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In-depth hepatoprotective mechanistic study of Phyllanthus niruri: In vitro and in vivo studies and its chemical characterization

Ezzat MI, Okba MM, Ahmed SH, El-Banna HA, Prince A, Mohamed SO, et al.

PLoS One, 2020;15(1):e0226185.
PMID: 31940365 DOI: 10.1371/journal.pone.0226185

Phyllanthus niruri L. is a widespread tropical plant which is used in Ayurvedic system for liver and kidney ailments. The present study aims at specifying the most active hepatoprotective extract of P. niruri and applying a bio-guided protocol to identify the active compounds responsible for this effect. P. niruri aerial parts were extracted separately with water, 50%, 70% and 80% ethanol. The cytoprotective activity of the extracts was evaluated against CCl4-induced hepatotoxicity in clone-9 and Hepg2 cells. Bioassay-guided fractionation of the aqueous extract (AE) was accomplished for the isolation of the active compounds. Antioxidant activity was assessed using DPPH (1, 1-diphenyl-2-picrylhydrazyl) radical scavenging method and ferric reducing antioxidant power (FRAP). The in vivo hepatoprotective activity of AE was evaluated in CCl4-induced hepatotoxicity in rats at different doses after determination of its LD50. Pretreatment of clone-9 and Hepg2 with different concentrations of AE (1, 0.1, 0.01 mg/ml) had significantly reduced the levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) against CCl4 injures, and restored the activity of the natural antioxidants; glutathione (GSH) and superoxide dismutase (SOD) towards normalization. Fractionation of AE gave four fractions (I-IV). Fractions I, II, and IV showed a significant in vitro hepatoprotective activity. Purification of I, II and IV yielded seven compounds; corilagin C1, isocorilagin C2, brevifolin C3, quercetin C4, kaempferol rhamnoside C5, gallic acid C6, and brevifolin carboxylic acid C7. Compounds C1, C2, C5, and C7 showed the highest (p< 0.001) hepatoprotective potency, while C3, C4, and C6 exhibited a moderate (p< 0.001) activity. The AE exhibited strong antioxidant DPPH (IC50 11.6 ± 2 μg/ml) and FRAP (79.352 ± 2.88 mM Ferrous equivalents) activity. In vivo administration of AE in rats (25, 50, 100 and 200 mg/kg) caused normalization of AST, ALT, alkaline phosphatase (ALP), lactate dehydrogenase (LDH), total cholesterol (TC), triglycyrides (TG), total bilirubin (TB), glucose, total proteins (TP), urea and creatinine levels which were elevated by CCl4. AE also decreased TNF-α, NF-KB, IL-6, IL-8, IL10 and COX-2 expression, and significantly antagonizes the effect of CCl4 on the antioxidant enzymes SOD, catalase (CAT), glutathione reductase (GR), and glutathione peroxidase (GSP). The histopathological study also supported the hepatoprotective effect of AE. P. niruri isolates exhibited a potent hepatoprotective activity against CCl4-induced hepatotoxicity in clone-9 and Hepg2 cell lines through reduction of lipid peroxidation and maintaining glutathione in its reduced form. This is attributable to their phenolic nature and hence antioxidative potential.

Matched MeSH terms: Glutathione Peroxidase
Profiling of anti-oxidative enzymes and lipid peroxidation in leaves of salt tolerant and salt sensitive maize hybrids under nac1 and cd stress

Ghulam Hasan Abbasi, Javaid Akhtar, Muhammad Anwar-ul-haq, Moazzam Jamil, Shafaqat Ali, Rafiq Ahmad, et al.

Sains Malaysiana, 2016;45:177-184.

Effects of NaCl salinity and cadmium on the anti-oxidative activity of enzymes like superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), ascorbate peroxidase (APX), glutathione reductase (GR) and lipid peroxidation contents; malondialdehyde (MDA) were studied in two maize hybrids of different salt tolerance characteristics. An increase in the amount of lipid peroxidation indicated the oxidative stress induced by NaCl and Cd. The results also depicted that NaCl stress caused an increase in the activities of POD, SOD, CAT, APX and GR while cadmium stress increased the activities of POD, SOD and APX but showed no significant effect on CAT and GR in both the studied hybrids. The combined effect of salinity and cadmium on these parameters was higher than that of sole effect of either NaCl or Cd. It was also found that maize hybrid 26204 had better tolerance against both stresses with strong antioxidant system as compared to that of maize hybrid 8441. A comparison of the antioxidants and lipid peroxidation in two maize hybrids having varying level of NaCl and Cd stress tolerance corroborated the importance of reactive oxygen species (ROS) in defense against abiotic stresses.

