EFFECTS OF GAMMA IRRADIATION ON ACTIVE COMPONENTS, FREE RADICALS AND TOXICITY OF CASSUMUNAR GINGER RHIZOMES

Objective: To study the effects of gamma irradiation (10 and 25 kGy) on volatile oil constituents, total phenolic content, and free radical scavenging activity of cassumunar ginger rhizomes. Moreover, the effects on toxicity were investigated on both non-irradiated and irradiated samples, and accompanied by measurements of free radical content. Methods: Electron paramagnetic resonance spectroscopy (EPR) and GC-MS were used to determine free radicals and active compounds in essential oils, respectively. Toxicity was estimated using Toxi-Chromo Test. Total phenolic content and Antioxidant properties were determined using the Folin–Ciocalteu and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging, respectively. Results: Irradiation at the doses of 10 and 25 kGy significantly (P < 0.05) increased free radicals in cassumunar ginger rhizomes. However, the volatile oils, total phenolic content, antioxidant activity and toxicity were not significantly (P > 0.05) affected by the irradiation doses. Conclusion: The present results suggest that gamma irradiation at the doses up to 25 kGy can safely be used to sanitize dried cassumunar ginger rhizomes

Hepatoprotectant Ursodeoxycholyl Lysophosphatidylethanolamide Increasing Phosphatidylcholine Levels as a Potential Therapy of Acute Liver Injury

It has been long known that hepatic synthesis of phosphatidylcholine (PC) is depressed during acute such as carbon tetrachloride-induced liver injury. Anti-hepatotoxic properties of PC as liposomes have been recognized for treatment of acute liver damage. Ursodeoxycholate (UDCA) is a known hepatoprotectant in stabilizing cellular membrane. For therapeutic management of liver injury, we coupled UDCA with a phospholipid known as ursodeoxycholyl lysophosphatidylethanolamide (UDCA-LPE). UDCA-LPE has been shown to first-in-class hepatoprotectant being superior to UDCA or PC. It inhibits mitochondrial damage and apoptosis, elicits survival signaling pathway, and promotes regeneration of hepatocytes. We herein report that a unique contribution of UDCA-LPE in increasing concentrations of PC in vitro and in vivo. UDCA-LPE-treated hepatocytes contained significantly increased PC levels. UDCA-LPE underwent the hydrolysis to LPE which was not the precursor of the increased PC. The levels of PC in the liver and blood were increased rapidly after intraperitoneally administration UDCA-LPE, and were found to be sustained even after 24 h. Among PC synthesis genes tested, UDCA-LPE treatment of mouse hepatocytes increased transcription of CDP-diacylglycerol synthase 1 which is an enzyme catalyzing phosphatidic acid to generate intermediates for PC synthesis. Thus, UDCA-LPE as a hepatoprotectant was able to induce synthesis of protective PC which would supplement for the loss of PC occurring during acute liver injury. This property has placed UDCA-LPE as a candidate agent for therapy of acute hepatotoxicity such as acetaminophen poisoning

SLPI Inhibits ATP-Mediated Maturation of IL-1β in Human Monocytic Leukocytes: A Novel Function of an Old Player

Interleukin-1β (IL-1β) is a potent, pro-inflammatory cytokine of the innate immune system that plays an essential role in host defense against infection. However, elevated circulating levels of IL-1β can cause life-threatening systemic inflammation. Hence, mechanisms controlling IL-1β maturation and release are of outstanding clinical interest. Secretory leukocyte protease inhibitor (SLPI), in addition to its well-described anti-protease function, controls the expression of several pro-inflammatory cytokines on the transcriptional level. In the present study, we tested the potential involvement of SLPI in the control of ATP-induced, inflammasome-dependent IL-1β maturation and release. We demonstrated that SLPI dose-dependently inhibits the ATP-mediated inflammasome activation and IL-1β release in human monocytic cells, without affecting the induction of pro-IL-1β mRNA by LPS. In contrast, the ATP-independent IL-1β release induced by the pore forming bacterial toxin nigericin is not impaired, and SLPI does not directly modulate the ion channel function of the human P2X7 receptor heterologously expressed in Xenopus laevis oocytes. In human monocytic U937 cells, however, SLPI efficiently inhibits ATP-induced ion-currents. Using specific inhibitors and siRNA, we demonstrate that SLPI activates the calcium-independent phospholipase A2β (iPLA2β) and leads to the release of a low molecular mass factor that mediates the inhibition of IL-1β release. Signaling involves nicotinic acetylcholine receptor subunits α7, α9, α10, and Src kinase activation and results in an inhibition of ATP-induced caspase-1 activation. In conclusion, we propose a novel anti-inflammatory mechanism induced by SLPI, which inhibits the ATP-dependent maturation and secretion of IL-1β. This novel signaling pathway might lead to development of therapies that are urgently needed for the prevention and treatment of systemic inflammation

