Stereospecific high-affinity TRPV1 antagonists: chiral N-(2-benzyl-3-pivaloyloxypropyl) 2-[4-(methylsulfonylamino)phenyl]propionamide analogues

Previously, we reported the thiourea antagonists 2a and 2b as potent and high affinity TRPV1 antagonists. For further optimization of the lead compounds, a series of their amide and alpha-substituted amide surrogates were investigated and novel chiral N-(2-benzyl-3-pivaloyloxypropyl) 2-[4-(methylsulfonylamino)phenyl]propionamide analogues were characterized as potent and stereospecific rTRPV1 antagonists. In particular, compounds 72 and 73 displayed high binding affinities, with K i values of 4.12 and 1.83 nM and potent antagonism with K i values of 0.58 and 5.2 nM, respectively, in rTRPV1/CHO cells. These values are comparable or more potent than those of 5-iodoRTX under the same assay conditions. A distinctive binding model that includes two hydrophobic pockets is proposed for this series of compounds based on docking studies of 57 and 72 with a homology model of the TM3/4 region of TRPV1.     

A beverage of Asiatic plantain extracts alleviated postprandial oxidative stress in overweight hyperlipidemic subjects challenged with a high-fat meal: a preliminary study

There is emerging interest in the potential of the phenolic compounds of Asiatic plantain (Plantago asiatica L.) to attenuate in vitro and in vivo oxidative stress. We hypothesized that a single administration of Asiatic plantain beverage may exert protective effects against postprandial oxidative stress. This preliminary study was designed to compare the ability of different doses of Asiatic plantain beverage to mitigate the postprandial effects of a high-fat meal on the oxidation of lipids and DNA in overweight hyperlipidemic subjects. In a randomized, double-blind, placebo-controlled parallel design (n = 10/group), 40 subjects were administered a single high-fat meal with either a placebo or 1 of 3 Asiatic plantain extract beverages (low, intermediate, or high dose). Blood samples were obtained at fasting and 60, 120, 240, and 360 minutes (total of 5 samples) after intervention. The data showed a tendency for plasma free fatty acid levels to decrease in response to high-dose Asiatic plantain at all time points. Plasma oxidized low-density lipoprotein levels were significantly reduced with high-dose Asiatic plantain at 120 minutes (P = .0251 vs placebo). A comet assay revealed that DNA damage in lymphocytes was significantly decreased by Asiatic plantain at 360 minutes (P = .0225 vs placebo). There were no treatment differences in triglyceride or malondialdehyde levels. The maximum suppression was achieved with a high dose (20 g Asiatic plantain extract/80 mL). These results suggest that by protecting low-density lipoprotein and DNA, an Asiatic plantain beverage may be useful to enhance antioxidant.     

Hypermethylation of repetitive DNA elements in livers of mice fed an atherogenic diet

ObjectiveDNA methylation status was examined in C57BL/6J obese mice fed an atherogenic diet (AD) to establish the correlation between epigenetic alterations and obesity-related abnormalities.MethodsSix-week-old male C57BL/6J mice were fed a normal diet (ND) or AD for 8 wk. Methylation levels of global DNA and repetitive DNA elements in livers of ND-fed mice and AD-fed mice were examined.ResultsThe total amounts of 5-MeC genomic contents in livers of AD-fed mice were increased as compared with those of ND-fed mice. Hypermethylation of repetitive DNA elements was observed in livers of AD-fed mice.ConclusionHypermethylation of repetitive DNA elements in livers of AD-fed mice proposes epigenetic changes by nutritional intervention.     

Modulation of P-glycoprotein-mediated resistance by kaempferol derivatives isolated from Zingiber zerumbet

This study examined the effects of the kaempferol derivatives extracted from Zingiber zerumbet on the accumulation and efflux of [(3)H]-daunomycin (DNM) in P-glycoprotein (P-gp) overexpressing multidrug resistant (MDR) human breast cancer cells, MCF-7/ADR. Of six kaempferol derivatives extracted from Z. zerumbet, kaempferol-3-O-methyl ether (1) and kaempferol-3,4'-O-dimethyl ether (2) showed a potent P-gp inhibitory effect as great as verapamil, a well-known P-gp inhibitor. The P-gp inhibitory activity of these two compounds was through a 3-fold increase of the level of [(3)H]-DNM accumulation and a decrease of P-gp-mediated efflux. These results suggest that the kaempferol derivative components of Z. zerumbet can be used as a scaffold for developing agents that reverse P-gp-mediated MDR in human cancer chemotherapy.     

The Effect of Caffeic Acid on Wound Healing in Skin-incised Mice

This study was carried out to investigate the wound healing effect of caffeic acid in skin-incised mice. Caffeic acid showed significant effects on anti-inflammatory activity and wound healing, such as myeloperoxidase activity, lipid peroxidation, phospholipase A₂ activity and collagen-like polymer synthesis, in incised-wound tissue. On the other hand, it significantly stimulated collagen-like polymer synthesis in NIH 3T3 fibroblast cells, while inhibited both silica-induced reactive oxygen species generation and melittin-induced arachidonic acid release and PGE₂ production in Raw 264.7 cells, and histamine release in RBL 2H3 cells stimulated by melittin or arachidonic acid. Therefore, caffeic acid appears to have a potent antioxidant and anti-inflammatory effect in cell culture system, which may be related to wound healing in skin-incised mice.     

