Jia-Sheng Wu

A Protein Tyrosine Phosphatase 1B Activity Inhibitor from the Fruiting Bodies of Ganoderma lucidum (Fr.) Karst and Its Hypoglycemic Potency on Streptozotocin-Induced Type 2 Diabetic Mice

Inhibition of protein tyrosine phosphatase 1B (PTP1B) activity has been considered to be a promising therapy approach to treat type 2 diabetes. In this work, a novel PTP1B activity inhibitor, named FYGL (Fudan-Yueyang-G. lucidum), was screened from the fruiting bodies of Ganoderma lucidum and showed an efficient PTP1B inhibitory potency with IC₅₀ = 5.12 ± 0.05 μg/mL. FYGL is a water-soluble macromolecular proteoglycan with a protein to polysaccharide ratio of 17:77 and a viscosity-average molecular weight (M(η)) of 2.6 × 10⁵. The type 2 diabetic mice treated orally by FYGL showed an obvious decrease in plasma glucose level compared with the diabetic controls without drug treatment, comparable with that of diabetic mice treated with metformin, a clinical drug. The toxicity of FYGL is very low. The results indicate that FYGL may serve as a drug candidate or a health-care food for diabetic therapy or protection.

Antidiabetic, Antihyperlipidemic and Antioxidant Activities of a Novel Proteoglycan from Ganoderma Lucidum Fruiting Bodies on db/db Mice and the Possible Mechanism

Previously, we screened a proteoglycan for anti-hyperglycemic, named FYGL, from Ganoderma Lucidum. For further research of the antidiabetic mechanisms of FYGL in vivo, the glucose homeostasis, activities of insulin-sensitive enzymes, glucose transporter expression and pancreatic function were analyzed using db/db mice as diabetic models in the present work. FYGL not only lead to a reduction in glycated hemoglobin level, but also an increase in insulin and C-peptide level, whereas a decrease in glucagons level and showed a potential for the remediation of pancreatic islets. FYGL also increased the glucokinase activities, and simultaneously lowered the phosphoenol pyruvate carboxykinase activities, accompanied by a reduction in the expression of hepatic glucose transporter protein 2, while the expression of adipose and skeletal glucose transporter protein 4 was increased. Moreover, the antioxidant enzyme activities were also increased by FYGL treatment. Thus, FYGL was an effective antidiabetic agent by enhancing insulin secretion and decreasing hepatic glucose output along with increase of adipose and skeletal muscle glucose disposal in the late stage of diabetes. Furthermore, FYGL is beneficial against oxidative stress, thereby being helpful in preventing the diabetic complications.

Effect of a novel proteoglycan PTP1B inhibitor from Ganoderma lucidum on the amelioration of hyperglycaemia and dyslipidaemia in db/db mice

Protein tyrosine phosphatase 1B (PTP1B) is implicated in the negative regulation of the insulin signalling pathway by dephosphorylating the insulin receptor (IR) and IR substrates. Ganoderma lucidum has traditionally been used for the treatment of diabetes in Chinese medicine; however, its anti-diabetic potency and mechanism in vivo is still unclear. Our previously published study reported a novel proteoglycan PTP1B inhibitor, named Fudan-Yueyang-Ganoderma lucidum (FYGL) from G. lucidum, with a half-maximal inhibitory concentration (IC₅₀) value of 5·12 (sem 0·05) μg/ml, a protein:polyglycan ratio of 17:77 and 78 % glucose in polysaccharide, and dominant amino acid residues of aspartic acid, glycine, glutamic acid, alanine, serine and threonine in protein. FYGL is capable of decreasing plasma glucose in streptozotocin-induced diabetic mice with a high safety of median lethal dose (LD₅₀) of 6 g/kg. In the present study, C57BL/6 db/db diabetic mice were trialed further using FYGL as well as metformin for comparison. Oral treatment with FYGL in db/db diabetic mice for 4 weeks significantly (P < 0·01 or 0·05) decreased the fasting plasma glucose level, serum insulin concentration and the homeostasis model assessment of insulin resistance. FYGL also controlled the biochemistry indices relative to type 2 diabetes-accompanied lipidaemic disorders. Pharmacology research suggests that FYGL decreases the plasma glucose level by the mechanism of inhibiting PTP1B expression and activity, consequently, regulating the tyrosine phosphorylation level of the IR β-subunit and the level of hepatic glycogen, thus resulting in the improvement of insulin sensitivity. Therefore, FYGL is promising as an insulin sensitiser for the therapy of type 2 diabetes and accompanied dyslipidaemia.

