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1.
Org Biomol Chem ; 22(26): 5333-5345, 2024 Jul 03.
Article in English | MEDLINE | ID: mdl-38853721

ABSTRACT

The reactivity of 4-hydroxy-2H-chromene-2-thione is investigated with aryl aldehydes and 5,5-dimethylcylohexane-1,3-dione (dimedone) in the presence of 20 mol% L-proline in toluene at 90 °C. Instead of the expected linear product with a sulphur atom in the ring provided by 4-hydroxydithiocoumarin or an angular product obtained from 4-hydroxycoumarin, the hitherto unreported products, 12-aryl substituted chromeno[2,3-b]chromenes (4), were obtained in good to excellent yields. The reaction proceeds through a three-component reaction via Knoevenagel condensation between dimedone with an aromatic aldehyde followed by Michael addition with 4-hydroxy-2H-chromene-2-thione. In addition, a molecular docking study of all the derivatives was performed and among them, four compounds exhibited anti-proliferative activity and elevated ROS generation in breast cancer (MCF7) cell lines.

3.
Bioorg Chem ; 141: 106900, 2023 12.
Article in English | MEDLINE | ID: mdl-37813073

ABSTRACT

The synthesis of hitherto unreported 3-sulfenylindole derivatives is achieved from 4-hydroxy-2H-chromene-2-thione (1) and indole (2) by employing an oxidative cross-dehydrogenative coupling reaction using a combination of 10 mol% of molecular iodine and 1 equivalent of TBHP in DMSO at room temperature. Then, the 3-sulfenylindole derivatives 3a, 3b, 3d, 3f, 3 h, and 3 k were converted into their corresponding sulfone derivatives because of lead likeness properties. Subsequently, a target prediction and docking study of six sulfone derivatives (5a-f) was performed, and four sulfones, namely 5a, 5d, 5e, and 5f, were selected for further in-vitro studies. The four sulfones mentioned above exhibited prominent anti-proliferative activity on breast cancer (MCF7) cell lines. In addition, this reaction was exergonic through quantum chemical analysis of the mechanistic steps. The salient features of this reaction are mild reaction conditions, good yields, and broad substrate scope.


Subject(s)
Antineoplastic Agents , Indoles , Thiones , Humans , Antineoplastic Agents/chemistry , Cell Line, Tumor , Drug Screening Assays, Antitumor , Indoles/chemistry , Molecular Structure , Oxidative Stress , Structure-Activity Relationship , Sulfones/pharmacology , Thiones/chemistry , Benzopyrans/chemistry
4.
Org Biomol Chem ; 19(26): 5818-5826, 2021 07 14.
Article in English | MEDLINE | ID: mdl-34113949

ABSTRACT

The hitherto unreported 2-aryl-10H-thiochromeno[3,2-b][1,4]oxathiin-10-one derivatives are obtained in a single pot from 4-hydroxydithiocoumarins, arylacetylenes and dimethyl sulfoxide in the presence of 10 mol% CuI and K2CO3 in an oil bath at 70 °C. The novelties of the present protocol are (i) selective C-H functionalization at the C-3 position of 4-hydroxydithiocoumarin, (ii) regioselective hydrothiolation with arylacetylenes and (iii) concomitant cyclisation. The major advantages are mild reaction conditions, broad substrate scope and good yield. Among the synthesized compounds, the following five compounds 3aa, 3bd, 3ec, 3fa, and 3fd showed anticancer activity against a human breast cancer cell line (MCF-7) and a cervical cancer cell line (HeLa).

