Hydroperoxylinoleic Acid Research Articles

Bioactive Compounds and Antioxidant Activity in Greek-style Yoghurt Infused with Shield Aralia Leaves

The objective of this study was to determine bioactive compounds, nutrition, antioxidant activity, total phenolic content (TPC) and total flavonoid content (TFC) in shield aralia yoghurt. Shield aralia leaves (SAL) have traditionally been used as herbal plant. Fortification of shield aralia in yoghurt increased the health-benefits of yoghurt by the incorporated phytochemical constituent of herb such as polyphenol and flavonoid groups which can be used to treat various disease including atherosclerosis, obesity, diabetes mellitus, and cardiovascular disease. The Greek-style yoghurt with addition SAL resulted on new bioactive compounds belong to α-linoleic acid (ALA) including -hydroperoxy-octadecadienoic acid (9-HpODE), (15Z)-9,12,13-Trihydroxy-15-octadeconoic acid, 13(s)-hydroperoxylinolenic acid (13(S)-HPOTrE), and (E)-6-hydroxyoctadec-4-eonoic acid or NP-011548. The proximate test results revealed that shield aralia yoghurt has high-protein content (15.46%), low-fat and carbohydrate content (0.16% and 0.88%, respectively). The antioxidant activity based on 2, 2-duphenylpicrylhydrazyl (DPPH) assay of shield aralia yoghurt was 68.66%, while TPC of SAL yogurt reached 62.61 mg GAE/g and the TFC was 201.05 mg QE/g. These results suggested that under fermentation by lactic-acid bacteria (LAB) increased the beneficial values of shield aralia leaves compared with shield aralia raw extract. Shield aralia yoghurt could be as promising supplementation for wellness care and also could be as exogenous antioxidant to increase body defense.

Correlation between immune-related Tryptophan-Kynurenine pathway and severity of severe pneumonia and inflammation-related polyunsaturated fatty acids.

Immune dysfunction and oxidative stress caused by severe pneumonia can lead to multiple organ dysfunction and even death, causing a significant impact on health and the economy. Currently, great progress has been made in the diagnosis and treatment of this disease, but the mortality rate remains high (approximately 50%). Therefore, there is still potential for further exploration of the immune response mechanisms against severe pneumonia. This study analyzed the difference in serum metabolic profiles between patients with severe pneumonia and health individuals through metabolomics, aiming to uncover the correlation between the Tryptophan-Kynurenine pathway and the severity of severe pneumonia, as well as N-3/N-6 polyunsaturated fatty acids (PUFAs). In this study, 44 patients with severe pneumonia and 37 health controls were selected. According to the changes in the disease symptoms within the 7 days of admission, the patients were divided into aggravation (n = 22) and remission (n = 22) groups. Targeted metabolomics techniques were performed to quantify serum metabolites and analyze changes between groups. Metabolomics analysis showed that serum kynurenine and kynurenine/tryptophan (K/T) were significantly increased and tryptophan was significantly decreased in patients with severe pneumonia; HETE and HEPE in lipids increased significantly, while eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA), docosahexaenoic acid (DHA), α-linolenic acid (linolenic acid, α-LNA), arachidonic acid (ARA), Dihomo-γ-linolenic acid (DGLA), and 13(s)-hydroperoxylinoleic acid (HPODE) decreased significantly. Additionally, the longitudinal comparison revealed that Linolenic acid, DPA, and Tryptophan increased significantly in the remission group, while and kynurenine and K/T decreased significantly. In the aggravation group, Kynurenine and K/T increased significantly, while ARA, 8(S)-hydroxyeicosatetraenoic acid (HETE), 11(S)-HETE, and Tryptophan decreased significantly. The correlation analysis matrix demonstrated that Tryptophan was positively correlated with DGLA, 12(S)-hydroxyeicosapentaenoic acid (HEPE), ARA, EPA, α-LNA, DHA, and DPA. Kynurenine was positively correlated with 8(S)-HETE and negatively correlated with DHA. Additionally, K/T was negatively correlated with DGLA, ARA, EPA, α-LNA, DHA, and DPA. This study revealed that during severe pneumonia, the Tryptophan-Kynurenine pathway was activated and was positively correlated with the disease progression. On the other hand, the activation of the Tryptophan-Kynurenine pathway was negatively correlated with N-3/N-6 PUFAs.