Matched MeSH terms: Peroxidase; Peroxidases; Ascorbate Peroxidases
Modelling of methylene blue adsorption using peroxidase immobilized functionalized Buckypaper/polyvinyl alcohol membrane via ant colony optimization

Jun LY, Karri RR, Mubarak NM, Yon LS, Bing CH, Khalid M, et al.

Environ Pollut, 2020 Apr;259:113940.
PMID: 31931415 DOI: 10.1016/j.envpol.2020.113940

Jicama peroxidase (JP) was covalently immobilized onto functionalized multi-walled carbon nanotube (MWCNT) Buckypaper/Polyvinyl alcohol (BP/PVA) membrane and employed for degradation of methylene blue dye. The parameters of the isotherm and kinetic models are estimating using ant colony optimization (ACO), which do not meddle the non-linearity form of the respective models. The proposed inverse modelling through ACO optimization was implemented, and the parameters were evaluated to minimize the non-linear error functions. The adsorption of MB dye onto JP-immobilized BP/PVA membrane follows Freundlich isotherm model (R2 = 0.99) and the pseudo 1st order or 2nd kinetic model (R2 = 0.980 & 0.968 respectively). The model predictions from the parameters estimated by ACO resulted values close the experimental values, thus inferring that this approach captured the inherent characteristics of MB adsorption. Moreover, the thermodynamic studies indicated that the adsorption was favourable, spontaneous, and exothermic in nature. The comprehensive structural analyses have confirmed the successful binding of peroxidase onto BP/PVA membrane, as well as the effective MB dye removal using immobilized JP membrane. Compared to BP/PVA membrane, the reusability test revealed that JP-immobilized BP/PVA membrane has better dye removal performances as it can retain 64% of its dye removal efficiency even after eight consecutive cycles. Therefore, the experimental results along with modelling results demonstrated that JP-immobilized BP/PVA membrane is expected to bring notable impacts for the development of effective green and sustainable wastewater treatment technologies.

Matched MeSH terms: Peroxidase; Peroxidases
Modeling and optimization by particle swarm embedded neural network for adsorption of methylene blue by jicama peroxidase immobilized on buckypaper/polyvinyl alcohol membrane

Jun LY, Karri RR, Yon LS, Mubarak NM, Bing CH, Mohammad K, et al.

Environ Res, 2020 04;183:109158.
PMID: 32044575 DOI: 10.1016/j.envres.2020.109158

Jicama peroxidase (JP) immobilized functionalized Buckypaper/Polyvinyl alcohol (BP/PVA) membrane was synthesized and evaluated as a promising nanobiocomposite membrane for methylene blue (MB) dye removal from aqueous solution. The effects of independent process variables, including pH, agitation speed, initial concentration of hydrogen peroxide (H2O2), and contact time on dye removal efficiency were investigated systematically. Both Response Surface Methodology (RSM) and Artificial Neural Network coupled with Particle Swarm Optimization (ANN-PSO) approaches were used for predicting the optimum process parameters to achieve maximum MB dye removal efficiency. The best optimal topology for PSO embedded ANN architecture was found to be 4-6-1. This optimized network provided higher R2 values for randomized training, testing and validation data sets, which are 0.944, 0.931 and 0.946 respectively, thus confirming the efficacy of the ANN-PSO model. Compared to RSM, results confirmed that the hybrid ANN-PSO shows superior modeling capability for prediction of MB dye removal. The maximum MB dye removal efficiency of 99.5% was achieved at pH-5.77, 179 rpm, ratio of H2O2/MB dye of 73.2:1, within 229 min. Thus, this work demonstrated that JP-immobilized BP/PVA membrane is a promising and feasible alternative for treating industrial effluent.