5.
J Nutr ; 150(2): 285-293, 2020 02 01.
Article in English | MEDLINE | ID: mdl-31586202

ABSTRACT

BACKGROUND: A Western-type diet (WD), rich in fat and cholesterol but deficient in fiber, induces development of diabetes and atherosclerosis. Colonic bacteria use the gut's mucous lining as an alternate energy source during periods of fiber deficiency, resulting in intestinal barrier erosion. OBJECTIVE: We hypothesized that supplementing a WD with galactooligosaccharide (GOS) fiber would attenuate WD-induced mucin layer disruption and attenuate development of metabolic diseases. METHODS: C57BL/6 mice (both sexes, 8-10 wk of age) were fed a standard rodent diet (TD7012, reference) or a high-fat, high-cholesterol-containing WD (TD88137, 21% fat, 0.15% cholesterol, 19.5% caesin) or a WD supplemented with 5% GOS fiber (TD170432, WD + GOS) for 16 wk. WD-fed mice that were gavaged daily with curcumin (100 mg/kg) served as positive controls. Glucose tolerance, colonic mucin layer, gene expression, and circulating macrophage/neutrophil levels were determined. Hyperlipidemic Ldlr-/- mice (both sexes, 8-10 wk of age) fed a WD with or without GOS supplementation (for 16 wk) were used to assess plasma LPS and atherosclerosis. Effects of dietary supplementation on different parameters were compared for each genotype. RESULTS: Compared with a WD, glucose tolerance was significantly improved in male C57BL/6 mice fed a WD + GOS (mean ± SEM: AUC = 53.6 ± 43.9 compared with 45.4 ± 33.3 g ⋅ min/dL; P = 0.015). Continuity of colonic mucin layer (MUC-2 expression) was improved in mice receiving GOS supplementation, indicating improved intestinal barrier. GOS supplementation also reduced circulating macrophages (30% decrease) and neutrophils (60% decrease), suggesting diminished systemic inflammation. In Ldlr-/- mice, GOS supplementation significantly reduced plasma LPS concentrations (mean ± SEM: 0.81 ±  0.43 EU/mL compared with 0.32 ± 0.26 EU/mL, P   < 0.0001, in females and 0.56 ± 0.24 EU/mL compared with 0.34 ± 0.12 EU/mL, P = 0.036, in males), improved glucose tolerance in male mice, and attenuated atherosclerotic lesion area (mean ± SEM: 54.2% ± 6.19% compared with 43.0% ± 35.12%, P   = 0.0006, in females and 54.6% ± 3.99% compared with 43.1% ± 8.11%, P = 0.003, in males). CONCLUSIONS: GOS fiber supplementation improves intestinal barrier in C57BL/6 and Ldlr-/- mice and significantly attenuates WD-induced metabolic diseases and, therefore, may represent a novel strategy for management of these diseases.


Subject(s)
Atherosclerosis/metabolism , Cholesterol, Dietary/administration & dosage , Diet, High-Fat , Dietary Supplements , Galactose/chemistry , Glucose Tolerance Test , Intestinal Mucosa/metabolism , Mucins/metabolism , Oligosaccharides/administration & dosage , Receptors, LDL/genetics , Animals , Female , Male , Mice , Mice, Inbred C57BL , Mice, Knockout , Oligosaccharides/chemistry
6.
Org Biomol Chem ; 18(21): 4104-4113, 2020 06 07.
Article in English | MEDLINE | ID: mdl-32432294

ABSTRACT

An expedient and efficient synthetic method was developed for the oxidative cross dehydrogenative coupling reaction between 4-hydroxydithiocoumarin and indole at the C-3 position regio-selectively using a combination of 10 mol% molecular iodine and TBHP in the presence of 10 mol% CuBr2 as an additive at room temperature. Mild reaction conditions, good yields and a broad substrate scope are some of the salient features of the present protocol. Additionally, the synthesized 3-sulfenylindoles derived from 4-hydroxydithiocoumarin were converted into biologically active sulfone derivatives. Interestingly, some of the compounds exhibit anti-cell proliferative activity on breast cancer (MCF-7) cells due to reactive oxygen species (ROS) mediated cell damage.

7.
Nephrol Dial Transplant ; 34(5): 783-794, 2019 05 01.
Article in English | MEDLINE | ID: mdl-30085297

ABSTRACT

BACKGROUND: The associated increase in the lipopolysaccharide (LPS) levels and uremic toxins in chronic kidney disease (CKD) has shifted the way we focus on intestinal microbiota. This study shows that a disruption of the intestinal barrier in CKD promotes leakage of LPS from the gut, subsequently decreasing insulin sensitivity. Butyrate treatment improved the intestinal barrier function by increasing colonic mucin and tight junction (TJ) proteins. This modulation further ameliorated metabolic functions such as insulin intolerance and improved renal function. METHODS: Renal failure was induced by 5/6th nephrectomy (Nx) in rats. A group of Nx and control rats received sodium butyrate in drinking water. The Nx groups were compared with sham-operated controls. RESULTS: The Nx rats had significant increases in serum creatinine, urea and proteinuria. These animals had impaired glucose and insulin tolerance and increased gluconeogenesis, which corresponded with decreased glucagon-like peptide-1 (GLP-1) secretion. The Nx animals suffered significant loss of intestinal TJ proteins, colonic mucin and mucin 2 protein. This was associated with a significant increase in circulating LPS, suggesting a leaky gut phenomenon. 5'adenosine monophosphate-activated protein kinase (AMPK) phosphorylation, known to modulate epithelial TJs and glucose metabolism, was significantly reduced in the intestine of the Nx group. Anti-inflammatory cytokine, interleukin 10, anti-bacterial peptide and cathelicidin-related antimicrobial peptide were also lowered in the Nx cohort. Butyrate treatment increased AMPK phosphorylation, improved renal function and controlled hyperglycemia. CONCLUSIONS: Butyrate improves AMPK phosphorylation, increases GLP-1 secretion and promotes colonic mucin and TJ proteins, which strengthen the gut wall. This decreases LPS leakage and inflammation. Taken together, butyrate improves metabolic parameters such as insulin resistance and markers of renal failure in CKD animals.


