Lipid Peroxidation In Rat Liver Microsomes Research Articles

A new lignan glucoside from stems and branches of Rhododendron ovatum

Ten lignans were isolated from the ethanol extract of stems and branches of Rhododendron ovatum through column chromatography over silica gel, ODS, Sephadex LH-20, and MCI-gel resin and semi-preparative RP-HPLC. The structures of all compounds were elucidated by extensive spectroscopic data analysis(UV, IR, HR-ESI-MS, ECD and NMR) as(-)-4-epi-lyoniresinol-9'-O-α-L-rhamnopyranoside(1),(+)-lyoniresinol-3α-O-α-L-rhamnopyranoside(2),(+)-5'-methoxyisolariciresinol-9'-O-α-L-rhamnopyranoside(3),(-)-lyoniresinol-3α-O-β-D-glucopyranoside(4),(+)-lyoniresinol-3α-O-β-D-glucopyranoside(5),(-)-4-epi-lyoniresinol-9'-O-β-D-glucopyransoide(6), racemiside(7), neociwujiaphenol(8),(+)-syringaresinol(9), and homohesperitin(10). Among them, compound 1 was a new aryltetralin-type lignan. All the isolated lignans were tested for antioxidant activities in Fe~(2+)-cysteine induced rat liver microsomal lipid peroxidation in vitro, and compounds 8 and 9 showed antioxidant activities on the formation of malondiadehyde(MDA) in rat liver microsomes at 1×10~(-5) mol·L~(-1), with significant inhibitory rates of 75.20% and 91.12%, respectively.

Evaluation of the Free Radical Scavenging Activities of Ellagic Acid and Ellagic Acid Peracetate by EPR Spectrometry.

The purpose of this study was to examine the free radical scavenging and antioxidant activities of ellagic acid (EA) and ellagic acid peracetate (EAPA) by measuring their reactions with the radicals, 2,2-diphenyl-1-picrylhydrazyl and galvinoxyl using EPR spectroscopy. We have also evaluated the influence of EA and EAPA on the ROS production in L-6 myoblasts and rat liver microsomal lipid peroxidation catalyzed by NADPH. The results obtained clearly indicated that EA has tremendous ability to scavenge free radicals, even at concentration of 1 µM. Interestingly even in the absence of esterase, EAPA, the acetylated product of EA, was also found to be a good scavenger but at a relatively slower rate. Kinetic studies revealed that both EA and EAPA have ability to scavenge free radicals at the concentrations of 1 µM over extended periods of time. In cellular systems, EA and EAPA were found to have similar potentials for the inhibition of ROS production in L-6 myoblasts and NADPH-dependent catalyzed microsomal lipid peroxidation.

Six new monacolin analogs from red yeast rice.

Six novel monacolin analogs, monacolins V1-V6 (1-6), together with seven known ones (7-13), were isolated from the ethyl acetate extract of red yeast rice. Their structures and absolute configurations were determined by spectroscopic methods, especially 2D NMR (1H-1HCOSY, HSQC, HMBC, and NOESY/ROESY) and CD spectroscopic analyses as well as chemical derivation. Monacolins V2 (2) and V3 (3) represent the first examples of monacolins with 3-hydroxybutyrate substitute. The anti-inflammatory inhibitory activities against the lipopolysaccharide (LPS) induced NO production in BV-2 cells as well as antioxidant activities against rat liver microsomal lipid peroxidation were evaluated.

Hepatoprotective glycosides from the rhizomes of Imperata cylindrical

Three new C-methylated phenylpropanoid glycosides (1, 2), a new 8–4′-oxyneolignan (3), together with two known analogs (4, 5), were isolated from the rhizomes of Imperata cylindrical Beauv. var. major (Nees) C. E. Hubb. Their structures were determined by spectroscopic and chemical methods. Compounds 1, 2, and 5 (10 μM) exhibited pronounced hepatoprotective activity against N-acetyl-p-aminophenol (APAP)-induced HepG2 cell damage in vitro assays. Furthermore, their antioxidant activities against Fe2+-cysteine-induced rat liver microsomal lipid peroxidation and the effects on the secretion of TNF-α in murine peritoneal macrophages (RAW264.7) induced by lipopolysaccharides were evaluated.