Matched MeSH terms: Peroxidase; Peroxidases
Fulltext Electrochemical Immunosensor for the Detection of Aflatoxin B₁ in Palm Kernel Cake and Feed Samples

Azri FA, Selamat J, Sukor R

Sensors (Basel), 2017 Nov 30;17(12).
PMID: 29189760 DOI: 10.3390/s17122776

Palm kernel cake (PKC) is the solid residue following oil extraction of palm kernels and useful to fatten animals either as a single feed with only minerals and vitamins supplementation, or mixed with other feedstuffs such as corn kernels or soy beans. The occurrence of mycotoxins (aflatoxins, ochratoxins, zearalenone, and fumonisins) in feed samples affects the animal's health and also serves as a secondary contamination to humans via consumption of eggs, milk and meats. Of these, aflatoxin B₁ (AFB₁) is the most toxically potent and a confirmed carcinogen to both humans and animals. Methods such as High Performance Liquid Chromatography (HPLC) and Liquid Chromatography-Mass Spectrometry (LC-MS/MS) are common in the determination of mycotoxins. However, these methods usually require sample pre-treatment, extensive cleanup and skilled operator. Therefore, in the present work, a rapid method of electrochemical immunosensor for the detection of AFB₁ was developed based on an indirect competitive enzyme-linked immunosorbent assay (ELISA). Multi-walled carbon nanotubes (MWCNT) and chitosan (CS) were used as the electrode modifier for signal enhancement.N-ethyl-N'-(3-dimethylaminopropyl)-carbodiimide (EDC) andN-hydroxysuccinimide (NHS) activated the carboxyl groups at the surface of nanocomposite for the attachment of AFB₁-BSA antigen by covalent bonding. An indirect competitive reaction occurred between AFB₁-BSA and free AFB₁ for the binding site of a fixed amount of anti-AFB₁ antibody. A catalytic signal based on horseradish peroxidase (HRP) in the presence of hydrogen peroxide (H₂O₂) and 3,3',5,5'-tetramethylbenzidine (TMB) mediator was observed as a result of attachment of the secondary antibody to the immunoassay system. As a result, the reduction peak of TMB(Ox)was measured by using differential pulse voltammetry (DPV) analysis. Based on the results, the electrochemical surface area was increased from 0.396 cm² to 1.298 cm² due to the electrode modification with MWCNT/CS. At the optimal conditions, the working range of the electrochemical immunosensor was from 0.0001 to 10 ng/mL with limit of detection of 0.1 pg/mL. Good recoveries were obtained for the detection of spiked feed samples (PKC, corn kernels, soy beans). The developed method could be used for the screening of AFB₁ in real samples.

Matched MeSH terms: Horseradish Peroxidase
Fulltext Analyses of antioxidant status and nucleotide alterations in genes encoding antioxidant enzymes in patients with benign and malignant thyroid disorders

Ramli NSF, Mat Junit S, Leong NK, Razali N, Jayapalan JJ, Abdul Aziz A

PeerJ, 2017;5:e3365.
PMID: 28584708 DOI: 10.7717/peerj.3365

BACKGROUND: Synthesis of thyroid hormones and regulation of their metabolism involve free radicals that may affect redox balance in the body. Thyroid disorders causing variations in the levels of thyroid hormones may alter cellular oxidative stress. The aim of this study was to measure the antioxidant activities and biomarkers of oxidative stress in serum and red blood cells (RBC) of patients with benign and malignant thyroid disorders and to investigate if changes in the antioxidant activities in these patients were linked to alterations in genes encoding the antioxidant enzymes.
METHODS: Forty-one patients with thyroid disorders from University of Malaya Medical Centre were recruited. They were categorised into four groups: multinodular goitre (MNG) (n = 18), follicular thyroid adenoma (FTA) (n = 7), papillary thyroid cancer (PTC) (n = 10), and follicular thyroid cancer (FTC) (n = 6). Serum and RBC of patients were analysed for antioxidant activities, antioxidant enzymes, and biomarkers of oxidative stress. Alterations in genes encoding the antioxidant enzymes were analysed using whole exome sequencing and PCR-DNA sequencing.
RESULTS: Patients with thyroid disorders had significantly higher serum superoxide dismutase (SOD) and catalase (CAT) activities compared to control, but had lower activities in RBC. There were no significant changes in serum glutathione peroxidase (GPx) activity. Meanwhile, GPx activity in RBC was reduced in PTC and FTC, compared to control and the respective benign groups. Antioxidant activities in serum were decreased in the thyroid disorder groups when compared to the control group. The levels of malondialdehyde (MDA) were elevated in the serum of FTA group when compared to controls, while in the RBC, only the MNG and PTC groups showed higher MDA equivalents than control. Serum reactive oxygen species (ROS) levels in PTC group of both serum and RBC were significantly higher than control group. Whole exome sequencing has resulted in identification of 49 single nucleotide polymorphisms (SNPs) in MNG and PTC patients and their genotypic and allelic frequencies were calculated. Analyses of the relationship between serum enzyme activities and the total SNPs identified in both groups revealed no correlation.
DISCUSSION: Different forms of thyroid disorders influence the levels of antioxidant status in the serum and RBC of these patients, implying varying capability of preventing oxidative stress. A more comprehensive study with a larger target population should be done in order to further evaluate the relationships between antioxidant enzymes gene polymorphisms and thyroid disorders, as well as strengthening the minor evidences provided in literatures.