Unveiling the Impact of Different Nitrogen Fertilizer Levels on Rice’s Eating Quality through Metabolite Evaluation

We investigated the variations in metabolites associated with the quality of rice consumption when exposed to varying nitrogen fertilizer levels, as well as the regulatory role of pivotal metabolites within metabolic pathways. This research employed Hongyang 5 as the subject of experimentation, examining the metabolites of Hongyang 5 at three different nitrogen levels using non-targeted metabonomic analysis. The findings indicated that the overall assessment of the eating quality/palatability (CEQ) and amylose contents (AC) of Low nitrogen (D1: 180 kg·ha−1) was notably greater than that of Medium nitrogen (D2: 270 kg·ha−1) and High nitrogen (D3: 315 kg·ha−1). Conversely, the amylopectin (APC), total starch (SC), and protein contents (AP) of D1 were remarkably lower than those observed in D2 and D3. The starch debranching enzyme (DBE) and granule-bound starch synthetase (GBSS) of D1 were remarkably higher than those of D2 and D3. The soluble starch synthase (SSS) of D1 was the lowest. The ADP-glucose pyro-phosphorylase (AGP) and starch branching enzyme (SBE) of D3 were remarkably higher than that of D1 and D2. We identified 76 differential metabolites (DMs) between D1 and D2 (20 up-regulated and 56 down-regulated). A total of 88 DMs were identified between D3 and D1 (42 up-regulated and 46 down-regulated). A total of 57 DMs were identified between D3 and D2. Most of the DMs related to rice-eating quality were involved in the lipid metabolic pathway and amino acid metabolic pathway. The essential metabolites within the metabolic pathway are classified as lipid metabolites and are (13(S)-hydroperoxylinolenic acid, PGB2, 3-phosphocholine, 7-epijasmonic acid, 20-carboxyleukotriene B4 and 11-dehydro-thromboxane B2), amino acid metabolites (4-guanidinobutanoic acid, (3R, 5S)-1-pyrroline-3-hydroxy-5-carboxylic acid, citric acid, (S)-2-Acetolactate, L-glutamine, L-2, 4-aminobutyric acid and putrescine). These key metabolites may be affected by nitrogen fertilizer conditions and play critical regulatory roles in the metabolic pathway, resulting in differences in rice eating quality.

Discovery of benzothiazole-based thiazolidinones as potential anti-inflammatory agents: anti-inflammatory activity, soybean lipoxygenase inhibition effect and molecular docking studies

ABSTRACT Despite the greatest achievement in the development of anti-inflammatory agents in the last two decades, the current clinical drugs suffer from a variety of complications in community settings and hospital. There is still an urgent need to design novel molecules with better safety profile and with different molecular targets from those in current clinical use. The aim of this research was to discover a series of benzothiazole-based thiazolidinones with lipoxygenase (LOX) inhibitory activity as a mechanism of anti-inflammatory action. Carrageenan-induced mouse foot paw oedema assay was carried out to determine the anti-inflammatory activity, while LOX inhibition was examined through the conversion of sodium linoleate to 13-hydroperoxylinoleic acid. Molecular docking studies were performed using AutoDock 4.2 software. The anti-inflammatory activity of the title compounds was determined in a range of 18.4%-69.57%, where compound #3 was found to be the most potent (69.57%) and also to be more active than the reference drug indomethacin (47%). Moreover, compound #3 showed the highest LOX inhibitory activity with IC50 of 13 μM being less potent to that of the reference NDGA (IC50 = 1.3 μM). Compound #3 has been identified as lead compound for further modification in an attempt to improve anti-inflammatory and LOX inhibitory activities.

Antilipoxygenase and Anti-Inflammatory Activities of Streblus asper Leaf Extract on Xylene-Induced Ear Edema in Mice

Streblus asper (SA) belonging to the Moraceae family is well known as a folk medicinal plant in Asian countries. This study aimed to investigate the antilipoxygenase activity and the anti-inflammatory effects of the SA leaf extract. An in vitro antilipoxygenase study was performed using a lipoxygenase assay, and the oxidation of linoleic acid into 13-hydroperoxy linoleic acid (HPODE) was detected with a UV spectrophotometer at a wavelength of 234 nm. In the animal study, twenty-five male ICR mice were induced as ear edema by topical xylene, and the ear thickness of the mice was measured. The lipoxygenase assay results showed that the IC50 values of diclofenac sodium and SA were 0.0015 and 37.96 μg/mL, respectively. In the animal study, mice that received diclofenac sodium exhibited significantly reduced ear edema induced by xylene from 30 min onward, while mice that received 250 mg/kg and 500 mg/kg SA exhibited significantly reduced ear edema compared with the control group 45 min after induction with xylene. These results suggested that the SA leaf extract had anti-inflammatory activity. However, further studies are required to evaluate these effects and the additional potential of the plant that might be beneficial for the development of pharmaceutical products that prevent and treat inflammation.

Anti-inflammatory properties of Xylopia aethiopica leaves: Interference with pro-inflammatory cytokines in THP-1-derived macrophages and flavonoid profiling.