A new styrene dimer derivative from Litsea greenmaniana

A new styrene dimer derivative has been isolated from the branch of Litsea greenmaniana by column chromatography over silica gel and Sephadex LH-20, as well as semi-preparative HPLC. Its structure was identified by spectroscopic data analysis (MS, UV, IR, 1D and 2D NMR) as (E)-2,4-bis(p-hydroxyphenyl)-2-butenol, named as listeanol. At a concentration of 1×10-5 mol•L⁻¹, compound 1 was inactive in the assays, including cytotoxicity against human tumor cell lines (HCT-8, Bel-7402, BGC-823, A549 and A2780), antioxidant activity in Fe²⁺-cystine-induced rat liver microsomal lipid peroxidation, neuroprotective activity against serum deprivation or glutamate induced neurotoxicity in cultures of PC12 cells, and the inhibitory activity against protein tyrosine phosphatase 1B (PTP1B).

Phenolic constituents from the roots of Alangium chinense

Three new phenolics (1–3) and twenty-eight known compounds (4–31) were isolated from an ethanolic extract of roots of Alangium chinense. Compound 11 exhibited antiviral activity against Coxsackie virus B3 with IC50 values of 16.89μmol/L. Compounds 1, 10–17, 19–21, and 23 showed strong antioxidant activity against Fe2+-cysteine-induced rat liver microsomal lipid peroxidation, with IC50 values of 0.14–8.18μmol/L.

4-Hydroxybenzyl-substituted glutathione derivatives from Gastrodia elata

Seven new 4-hydroxybenzyl-substituted glutathione derivatives (2–8), together with a known analogue (1), were isolated from the aqueous extract of Gastrodia elata Blume rhizomes. Their structures were determined by using spectroscopic and chemical methods. The absolute configurations of 1–8 were assigned by using Marfey's method, combined with comparing the NMR and CD spectroscopic data of sulfoxide moieties in 3–6 with those of S-(4-hydroxybenzyl)cysteine sulfoxide stereoisomers (9–12) synthesized as authentic samples. The configurations of 9–12 were confirmed by electronic CD calculations based on the quantum-mechanical time-dependent density functional theory. Furthermore, the structures of 1, 3, 5, 7, and 8 were verified by synthesis. Compound 3 was active against serum deprivation-induced PC12 cell damage and synthetic 9–14 exhibited activity against Fe2+-cysteine induced rat liver microsomal lipid peroxidation.

Ethyl acetate-soluble chemical constituents from branch of Hypericum petiolulatum

The stems and branches of Hypericum petiolulatum were extracted by alcohol and liquid-liquid extraction. Seven furofuran lignans were isolated from the ethyl acetate fraction of ethanol extract of H. petiolulatum by using silica gelchromatography, Sephadex LH-20 chromatography, medium-pressure liquid chromatography and preparative HPLC. Their structures were identified by the spectroscopic methods as pinoresinol (1), medioresinol (2), 8-acetoxypinoresinol (3), epipinoresinol (4), (+)-syringaresinol (5), (+)-1-hydroxysyringaresinol (6) and erythro-buddlenolE (7). All the isolates were firstly found in H. petiolulatum. In the bioassay, compound 7 showed remarkable antioxidative activity inhibiting Fe(+2)-cystine induced rat liver microsomal lipid peroxidation with inhibitory rate 38% at a concentration of 1 x 10(-6) mol · L(-1) (positive control Vit E with the inhibitory rate of 35% at the same concentration).

4-Hydroxybenzyl-substituted amino acid derivatives from Gastrodia elata

Seven new 4-hydroxybenzyl-substituted amino acid derivatives (1−7), together with 11 known compounds, were isolated from an aqueous extract of the rhizomes of Gastrodia elata Blume. Their structures were determined by spectroscopic and chemical methods. Compounds 1−3 are pyroglutamate derivatives containing 4-hydroxybenzyl units at the N atom and 4−7 are the first examples of natural products with the 4-hydroxybenzyl unit linked via a thioether bond to 2-hydroxy-3-mercaptopropanoic acid (4−6) and 2-hydroxy-4-mercaptobutanoic acid (7), which would be biogenetically derived from cysteine and homocysteine, respectively. The structures of 1 and 2 were verified by synthesis, while the absolute configurations of 4, 5 and 7 were assigned using Mosher’s method based on the MPA determination rule of ΔδRS values. The known compound 4-(hydroxymethyl)-5-nitrobenzene-1,2-diol (8) exhibited activity against Fe2+-cysteine induced rat liver microsomal lipid peroxidation with IC50 values of 9.99×10−6mol/L.