Subject(s)
Butyric Acid/pharmacology , Insulin Resistance/physiology , Intestinal Mucosa/metabolism , Mucins/biosynthesis , Renal Insufficiency, Chronic/drug therapy , Animals , Disease Models, Animal , Histamine Antagonists/pharmacology , Immunohistochemistry , Male , Permeability , Rats , Renal Insufficiency, Chronic/metabolism
8.
Biotechnol Bioeng ; 115(5): 1116-1127, 2018 05.
Article in English | MEDLINE | ID: mdl-29384195

ABSTRACT

Amalgamation of delivery and tracking of therapeutically relevant moieties on a single platform is made possible by the application of metal nanoclusters, an innovative class of luminescent nanomaterials. Metal nanoclusters, possessing molecule-like attributes, display extraordinary size and shape tunable properties befitting theranostic applications. Herein, we report successful assembly of therapeutically significant phosphatase protein PTEN and fluorescent lysozyme-stabilized silver nanoclusters to accomplish delivery and tracking of the protein. Down-regulation of PTEN perturbs the cellular networking leading to copious pathological conditions. The integration of purified recombinant PTEN with silver nanoclusters was evaluated by fluorescence spectroscopy study. A key feature of this study is the use of polyethylene glycol coating that allows fabrication of the assembly into spherical nanocomposites as characterized by transmission electron microscope along with retention of both optical functionality of the cluster and biological activity of the protein. Prior to cellular application, the functional integrity of PTEN in the composite was determined in vitro, by enzymatic assay employing para-nitrophenylphosphate as substrate. Cellular internalization of the cargo was studied by confocal microscopy and flow cytometry analysis. The efficacy of the payload on modulation of cellular signaling was assessed on cell lines that expressed PTEN differentially. PTEN null U-87 MG and PTEN expressing MCF7 cell lines displayed successful alteration of AKT and FAK signaling proteins culminating in cell cycle arrest and reduced wound healing capacity. A dose dependent reduction in cell proliferation of MCF7 cells was achieved. For U-87 MG, treatment with the payload resulted in chemosensitization toward anti-cancer drug erlotinib. Thus, PEG coated GST-PTEN loaded silver nanoclusters serves as a comprehensive system encompassing cellular imaging and protein delivery with potential biomedical implications.


Subject(s)
Muramidase/metabolism , Neoplasms/diagnostic imaging , Neoplasms/diagnosis , PTEN Phosphohydrolase/metabolism , Silver/metabolism , Theranostic Nanomedicine/methods , Antineoplastic Agents/pharmacology , Cell Proliferation/drug effects , Disease Transmission, Infectious , Erlotinib Hydrochloride/pharmacology , Flow Cytometry , Humans , MCF-7 Cells , Microscopy, Confocal , Models, Biological , Spectrometry, Fluorescence
9.
Am J Physiol Cell Physiol ; 312(4): C438-C445, 2017 Apr 01.
Article in English | MEDLINE | ID: mdl-28249988