Ethnopharmacological surveys on Guinea-Bissauan flora reveal that several species are used to treat or ameliorate the symptomatology of conditions with an inflammatory background. As such, extracts obtained from a series of plants recorded in those surveys were screened for their anti-inflammatory properties, a hydroethanolic extract obtained from the leaves of Xylopia aethiopica (Dunal) A. Rich, (Annonaceae), used on the treatment of headache, muscular pain and rheumatic pain, scoring positively and being further investigated. In order to identify species with anti-inflammatory properties, extracts were screened for their ability to interfere with LPS-induced TNF-α levels. Since significant effects were recorded upon treatment with the extract of the leaves obtained from X. aethiopica, further assays were conducted to elucidate additional mechanisms underlying its anti-inflammatory potential. Since little is known on the chemical composition of the plant, we also aimed to characterise its phenolic profile. Interference with cytokines was evaluated by ELISA assay, through the quantification of TNF-α and IL-6 levels in the culture medium collected from LPS-activated THP-1-derived-macrophages. Inhibition of 5-lipoxygenase was assessed based on the oxidation of linoleic acid to 13-hydroperoxylinoleic acid. Characterization of the phenolic profile was attained by HPLC-DAD. Evaluation of TNF-α levels in LPS-challenged THP-1 macrophages evidenced a significant inhibition (>90%) upon treatment with the hydroethanolic extract obtained from X. aethiopica leaves at a concentration of 500 μg/mL. Additional anti-inflammatory effects were recorded, including a significant decrease on IL-6 levels at 250 and 500 μg/mL. The extract proved to be active towards 5-LOX, leading to significant inhibition at concentrations ranging from 16 to 250 μg/mL (IC50 = 85 μg/mL). Phenolic profiling allowed the identification and quantitation of eight constituents, including caffeoylquinic acids (1-3), mono-O-glycosylated flavonols (5-8), and the mono-O-glycosyl flavone luteolin-7-O-glucoside (4). The main phenolic constituent, kaempferol-3-O-rutinoside (8), was found to significantly contribute to the anti-inflammatory effects, namely through the inhibition of 5-LOX. However, no effects on the decrease of TNF-α and IL-6 levels caused by this phenolic compound were found. The anti-inflammatory effects of X. aethiopica leaves are demonstrated experimentally, thus substantiating its use in folk Medicine. Relevantly, the observed anti-inflammatory properties can stimulate further studies in order to fully unveil the therapeutic potential of the plant, namely as a source of phenolic compounds with a significant ability to interfere with conventional inflammatory targets.

Silver complex of salicylic acid and its hydrogel-cream in wound healing chemotherapy

The known metallotherapeutic [Ag(salH)]2 (AGSAL-1) of salicylic acid (salH2), was used for the development of new efficient silver based material for wounds healing. AGSAL-1 was characterized by spectroscopic techniques and X-ray crystallography. The wound healing epithelialization of AGSAL-1 was investigated by the means of scratch assay against immortalized human keratinocytes (HaCaT) cells. The anti-inflammatory activity of AGSAL-1 was evaluated by monitoring the catalytic peroxidation of linoleic acid to hydroperoxylinoleic acid by the enzyme lipoxygenase (LOX). The antibacterial activity of AGSAL-1 was evaluated against bacterial species which colonize wounds, such as: Pseudomonas aeruginosa (PAO1), Staphylococcus epidermidis and Staphylococcus aureus, by the means of Minimum Inhibitory Concentration (MIC), Minimum Bactericidal Concentration (MBC) and their Inhibition Zone (IZ). Moreover, the influence of AGSAL-1 against the formation of biofilm of PAO1 and St. aureus was also evaluated by the mean of Biofilm Elimination Concentration (ΒΕC). A hydrogel material CMC@AGSAL-1, based on the dispersion of AGSAL-1 in to carboxymethyl cellulose (CMC) was tested for its antimicrobial activity. Molecular Docking was performed, to explore the molecular interaction of AGSAL-1 with (i) the transcriptional regulator of PAO1, LasR. (ii) the mevalonate pathway for the biosynthesis of isoprenoids which is essential for gram-positive bacteria St. epidermidis and St. aureus. The toxicity of AGSAL-1 was examined against the HaCaT cells. Its genotoxicity was evaluated using Allium cepa model, in vivo. No genotoxicity was detected, indicating that AGSAL-1 is a candidate towards the development on a new efficient medication of the silver based metallodrugs.

The hydroperoxide lyase branch of the oxylipin pathway protects against photoinhibition of photosynthesis.