Matched MeSH terms: Glutathione Peroxidase
Fulltext Thiolate-Capped CdSe/ZnS Core-Shell Quantum Dots for the Sensitive Detection of Glucose

Abd Rahman S, Ariffin N, Yusof NA, Abdullah J, Mohammad F, Ahmad Zubir Z, et al.

Sensors (Basel), 2017 Jul 01;17(7).
PMID: 28671559 DOI: 10.3390/s17071537

A semiconducting water-soluble core-shell quantum dots (QDs) system capped with thiolated ligand was used in this study for the sensitive detection of glucose in aqueous samples. The QDs selected are of CdSe-coated ZnS and were prepared in house based on a hot injection technique. The formation of ZnS shell at the outer surface of CdSe core was made via a specific process namely, SILAR (successive ionic layer adsorption and reaction). The distribution, morphology, and optical characteristics of the prepared core-shell QDs were assessed by transmission electron microscopy (TEM) and spectrofluorescence, respectively. From the analysis, the results show that the mean particle size of prepared QDs is in the range of 10-12 nm and that the optimum emission condition was displayed at 620 nm. Further, the prepared CdSe/ZnS core shell QDs were modified by means of a room temperature ligand-exchange method that involves six organic ligands, L-cysteine, L-histidine, thio-glycolic acid (TGA or mercapto-acetic acid, MAA), mercapto-propionic acid (MPA), mercapto-succinic acid (MSA), and mercapto-undecanoic acid (MUA). This process was chosen in order to maintain a very dense water solubilizing environment around the QDs surface. From the analysis, the results show that the CdSe/ZnS capped with TGA (CdSe/ZnS-TGA) exhibited the strongest fluorescence emission as compared to others; hence, it was tested further for the glucose detection after their treatment with glucose oxidase (GOx) and horseradish peroxidase (HRP) enzymes. Here in this study, the glucose detection is based on the fluorescence quenching effect of the QDs, which is correlated to the oxidative reactions occurred between the conjugated enzymes and glucose. From the analysis of results, it can be inferred that the resultant GOx:HRP/CdSe/ZnS-TGA QDs system can be a suitable platform for the fluorescence-based determination of glucose in the real samples.

Matched MeSH terms: Horseradish Peroxidase
Alterations of serum and saliva oxidative markers in patients with bronchial asthma

Abboud MM, Al-Rawashde FA, Al-Zayadneh EM

J Asthma, 2022 Nov;59(11):2154-2161.
PMID: 34855555 DOI: 10.1080/02770903.2021.2008426

BACKGROUNDS: The development of asthma is highly affected by exposure to exogenous and endogenous oxidative molecules, but the impact of this exposure on the pathophysiology of asthma has received little attention.
OBJECTIVES: Evaluating group of selective oxidative stress markers as a tool in the management of asthma disease.
METHODS: In comparison with matched healthy controls, levels of the oxidant and antioxidant markers: lipid peroxidation malondialdehyde (MDA), Total glutathione (tGSH), Uric acid (UA), Glutathione peroxidase (GPx), Catalase (CAT) superoxide dismutase (SOD), and Total antioxidant capacity (TAC) were assessed in serum and saliva of different asthma groups.
RESULTS: All oxidative markers in serum and saliva of asthma patients showed significant alterations from normal healthy controls (P 0.05).
CONCLUSION: Determination of the oxidative markers GPx, CAT, UA in serum or saliva can distinguish asthma from healthy states. The serum levels of UA and TAC are highly effective in monitoring asthma severity, while the salivary GPx, CAT, UA, MDA are beneficial in the management of childhood asthma. Discrimination of the age factor between asthma groups can be achieved by testing GPx, SOD, TAC in serum.

