MyMedR

Displaying publications 61 - 80 of 127 in total

Abstract:

Sort:

Fulltext The role of vitamin E in preventing and treating osteoarthritis - a review of the current evidence

Chin KY, Ima-Nirwana S

Front Pharmacol, 2018;9:946.
PMID: 30186176 DOI: 10.3389/fphar.2018.00946

Osteoarthritis is a debilitating disease of the joint involving cartilage degeneration and chondrocytes apoptosis. Oxidative stress is one of the many proposed mechanisms underpinning joint degeneration in osteoarthritis. The current pharmacotherapies emphasize pain and symptomatic management of the patients but do not alter the biological processes underlying the cartilage degeneration. Vitamin E is a potential agent to prevent or treat osteoarthritis due to its antioxidant and anti-inflammatory effects. This review aims to summarize the current evidence on the relationship between vitamin E and osteoarthritis derived from preclinical and human studies. Cellular studies showed that vitamin E mitigated oxidative stress in cartilage explants or chondrocyte culture invoked by mechanical stress or free radicals. Animal studies suggested that vitamin E treatment prevented cartilage degeneration and improve oxidative status in animal models of osteoarthritis. Low circulating or synovial vitamin E was observed in human osteoarthritic patients compared to healthy controls. Observational studies also demonstrated that vitamin E was related to induction or progression of osteoarthritis in the general population. Vitamin E supplementation might improve the outcomes in patients with osteoarthritis, but negative results were also reported. Different isomers of vitamin E might possess distinct anti-osteoarthritic effects. As a conclusion, vitamin E may retard the progression of osteoarthritis by ameliorating oxidative stress and inflammation of the joint. Further studies are warranted to develop vitamin E as an anti-osteoarthritis agent to reduce the global burden of this disease.

Matched MeSH terms: Free Radicals
Fulltext Radiation dose enhancement effects of superparamagnetic iron oxide nanoparticles to the t24 bladder cancer cell lines irradiated with megavoltage photon beam radiotherapy

Rosmazihana Mat Lazim, Raizulnasuha Ab Rashid, Wan Nordiana Rahman, Binh. T.T. Pham, Brian S. Hawkett, Moshi Geso

Jurnal Sains Nuklear Malaysia, 2018;30(2):30-38.
MyJurnal

Therapeutic application of metallic nanoparticles such as gold nanoparticles have been extensively investigated and intriguing finding have been reported. Superparamagnetic iron oxide nanoparticles (SPION) could also potentially have therapeutic properties that can be exploited to enhance radiotherapy outcome. In this study, investigations on the dose enhancement effects inflicted by SPIONs under irradiation with megavoltage photon beam radiotherapy were conducted. T24 human bladder cancer cell lines were pretreated with 1 mMol/L of SPION and irradiated with 6 MV and 10 MV photon beam at different doses.The non-treated cells irradiation was used as a control. Clonogenic assay was performed to determine the cell survival. Linear quadratic (LQ) model are used as fitting curve and does enhancement factors (DEF) were extrapolated from the curves. The cytotoxicity indicated cell growth normally after 72 hours and no long term cytotoxicity effects of SPIONs towards the cells were observed. The dose enhancement effects were observed for both 6 MV and 10 MV photon beam with DEF obtained 1.71 and 2.50, respectively. This reduction of cell colonies growth could be resulted from the interaction that induced free radical and reactive oxygen species (ROS) by megavoltage photon beams. The SPIONs were therefore act as multifunction nanoparticle both in diagnostic agent and radiotherapy as radiation dose enhancer, thus clearly qualified as future theranostic agents.

Matched MeSH terms: Free Radicals
Antioxidant activity of methanol extract of tinospora crispa and tabernaemontana corymbosa

Heida Nadia Zulkefli, Jamaludin Mohamad, Nurhayati Zainal Abidin

Sains Malaysiana, 2013;42:697-706.

