Kefeng Ruan

MDG-1, a polysaccharide from Ophiopogon japonicus exerts hypoglycemic effects through the PI3K/Akt pathway in a diabetic KKAy mouse model

ETHNOPHARMACOLOGICAL RELEVANCE Ophiopogon japonicus is a traditional Chinese medicine that might be helpful for the treatment of type 2 diabetes. Recent studies have confirmed its beneficial properties, but not the mechanism of action. AIM OF STUDY In this study, we examined the effects of a water-soluble β-d-fructan (MDG-1) from O. japonicus on type 2 diabetes through the PI3K/Akt pathway in a diabetic KKAy mouse model. MATERIALS AND METHODS MDG-1 was extracted from the tube root of O. japonicus and purified as described previously (Xu et al., 2005). The KKAy mice were gavaged once daily with either distilled water, MDG-1or rosiglitazonefor 8 weeks. Blood glucose levels were tested regularly for the fed and fasted mice. In order to evaluate the effect of MDG-1 on disease progression, the proteins of InsR/IRS-1/PI3K/Akt/GSK-3/Glut-4 were detected by Western blotting and serum TG, TC, HDL-C, LDL-C were also dertermined. RESULTS MDG-1 reduced the hyperglycemia, hyperinsulinemia and hyperlipidemia in the KKAy mice. The oral glucose tolerance test (OGTT) and the level of insulin in the serun showed that insulin resistance in KKAy mice was ameliorated after MDG-1 treated. After 8 weeks treatment with 300mg/kg MDG-1, the content of triglycerides (TG) and low density lipoprotein cholesterol (LDL-C) the serum decreased significantly. Meanwhile high density lipoprotein cholesterol (HDL-C) content increased notably. MDG-1 did not have any effect on total cholesterol (TC) content in the serum, whereas rosiglitazone significantly decreased the TC content. In addition, MDG-1 upregulates the phosphoinositide 3-kinase p85 subunit, Akt, insulin receptor (InsR), insulin receptor substrate-1 (IRS-1) and Glut-4 expression, but downregulates glycogen synthase kinase 3β expression. CONCLUSIONS These data indicate that MDG-1 has remarkable anti-diabetic activity through the InsR/IRS-1/PI3K/Akt/GSK-3/Glut-4 signaling pathway. We believe that MDG-1 is a promising anti-diabetic compound that will be helpful for the treatment of T2DM.

Hypoglycemic effects of MDG-1, a polysaccharide derived from Ophiopogon japonicas, in the ob/ob mouse model of type 2 diabetes mellitus

Ophiopogon japonicus is a traditional Chinese medicine used to treat diabetes mellitus. We investigate the anti-ischemic properties of a water-soluble β-D-fructan (MDG-1) from O. japonicus, and assess the antidiabetic effects of MDG-1. In the study, ob/ob mice were treated with 150 mg/kg or 300 mg/kg MDG-1 by gavage for 23 d. Blood glucose levels were measured regularly. An oral glucose tolerance test (OGTT) was preformed on day 21. The levels of insulin, total cholesterol and triglyceride in the serum were measured at the end of administration. The liver triglyceride content and tissue weights were also determined. Results show that MDG-1 (300 mg/kg) was demonstrated to exert acute and long-term hypoglycemic effects on fed blood glucose in ob/ob mice. However, only a marginal hypoglycemic effect on fasting blood glucose levels was observed. MDG-1 (300 mg/kg) improved oral glucose tolerance and reduced serum insulin levels and triglyceride content in the liver in ob/ob mice. Furthermore, a reduction in body weight gain and the weight of subcutaneous fat were observed following treatment with MDG-1 (150 mg/kg) compared with the control group. MDG-1 had no significant effects on the total cholesterol and triglyceride levels, food intake and other adipose and organ tissues. These data suggest that MDG-1 exhibits hypoglycemic activity and reduces insulin resistance.