This study describes a new role for hydroperoxide lyase branch of oxylipin biosynthesis pathway in protecting photosynthetic apparatus under high light conditions. Lipid-derived signaling molecules, oxylipins, produced by a multi-branch pathway are central in regulation of a wide range of functions. The two most known branches, allene oxide synthase (AOS) and 13-hydroperoxide lyase (HPL) pathways, are best recognized as producers of defense compounds against biotic challenges. In the present work, we examine the role of these two oxylipin branches in plant tolerance to the abiotic stress, namely excessive light. Towards this goal, we have analyzed variable chlorophyll fluorescence parameters of intact leaves of Arabidopsis thaliana genotypes with altered oxylipin profile, followed by examining the impact of exogenous application of selected oxylipins on functional activity of photosynthetic apparatus in intact leaves and isolated thylakoid membranes. Our findings unequivocally bridge the function of oxylipins to photosynthetic processes. Specifically, HPL overexpressing lines display enhanced adaptability in response to high light treatment as evidenced by lower rate constant of photosystem 2 (PS2) photoinhibition and higher rate constant of PS2 recovery after photoinhibition. In addition, exogenous application of linolenic acid, 13-hydroperoxy linolenic acid, 12-oxophytodienoic acid, and methyl jasmonate individually, suppresses photochemical activity of PS2 in intact plants and isolated thylakoid membranes, while application of HPL-branch metabolites-does not. Collectively these data implicate function of HPL branch of oxylipin biosynthesis pathway in guarding PS2 under high light conditions, potentially exerted through tight regulation of free linolenic acid and 13-hydroperoxy linolenic acid levels, as well as competition with production of metabolites by AOS-branch of the oxylipin pathway.

Synthesis characterization and biological activity of mixed ligand silver(I) complex of 2-benzimidazolylurea and triphenylphosphine

The treatment with triphenylphosphine (TPP) in DMF solution of the white precipitation derived from the reaction of silver(I) nitrate with 2-benzimidazolylurea (BZIMU) results in the [Ag(TPP)2(BZIMU)NO3] (1) complex. The product was characterized by elemental analysis and spectroscopic techniques (FT-IR and 1H, 13C NMR). Single crystal X-ray diffraction analysis of 1 have been carried out at 293K. Mixed ligand complexes of silver(I) nitrate with urea derivatives and phosphines which exhibits significant biological effects are rare in the literature.Complex 1 was evaluated for its in vitro cytotoxic activity (cell viability) against: (i) human breast adenocarcinoma cancer cell line (MCF-7) and (ii) normal human fetal lung fibroblast cells (MRC-5) with SRB assay. The results showed that 1 mediates a strong cytotoxic response to the tested normal (MRC-5) and cancer cell lines (MCF-7). It is also exhibits four time stronger activity against cancer cells (MCF-7) than cisplatin while it is less toxic against normal cells (MRC-5). The therapeutic potency index (TPI) which is define as the IC50 value of 1 against normal cells divided by its IC50 value against cancerous cells is 0.9 in contrast to the 0.2 of cisplatin. The influence of the complex 1, upon the catalytic peroxidation of linoleic acid to hydroperoxylinoleic acid by the enzyme lipoxygenase (LOX) was kinetically and theoretically studied.

Methyl Jasmonate-Induced Lipidomic and Biochemical Alterations in the Intertidal Macroalga Gracilaria dura (Gracilariaceae, Rhodophyta).

The role of exogenously added methyl jasmonate (MeJA), a lipid-derived signaling compound, in inducing oxidative stress in the marine red macroalga Gracilaria dura was investigated. MeJA at a concentration of 1-100 µM was a strong stimulant of reactive oxygen species (H(2)O(2), HO· and O(2) (·-)) (P < 0.05) causing considerable oxidative stress in G. dura. This further led to lipid peroxidation and degradation of the pigments Chl a and phycocyanin, with a concomitant increase in phycoerythrin. The MeJA-induced oxidative burst also led to the induction of a fatty acid oxidation cascade, resulting in the synthesis of hydroxy-oxylipins and the up-regulation of the 13-lipoxygenase pathway. Electrospray ionization-mass spectrometry-based shotgun lipidomic analysis revealed that monogalactosyldiacylglycerol (a chloroplastic glycerolipid) and phosphatidylcholine (extrachloroplastidic phopholipid) were the most affected lipid classes. The degradation of 18:3-fatty acid-containing monogalactosyldiacylglycerol inferred that it provided fatty acyl chains for the biosynthesis of 13-hydroperoxylinolenic acid, which was further directed towards either the jasmonate pathway or other alternative pathways of the fatty acid oxidation cascade, analogous to higher plants. Also, G. dura modulated the lipid acyl chains in such a way that no significant change was observed in the fatty acid profile of the treated thalli as compared with those of the control, except for C16:0, C16:1 (n-9), C20:3 (n-6) and C20:4 (n-6) (P < 0.05). Furthermore, MeJA caused the accumulation of phenolic compounds and the up-regulation of enzymes involved in secondary metabolism such as polyphenol oxidase, shikimate dehydrogenase and phenylalanine ammonia-lyase, indicating a shift towards secondary metabolism as a defense strategy to combat the induced oxidative stress.