Skin permeability barrier formation by the ichthyosis-causative gene FATP4 through formation of the barrier lipid omega-O-acylceramide

The epidermis-specific lipid acylceramide plays a pivotal role in the formation of the permeability barrier in the skin; abrogation of its synthesis causes the skin disorder ichthyosis. However, the acylceramide synthetic pathway has not yet been fully elucidated: Namely, the acyl-CoA synthetase (ACS) involved in this pathway remains to be identified. Here, we hypothesized it to be encoded by FATP4/ACSVL4, the causative gene of ichthyosis prematurity syndrome (IPS). In vitro experiments revealed that FATP4 exhibits ACS activity toward an omega-hydroxy fatty acid (FA), an intermediate of the acylceramide synthetic pathway. Fatp4 knockout (KO) mice exhibited severe skin barrier dysfunction and morphological abnormalities in the epidermis. The total amount of acylceramide in Fatp4 KO mice was reduced to similar to 10% of wild-type mice. Decreased levels and shortening of chain lengths were observed in the saturated, nonacylated ceramides. FA levels were not decreased in the epidermis of Fatp4 KO mice. The expression levels of the FA elongase Elovl1 were reduced in Fatp4 KO epidermis, partly accounting for the reduction and shortening of saturated, nonacylated ceramides. A decrease in acylceramide levels was also observed in human keratinocytes with FATP4 knockdown. From these results, we conclude that skin barrier dysfunction observed in IPS patients and Fatp4 KO mice is caused mainly by reduced acylceramide production. Our findings further elucidate the molecular mechanism governing acylceramide synthesis and IPS pathology

Rescue of Hepatic Phospholipid Remodeling Defect in iPLA2β-Null Mice Attenuates Obese but Not Non-Obese Fatty Liver

Polymorphisms of group VIA calcium-independent phospholipase A2 (iPLA(2)beta or PLA2G6) are positively associated with adiposity, blood lipids, and Type-2 diabetes. The ubiquitously expressed iPLA(2)beta catalyzes the hydrolysis of phospholipids (PLs) to generate a fatty acid and a lysoPL. We studied the role of iPLA(2)beta on PL metabolism in non-alcoholic fatty liver disease (NAFLD). By using global deletion iPLA(2)beta-null mice, we investigated three NAFLD mouse models; genetic Ob/Ob and long-term high-fat-diet (HFD) feeding (representing obese NAFLD) as well as feeding with methionine- and choline-deficient (MCD) diet (representing non-obese NAFLD). A decrease of hepatic PLs containing monounsaturated- and polyunsaturated fatty acids and a decrease of the ratio between PLs and cholesterol esters were observed in all three NAFLD models. iPLA(2)beta deficiency rescued these decreases in obese, but not in non-obese, NAFLD models. iPLA(2)beta deficiency elicited protection against fatty liver and obesity in the order of Ob/Ob (sic) HFD >> MCD. Liver inflammation was not protected in HFD NAFLD, and that liver fibrosis was even exaggerated in non-obese MCD model. Thus, the rescue of hepatic PL remodeling defect observed in iPLA(2)beta-null mice was critical for the protection against NAFLD and obesity. However, iPLA(2)beta deletion in specific cell types such as macrophages may render liver inflammation and fibrosis, independent of steatosis protection

Homopolygalacturonan Molecular Size in Plant Cell Wall Matrices Via Paramagnetic Ion and Nitroxyl Amide Dipolar Spin-Spin Interactions