ABSTRACT

Association between circulating lipopolysaccharide (LPS) and metabolic diseases (such as type 2 diabetes and atherosclerosis) has shifted the focus from high-fat high-cholesterol containing Western-type diet (WD)-induced changes in gut microbiota per se to release of gut bacteria-derived products (e.g., LPS) into circulation due to intestinal barrier dysfunction as the possible mechanism for the chronic inflammatory state underlying the development of these diseases. We demonstrated earlier that oral supplementation with curcumin attenuates WD-induced development of type 2 diabetes and atherosclerosis. Poor bioavailability of curcumin has precluded the establishment of a causal relationship between oral supplementation and it is in vivo effects. We hypothesized that curcumin attenuates WD-induced chronic inflammation and associated metabolic diseases by modulating the function of intestinal epithelial cells (IECs) and the intestinal barrier function. The objective of the present study was to delineate the underlying mechanisms. The human IEC lines Caco-2 and HT-29 were used for these studies and modulation of direct as well as indirect effects of LPS on intracellular signaling as well as tight junctions were examined. Pretreatment with curcumin significantly attenuated LPS-induced secretion of master cytokine IL-1ß from IECs and macrophages. Furthermore, curcumin also reduced IL-1ß-induced activation of p38 MAPK in IECs and subsequent increase in expression of myosin light chain kinase involved in the phosphorylation of tight junction proteins and ensuing disruption of their normal arrangement. The major site of action of curcumin is, therefore, likely the IECs and the intestinal barrier, and by reducing intestinal barrier dysfunction, curcumin modulates chronic inflammatory diseases despite poor bioavailability.


Subject(s)
Cell Communication/immunology , Colitis/immunology , Curcumin/administration & dosage , Intestinal Absorption/immunology , Intestinal Mucosa/immunology , Tight Junctions/immunology , Caco-2 Cells , Cell Communication/drug effects , Colitis/chemically induced , Colitis/drug therapy , Colon/drug effects , Colon/immunology , Dose-Response Relationship, Drug , Epithelial Cells , HT29 Cells , Humans , Intestinal Absorption/drug effects , Intestinal Mucosa/drug effects , Lipopolysaccharides , Tight Junctions/drug effects
10.
Liver Int ; 36(6): 865-73, 2016 06.
Article in English | MEDLINE | ID: mdl-26583566

ABSTRACT

BACKGROUND & AIMS: Infectious acute kidney injury (AKI) is a life threatening complication of cirrhosis with limited therapeutic options. The aim of this study was to develop a model of infectious AKI in cirrhotic mice. METHODS: Cirrhosis was established by intragastric administration of carbon tetrachloride (CCl4 ). Systemic haemodynamics was assessed invasively while cardiac function was assessed by echocardiography. AKI was induced using varying doses of lipopolysaccharide (LPS) titrated to produce 50% lethality. Renal function was assessed from serum creatinine and urine output (UOP). Renal injury was evaluated by urinalysis (proteinuria and casts) and renal histology. These mice were compared to: (i) normal mice, (ii) normal mice + LPS, and (iii) mice treated with CCl4 alone. RESULTS: Cirrhosis with increased cardiac output, decreased systemic vascular resistance, activation of renin-angiotensin-aldosterone axis developed after 12 weeks of CCl4 administration. LPS injection produced a dose-dependent increase in mortality (33% at 2 mg/kg vs. 80% at 6 mg/kg) without urine (casts or proteinuria) or histological evidence of tubular injury. 2 mg/kg LPS injection produced a rise in creatinine (0.79 ± 0.27 mg/dl in CCl4 +LPS compared to 0.45 ± 0.14 in CCl4 alone, P < 0.05) and a decrease in UOP (0.86 ± 0.4 ml/16 h in CCl4 + LPS compared to 1.70 ± 0.7 ml/16 h in CCl4 mice, P < 0.05). UOP remained low in mice that died while it recovered over 48-72 h in those that recovered. Control mice treated with 2 mg/kg LPS did not experience AKI. CONCLUSIONS: Cirrhotic CCl4 treated mice develop functional AKI and mimic most of the features of infectious AKI following LPS injection.


Subject(s)
Acute Kidney Injury/drug therapy , Disease Models, Animal , Liver Cirrhosis/complications , Acute Kidney Injury/chemically induced , Animals , Carbon Tetrachloride , Creatinine/analysis , Echocardiography , Kidney/physiopathology , Kidney Function Tests , Lipopolysaccharides , Liver/pathology , Liver Cirrhosis/chemically induced , Mice , Mice, Inbred C57BL
12.
Biotechnol Lett ; 38(2): 243-9, 2016 Feb.
Article in English | MEDLINE | ID: mdl-26549378