Abstract 581: Lipid Peroxide Derived Dicarboxylic Acids Induce Atherosclerotic Calcification

Background: Cardiovascular diseases, including atherosclerosis, are the leading cause of death in the United States. Atherosclerotic lesions are formed by deposition of lipids in the intima of arteries. Upon exposure to oxidative stresses, low-density lipoprotein (LDL) is converted to highly atherogenic oxidized LDL (ox-LDL) particles, which contribute to disease development and progression. Advanced disease stages may result in calcification of lesions. This calcification process is important, as it has been shown to be associated with stable plaques that are less prone to rupture. Calcification is present in lipid rich domains of lesions, however neither the composition of the mineralized calcium deposits nor its relationship to lipid peroxidation is known. Hypothesis: Lipid peroxide derived AZA induces calcification of smooth muscle cells thereby providing the link between calcification and overall plaque burden, and association of calcification with the lipophilic region of the lesion. Methods: In this study, the potential of lipid peroxide-derived lipophilic dicarboxylic acid (DCA, e.g. azelaic acid) to promote calcification upon exposure to vascular smooth muscle cells was tested. Using 13-Hydroperoxyoctadecadienoic acid (13-hydroperoxylinoleic acid, 13-HPODE) and thin-layer and gas chromatography[[Unable to Display Character: &amp;#8211;]]mass spectrometry we characterized the conditions where HPODE is decomposed to aldehyde product 9-oxo-nonanoic acid and its corresponding DCA azelaic acid (AZA). Results: Both free AZA and intracellular delivery of AZA via lysophosphatidylcholine (lysoPtdCho) micelles induced calcification of aortic smooth muscle cells, as determined by Von Kossa and alizarin red staining. HPODE treatment resulted in the cellular conversion to ONA and AZA as determined by GC-MS. Conclusion: These results demonstrate that DCAs could contribute to atherosclerotic calcification thus accounting for the latter’s relationship to plaque burden and association with lipids. This study also challenges the dogma that arterial calcification represents the deposition of calcium phosphate. Our future work aims to delineate the association of calcium with lipid rich plaques and lipid oxidation with calcification in animal and human atherosclerosis.

Silver(I) compounds of the anti-inflammatory agents salicylic acid and p-hydroxyl-benzoic acid which modulate cell function

Silver nitrate reacts with salicylic acid (salH2) or p-hydroxy-benzoic acid (p-HbzaH2) and equimolar amount of NaOH to yield a white precipitations which are then treated with tri(p-tolyl)phosphine (tptp) or tri(m-tolyl)phosphine (tmtp) to yield the complexes [Ag(tptp)2(salH)] (1), [Ag(tptp)2(p-Hbza)] (2) and [Ag(tmtp)2(salH)] (3). Complexes 1 and 3 are also obtained when aspirin (aspH) is used. The acetic ester of salicylic acid is hydrolyzed to form the complexes 1 and 3. However, when aspirin and tptp are used, a mixture of products was obtained which contains both 1 and an ionic complex of formula {[Ag(tptp)4]+[(salH)−]∙[(CH3)2NCHO)]∙(H2O)} (1a). The complexes were characterized by m.p., e.a., mid-FT-IR, 1H-,31P-NMR, HRMS, UV–vis spectroscopic techniques and X-ray crystallography. Two phosphorus and one carboxylic oxygen atoms form a trigonal planar geometry around Ag(I) ions in complexes 1–3. Complex 1a consists of a [Ag(tptp)4]+ cation and a deprotonated salH− counter anion. The influence of 1–3 on the viability of MCF-7 (breast) and HeLa (cervix) adenocarcinoma cells, is evaluated. DNA binding tests indicate the ability of 1–3 to modify the activity of cells. The binding constants of 1–3 towards calf-thymus DNA, reveal stronger interaction of 2. Changes in fluorescent emission light of ethidium bromide (EB) in the presence of DNA suggest intercalation or electrostatic interactions into DNA for 1 and 3. Docking studies on DNA-complex interactions confirm the binding of 1–3 in the minor groove of B-DNA. Moreover, the influence of 1–3 on the peroxidation of linoleic acid to hydroperoxylinoleic acid by the enzyme lipoxygenase (LOX) was kinetically and theoretically studied.

A novel silver iodide metalo-drug: Experimental and computational modelling assessment of its interaction with intracellular DNA, lipoxygenase and glutathione