Tinospora crispa and Tabernaemontana corymbosa have been used traditionally to treat fever, diabetes, rheumatism and sinusitis. The objective of this study was to evaluate the antioxidant activity of Tinospora crispa and Tabernaemontana corymbosa. The presence of apigenin and magnoflorine was detected using LCMS/MS in Tinospora crispa (Patawali) whereas appararicine, voafinine, conodusarine, conodurine, voacamine and voacangine were detected in Tabernaemontana corymbosa (Susur kelapa) methanol extract. The stem extract of Tinospora crispa showed high antioxidant activity in the following order: DPPH radical scavenging, reducing power and metal chelating assay (98.8%, 0.957, 81.97%) than Tabernaemontana corymbosa of leaves (90.04%, 0.652, 69.64%), stem (82.78%, 0.819, 36.70%) and root extracts (63.25%, 0.469, 51.56%), respectively. The high antioxidant activity in the stem extract of Tinospora crispa is due to the presence of apigenin and magnoflorine. The high antioxidant activity in Tabernaemontana corymbosa extract is due to its high phenol contents. There were significant linear positive correlation (r=0.788, p<0.001, r2=0.621) between the total phenolic content and DPPH free radical scavenging assay in the crude extracts of Tinospora crispa and Tabernaemontana corymbosa. Meanwhile, a significant moderate positive correlation was observed between the total phenolic content and ferric reducing power assay (r= 0.556, p<0.05, r2= 0.309). However, there was no significant difference in the correlation coefficient of total phenolic content and metal chelating assay.

Matched MeSH terms: Free Radicals
Role of ambrisentan (selective endothelin-A receptor antagonist) on cigarette smoke exposure induced cognitive impairment in Danio rerio

Muthuraman A, Nafisa K, Sowmya MS, Arpitha BM, Choedon N, Sandy CD, et al.

Life Sci, 2019 Mar 04.
PMID: 30844374 DOI: 10.1016/j.lfs.2019.03.002

BACKGROUND: Cigarette smoke is exogenous modifiable factors to changes the neurovascular complication. The chronic exposure of cigarette smoke enhances neurocognitive dysfunction.
AIMS: The present study is focused on evaluating the role of ambrisentan (selective endothelin-A receptor antagonist) on cigarette smoke-induced cognitive impairment in Danio rerio.
MAIN METHODS: The cognitive dysfunction was developed by cigarette smoke exposure (CSE; 10 min in 25 ml of CSE per day) for five days. The selective endothelin-A receptor antagonist i.e., ambrisentan (2.5 to 5 mg/kg; i.p. for five consecutive days) was used for testing of CSE induced cognitive dysfunction. In addition, treatment of reference drug i.e., donepezil (10 mg/kg; i.p. for five consecutive days) was used for this cognitive function study. The cognitive functions were assessed by light and dark chamber; color recognition; partition preference; horizontal compartment; and T-Maze tests. Further, the CSE induced biomarkers changes of the zebrafish brain samples were estimated.
KEY FINDINGS: The treatment of ambrisentan showed a potential ameliorative effect against the CSE induced cognitive functions along with attenuation of biochemical changes. The results are comparable to donepezil-treated groups.
SIGNIFICANCE: Therefore, ambrisentan can be considered for the attenuation of CSE induced impairment neurocognitive functions due to its reduction of free radical scavenging and neuroinflammatory actions as well as regulation of cholinergic neurotransmitter functions.

Matched MeSH terms: Free Radicals
Fulltext Optimal antioxidant activity with moderate concentrations of Tocotrienol rich fraction (TRF) in in vitro assays

Muid, S., Ali, A.M., Yusoff, K., Nawawi, H.M.

International Food Research Journal, 2013;20(2):687-694.
MyJurnal

Vitamin E is known to have potent antioxidant activity and plays an important role in reducing oxidative stress, a pivotal step in atherogenesis. However, several randomised clinical trials using α-tocopherol have failed to demonstrate consistent beneficial effects of antioxidants against atherosclerosis and clinical endpoints. Tocotrienol, a vitamin E compound analogue is shown to have more potent antioxidant activity compared to tocopherol. Finding the optimal anti-oxidative dose is crucial and may effectively be applied for cardioprotection in human. The objective of this study was to determine the optimal dose of tocotrienol rich fraction (TRF) with highest antioxidant activity in vitro using the ferric thiocyanate (FTC), 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity and 2’, 7’- dichlorofluorescein diacetate (DCFHDA) assays. It was found that TRF exhibited potent antioxidant and free radical scavenging activities with an IC50 of 22.10 + 0.01 µg/ml. In all assays, TRF had optimal antioxidant activity at moderate concentrations (10-100 µg/ml). In conclusion, TRF has potent antioxidant activity, which is optimal at moderate concentrations.