Combination of Active Components of Xiexin Decoction Ameliorates Renal Fibrosis Through the Inhibition of NF-κB and TGF-β1/Smad Pathways in db/db Diabetic Mice

Xiexin decoction, a herbal therapeutic agent commonly used in traditional Chinese medicine, is recognized for its beneficial effects on diabetic nephropathy exerted through the combined action of multiple components, including Rhizoma Coptidis alkaloids (A), Radix et Rhizoma Rhei polysaccharides (P), and Radix Scutellaria flavones (F). Our previous studies have shown that a combination of A, P, and F (APF) exhibits renoprotective effects against diabetic nephropathy. This study was aimed at determining the effects of APF on renal fibrosis in diabetic nephropathy and elucidating the underlying molecular mechanisms. To evaluate the effects of APF, in vivo, db/db diabetic mice were orally administered a low or high dose of APF (300 or 600 mg/kg, respectively) once a day for 8 weeks. We evaluated the blood and urine indices of metabolic and renal function, renal tissue histopathology, renal inflammation, and fibrosis. APF treatment significantly ameliorated glucose and lipid metabolism dysfunction, decreased urinary albumin excretion, normalized creatinine clearance, and reduced the morphological changes in renal tissue. Additionally, APF administration in db/db diabetic mice reduced the elevated levels of renal inflammation mediators such as intercellular adhesion molecule-1, monocyte chemotactic protein-1, tumor necrosis factor-α, interleukin-1β, and active nuclear factor κB (NF-κB). APF treatment also reduced type I and IV collagen, transforming growth factor-β1 (TGF-β1), and TGF-β1 type II receptor expression levels, and decreased the phosphorylation of Smad2/3 in the kidneys of db/db diabetic mice. These results suggest that APF reduces renal fibrosis in diabetic nephropathy through the NF-κB and TGF-β1/Smad signaling pathways. In vitro, APF treatment reduced cell proliferation and protein expression of α-smooth muscle actin, collagen I, TGF-β1 and NF-κB in mesangial cells cultured with high glucose concentrations. Our findings indicate that treatment with multi-component herbal therapeutic formulations may be a useful approach for the treatment of diabetic nephropathy.

Simultaneous quantification of catechin, epicatechin, liquiritin, isoliquiritin, liquiritigenin, isoliquiritigenin, piperine and glycyrrhetinic acid in rat plasma by HPLC-MS/MS: application to a pharmacokinetic study of Longhu Rendan pills

A sensitive, specific, accurate HPLC-MS/MS method was developed and validated for the simultaneous quantification of catechin, epicatechin, liquiritin, isoliquiritin, liquiritigenin, isoliquiritigenin, piperine and glycyrrhetinic acid from Longhu Rendan pills in rat plasma. Chromatographic separation was performed with a Hypersil Gold C18 column using a gradient of methanol and 0.01% acetic acid containing 0.2 mm ammonium acetate as mobile phase. The analytes were quantified on a triple quadrupole mass spectrometer, operating in selected reaction monitoring mode and switching the electrospray ion source polarity between positive and negative modes in a single run. The calibration curves of catechin, epicatechin, liquiritin, isoliquiritin, liquiritigenin, isoliquiritigenin, piperine and glycyrrhetinic acid were linear over the concentration ranges of 5-2000, 5-2000, 0.5-200, 0.5-200, 0.25-100, 0.25-100, 0.025-10 and 0.50-200 ng mL(-1) , respectively. The intra- and inter-assay precisions and accuracies were <11.6 and 91.9-108.2%, respectively, for all analytes. Matrix effects for all analytes were between 88.2 and 114.2%. Stability testing showed that all analytes were stable in plasma at 24 °C for 3 h, at 4 °C for 24 h, after three freeze-thaw cycles, and at -80 °C for 15 days. The method was successfully applied to an in vivo study evaluating the pharmacokinetics of multiple nonvolatile compounds following intragastric administration of Longhu Rendan pills to rats. Copyright

Simultaneous quantification of multiple components in rat plasma by UPLC-MS/MS and pharmacokinetic study after oral administration of Huangqi decoction

A rapid, sensitive and accurate UPLC-MS/MS method was developed for the simultaneous quantification of components of Huangqi decoction (HQD), such as calycosin-7-O-β-d-glucoside, calycosin-glucuronide, liquiritin, formononetin-glucuronide, isoliquiritin, liquiritigenin, ononin, calycosin, isoliquiritigenin, formononetin, glycyrrhizic acid, astragaloside IV, cycloastragenol, and glycyrrhetinic acid, in rat plasma. After plasma samples were extracted by protein precipitation, chromatographic separation was performed with a C18 column, using a gradient of methanol and 0.05% acetic acid containing 4mm ammonium acetate as the mobile phase. Multiple reaction monitoring scanning was performed to quantify the analytes, and the electrospray ion source polarity was switched between positive and negative modes in a single run of 10 min. Method validation showed that specificity, linearity, accuracy, precision, extraction recovery, matrix effect and stability for 14 components met the requirements for their quantitation in biological samples. The established method was successfully applied to the pharmacokinetic study of multiple components in rats after intragastric administration of HQD. The results clarified the pharmacokinetic characteristics of multiple components found in HQD. This research provides useful information for understanding the relation between the chemical components of HQD and their therapeutic effects.