Phenolic compounds and antioxidant properties of high hydrostatic pressure and conventionally treated ginseng (Panax ginseng) products

High hydrostatic pressure (HHP) is an attractive method for food preservation due to resulting improvements in the quality characteristics of foods, in addition to microbial inactivation. This study aimed at improving the nutraceutical potential of red ginseng (Panax ginseng C.A. Meyer). HHP treatment of 600 MPa for 1 min at room temperature in conjunction with conventional steaming and drying processes during red ginseng manufacture significantly (P<0.05) increased the total phenolic compounds (from 1.13 to 1.37 mg maltol equivalent/g of red ginseng), particularly maltol (4.38 to 12.61 mg/100 g of red ginseng). Comparison of HHP-red ginseng with conventional red ginseng and white ginseng showed that HHP-red ginseng had a stronger ability to scavenge 1,1-diphenyl-2-picrylhydrazyl, hydroxyl, and nitric oxide radicals. The ferrous ion chelating and superoxide dismutase activities of HHP-red ginseng were also improved. HHP-red ginseng exhibited a stronger inhibition of rat liver microsomal lipid peroxidation than normal red ginseng. The application of HHP in red ginseng processing is a promising technique to enhance availability of phenolic compounds and nutraceutical characteristics.

Aromatic Glucosides from the Seeds of Prunus davidiana

Chemical investigation of the seeds of Prunus davidiana afforded seven new aromatic glucosides, i.e., the prupersins A-E (1-5) and compounds 6 and 7, as well as 11 known compounds. The structures of 1-7 were elucidated by spectroscopic data analysis and chemical evidence, and configurations were determined by hydrolysis experiments (1, 2, and 5) or electronic circular dichroism (6). Compounds 1-6 exhibited antioxidant activity aganist Fe²⁺-cysteine-induced rat liver microsomal lipid peroxidation, with malondialdehyde inhibitory rates of 50-67% and 53-57% at concentrations of 10⁻⁵ and 10⁻⁶ mol/L, respectively.

Sesquiterpenes and Alkaloids from the Roots of Alangium chinense

Four new sesquiterpenes (1-4), four new alkaloids (5a, 6a, 6b, and 7), and nine known compounds (5b and 8-15) were isolated from an ethanolic extract of roots of Alangium chinense. The structure of 1 was confirmed by X-ray crystallography. The configurations of 5 and 6 were assigned by chiral HPLC analysis and CD spectra. Compounds 3, 4, 8-13, and 15 exhibited antiviral activity against Coxsackie virus B3 with IC50 values of 1.4-15.4 μM. Compounds 2-4, 7, and 9-13 showed antioxidant activities against Fe(2+)-cysteine-induced rat liver microsomal lipid peroxidation, with IC50 values of 3.8-45.7 μM. Compound 5b displayed neuritis inhibitory activity against microglial inflammation factor, with an IC50 value of 6.7 μM. None of the compounds exhibited detectable cytotoxic activity toward any of five tumor cell lines (A549, Be-17402, BGC-823, HCT-8, and A2780) in the MTT assay.

Sesquiterpenes and neolignans from the roots of Illicium dunnianum

Two new sesquiterpenes, dunnianoside I (1) and 8′-oxo-6-hydroxy-dihydrophaseic acid methyl ester (2), a new glycoside, dunnianoside J (3), two new neolignans, dunnianeolignans A–B (4, 5), together with 10 known compounds (6–15), were isolated from the roots of Illicium dunnianum. The structures of these new compounds were elucidated by spectroscopic methods including 1D and 2D NMR, HR-ESI-MS, and chemical methods. Compounds 7, 8, and 13–15 exhibited potent antioxidant activities against Fe2+-cystine-induced rat liver microsomal lipid peroxidation, with IC50 values ranging from 4.2 ± 0.4 to 38.4 ± 2.6 μM.

Antioxidant phenolic glycosides from the roots of Illicium dunnianum

Eight new phenolic glycosides, dunnianosides A–H (1–8), and nine known phenolic glycosides (9–17), were isolated from the roots of Illicium dunnianum. The structures of these new compounds were elucidated by spectroscopic methods including 1D and 2D NMR, HRESIMS, and chemical methods. Compounds 1–5, 7, and 9 exhibited potent antioxidant activities against Fe2+-cystine-induced rat liver microsomal lipid peroxidation, with IC50 values ranging from 3.8±0.6 to 23.0±2.2μM.