ABSTRACT

OBJECTIVES: Granulocyte macrophage colony stimulating factor (GMCSF), an important therapeutic cytokine, was immobilized onto silica nanoparticles. Maintenance of structural integrity and biological performance in immobilized cytokine was assessed to augment its applicability in possible biomedical implications. RESULTS: Following its cloning and expression in E. coli, the recombinant human GMCSF (hGMCSF) was purified as a GST-tagged protein corresponding to a 42 kDa band on SDS-PAGE. The purified cytokine was immobilized onto biocompatible silica nanoparticles (~129.4 nm) by adsorption and the binding was confirmed by dynamic light scattering and infrared spectroscopy. Maximum binding of hGMCSF was at 6.4 µg mg(-1) silica nanoparticles. Efficient release of the cytokine from the nanoparticles with its structural integrity intact was deduced from circular dichroism spectroscopy. hGMCSF-immobilized silica nanoparticles efficiently increased the proliferation of RAW 264.7 macrophage cells with 50 % increase in proliferation at 600 ng hGMCSF µg(-1) silica nanoparticles. CONCLUSIONS: Silica nanoparticles successfully immobilized hGMCSF maintaining its structural integrity. The release of the immobilized cytokine from silica nanoparticles resulted in the increased proliferation of macrophages indicating the potential of the system in future applications.


Subject(s)
Drug Carriers , Granulocyte Colony-Stimulating Factor/metabolism , Immobilized Proteins/metabolism , Nanoparticles , Silicon Dioxide , Adsorption , Animals , Cell Proliferation/drug effects , Circular Dichroism , Cloning, Molecular , Dynamic Light Scattering , Escherichia coli/genetics , Escherichia coli/metabolism , Gene Expression , Granulocyte Colony-Stimulating Factor/chemistry , Granulocyte Colony-Stimulating Factor/isolation & purification , Humans , Immobilized Proteins/chemistry , Immobilized Proteins/isolation & purification , Macrophages/drug effects , Macrophages/physiology , Mice , Molecular Weight , RAW 264.7 Cells , Recombinant Proteins/chemistry , Recombinant Proteins/isolation & purification , Recombinant Proteins/metabolism , Spectrophotometry, Infrared
13.
J Lipid Res ; 55(4): 729-38, 2014 Apr.
Article in English | MEDLINE | ID: mdl-24563511

ABSTRACT

The liver plays a central role in the final elimination of cholesterol from the body either as bile acids or as free cholesterol (FC), and lipoprotein-derived cholesterol is the major source of total biliary cholesterol. HDL is the major lipoprotein responsible for removal and transport of cholesterol, mainly as cholesteryl esters (CEs), from the peripheral tissues to the liver. While HDL-FC is rapidly secreted into bile, the fate of HDL-CE remains unclear. We have earlier demonstrated the role of human CE hydrolase (CEH, CES1) in hepatic hydrolysis of HDL-CE and increasing bile acid synthesis, a process dependent on scavenger receptor BI expression. In the present study, we examined the hypothesis that by enhancing the elimination of HDL-CE into bile/feces, liver-specific transgenic expression of CEH will be anti-atherogenic. Increased CEH expression in the liver significantly increased the flux of HDL-CE to bile acids. In the LDLR(-/-) background, this enhanced elimination of cholesterol led to attenuation of diet-induced atherosclerosis with a consistent increase in fecal sterol secretion primarily as bile acids. Taken together with the observed reduction in atherosclerosis by increasing macrophage CEH-mediated cholesterol efflux, these studies establish CEH as an important regulator in enhancing cholesterol elimination and also as an anti-atherogenic target.


Subject(s)
Atherosclerosis/enzymology , Liver/enzymology , Sterol Esterase/genetics , Animals , Atherosclerosis/blood , Bile Acids and Salts/metabolism , Cholesterol/blood , Female , Gene Expression , Glucose Intolerance , Humans , Macrophages/enzymology , Male , Mice , Mice, Inbred BALB C , Mice, Inbred C57BL , Mice, Knockout , Organ Specificity , Receptors, LDL/genetics , Receptors, LDL/metabolism , Sterol Esterase/biosynthesis , Transgenes , Triglycerides/metabolism
14.
Arterioscler Thromb Vasc Biol ; 33(8): 1795-802, 2013 Aug.
Article in English | MEDLINE | ID: mdl-23744992