The new mixed ligand silver(I) complex of formula [AgI(TPP)2(MBZT)] (1) was obtained by reacting 2-mercapto-benzothiazole (MBZT) with triphenylphosphine (TPP). The complex was characterized by m.p., vibrational spectroscopy (FT-IR), 1H NMR, UV–vis, ESI-MS spectroscopic techniques and its structure was confirmed by X-ray crystallography. Mixed ligand complexes of silver(I) iodide with thiones and phosphines are very rare in the literature and to the best of our knowledge compound 1 is the first of this kind exhibiting significant biological effects.Complex 1 was evaluated for its in vitro cytotoxic activity (cell viability) under irradiation with UV light and without irradiation against human cancer cell lines: MCF-7 (breast, ER positive), MDA-MB-231 (breast, ER negative), Caki-1 (renal), A549 (lung), OAW-42 (ovarian), HeLa (cervical) and additionally against the normal human lung cell line MRC-5 (normal human fetal lung fibroblast cells) and normal immortalized human mammary gland epithelial cell line (MTSV17) with SRB assay. The results showed that 1 mediates a strong cytotoxic response to the tested normal and cancer cell lines. It exhibits equal activity against MDA-MB-231 cells where estrogen receptors (ERs) are devoid with the one against MCF-7 where ERs are present. Molecular docking studies have shown that 1 is docked in the different pocket than that of the ERs modulators. The binding affinity of 1 towards the intracellular molecules DNA and lipoxygenase (LOX) was studied for the evaluation of the mechanism of its cytostasis. The binding constant (Kb) of 1 towards CT-DNA was calculated by UV–Vis and fluorescent spectra suggesting intercalation or electrostatic interactions of 1 into DNA. Docking studies on DNA-complex interactions confirm the binding of 1. Moreover, the influence of complex 1 on the catalytic peroxidation of linoleic acid to hydroperoxylinoleic acid by the enzyme lipoxygenase (LOX) was kinetically and theoretically studied. In addition, since the deactivation of cisplatin caused by glutathione, seems to be an important determinant of its cytotoxic effects, the reaction of 1 with glutathione (GSH) was investigated by UV-absorption spectroscopy.

Synthesis, characterization, and binding properties towards CT-DNA and lipoxygenase of mixed-ligand silver(I) complexes with 2-mercaptothiazole and its derivatives and triphenylphosphine

Mixed-ligand silver(I) complexes of formulae [AgCl(TPP)2(MTZD)] (1), {[AgCl(TPP)2(MBZT)]·(MBZT)·2(toluene)} (2), and [AgCl(TPP)2(CMBZT)] (3) were obtained by refluxing toluene solutions of silver(I) chloride with triphenylphosphine (TPP) and the appropriate heterocyclic thioamides 2-mercaptothiazolidine (MTZD), 2-mercaptobenzothiazole (MBZT), and 5-chloro-2-mercaptobenzothiazole (CMBZT). The complexes were characterized by the melting point, vibrational spectroscopy (Fourier transform mid-IR), (1)H-NMR spectroscopy, UV-vis spectroscopy, and X-ray crystallography. DNA binding tests indicate the ability of complexes 1-3 to modify the activity of cells. The binding constants of 1-3 towards calf-thymus DNA (CT-DNA) [(3.5±8.5)×10(4)M(-1) for 1, (10.0±0.0)×10(4)M(-1) for 2, and (46.4±7.0)×10(4)M(-1) for 3] indicate strong interaction of 3. Changes in the fluorescence of ethidium bromide in the presence of DNA suggest intercalation into or electrostatic interactions with DNA. The corresponding apparent binding constants (K app) towards CT-DNA calculated through fluorescence spectra are (3.5±0.7)×10(4)M(-1) for 1, (10.0±0.0)×10(4)M(-1) for 2, and (46.4±7.0)×10(4)M(-1) for 3. Docking studies on DNA complexes confirm the binding of 1 and 2 in the major groove of CT-DNA and of 3 in the minor groove. Moreover, the influence of 1-3 on the catalytic peroxidation of linoleic acid to hydroperoxylinoleic acid by the enzyme lipoxygenase was studied kinetically and theoretically. The antibacterial effect of 1-3 against the bacterial species Pseudomonas aeruginosa and Escherichia coli was evaluated. Complex 1 exhibits the strongest activity.

Novel metallo-therapeutics of the NSAID naproxen. Interaction with intracellular components that leads the cells to apoptosis

