermore, it is clarified that CY-10 can promote lipid metabolism balance by regulating AMPK/FXR/SREPB-1c/PPAR-γ signal pathway. Ultimately, the main active compound was proved to be cryptochlorogenic acid, which has a strong promoting effect on the metabolism of fatty acids in cells. Impressively, the activities of CY-10 and cryptochlorogenic acid were stronger than simvastatin in vitro and in vivo. CONCLUSION: For the first time, it is clarified that the extract rich in chlorogenic acids and its analogues in Silphium perfoliatum L. have good therapeutic effects on non-alcoholic fatty liver disease. It is confirmed that cryptochlorogenic acid is the main active compound and has good potential for medicine.

Inhibitory activities and rules of plant gallotannins with different numbers of galloyl moieties on sucrase, maltase and α-amylase in vitro and in vivo.

BACKGROUND: α-Glucosidase inhibitors could effectively reduce postprandial blood glucose (PBG) levels and control the occurrence of complications of diabetes. Gallotannins (GTs) in plants have attracted much attention due to their significant α-glucosidase inhibitory activities in vitro. However, there is still a lack of systematic comparative studies to further elucidate inhibitory activities in vivo and in vitro of these compounds against α-glucosidase, especially for mammalian sucrase and maltase, and analyze their structure-activity relationship. PURPOSE: Determine the in vitro and in vivo inhibitory activities of five GTs with different number of galloyl moieties (GMs) on sucrase, maltase and α-amylase, and elucidate the relationship between α-glucosidase inhibitory activities and the number and connection mode of GMs. METHODS: Molecular docking and dynamics were used to study the binding mode and binding ability of five GTs against sucrase, maltase and α-amylase. Then, the inhibitory activities and inhibitory mechanisms of these compounds on sucrase, maltase and α-amylase in vitro were studied using inhibitory assay and enzyme inhibition kinetics. Further, the hypoglycemic effects in vivo of these compounds were demonstrated by three polysaccharides tolerance experiments on diabetes model mice. RESULTS: The results of molecular docking showed that these compounds could bind to enzymes through hydrogen bonds, hydrophobic interactions, etc. In addition, the α-glucosidase inhibition comparative studies in vitro and in vivo demonstrated that the inhibitory activities of these compounds on all three sucrase, maltase and α-amylase were ranked as TA ≈ PGG > TeGG > TGG > 1GG, and their inhibitory activities increases with the increase in the number of GMs. Moreover, the hypoglycemic effects of 1,2,3,4,6-pentagalloylglucose (PGG) and tannic acid (TA) in vitro and in vivo were also confirmed to be equivalent to or even stronger than that of acarbose. CONCLUSION: α-Glucosidase inhibitory activities in vitro and in vivo of GTs were positively correlated with the number of GTs, and the more the number, the stronger the activity. However, PGG with five GTs and TA with ten GTs showed almost identical α-glucosidase inhibitory activities, possibly due to the reduced binding force with the enzyme caused by spatial hindrance.

Hypoglycemic activity of Codonopsis pilosula (Franch.) Nannf. in vitro and in vivo and its chemical composition identification by UPLC-Triple-TOF-MS/MS.

Codonopsis pilosula (Franch.) Nannf. (CPN), mainly planted in the northwest region, is a traditional Chinese medicine/good health food for nourishing qi and promoting blood circulation. This study firstly evaluated the inhibitory effects of the CPN extraction (CPNE) on α-glucosidase in vitro and in vivo, and tentatively confirmed its chemical ingredients by employing UHPLC-Triple-TOF-MS/MS. The CPNE had strong inhibitory activities against mammalian α-glucosidase (sucrase and maltase) and yeast α-glycosidase with semi-inhibitory concentrations (IC50) of 0.241 mg mL-1, 0.326 mg mL-1 and 1.167 mg mL-1, respectively. In addition, the CPNE could significantly decrease the postprandial blood glucose (PBG) levels in the sucrose/maltose/starch tolerance assays of diabetic mice. Furthermore, a total of 29 compounds, including 3 alkaloids, 13 phenolic acids, 8 alcohol glycosides and 5 alkynosides, were assigned based on comparison with the standards and references, as well as the analysis of main fragments. These results demonstrated that CPN could be used as an adjuvant therapy or dietary supplements to effectively control the occurrence and development of diabetes.

Resveratroloside Alleviates Postprandial Hyperglycemia in Diabetic Mice by Competitively Inhibiting α-Glucosidase.

The regulation of postprandial blood glucose (PBG) levels is an effective therapeutic method to treat diabetes and prevent diabetes-related complications. Resveratroloside is a monoglucosylated form of stilbene that is present in red wine, grapes, and several traditional medicinal plants. In our study, the effect of resveratroloside on reducing PBG was studied in vitro and in vivo. In comparison to the starch treatment alone, the oral administration of resveratroloside-starch complexes significantly inhibited the PBG increase in a dose-dependent pattern in normal and diabetic mice. The PBG level treated with resveratrol (30 mg/kg) was not lower than that of resveratroloside. Further analyses demonstrated that resveratroloside strongly and effectively inhibited α-glucosidase, with an 50% inhibitory concentration value of 22.9 ± 0.17 µM, and its inhibition was significantly stronger than those of acarbose and resveratrol (264 ± 3.27 and 108 ± 2.13 µM). Moreover, a competitive inhibition mechanism of resveratroloside on α-glucosidase was determined by enzyme kinetic assays and molecular docking experiments. The molecular docking of resveratroloside with α-glucosidase demostrated the competitive inhibitory effect of resveratroloside, which occupies the catalytic site and forms strong hydrogen bonds with the residues of α-glucosidase. Resveratrol was also determined to be a competitive inhibition mechanism on α-glucosidase by enzyme kinetic assays and molecular docking experiments. This study suggested that resveratroloside had the ability to regulate PBG levels and can be considered a potential agent for the treatment of diabetes mellitus.