Non-anthraquinones constituents from the roots of Knoxia valerianoides

Twenty-one non-anthraquinones constituents were isolated for the first time from an ethanol extract of the roots of Knoxia valerianoides by using a combination of various chromatographic techniques including column chromatography over silica gel, Sephadex LH-20, and reversed-phase HPLC. Their structures were identified by their physical-chemical properties and spectroscopic analysis including NMR and MS. The compounds include ten triterpenoids: ursolic acid (1), oleanolic acid (2), 2-oxo pomolic acid (3), pomolic acid (4), maslinic acid (5), rotungenic acid (6), tormentic accid (7), rotundic acid 3,23-acetonide (8), arjungenin (9), and 2alpha, 3beta, 19alpha, 23-tetrahydroxy-urs-12-en-28-oic acid (10), four sitosterones: (24R)-24-ethylcholesta-4,22-dien-3-one (11), 3-oxo-4-en-sitosterone (12), 7-oxostigmasterol (13), and 7-oxo-beta-sitosterol (14), two lignans: eudesmin (15) and ciwujiatone (16), one coumarin: cnidilin (17), and four simple aromatic analogues: 5-hydroxymethylenefural (18), 3-hydroxy-4-methoxybenzoic acid (19), benzoic acid (20), and 2-hydroxy-5-methxoycinnamaldehydes (21). In the in vitro assays against human cancer cell lines (HCT-8, Bel7402, BGC-823, A549, and A2780), against deserum and glutamate induced PC12-syn cell damage, and against HIV-1 replication, and inhibiting protein tyrosine phosphatase 1B (PTP1 B), LPS induced NO production in macrophage, and Fe(2+)-cystine induced rat liver microsomal lipid peroxidation, at a concentration of 1 x 10(-5) mol x L(-1), no compound showed activity.

Synthesis and Evaluation of Antioxidant Properties of Novel 2‐[2‐(4‐chlorophenyl) benzimidazole‐1‐yl]‐N‐(2‐arylmethylene amino) acetamides and 2‐[2‐(4‐chlorophenyl) benzimidazole‐1‐yl]‐N‐(4‐oxo‐2‐aryl‐thiazolidine‐3‐yl) acetamides‐I

Our approach was to synthesize and examine the antioxidant properties of some new 2-[2-(4-chlorophenyl)benzimidazole-1-yl]-N-(2-arylmethyleneamino) acetamide (1-18) and 2-[2-(4-chlorophenyl)benzimidazole-1-yl]-N-(4-oxo-2-aryl-thiazolidine-3-yl)acetamide (1t-18t) derivatives. Their in vitro effects on rat liver microsomal NADPH-dependent lipid peroxidation levels (LP assay) and microsomal ethoxyresorufin O-deethylase activities (EROD assay) were determined. The free radical scavenging properties of the compounds were also examined in vitro determining the interaction of 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical. The compounds showed significant effects in the above tests.

Anthraquinones from the Roots of Knoxia valerianoides

To investigate the chemical constituents of the roots of Knoxia valerianoides and their biological activities. The anthraquinones were isolated by using a combination of various chromatographic techniques including column chromatography over silica gel, Sephadex LH-20, and reversed-phase HPLC. Structures of the isolates were identified by their physical-chemical properties and spectroscopic analysis including 2D NMR and MS. Antioxidant, anti-HIV, neuroprotective, and cytotoxic activities were screened by using cell-based models. Twenty-two constituents were isolated from an ethanolic extract of the roots of K. valerianoides. Their structures were identified as nordamnacanthal (1), ibericin (2), rubiadin (3), damnacanthol (4), 2-ethoxymethylknoxiavaledin (5), 3-hydroxymorindone (6), knoxiadin (7), 2-formyl knoxiavaledin (8), lucidin (9), xanthopurpurin (10), 1, 3-dihydroxy-2-methoxy-9, 10- anthraquinone (11), lucidin(-methyl ether (12), digiferruginol (13), 3-hydroxy-2-methyl-9,10-anthraquinone (14), rubiadin-1-methyl ether (15), 6-methoxylucidin (-ethyl ether (16), 1,3,6-trihydroxy-2-methyl-9,10-anthraquinone (17), 1,3-dihydroxy-2-hydroxy methyl-6-methoxy-9,10-anthraquinone (18), 1,3,6-trihydroxy-2-methoxymethyl-9,10- anthraquinone (19), 3,6-dihydroxy-2- hydroxymethyl-9,10-anthraquinone (20), and 1,6-dihydroxy-2-methyl-9,10-anthra quinone (21). In the in vitro assays, at a concentration of 1 x 10(-5) mol x L(-1), no compounds were active against human cancer cell lines (HCT-8, Bel7402, BGC-823, A549, and A2780), deserum and glutamate induced PC12-syn cell damage, LPS induced NO production in macrophage, Fe2+-cystine induced rat liver microsomal lipid peroxidation, HIV-1 replication, and protein tyrosine phosphatase 1B (PTP1B). Compounds 9-21 were obtained from the roots of K. valerianoides for the first time.