Development of potential novel cushioning agents for the compaction of coated multi-particulates by co-processing micronized lactose with polymers.

This work aimed to explore the potential of lactose as novel cushioning agents with suitable physicomechanical properties by micronization and co-spray drying with polymers for protecting coated multi-particulates from rupture when they are compressed into tablets. Several commercially available lactose grades, micronized lactose (ML) produced by jet milling, spray-dried ML (SML), and polymer-co-processed SMLs, were evaluated for their material characteristics and tableting properties. Hydroxypropylcellulose (HPC), hydroxypropylmethylcellulose (HPMC), and polyvinylpyrrolidone (PVP) at three different levels were evaluated as co-processed polymers for spray drying. Sugar multi-particulates layered with chlorpheniramine maleate followed by an ethylcellulose coat were tableted using various lactose types as fillers. Drug release from compacted multi-particulate tablets was used to evaluate the cushioning effect of the fillers. The results showed that the cushioning effect of lactose principally depended on its particle size. Micronization can effectively enhance the protective action of lactose. Although spray drying led to a small reduction in the cushioning effect of ML, it significantly improved the physicomechanical properties of ML. Co-spray drying with suitable polymers improved both the cushioning effect and the physicomechanical properties of SML to a certain degree. Among the three polymers studied, HPC was the most effective in terms of enhancing the cushioning effect of SML. This was achieved by reducing yield pressure, and enhancing compressibility and compactibility. The combination of micronization and co-spray drying with polymers is a promising method with which new applications for lactose can be developed.

MDG-1, a polysaccharide from Ophiopogon japonicus, prevents high fat diet-induced obesity and increases energy expenditure in mice.

MDG-1, a water-soluble polysaccharide extracted from Ophiopogon japonicus, has potent hypoglycemic and weight control effects. We investigated the impact of MDG-1 on body weight, indirect calorimetry, body composition, plasma biochemical indices and obesity-related mitochondrial activity in diet-induced obese mice. Obese C57BL/6 mice induced by a high fat diet were given either vehicle or vehicle plus MDG-1 at 300 mg per body weight for 16-weeks. MDG-1 could evoked weight loss and reduce adipose tissue mass (by up to ∼ 50%) in the obese animals by increasing oxygen consumption and energy expenditure without inhibiting appetite or increasing physical activity. In addition, MDG-1 could ameliorate plasma lipid profiles, decrease leptin secretion, attenuate hepatic lipid accumulation and increased the expressions of genes related to lipid and energy metabolism in the liver. MDG-1 is a promising candidate drug to treat obesity-related metabolic diseases.

Pharmacokinetics, tissue distribution and metabolism of senkyunolide I, a major bioactive component in Ligusticum chuanxiong Hort. (Umbelliferae)

ETHNOPHARMACOLOGICAL RELEVANCE Ligusticum chuanxiong Hort. (Umbelliferae) is widely prescribed for treatment of cardiovascular diseases in China for centuries. One of the major bioactive components in L. chuanxiong is senkyunolide I (SEI), which shows pharmacological activities in anti-migraine and anti-oxidative damage. MATERIALS AND METHODS The aim of this study was to investigate in vivo pharmacokinetics, tissue distribution and metabolism of SEI in rats. The concentrations of SEI in plasma and tissues were determined by a high performance liquid chromatography (HPLC) method, and the pharmacokinetic parameters were calculated using and non-compartmental analysis. The metabolites were identified using high performance liquid chromatography tandem mass (HPLC-ESI-MS/MS) method. RESULTS After oral and intravenous administration, SEI was quickly eliminated from plasma and its oral bioavailability (BA) was about 37.25%, which was smaller than intraportal BA (81.17%), but similar to intraduodenal BA (36.91%), suggesting that gastric first-pass effect of SEI is negligible, and hepatic first-pass effect was approximately 18.83%. After oral administration, SEI could penetrate blood brain barrier and extensively distribute in tested tissues, with the descending order of AUC being kidney, liver, lung, muscle, brain, heart, thymus, and spleen in rat. The parent compound and nine metabolites were found and identified in rat bile after oral administration of SEI (36 mg/kg). The metabolic mechanism of SEI in rat mainly involves methylation, glucuronidation and glutathione conjugation during the phase II biotransformation pathway in rats. CONCLUSIONS The information gained here may provide a meaningful basis for clinical application of such a bioactive compound of herbal medicines.