Two new mixed ligand-silver(I) complexes of the anti-inflammatory drug naproxen (naprH) and triphenylphosphine (tpp) or tri(p-tolyl)phosphine (tptp) of formulae {[Ag(tpp)3(napr)](H2O)} (1) and [Ag(tptp)2(napr)] (2) have been synthesized and characterized by m.p., vibrational spectroscopy (mid-FT-IR), Raman, (1)H-NMR, UV-Vis, ESI-MS spectroscopic techniques and X-ray crystallography. The complexes show high photo-sensitivity to UVC light. Photolysis of 1-2 was studied and the results showed monotonic degradation of the complexes with simultaneous triarylphosphine oxide formation. The complexes 1-2 were tested for their antiproliferative activity against human breast adenocarcinoma (MCF-7) cells. Complexes 1-2 were more active than cisplatin against cells. UVC light increases the effectiveness of complexes 1-2 on MCF-7 cells by 13% and 38% respectively. Due to the morphology of the MCF-7 cells, which were incubated with the complexes 1-2, the cell death was ascribed to apoptosis. Electrophoresis to genomic DNA of MCF-7 cells confirmed the apoptosis through DNA fragmentation. The binding affinity of 1-2 towards the intracellular molecules CT-DNA and lipoxygenase (LOX) was studied for the evaluation of the mechanism of cell death. Thus, the binding constants (K(b)) of 1-2 towards CT-DNA calculated by UV-Vis spectra are 32.8 ± 8.5 × 10(4) (1) and 4.7 ± 1.8 × 10(4) (2) M(-1), respectively. Changes in fluorescent emission light of ethidium bromide (EB) in the presence of DNA suggest intercalation or electrostatic interactions into DNA of both complexes 1-2 in the minor groove. The corresponding apparent binding constants (K(app)) of 1-2 towards CT-DNA calculated through fluorescence spectra are 2.9 ± 0.3 × 10(4) (1) and 1.6 ± 0.4 × 10(4) (2) M(-1) respectively. Docking studies on DNA-complexes interactions show the binding of 1 in the major groove and the corresponding one of 2 in the minor one. Moreover, the influence of complexes 1-2 on the catalytic peroxidation of linoleic acid to hydroperoxylinoleic acid by the enzyme lipoxygenase (LOX) was kinetically and theoretically studied. Only 1 inhibits lipoxygenase activity (IC50 = 5.1 (1), >30 (2) μM).

Abstract 425: Hydrogen Peroxide and 13-hydroperoxylinoleic Acid Induce the Expression of Insulin-like Growth Factor-binding Protein 3 in HepG2 Cells

Background Patients with type 2 diabetes are reported to have increased oxidative stress. Oxidized LDL is reported to suppress the expression of insulin-like growth factor I receptor (IGF1R). IGF1 emerges as a potential therapeutic target for insulin resistance and deficiency. The functions of IGF1 are regulated by its receptors as well as binding proteins (IGFBPs). IGFBP3 is known as the main binding protein for IGF1, and shows inhibitory effects on IGF1 through binding to extracellular matrix. The present study investigates whether oxidative stress regulates IGF binding proteins. Methods HepG2 (hepatocellular carcinoma) cells were treated with either hydrogen peroxide (H2O2) or 13-hydroperoxylinoleic acid (HPODE) with/without catalase in serum free medium for 24 hours, and total RNA and protein were isolated for quantitative PCR or Western blot analyses. Results H2O2 of variant concentrations induced IGFBP3 expression, which was abolished by the addition of catalase. HPODE also induced IGFBP3 expression in a dose-dependent manner. The induction was found for both isoforms A and B of IGFBP3. Conclusion Our findings shed light on the potential synergetic regulation of IGF1 by oxidative stress through both the receptor and binding protein, and advance the understanding of the IGF1 resistance in type 2 diabetes. Furthermore, antioxidants are indicated to be able to increase the IGF1 sensitivity, and reduce the dosage and side effects of IGF1 administration for patients with diabetes.

Interactions among LOX metabolites regulate temperature-mediated flower bud formation in morning glory (Pharbitis nil)

We examined the relationship between temperature (15–35°C) and flower induction as it is influenced by linolenic acid (LA) cascade products, lipoxygenase (LOX; EC 1.13.11.12), allene oxide synthase (AOS; EC 4.2.1.92), and allene oxide cyclase (AOC; EC 5.3.99.6) generated in morning glory (Pharbitis nil Choisy). The maximum amount of LOX protein was detected when plants were grown at 30°C, whereas endogenous AOS and AOC proteins were markedly accumulated at 15°C. Although both test levels of 9(S)- and 13(S)-hydroperoxy linolenic acid (HPOT) showed similar temperature dependencies, reflecting the profile of LOX, the relative amount of 13(S)-HPOT was much higher than that of 9(S)-HPOT, regardless of temperature regime. This implied a faster reaction pathway to 9,10-α-ketol octadecadienoic acid (KODA) in the LA cascade. In the 13(S)-HPOT pathway, the highest level of endogenous jasmonic acid (JA) was observed at 15°C. Our results suggest that at a high temperature (30°C), 9(S)-HPOT may be readily metabolized into KODA to promote flower bud formation. By contrast, at a low temperature, high levels of AOS and AOC result in an accumulation of JA that inhibits this developmental process. Accordingly, depending on the growing temperature, flower bud formation in P. nil is possibly regulated by the interactions among LOX metabolites, with KODA serving as a promoter and JA as an inhibitor.