Matched MeSH terms: Glutathione Peroxidase
Tailoring of peroxidase mimetics bifunctional nanocomposite: Dual mode electro-spectroscopic screening of cholesterol and hydrogen peroxide in real food samples and live cells

Arul P, Nandhini C, Huang ST, Gowthaman NSK, Huang CH

Food Chem, 2023 Jul 15;414:135747.
PMID: 36841102 DOI: 10.1016/j.foodchem.2023.135747

A simple and rapid screening of biomarkers in clinical and food matrices is urgently needed to diagnose cardiovascular diseases. The cholesterol (Chol) and hydrogen peroxide (H2O2) are critical bio-indicators, which require more inventive detection techniques to be applied to real food, and bio-samples. In this study, a robust dual sensor was developed for Chol and H2O2 using hybrid catalyst. Bovine serum albumin (BSA)-capped nanocatalyst was potentially catalyzed 3,3',5,5'-tetramethylbenzidine (TMB), and H2O2. The enzymatic nanoelectrocatalyst delivered a wide range of signaling concentrations from 250 nM to 3.0 mM and 100 nM to 10 mM, limit of detection (LOD) of 53.2 nM and 18.4 nM for Chol and H2O2. The cholesterol oxidase-BSA-AuNPs-metal-free organic framework (ChOx-BSA-AuNPs-MFOF) based electrode surface effectively operated in live-cells and real-food samples. The enzymatic sensor exhibits adequate recovery of real-food samples (96.96-99.44%). Finally, the proposed system is a suitable choice for the potential applications of Chol and H2O2 in clinical and food chemistry.

Matched MeSH terms: Peroxidase; Peroxidases
Fulltext A comparison of wound healing rate following treatment with aftamed and chlorine dioxide gels in streptozotocin-induced diabetic rats

Al-Bayaty F, Abdulla MA

Evid Based Complement Alternat Med, 2012;2012:468764.
PMID: 22666291 DOI: 10.1155/2012/468764

Background and Purpose. This study aimed to evaluate the wound healing activities of Aftamed and chlorine dioxide gels in streptozotocin-induced diabetic rats. Experimental Approach. Forty-eight Sprague Dawley rats were chosen for this study, divided into 4 groups. Diabetes was induced. Two-centimeter-diameter full-thickness skin excision wounds were created. Animals were topically treated twice daily. Groups 1, the diabetic control group, were treated with 0.2 mL of sterile distilled water. Group 2 served as a reference standard were treated with 0.2 mL of Intrasite gel. Groups 3 and 4 were treated with 0.2 mL of Aftamed and 0.2 mL of chlorine dioxide gels respectively. Granulation tissue was excised on the 10th day and processed for histological and biochemical analysis. The glutathione peroxidase ,superoxide dismutase activities and the malondialdehyde (MDA) levels were determined. Results. Aftamed-treated wounds exhibited significant increases in hydroxyproline, cellular proliferation, the number of blood vessels, and the level of collagen synthesis. Aftamed induced an increase in the free radical-scavenging enzyme activity and significantly reduced the lipid peroxidation levels in the wounds as measured by the reduction in the MDA level. Conclusions. This study showed that Aftamed gel is able to significantly accelerate the process of wound healing in diabetic rats.

Matched MeSH terms: Glutathione Peroxidase
Fulltext The effects of virgin coconut oil on bone oxidative status in ovariectomised rat

Abujazia MA, Muhammad N, Shuid AN, Soelaiman IN

Evid Based Complement Alternat Med, 2012;2012:525079.
PMID: 22927879 DOI: 10.1155/2012/525079

Virgin coconut oil (VCO) was found to have antioxidant property due to its high polyphenol content. The aim of this study was to investigate the effect of the virgin coconut oil on lipid peroxidation in the bone of an osteoporotic rat model. Normal female Sprague-Dawley rats aged 3 months old were randomly divided into 4 groups, with 8 rats in each group: baseline, sham, ovariectomised (OVX) control group, and OVX given 8% VCO in the diet for six weeks. The oxidative status of the bone was assessed by measuring the index of lipid peroxidation, which is malondialdehyde (MDA) concentration, as well as the endogenous antioxidant enzymes glutathione peroxidase (GPX) and superoxide dismutase (SOD) in the tibia at the end of the study. The results showed that there was a significant decrease in MDA levels in the OVX-VCO group compared to control group. Ovariectomised rats treated with VCO also had significantly higher GPX concentration. The SOD level seemed to be increased in the OVX-VCO group compared to OVX-control group. In conclusion, VCO prevented lipid peroxidation and increased the antioxidant enzymes in the osteoporotic rat model.