Huangqi Decoction Alleviates Alpha-Naphthylisothiocyanate Induced Intrahepatic Cholestasis by Reversing Disordered Bile Acid and Glutathione Homeostasis in Mice

Intrahepatic cholestasis is a serious symptom of liver disorders with limited therapies. In this study, we investigated the efficacy of Huangqi decoction (HQD), a two-herb classic traditional Chinese medicine (TCM), in the treatment of alpha-naphthylisothiocyanate (ANIT)-induced intrahepatic cholestasis in mice. HQD treatment ameliorated impaired hepatic function and tissue damage. A metabolomics study revealed that the endogenous metabolites significantly affected by HQD were related to bile acid (BA) biosynthesis and glutathione metabolism pathways. HQD treatment decreased the intrahepatic accumulation of cytotoxic BAs, normalized serum BA levels, and increased biliary and urinary BA excretion. Additionally, HQD restored the hepatic glutathione content and suppressed reactive oxygen species (ROS) in cholestatic mice. Protein and gene analysis revealed that HQD increased the expression of the hepatic metabolizing enzymes cytochrome P450 (CYP) 2B10 and UDP glucuronosyltransferase family 1 member A1 (UGT1A1), as well as multidrug resistance-associated protein 2 (Mrp2), Mrp3, and Mrp4, which play crucial roles in BA homeostasis. Further, HQD increased the protein expression of glutamate-cysteine ligase, which is involved in the synthesis of glutathione. Importantly, HQD increased the nuclear expression of nuclear factor-E2-related factor-2 (Nrf2). In conclusion, HQD protects against intrahepatic cholestasis by reversing the disordered homeostasis of BAs and glutathione.

Involvement of P-glycoprotein and multidrug and toxin extrusion protein 1 in hepatic and renal berberine efflux in mice

Berberine (BBR) is a natural alkaloid and commonly used drug with extensive pharmacological effects. The blood exposure of BBR is known to be extremely low while its tissue exposure is extremely high, especially in the liver and kidney where its uptake is mediated by organic cation transporters and organic anion-transporting polypeptides. However, the efflux mechanism in the liver and kidney is not clear. Therefore, the present study was designed to investigate the mechanism of hepatic and renal efflux of BBR. A transport assay of BBR using rat Madin–Darby canine kidney (MDCK)-multidrug and toxin extrusion protein 1 (rMate1) cells and a transcellular transport assay using MDCK-multidrug resistance protein 1 (MDR1) cells were conducted to evaluate the efflux mechanism. Tissue distribution and excretion of BBR were measured using liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis of specimens from C57BL/6J mice co-administered BBR and itraconazole (ITZ, a P-glycoprotein, P-gp inhibitor) or pyrimethamine (PYR, a MATE1 inhibitor). The inhibitory effect of ITZ and PYR on the combined effects of BBR with P-gp and MATE1 was verified using Glide docking within the Schrodinger program. BBR uptake was observed to be pH-, time-, temperature- and concentration-dependent and was inhibited by PYR in MDCK-rMate1 cells. ITZ significantly decreased the Pappb→a values of BBR in MDCK-MDR1 cells. Co-administration with PYR or ITZ increased the concentration of BBR in the liver and kidney and decreased its excretion in urine and bile in mice. In addition, co-administration with ITZ increased the plasma concentration of BBR. Both ITZ and PYR had higher docking scores than BBR did to P-gp and rMate1, respectively and separately prevented the combination of BBR with rMate1 and P-gp. This study indicated that both MATE1 and P-gp mediated hepatic and renal efflux of BBR. These results provide salient information that enhances the understanding of the pharmacokinetics properties of BBR and its interaction with other drugs.

Chicken bile powder protects against α-naphthylisothiocyanate-induced cholestatic liver injury in mice

This study explored the effects of chicken bile powder (CBP), a 2000-year-old Chinese medicine, on α-naphthyl isothiocyanate (ANIT)-induced intrahepatic cholestasis in mice. CBP treatment for 14 days significantly ameliorated ANIT-induced changes in serum alanine aminotransferase, aspartate aminotransferase, bile acids, bilirubin, γ-glutamyl transpeptidase, alkaline phosphatase, and liver tissue morphology. Serum metabolomics showed changes in 24 metabolites in ANIT-exposed mice; 16 of these metabolites were reversed by CBP treatment via two main pathways (bile acid biosynthesis and arachidonic acid metabolism). Additionally, CBP administration markedly increased fecal and biliary bile acid excretion, and reduced total and hydrophobic bile acid levels in the livers of cholestatic mice. Moreover, CBP increased liver expression of bile acid efflux transporters and metabolic enzymes. It also attenuated ANIT-induced increases in hepatic nuclear factor-κB-mediated inflammatory signaling, and increased liver expression of the nuclear farnesoid X receptor (FXR) in cholestatic mice. CBP also activated FXR in vitro in HEK293T cells expressing mouse Na+-taurocholate cotransporting polypeptide. It did not ameliorate the ANIT-induced liver injuries in FXR-knockout mice. These results suggested that CBP provided protection from cholestatic liver injury by restoring bile acid homeostasis and reducing inflammation in a FXR-dependent manner.