The rice hydroperoxide lyase OsHPL3 functions in defense responses by modulating the oxylipin pathway

As important signal molecules, jasmonates (JAs) and green leaf volatiles (GLVs) play diverse roles in plant defense responses against insect pests and pathogens. However, how plants employ their specific defense responses by modulating the levels of JA and GLVs remains unclear. Here, we describe identification of a role for the rice HPL3 gene, which encodes a hydroperoxide lyase (HPL), OsHPL3/CYP74B2, in mediating plant-specific defense responses. The loss-of-function mutant hpl3-1 produced disease-resembling lesions spreading through the whole leaves. A biochemical assay revealed that OsHPL3 possesses intrinsic HPL activity, hydrolyzing hydroperoxylinolenic acid to produce GLVs. The hpl3-1 plants exhibited enhanced induction of JA, trypsin proteinase inhibitors and other volatiles, but decreased levels of GLVs including (Z)-3-hexen-1-ol. OsHPL3 positively modulates resistance to the rice brown planthopper [BPH, Nilaparvata lugens (Stål)] but negatively modulates resistance to the rice striped stem borer [SSB, Chilo suppressalis (Walker)]. Moreover, hpl3-1 plants were more attractive to a BPH egg parasitoid, Anagrus nilaparvatae, than the wild-type, most likely as a result of increased release of BPH-induced volatiles. Interestingly, hpl3-1 plants also showed increased resistance to bacterial blight (Xanthomonas oryzae pv. oryzae). Collectively, these results indicate that OsHPL3, by affecting the levels of JA, GLVs and other volatiles, modulates rice-specific defense responses against different invaders.

The Patatin-Containing Phospholipase A pPLAIIα Modulates Oxylipin Formation and Water Loss in Arabidopsis thaliana

The patatin-related phospholipase A (pPLA) hydrolyzes membrane glycerolipids to produce monoacyl compounds and free fatty acids. Phospholipids are cleaved by pPLAIIα at the sn-1 and sn-2 positions, and galactolipids, including those containing oxophytodienoic acids, can also serve as substrates. Ablation of pPLAIIα decreased lysophosphatidylcholine and lysophosphatidylethanolamine levels, but increased free linolenic acid. pPLAIIα-deficient plants displayed a higher level of jasmonic acid and methyl jasmonate, as well as the oxylipin-biosynthetic intermediates 13-hydroperoxylinolenic acid and 12-oxophytodienoic acid than wild-type (WT) plants. The expression of genes involved in oxylipin production was also higher in the pPLAIIα-deficient mutant than in WT plants. The mutant plants lost water more quickly than WT plants. The stomata of WT and mutant plants responded similarly to abscisic acid. In response to desiccation, the mutant and WT leaves produced abscisic acid at the same rate, but, after 4 h of desiccation, the jasmonic acid level was much higher in mutant than WT leaves. These results indicate that pPLAIIα negatively regulates oxylipin production and suggest a role in the removal of oxidatively modified fatty acids from membranes.

Structural and In Vitro Biological Studies of Organotin(IV) Precursors; Selective Inhibitory Activity Against Human Breast Cancer Cells, Positive to Estrogen Receptors

Crystals of Ph3SnCl (1) were grown from a methanol/acetonitrile solution. Compounds [Ph3SnOH]n (2) and [(Ph2Sn)4Cl2O2(OH)2] (3) were crystallized from diethyl ether/methanol/acetonitrile and hot acetone/water solutions respectively, of the white precipitation, formed by adding KOH to solutions of 1 and [Ph2SnCl2] in 1 : 1 and 1 : 2 molar ratios respectively. Complex 1 was characterized by X-ray crystallography. X-ray structure determination of compounds 2 and 3 confirmed the previously reported identities. The molecular structure of 1, reported here, is a new polymorphic form of the known one for Ph3SnCl. Four independent [Ph3SnCl] molecules constitute the crystal structure of 1. The moieties are packed in two pairs in a tail-to-tail arrangement. Complexes 1–3 were evaluated for their in vitro cytotoxic activity (cell viability) against human cancer cell lines: HeLa (human cervical), MCF-7 (breast, estrogen receptor (ER) positive), MDA-MB-231 (breast, ER negative), A549 (lung), Caki-1 (kidney carcinoma), 786-O (renal adenocarcinoma), K1 (thyroid carcinoma), and the normal human lung cell line MRC-5 (normal human fetal lung fibroblast cells) versus, the normal immortalized human mammary gland epithelial cell line MTSV17 with a sulforhodamine B (SRB) assay. The results show potent cytotoxic activity of the complexes against all cell lines used, which was superior to that of cisplatin (CDDP). Compounds 1–3 showed higher activity against breast cancer cells MCF-7 (ER positive) than against of MDA-MB-231 (ER negative). These findings prompted us to search for possible interaction of these complexes with other cellular elements of fundamental importance in cell proliferation. The influence of these complexes 1–3 upon the catalytic peroxidation of linoleic acid to hydroperoxylinoleic acid by the enzyme lipoxygenase (LOX), as well as their binding affinity towards calf thymus-DNA, were kinetically and theoretically studied.