Matched MeSH terms: Glutathione Peroxidase
Fulltext A chemometric approach to evaluate the effects of probe-type ultrasonication on the enzyme inactivation and quality attributes of fresh amla juice

Aslam R, Alam MS, Ali A, Tao Y, Manickam S

Ultrason Sonochem, 2023 Jan;92:106268.
PMID: 36543045 DOI: 10.1016/j.ultsonch.2022.106268

The enzymatic browning induced in amla juice due to the high activity of polyphenol oxidase (PPO) and peroxidase (POD) is one of the critical issues faced by the industry. The present study assessed the suitability of non-thermal, high-intensity ultrasound (US) on the inactivation of PPO and POD in fresh Indian Gooseberry juice. Ultrasonic waves, using a 6 mm titanium alloy probe were irradiated in the juice at a maximum power of 455 W and frequency of 20 kHz. The subsequent effects on biochemical attributes were studied using response surface methodology. Inactivation rates of 90.72 % and 73.18 %, respectively, for PPO and POD enzymes, were observed at the highest US intensity and exposure time. Numerical optimisation using the three-factor, three-level Box-Behnken design suggested that an optimum process at 70 % (energy density: 1610 Wcm-2) pulsed at 5 s on and 5 s off for 7 min 30 s resulted in PPO and POD inactivation of the order of 76.42 % and 64.57 % respectively. At these experimental conditions, the optimized levels of biochemical attributes i.e., ascorbic acid (738.50 mg/100 mL), total phenols (17.10 mg/mL), DPPH antioxidant activity (58.47 %), tannins (7.11 µg/mL), colour change (ΔE = 9.04) and flavonoids (6.14 mg/mL) were achieved. The overall statistical models were significant for all the responses except for reducing sugars. Furthermore, the approximation equations for individual responses indicated that the goodness of fit was adequate (R2 > 0.90). The results suggested that ultrasound is a suitable processing technique for amla juice stabilisation compared to thermal treatments that result in the loss of quality.

Matched MeSH terms: Peroxidase; Peroxidases
Long-term tocotrienol supplementation and glutathione-dependent enzymes during hepatocarcinogenesis in the rat

Rahmat A, Wan Ngah WZ, Gapor A, Khalid BA

Asia Pac J Clin Nutr, 1993 Sep;2(3):129-34.
PMID: 24352144

The effects of long-term administration of tocotrienol on hepatocarcinogenesis in rats induced by diethyl nitrosamine (DEN) and 2-acetylaminofluorene (AAF) were investigated by the determination of plasma and liver gamma-glutamyl transpeptidase (GGT), cytosolic glutathione reductase (GSSG-Rx), glutathione peroxidase (GSH-Px) and glutathione S-transferase (GST). Twenty-eight male Rattus norwegicus rats (120-160g) were divided according to treatments into four groups: control group, tocotrienol - supplemented diet group (30mg/kg food), DEN/AAF-treated group and DEN/AAF treated plus tocotrienol-supplemented-diet group (30mg/kg food). The rats were sacrificed after nine months. The results obtained indicated no difference in the morphology and histology of the livers of control and tocotrienol-treated rats. Greyish-white neoplastic nodules (two per liver) were found in all the DEN/ AAF treated rats (n-10) whereas only one nodule was found in one of the carcinogen treated rats receiving tocotrienol supplementation (n-6). Histological examination showed obvious cellular damage for both the DEN/AAF-treated rats and the tocotrienol-supplemented rats but were less severe in the latter. Treatment with DEN/AAF caused increases in GGT, GSH-Px, GST and GSSG-Rx activities when compared to controls. These increases were also observed when tocotrienol was supplemented with DEN/AAF but the increases were less when compared to the rats receiving DEN/AAF only.

Matched MeSH terms: Glutathione Peroxidase
Fulltext Interaction between vitamin E and glutathione in rat brain: Effect of chronic ethanol administration

Marcus SR, Chandrakala MV, Nadiger HA

Asia Pac J Clin Nutr, 1998 Dec;7(3/4):201-5.
PMID: 24393672

The protection against ethanol-induced lipid peroxidation is rendered by antioxidants such as vitamin E and glutathione (GSH) interacting with each other and also functioning independently. A study of the levels of GSH and activities of glutathione peroxidase (GP), glutathione reductase (GR) and glutathione transferase (GST) in the cerebral cortex (CC), cerebellum (CB) and brain stem (BS) of vitamin E-supplemented and -deficient rats subjected to ethanol administration for 30 days was carried out. Chronic ethanol administration to vitamin E-supplemented rats elevated GP, GR and GST activities in the three regions and GSH levels in the CB. Chronic ethanol administration to vitamin E-deficient rats elevated GR activity in the three regions and GP activity in the CC and CB, decreased GST activity in the CC and CB, but did not alter GSH levels compared with normal rats subjected to chronic ethanol administration. The results indicate that vitamin E helps to maintain GSH levels to combat increased peroxidation while its absence has a deleterious effect.