A new stilbene glucoside gallate from the roots of Polygonum multiflorum

A new stilbenoid (1) was isolated from the root extract of Polygonum multiflorum together with eight known constituents (2∼9). The chemical structure of 1 was established as the 6″-O-monogalloyl ester of (E)-2,3,4′,5-β-tetrahydroxystilbene-2-β-D-glucopyranoside based on physicochemical and spectroscopic analyses, particularly by NMR spectroscopic data, i.e., COSY, HMQC and HMBC. Compound 1 weakly inhibited acetylcholinesterase in vitro.     

Identification of glutathione conjugates of 1-bromopentane and its hepatotoxicity in female BALB/c mice

Halogenated organic compounds, such as 1-bromopentane (1-BPT), are used as cleaning agents, synthesis agents, or extraction solvents in the workplace. In the present study, glutathione (GSH) conjugation and hepatotoxicity induced by 1-BPT were investigated in female BALB/c mice. S-Bromopentyl GSH, S-bromopentyl cysteine, and mono-hydroxypentyl mercapturic acid were identified in liver by liquid chromatography-electrospray ionization tandem mass spectrometry. Oral treatment of mice with 1-BPT at 1500 mg/kg produced maximum GSH conjugates at 6 h after treatment. For hepatotoxicity tests, the animals were treated orally with 1-BPT at 375, 750, or 1500 mg/kg in corn oil once for a dose response study or at 1500 mg/kg for 6, 12, 24, or 48 h for a time course study. 1-BPT dose-dependently increased serum activity of ALT and AST and decreased hepatic GSH levels, peaking at 6 and 12 h after treatment. 1-BPT (750 and 1500 mg/kg) also significantly increased the hepatic content of malondialdehyde. Thus, 1-BPT could cause hepatotoxicity and depletion of GSH content by forming GSH conjugates, presenting a toxicity mechanism and potential biomarkers for low molecular weight haloalkanes.     

A new abietane diterpenoid from Isodon inflexus

A new ent-abietane diterpenoid, 3α,6β-dihydroxy-7,17-dioxo-ent-abieta-15(16)-ene (1), and three known ent-kaurane diterpenids, kamebacetal A (2), kamebakaurin (3), and excisanin A (4), and a known triterpenoid, ursolic acid (5), were isolated from the aerial parts of Isodon inflexus. Their chemical structures were determined by extensive analysis of spectroscopic data including 1D-and 2D-NMR experiments. All isolates (1–5) were evaluated for their potential to inhibit LPS-induced nitric oxide production in RAW264.7 cells. Of these, compounds 1–4 inhibited the production of NO with IC₅₀ values ranging from 1.0 to 26.5 μM.     

Water-free microencapsulation of proteins within PLGA microparticles by spray drying using PEG-assisted protein solubilization technique in organic solvent

Poly(d,l-lactic-co-glycolic acid) (PLGA) microparticles encapsulating therapeutic proteins were prepared under a water-free formulation condition. Bovine serum albumin (BSA) and recombinant human growth hormone (rhGH) were homogeneously solubilized as nano-scale complexes in methylene chloride phase by using polyethylene glycol (PEG) as a complex-forming agent. The organic phase containing dissolved PLGA and PEG/protein complexes was directly spray dried to obtain PLGA microparticles encapsulating proteins. They exhibited sustained release profiles of BSA and rhGH up to 30 days with reduced initial bursts. The released protein molecules from the microparticles maintained structural integrity without aggregation, suggesting that the current single-step protein microencapsulation method without using water could be potentially applied for sustained delivery of a wide range of therapeutic protein drugs that are not soluble in organic solvents.     

Comparative effect of genistein and daidzein on the expression of MCP-1, eNOS, and cell adhesion molecules in TNF-��-stimulated HUVECs

We compared the effects of genistein and daidzein on the expression of chemokines, cell adhesion molecules (CAMs), and endothelial nitric oxide synthase (eNOS) in tumor necrosis factor (TNF)-α-stimulated human umbilical vascular endothelial cells (HUVECs). TNF-α exposure significantly increased expression of monocyte chemoattractant protein (MCP)-1, vascular adhesion molecule (VCAM)-1, and intercellular adhesion molecule-1. Genistein significantly decreased MCP-1 and VCAM-1 production in a dose-dependent manner, whereas CAM expression was not significantly lowered by genistein treatment. However, daidzein slightly decreased MCP-1 production. The effects of genistein and daidzein on MCP-1 secretion coincided with mRNA expression. Pre-treatment with either genistein or daidzein elevated eNOS expression and nitric oxide production disturbed by TNF-α exposure. A low concentration of isoflavones significantly inhibited nuclear factor (NF)κB activation, whereas a high dose slightly ameliorated these inhibitive effects. These results suggest that genistein had a stronger effect on MCP-1 and eNOS expression than that of daidzein. Additionally, NFκB transactivation might be partially related to the down-regulation of these mRNAs in TNF-α-stimulated HUVECs.