ABSTRACT

OBJECTIVE: Liver is the major organ responsible for the final elimination of cholesterol from the body either as biliary cholesterol or as bile acids. Intracellular hydrolysis of lipoprotein-derived cholesteryl esters (CEs) is essential to generate the free cholesterol required for this process. Earlier, we demonstrated that overexpression of human CE hydrolase (Gene symbol CES1) increased bile acid synthesis in human hepatocytes and enhanced reverse cholesterol transport in mice. The objective of the present study was to demonstrate that liver-specific deletion of its murine ortholog, Ces3, would decrease cholesterol elimination from the body and increase atherosclerosis. APPROACH AND RESULTS: Liver-specific Ces3 knockout mice (Ces3-LKO) were generated, and Ces3 deficiency did not affect the expression of genes involved in cholesterol homeostasis and free cholesterol or bile acid transport. The effects of Ces3 deficiency on the development of Western diet-induced atherosclerosis were examined in low density lipoprotein receptor knock out(-/-) mice. Despite similar plasma lipoprotein profiles, there was increased lesion development in low density lipoprotein receptor knock out(-/-)Ces3-LKO mice along with a significant decrease in the bile acid content of bile. Ces3 deficiency significantly reduced the flux of cholesterol from [(3)H]-CE-labeled high-density lipoproteins to feces (as free cholesterol and bile acids) and decreased total fecal sterol elimination. CONCLUSIONS: Our results demonstrate that hepatic Ces3 modulates the hydrolysis of lipoprotein-delivered CEs and thereby regulates free cholesterol and bile acid secretion into the feces. Therefore, its deficiency results in reduced cholesterol elimination from the body, leading to significant increase in atherosclerosis. Collectively, these data establish the antiatherogenic role of hepatic CE hydrolysis.


Subject(s)
Atherosclerosis/genetics , Atherosclerosis/metabolism , Carboxylic Ester Hydrolases/genetics , Receptors, Lipoprotein/genetics , Sterols/metabolism , Animal Feed , Animals , Bile Acids and Salts/metabolism , Carboxylic Ester Hydrolases/deficiency , Carboxylic Ester Hydrolases/metabolism , Cholesterol, HDL/blood , Cholesterol, LDL/blood , Cholesterol, VLDL/blood , Feces/enzymology , Female , Homeostasis/physiology , Humans , Liver/enzymology , Male , Mice , Mice, Knockout , Receptors, Lipoprotein/metabolism
15.
Molecules ; 19(12): 20139-56, 2014 Dec 02.
Article in English | MEDLINE | ID: mdl-25474287

ABSTRACT

Curcumin, an active ingredient in the traditional herbal remedy and dietary spice turmeric (Curcuma longa), has significant anti-inflammatory properties. Chronic kidney disease (CKD), an inflammatory disease, can lead to end stage renal disease resulting in dialysis and transplant. Furthermore, it is frequently associated with other inflammatory disease such as diabetes and cardiovascular disorders. This review will focus on the clinically relevant inflammatory molecules that play a role in CKD and associated diseases. Various enzymes, transcription factors, growth factors modulate production and action of inflammatory molecules; curcumin can blunt the generation and action of these inflammatory molecules and ameliorate CKD as well as associated inflammatory disorders. Recent studies have shown that increased intestinal permeability results in the leakage of pro-inflammatory molecules (cytokines and lipopolysaccharides) from gut into the circulation in diseases such as CKD, diabetes and atherosclerosis. This change in intestinal permeability is due to decreased expression of tight junction proteins and intestinal alkaline phosphatase (IAP). Curcumin increases the expression of IAP and tight junction proteins and corrects gut permeability. This action reduces the levels of circulatory inflammatory biomolecules. This effect of curcumin on intestine can explain why, despite poor bioavailability, curcumin has potential anti-inflammatory effects in vivo and beneficial effects on CKD.


Subject(s)
Alkaline Phosphatase/metabolism , Curcumin/therapeutic use , Renal Insufficiency, Chronic/drug therapy , Renal Insufficiency, Chronic/enzymology , Biological Availability , Curcumin/pharmacology , Gastrointestinal Tract/drug effects , Humans , Inflammation Mediators/metabolism , Renal Insufficiency, Chronic/pathology
16.
J Lipid Res ; 54(11): 3078-84, 2013 Nov.
Article in English | MEDLINE | ID: mdl-23990661