Matched MeSH terms: Glutathione Peroxidase
Serum lipids, lipid peroxidation and glutathione peroxidase activity in rats on long-term feeding with coconut oil or butterfat (ghee)

Soelaiman IN, Merican Z, Mohamed J, Kadir KB

Asia Pac J Clin Nutr, 1996 Dec;5(4):244-8.
PMID: 24394618

We determined the relative atherogenicity of two saturated fats by studying their effects on lipid peroxidation (LP), by way of malonaldehyde (MDA) and conjugated dienes (CD) and glutathione peroxidase (GSHPx) activity in serum, liver and heart; and on serum lipid profile after 4 months and 9 months of feeding. Male Rattus norwegicus rats were fed a basal diet (control) or basal diet fortified with 20% weight/weight butterfat (ghee) (BF) or coconut oil (CO). Serum high-density-lipoprotein-cholesterol (HDL-chol) and HDL-chol:LDL-chol ratio was lower in the BF group compared to CO after both feeding periods. Conjugated dienes (CDs) were higher in the serum and liver after 4 months, and heart after 9 months, of the rats fed BF compared to CO. Serum low-density-lipoprotein-cholesterol (LDL-chol) was higher, but CD were lower at 9 months than at 4 months feeding for all three groups. Liver and heart MDA and CD were higher in both groups after 9 months compared to 4 months. Liver GSHPx activity was higher after 9 months compared to 4 months in the BF group. Heart GSHPx activity was lower after 9 months compared to 4 months for both BF and CO groups. In conclusion, BF is potentially more atherogenic than CO in terms of serum lipids and LP. The unfavourable responses in serum lipids, with the exception of triglycerides, and LP were exaggerated with the longer duration of feeding with both oils.

Matched MeSH terms: Glutathione Peroxidase
Serum lipids, lipid peroxidation and glutathione peroxidase activity in rats on long-term feeding with soybean oil or palm oil

Ima-Nirwana S, Merican Z, Jamaluddin M, Viswanathan P, Khalid BA

Asia Pac J Clin Nutr, 1996 Jun;5(2):100-4.
PMID: 24394519

The atherogenic potential of soybean oil (Sb) and palm oil (PO) was compared by measuring lipid profile, lipid peroxidation (LP) and activity of the antioxidant enzyme glutathione peroxidase (GSHPx) in rat sera and liver and heart homogenates. Male Rattus norwegicus rats were fed a basal diet, or basal diet fortified with 20% weight/ weight Sb or PO for 4 or 9 months. There was no difference in high density lipoprotein cholesterol:low density lipoprotein cholesterol ratio between the two groups, but triglyceride concentrations were higher in the PO fed rats compared to the Sb fed rats, although the difference diminished after 9 months. No differences in serum LP and GSHPx activity were seen between the two groups. In the liver and heart, LP was lower in PO after 4 months feeding, but the reverse was seen after 9 months. Liver and heart GSHPx activity was higher in the PO group after both treatment periods. In conclusion, both PO and Sb fed rats appeared comparable in their lipid profile, but the PO food had a temporary beneficial effect on the LP process in liver and heart. GSHPx activity however did not correlate well with LP in liver and heart, suggesting involvement of other antioxidants.

Matched MeSH terms: Glutathione Peroxidase
Fulltext Functional analyses of C.2268dup in thyroid peroxidase gene associated with goitrous congenital hypothyroidism