Effect of metformin on the urinary metabolites of diet-induced-obese mice studied by ultra performance liquid chromatography coupled to time-of-flight mass spectrometry (UPLC-TOF/MS)

Obesity is becoming a health concern worldwide and metformin, a first line anti-diabetic drug, was associated with weight loss under different backgrounds. However, most researches focused on the anti-diabetic mechanism and less attention has been paid on the mechanism of weight loss of metformin. Therefore, we established a metabonomic method to evaluate metformin action in preventing obesity in a high fat diet-induced-obesity (DIO) mice model. 36 male C57BL/6 mice (8-week old) were randomly divided into control group (n=12, normal chow), model group (n=12, high fat chow) and metformin group (n=12, high fat chow and dosed with metformin) over 16 weeks. A urinary metabonomic study using UPLC-TOF/MS was performed in combination with multivariate statistical analysis. In addition, indices of body weight and food intake as well as fasting blood glucose, fed blood glucose, oral glucose tolerance test (OGTT) and plasma insulin were collected. Significant weight loss in metformin-treated mice was achieved and 21 potential biomarkers were identified. Decreased glucose, myristic acid, stearidonic acid, lysoPC (16:0), lysoPC (18:0), L-glutamic acid, L-methionine, L-threonine, L-phenylalanine, L-histidine, L-carnitine, L-malic acid and pantothenic acid in urine indicated that metformin may have exerted effects on energy metabolism. Further, based on the biomarkers, we cautiously propose that tricarboxylic acid cycle (TCA) may have been compromised by metformin and might contribute to the activation of adenosine monophosphate kinase (AMPK), then AMPK activation led to more β-oxidation of certain fatty acids and augmented lipolysis and thus induced weight loss. Related cellular and molecular studies are being considered to further investigate the underlying mechanism.

Mono-PEGylated radix ophiopogonis polysaccharide for the treatment of myocardial ischemia

This work aimed to improve the clinical application of Radix Ophiopogonis polysaccharide (ROP), a natural anti-myocardial ischemic fructan with Mw of 4.80 kDa, by mono-PEGylation. Three mono-PEGylated ROPs were prepared by a moderate coupling reaction between amino-terminated methoxy-PEG (20-, 30-, or 40-kDa) and excessive hydroxyl-activated ROP. After being fully characterized by proton nuclear magnetic resonance as well as high-performance gel permeation chromatography and anthrone-sulfuric acid colorimetry coupled assay, they were evaluated for pharmacokinetics and anti-myocardial ischemic activities in rats with coronary artery ligation. The results showed that mono-PEGylated ROPs were successfully and effectively prepared. Compared with ROP, the three mono-PEGylated ROPs showed approximately 32-, 85-, and 100-fold prolonged retention in systemic circulation with plasma half-lives reaching 16.1, 42.4, and 49.8 h, respectively. Studies on anti-myocardial ischemic effects of the conjugates showed that administrated at the same molar dose of 4 μ mol/kg per injection as ROP, they could achieve comparable or even better therapeutic effects although their administration intervals were 2- to 6-fold longer than that of ROP. These findings confirm that PEGylation would be a promising approach to markedly reducing the injection-administered frequency of ROP and hence patient compliance without sacrifice of the therapeutic efficacy by significantly improving its pharmacokinetics.