ABSTRACT

Liver is the sole organ responsible for the final elimination of cholesterol from the body either as biliary cholesterol or bile acids. High density lipoprotein (HDL)-derived cholesterol is the major source of biliary sterols and represents a mechanism for the removal of cholesterol from peripheral tissues including artery wall-associated macrophage foam cells. Via selective uptake through scavenger receptor BI (SR-BI), HDL-cholesterol is thought to be directly secreted into bile, and HDL cholesteryl esters (HDL-CEs) enter the hepatic metabolic pool and need to be hydrolyzed prior to conversion to bile acids. However, the identity of hepatic CE hydrolase (CEH) as well as the role of SR-BI in bile acid synthesis remains elusive. In this study we examined the role of human hepatic CEH (CES1) in facilitating hydrolysis of SR-BI-delivered HDL-CEs. Over-expression of CEH led to increased hydrolysis of HDL-[³H]CE in primary hepatocytes and SR-BI expression was required for this process. Intracellular CEH associated with BODIPY-CE delivered by selective uptake via SR-BI. CEH and SR-BI expression enhanced the movement of [³H]label from HDL-[³H]CE to bile acids in vitro and in vivo. Taken together, these studies demonstrate that SR-BI-delivered HDL-CEs are hydrolyzed by hepatic CEH and utilized for bile acid synthesis.


Subject(s)
CD36 Antigens/metabolism , Cholesterol Esters/metabolism , Lipoproteins, HDL/metabolism , Liver/enzymology , Sterol Esterase/metabolism , Animals , Bile Acids and Salts/biosynthesis , Biological Transport , Gene Expression Regulation, Enzymologic , Humans , Hydrolysis , Liver/metabolism , Mice , Mice, Inbred C57BL
17.
Biochim Biophys Acta ; 1818(12): 3149-57, 2012 Dec.
Article in English | MEDLINE | ID: mdl-22921758

ABSTRACT

An acidic phospholipase A2 (RVVA-PLA2-I) purified from Daboia russelli venom demonstrated dose-dependent catalytic, mitochondrial and erythrocyte membrane damaging activities. RVVA-PLA2-I was non-lethal to mice at the tested dose, however, it affected the different organs of mice particularly the liver and cardiac tissues as deduced from the enzymatic activities measured in mice serum after injection of this PLA2 enzyme. RVVA-PLA2-I preferentially hydrolyzed phospholipids (phosphatidylcholine) of erythrocyte membrane compared to the liver mitochondrial membrane. Interestingly, RVVA-PLA2-I failed to hydrolyze membrane phospholipids of HT-29 (colon adenocarcinoma) cells, which contain an abundance of phosphatidylcholine in its outer membrane, within 24h of incubation. The gas-chromatographic (GC) analysis of saturated/unsaturated fatty acids' release patterns from intact mitochondrial and erythrocyte membranes after the addition of RVVA-PLA2-I showed a distinctly different result. The results are certainly a reflection of differences in the outer membrane phospholipid composition of tested membranes owing to which they are hydrolyzed by the venom PLA2s to a different extent. The chemical modification of essential amino acids present in the active site, neutralization study with polyvalent antivenom and heat-inactivation of RVVA-PLA2-I suggested the correlation between catalytic and membrane damaging activities of this PLA2 enzyme. Our study advocates that the presence of a large number of PLA2-sensitive phospholipid domains/composition, rather than only the phosphatidylcholine (PC) content of that particular membrane may determine the extent of membrane damage by a particular venom PLA2 enzyme.


Subject(s)
Cell Membrane/metabolism , Membrane Lipids/metabolism , Phospholipases A2/metabolism , Phospholipids/metabolism , Viper Venoms/metabolism , Animals , Cell Line, Tumor , Cell Membrane/drug effects , Erythrocyte Membrane/metabolism , Erythrocytes/drug effects , Heart/drug effects , Liver/drug effects , Mice , Mitochondria/drug effects , Phosphatidylcholines/metabolism , Viperidae/metabolism
18.
Methods Mol Biol ; 2455: 63-71, 2022.
Article in English | MEDLINE | ID: mdl-35212986

ABSTRACT

Intestinal lipid absorption as well as secretion of absorbed lipids as chylomicrons by the enterocytes is a direct measure of the availability of dietary lipids. Measurement of this parameter is central to the understanding of the influence of diet on plasma lipids, specifically when modulation of intestinal lipid absorption by targeted interventions is being examined. In the post-prandial state, very low-density lipoprotein (VLDL) secreted from the liver represent the major source of plasma lipids and rate of VLDL secretion reports on hepatic lipid homeostasis. Here, we describe the methods to specifically measure secretion of chylomicron and VLDL in vivo. Tight regulation of dietary lipid absorption (chylomicron secretion) and hepatic secretion of VLDL underlies the development of dyslipidemia preceding hepatic lipid accumulation seen in non-alcoholic fatty liver disease (NAFLD) and subsequent progression to non-alcoholic steatohepatitis (NASH) underscoring the importance of measurement of lipoprotein secretion in vivo.