Mn(2+), Cu(2+), and nitroxyl amines have been shown to bond to plant homopolygalacturonan matrices in a spatially sequential fashion. As a consequence of this special form of cooperativity the lattice constant (κ), determined from Van Vleck's second moment relationship, approaches 1 only when the average number of dipolar interactions per spin approaches 1 (e.g., an array of dimers). Assuming that one paramagnetic ion or nitroxyl amide pair is bonded per polymer block within the matrix when κ = 1, the anionic ligand's average degree of polymerization ([unk]) can be estimated from the concentration of bonded paramagnetic dimers (e.g., [1/χ](κ∼1) = [unk]; χ is the mole fraction of bonded paramagnetic dimers). We have utilized this technique to estimate the average molecular size of homopolygalacturonan blocks in intact higher plant cortical cell walls ([unk] ∼83), Nitella cell walls ([unk] ∼27) and a commercially available galacturonic acid polymer ([unk] ∼35). The [unk] determined from both the intact cortical cell wall lattice and the polygalacturonan were similar to literature values; these findings argue that the electron paramagnetic resonance, (EPR) dipolar spin-spin interaction technique reported herein is a valid approach for estimating molecular size in plant cell walls

Study designs to investigate Nox1 acceleration of neoplastic progression in immortalized human epithelial cells by selection of differentiation resistant cells

To investigate the role of NADPH oxidase homolog Nox1 at an early step of cell transformation, we utilized human gingival mucosal keratinocytes immortalized by E6/E7 of human papillomavirus (HPV) type 16 (GM16) to generate progenitor cell lines either by chronic ethanol exposure or overexpression with Nox1. Among several cobblestone epithelial cell lines obtained, two distinctive spindle cell lines – FIB and NuB1 cells were more progressively transformed exhibiting tubulogenesis and anchorage-independent growth associated with increased invasiveness. These spindle cells acquired molecular markers of epithelial mesenchymal transition (EMT) including mesenchymal vimentin and simple cytokeratins (CK) 8 and 18 as well as myogenic alpha-smooth muscle actin and caldesmon. By overexpression and knockdown experiments, we showed that Nox1 on a post-translational level regulated the stability of CK18 in an ROS-, phosphorylation- and PKCepilon-dependent manner. PKCepilon may thus be used as a therapeutic target for EMT inhibition. Taken together, Nox1 accelerates neoplastic progression by regulating structural intermediate filaments leading to EMT of immortalized human gingival epithelial cells

Compositional Changes Among Triglycerides and Phospholipids During FATP4 Sensitization with Palmitate Lead to ER Stress in Cultured Cells

FATP4 expression is upregulated in acquired obesity and polymorphisms in the FATP4 gene are associated with increased blood triglycerides (TG). Since non-alcoholic fatty liver disease (NAFLD) is a manifestation of obesity, it is of interest to understand how FATP4 upon fat overload mediates alterations of lipids that lead to pathogenesis of fatty liver. A model system with FATP4-overexpressed (FATP4) and control Huh-7 cell lines is used to determine FATP4 response to palmitate (Pal). By lipidomics methods, cellular phospholipids (PL), neutral lipids TG, free cholesterol (FC), and cholesterol esters (CE) as well as lipoprotein secretion are determined. Without Pal, FATP4 cells show a significant increase of TG, phosphatidylcholine (PC), and the release of TG-rich and cholesterol-rich low density lipoproteins. Pal-treated FATP4 cells show an increase of all PL subclasses except for phosphatidylserine (PS), TG, FC, and CE. By analyses of ratios among PL subclasses and between PL and neutral lipids, it is determined that FATP4 in response to Pal causes sequentially fatty-acid channeling with a shift from PC and phosphatidylinositol (PI) to neutral lipids and from neutral lipids to PS and phosphatidylethanolamine (PE). This response is concomitant with an activation of CAAT/enhancer binding homologous protein and MAP Kinase JNK. Thus, FATP4 overexpression in response to Pal leads to enhancement of neutral lipids which play a central role in fatty-acid distribution from PC and PI to PE and PS that led to an alteration of ER and mitochondrial membranes and subsequent stress signalling.Practical Applications: Activation of fatty acids by fatty acid transport proteins (FATP) plays an important role in development of obesity and NAFLD. This work highlights functional role of FATP4 on fatty-acid distribution among neutral lipids and phospholipids upon fat overload. These changes may contribute to stress signalling in the pathogenesis of NAFLD. Compositional shift among total PL subclasses and neutral lipids