Comparison of tissue distribution of a PEGylated Radix Ophiopogonis polysaccharide in mice with normal and ischemic myocardium

PEGylation was found to be a promising approach to improve the anti-myocardial ischemic activity of Radix Ophiopogonis polysaccharide (ROP) by prolonging its retention in plasma. To fully evaluate the effectiveness and safety of this strategy, the tissue distribution of PEGylated ROP was investigated in this study. A long-circulating and bioactive PEGylated ROP with 1.04 mol 20-kDa mPEG per mol ROP ((1.04)P(20k)-R) was prepared by a moderate coupling reaction between the hydroxyl-activated ROP and the amino-terminated mPEG. Its tissue distribution in mice with normal and ischemic myocardium was studied and compared with ROP. The results show that the descending order of tissue distribution of (1.04)P(20k)-R ranked by AUC was kidney, lung, heart, liver, and brain in normal mice and kidney ≈ lung ≈ heart, liver and brain in mice with myocardial ischemia. With the exception of the heart, myocardial ischemia did not cause obvious changes in the distribution of (1.04)P(20k)-R in the other tissues studied. Owing to the enhanced permeability and retention effect caused by ischemia, the AUC of (1.04)P(20k)-R in ischemic hearts was approximately 1.6-fold greater than in normal hearts. Compared with ROP in rats, the distribution tendency of (1.04)P(20k)-R in mouse kidney, brain, and lung was reduced by approximately 42, 1.6, and 1.3 times, respectively, whereas it was increased by approximately 1.3-fold in the liver. The results of this study are highly instructive for the further pharmaceutical development of PEGylated ROP.

A Review of Experimental Research on Herbal Compounds in Amyotrophic Lateral Sclerosis

Amyotrophic lateral sclerosis (ALS) is the most common form of motor neuron disease worldwide, leading to progressive muscle atrophy and paralysis. The limited success of conventional treatment for ALS has prompted investigations into complementary and alternative therapies. Herbal remedies provide good prospects of ALS prevention and treatment, with advantages such as multiple targets, multiple links, and few side effects. Studies in vitro and in vivo have shown that herbs have a great potential for treatment of ALS, with therapeutic effects against oxidative stress, excitatory amino acid toxicity, neuroinflammation, and calcium cytotoxicity. Active monomers or ingredients extracted from herbs are considered promising candidates for ALS. Therefore, we review recent experimental research on monomers and compounds isolated from herbal remedies for preventing and treating ALS. Copyright

A polysaccharides MDG-1 augments survival in the ischemic heart by inducing S1P release and S1P1 expression

Ophiopogon japonicus is a traditional Chinese medicine used to treat cardiovascular disease. Recent studies have confirmed the anti-ischemic properties of a water-soluble β-D-fructan (MDG-1) from O. japonicus. The sphingosine 1-phosphate (S1P) signaling pathway is involved in its cytoprotective effects. Herein, we explore the role of the S1P signaling pathway in the anti-ischemic effect of MDG-1 and assess one possible mechanism by which it induces S1P release and sphingosine 1-phosphate receptor 1 (S1P(1)) expression in human microvascular endothelial cells (HMEC-1) and cardiomyocytes. Our evidence demonstrates that MDG-1 promotes sphingosine kinase (SPHK) activity in HMEC-1 cells. An analytical method for measuring the mass of S1P using ESI/MS/MS was developed and we found that MDG-1 increases intracellular S1P levels. Meanwhile, MDG-1 is protective during hypoxia and ischemia through mechanisms that require S1P(1) receptor activation, which was confirmed both in oxygen glucose deprivation (OGD) and coronary artery ligation models by using transfection of cloned human S1P(1) receptor and RNA interference. These data indicate that the increase of intracellular S1P generation, particularly by activation of the SPHK enzyme, coupled with the autocrine and paracrine stimulation of cell surface S1P receptors, is a potential mechanism in the anti-ischemic and cell protective effect of MDG-1.