Subject(s)
Chylomicrons , Lipoproteins, VLDL , Dietary Fats , Lipoproteins , Liver , Triglycerides
19.
Nanomedicine (Lond) ; 16(21): 1843-1856, 2021 09.
Article in English | MEDLINE | ID: mdl-34369819

ABSTRACT

Aim: The primary aim of this study was to develop biomimetic nanocarriers for specific homologous targeting of the anticancer drugs ammonium pyrrolidine dithiocarbamate (PDTC) and doxorubicin. Methods: Membranous nanovesicles were synthesized from a breast cancer cell line (MCF7) by syringe extrusion process and were loaded with PDTC and doxorubicin. Besides their abilities for self-homing, the drug-loaded nanovesicles showed anti-cell proliferative effects via the generation of reactive oxygen species. Results: The nanovesicles demonstrated efficient internalization via homologous targeting. Delivery of PDTC showed a higher killing effect for homologous cell targeting than other cell types. Experimental results demonstrated increased antiproliferative potency of PDTC, which induced apoptosis via reactive oxygen species generation. Conclusion: The developed membrane-derived nanocarrier is an attractive biocompatible system for ex vivo targeted drug delivery.


Subject(s)
Antineoplastic Agents , Neoplasms , Antineoplastic Agents/pharmacology , Antineoplastic Agents/therapeutic use , Apoptosis , Cell Line, Tumor , Doxorubicin/pharmacology , Doxorubicin/therapeutic use , Neoplasms/drug therapy , Reactive Oxygen Species
20.
Am J Physiol Heart Circ Physiol ; 299(4): H975-84, 2010 Oct.
Article in English | MEDLINE | ID: mdl-20601462

ABSTRACT

The prevalence of left ventricular hypertrophy (LVH) is frequent in patients with end-stage renal disease following chronic renal failure (CRF). We investigated the therapeutic efficacy of curcumin, the principal curcuminoid of the Indian curry spice turmeric, in attenuation of LVH and sought to delineate the associated signaling pathways in blunting the hypertrophic response in nephrectomized rats. Adult Sprague-Dawley rats underwent nephrectomy (Nx) by removal of 5/6 of the kidneys. Four groups were studied for 7 wk: 1) control (sham), 2) Nx, 3) Nx + curcumin (150 mg/kg bid), and 4) Nx + enalapril (15 mg/kg bid) as positive control. Subtotal nephrectomy caused renal dysfunction, as evidenced by a gradual increase in proteinuria and elevation in blood urea nitrogen and plasma creatinine. Nx rats showed a significant hypertrophic response and increased diameter of inferior vena cava at inspiration, which was inhibited by treatment with curcumin or enalapril. Moreover, the Nx rats demonstrated changes in the signaling molecules critically involved in the hypertrophic response. These include increased glycogen synthase kinase-3ß phosphorylation, ß-catenin expression, calcineurin, phosphorylated (p) nuclear factor of activated T cells, pERK, and p-cAMP-dependent kinase. Both curcumin and enalapril variably but effectively deactivated these pathways. Curcumin attenuates cardiac hypertrophy and remodeling in nephrectomized rats through deactivation of multiple hypertrophic signaling pathways. Considering the safety of curcumin, these studies should facilitate future clinical trials in suppressing hypertrophy in patients with CRF.


Subject(s)
Curcumin/therapeutic use , Hypertrophy, Left Ventricular/etiology , Hypertrophy, Left Ventricular/prevention & control , Kidney Failure, Chronic/complications , Ventricular Remodeling , Angiotensin-Converting Enzyme Inhibitors/pharmacology , Animals , Blood Pressure/drug effects , Blood Urea Nitrogen , Calcineurin/metabolism , Creatinine/blood , Curcumin/pharmacology , Disease Models, Animal , Enalapril/pharmacology , Glycogen Synthase Kinase 3/metabolism , Glycogen Synthase Kinase 3 beta , Hypertrophy, Left Ventricular/metabolism , Kidney Failure, Chronic/etiology , NFATC Transcription Factors/metabolism , Nephrectomy , Rats , Rats, Sprague-Dawley , Ventricular Remodeling/drug effects , Ventricular Remodeling/physiology
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