Lee CC, Harun F, Jalaludin MY, Lim CY, Ng KL, Mat Junit S

Biomed Res Int, 2014;2014:370538.
PMID: 24745015 DOI: 10.1155/2014/370538

The c.2268dup mutation in thyroid peroxidase (TPO) gene was reported to be a founder mutation in Taiwanese patients with dyshormonogenetic congenital hypothyroidism (CH). The functional impact of the mutation is not well documented. In this study, homozygous c.2268dup mutation was detected in two Malaysian-Chinese sisters with goitrous CH. Normal and alternatively spliced TPO mRNA transcripts were present in thyroid tissues of the two sisters. The abnormal transcript contained 34 nucleotides originating from intron 12. The c.2268dup is predicted to generate a premature termination codon (PTC) at position 757 (p.Glu757X). Instead of restoring the normal reading frame, the alternatively spliced transcript has led to another stop codon at position 740 (p.Asp739ValfsX740). The two PTCs are located at 116 and 201 nucleotides upstream of the exons 13/14 junction fulfilling the requirement for a nonsense-mediated mRNA decay (NMD). Quantitative RT-PCR revealed an abundance of unidentified transcripts believed to be associated with the NMD. TPO enzyme activity was not detected in both patients, even though a faint TPO band of about 80 kD was present. In conclusion, the c.2268dup mutation leads to the formation of normal and alternatively spliced TPO mRNA transcripts with a consequential loss of TPO enzymatic activity in Malaysian-Chinese patients with goitrous CH.

Matched MeSH terms: Iodide Peroxidase/genetics*
Fulltext Comparative effect of Piper betle, Chlorella vulgaris and tocotrienol-rich fraction on antioxidant enzymes activity in cellular ageing of human diploid fibroblasts

Makpol S, Yeoh TW, Ruslam FA, Arifin KT, Yusof YA

BMC Complement Altern Med, 2013;13:210.
PMID: 23948056 DOI: 10.1186/1472-6882-13-210

Human diploid fibroblasts (HDFs) undergo a limited number of cellular divisions in culture and progressively reach a state of irreversible growth arrest, a process termed cellular ageing. Even though beneficial effects of Piper betle, Chlorella vulgaris and tocotrienol-rich fraction (TRF) have been reported, ongoing studies in relation to ageing is of interest to determine possible protective effects that may reverse the effect of ageing. The aim of this study was to evaluate the effect of P. betle, C. vulgaris and TRF in preventing cellular ageing of HDFs by determining the activity of antioxidant enzymes viz.; catalase, superoxide dismutase (SOD) and glutathione peroxidase.

Matched MeSH terms: Glutathione Peroxidase/metabolism
Association of oxidative stress and memory performance in postmenopausal women receiving estrogen-progestin therapy

Shafin N, Zakaria R, Hussain NH, Othman Z

Menopause, 2013 Jun;20(6):661-6.
PMID: 23715378 DOI: 10.1097/GME.0b013e31827758c6

The aim of this study was to examine the association between changes in blood oxidative stress level/activity and changes in memory performance among postmenopausal women.

Matched MeSH terms: Glutathione Peroxidase/blood
Fulltext Comparison of antioxidant effects of honey, glibenclamide, metformin, and their combinations in the kidneys of streptozotocin-induced diabetic rats

Erejuwa OO, Sulaiman SA, Wahab MS, Salam SK, Salleh MS, Gurtu S

Int J Mol Sci, 2011;12(1):829-43.
PMID: 21340016 DOI: 10.3390/ijms12010829

Hyperglycemia-induced increase in oxidative stress is implicated in diabetic complications. This study investigated the effect of metformin and/or glibenclamide in combination with honey on antioxidant enzymes and oxidative stress markers in the kidneys of streptozotocin (60 mg/kg; intraperitoneal)-induced diabetic rats. Diabetic rats were randomized into eight groups of five to seven rats and received distilled water (0.5 mL); honey (1.0 g/kg); metformin (100 mg/kg); metformin (100 mg/kg) and honey (1.0 g/kg); glibenclamide (0.6 mg/kg); glibenclamide (0.6 mg/kg) and honey (1.0 g/kg); metformin (100 mg/kg) and glibenclamide (0.6 mg/kg); or metformin (100 mg/kg), glibenclamide (0.6 mg/kg) and honey (1.0 g/kg) orally once daily for four weeks. Malondialdehyde (MDA) levels, glutathione peroxidase (GPx) and superoxide dismutase (SOD) activities were significantly elevated while catalase (CAT) activity, total antioxidant status (TAS), reduced glutathione (GSH), and GSH:oxidized glutathione (GSSG) ratio was significantly reduced in the diabetic kidneys. CAT, glutathione reductase (GR), TAS, and GSH remained significantly reduced in the diabetic rats treated with metformin and/or glibenclamide. In contrast, metformin or glibenclamide combined with honey significantly increased CAT, GR, TAS, and GSH. These results suggest that combination of honey with metformin or glibenclamide might offer additional antioxidant effect to these drugs. This might reduce oxidative stress-mediated damage in diabetic kidneys.

Matched MeSH terms: Glutathione Peroxidase/metabolism

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