Constituents of Gymnadenia conopsea

To investigate the chemical constituents of tuber of Gymnadenia conopsea. The constituents were isolated by using a combination of various chromatographic techniques including column chromatography over silica gel, Sephadex LH-20, and C-18, as well as reversed-phase HPLC. Structures of the isolates were identified by spectroscopic data analysis. Thirty-four compounds were isolated. Their structures were identified as six 2-isobutyltartrate benzyl ester glucosides: coelovirin A (1), coelovirin B (2), coelovirin E (3), coelovirin D (4), dactylorhin B (5) and loroglossin (6). Three 2-isobutylmalate benzyl ester glucosides: dactylorhin A (7), dactylorhin E (8) and militarine (9). Three lignans: arctigenin (10), lappaol A (11) and lappaol F (12). Six aromatic acid (alhyde or alcohol) derivatives: 4-beta-D-glucopyranosyloxyl-trans-phenylpropenoic acid (13), 4-beta-D-glucopyranosyloxyl-cis-phenylpropenoic acid (14), gastrodin (15), 4-beta-D-glucopyranosyloxylphenylaldehyde (16), 4-beta-D-glucopyranosyloxylbenzyl methyl ether (17), 4-beta-D-glucopyranosyloxyloxylbenzyl ethyl ether (18), and bis(4-hydroxybenzyl) ether mono 4-O-beta-D-glucopyranoside (19). Four cyclodipeptides: cyclo(L-Leu-L-Tyr) (20), cyclo(L-Leu-L-Pro) (21), cyclo(L-Val-L-Tyr) (22), and cyclo(L-Ala-D-Phe) (23). One N6-substituted andenosine: N6-(4-hydroxybenzyl)-adenine riboside (24). An aromatic amide: N-trans-feruloyltyramine (25). Nine aromatic acids (or aldehyde or alcohol): 3-hydroxybenzoic acid (26), 4-hydroxyisophthalic acid (27), 4-hydroxybenzyl alcohol (28), 4-hydroxybenzyl methyl ether (29), 4-hydroxybenzylaldehyde (30), 4-hydroxybenzoic acic (31), 4-hydroxy-3-methoxybenzoic acid (32), trans-p-hydroxyphenylpropenoic acid (33), and cis-p-hydroxyphenylpropenoic acid (34). At a concentration of 1.0 x 10(-6) mol x L(-1), compounds 10-12 showed antioxidative activity inhibiting Fe(+2) -cystine induced rat liver microsomal lipid peroxidation with inhibitory rates of 53%, 59%, and 52%, respectively(positive control VE with 35% inhibition). These compounds were obtained from the genus Gymnadenia for the first time except for 5-7, 9, 15, 28-34. Compounds 10-12 possess antioxidant activity.

Cytochrome-P450 2B1 gene silencing attenuates puromycin aminonucleoside-induced cytotoxicity in glomerular epithelial cells

Previously, we demonstrated that cytochrome P450 2B1 (CYP2B1) can generate reactive oxygen species in puromycin aminonucleoside (PAN)-induced nephrotic syndrome, an animal model of minimal-change disease in humans. In this study we found that overexpression of CYP2B1 in rat glomerular epithelial cells in vitro significantly increased PAN-induced reactive oxygen species generation, cytotoxicity, cell death, and collapse of the actin cytoskeleton. All of these pathological changes were markedly attenuated by siRNA-induced CYP2B1 silencing. The cellular CYP2B1 protein content was significantly decreased whereas its mRNA level was markedly increased, suggesting regulation by protein degradation rather than transcriptional inhibition in the PAN-treated glomerular epithelial cells. This degradation of CYP2B1 was accompanied by the induction of heme oxygenase-1, an important indicator of heme-induced oxidative stress. In PAN-treated CYP2B1-silenced glomerular epithelial cells the induction of heme oxygenase-1 and caspase-3 activity were significantly decreased. Further, cleavage of the stress-induced pro-apoptotic endoplasmic reticulum-specific pro-caspase-12 was prevented in the silenced cells. Our results support a pivotal role of CYP2B1 for reactive oxygen species production in the endoplasmic reticulum in PAN-induced cytotoxicity.

ChemInform Abstract: Synthesis and Antioxidant Properties of Some New Flavone Derivatives on Lipid Peroxidation in the Rat Liver.

A series of 2'-, 3'-, 4'- and 6-substituted flavone derivatives was synthesized and their in vitro effects on rat liver microsomal NADPH-dependent lipid peroxidation (LP) levels were determined. Retinoic acid, at 10(-4) M concentration, decreased the LP level by about 34%. A significant decrease in male liver microsomal LP level was noted for the compounds 3d, 1a, 3b and 4b at a concentration of 10(-4) M (100%, 95%, 75% and 62%, respectively).