Matched MeSH terms: Free Radicals
Total phenolic content and primary antioxidant activity of methanolic and ethanolic extracts of aromatic plants' leaves

Azlim Almey, A.A., Ahmed Jalal Khan, C., Syed Zahir, I., Mustapha Suleiman, K., 'Aisyah, M.R., Kamarul Rahim, K.

International Food Research Journal, 2010;17(4):1077-1084.
MyJurnal

The aim of this study is to determine the total phenolic content and primary antioxidant activity of methanolic and ethanolic extracts of four aromatic plants’ leaves namely knotweed (Polygonum minus), curry (Murraya koenigii), kaffir lime (Citrus hysrix) and fragrant screwpine (Pandanus odurus). Total phenolic content (TPC) assay using Folin-Ciocalteu method was used to assess the presence and level of phenolic compounds in each sample. The present study showed that both methanolic and ethanolic extracts of P. minus had the highest TPC and followed by M. koenigii, C. hystrix and P. odorus. Primary antioxidant activity in terms of free radical scavenging activities of both methanolic and ethanolic extracts was then measured by 2, 2, diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity assay. The lowest EC50 values based on the DPPH. radical scavenging activity were shown by P. minus extracts as compared to the other samples. For both ethanolic and methanolic extracts, the correlations between TPC and EC50 based on the DPPH. radical scavenging activity assay were negative and weak. Relatively, the present results suggest that of the four aromaticplants, P. minus and M. koenigii have shown potential as sources of natural antioxidants.

Matched MeSH terms: Free Radicals
In-vitro anti-inflammatory activity, free radical (DPPH) scavenging, and ferric reducing ability (FRAP) of Sargassum cristaefolium lipid-soluble fraction and putative identification of bioactive compounds using UHPLC-ESI-ORBITRAP-MS/MS

Saraswati, Giriwono PE, Iskandriati D, Tan CP, Andarwulan N

Food Res Int, 2020 Nov;137:109702.
PMID: 33233276 DOI: 10.1016/j.foodres.2020.109702

Sargassum brown seaweed is well-known to contain several bioactive compounds which exhibit various biological activities, including anti-inflammatory and antioxidant activity. Lipophilic extracts and fractions of Sargassum were reported to possess promising anti-inflammatory activity. This study, therefore, aims to evaluate the anti-inflammatory and antioxidant activity of Sargassum cristaefolium crude lipid extract and its fractions. The brown seaweed was obtained from Awur Bay, Jepara - Indonesia. Crude lipid fractionation was performed using normal phase column chromatography, and three different fractions (dichloromethane, acetone, methanol) were produced. The results showed that treatment of acetone fraction exerted strongest nitric oxide inhibition in lipopolysaccharide-induced RAW 264.7 cells, both in pre-incubated and co-incubated cell culture models. This outcome was in accordance with its 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity and ferric reducing antioxidant power (FRAP). Metabolite profiling of lipid fractions was performed by ultra-high-performance liquid chromatography electrospray ionization orbitrap tandem mass spectrometry, while the orthogonal projection to latent structures analysis was conducted to determine some features with significant correlation to the bioactivity. There were 14 feature candidates considered from both positive and negative ionization mode datasets. Seven out of them were putatively identified as pheophytin a (1), all-trans fucoxanthin (2), 132-hydroxy-pheophytin a (3), pheophorbide a (4), 1-hexadecanoyl-2-(9Z-octadecenoyl)-3-O-β-D-galactosyl-sn-glycerol (6), 1-(5Z,8Z,11Z,14Z,17Z-eicosapentaenoyl)-2-(9Z,12Z,15Z-octadecatrienoyl)-3-O-β-D-galactosyl-sn-glycerol (10), and 1-(9Z,12Z,15Z-octadecatrienoyl)-2-(6Z,9Z,12Z,15Z-octadecatetraenoyl)-3-O-β-D-galactosyl-sn glycerol (12).

Matched MeSH terms: Free Radicals
Fulltext Vitamin E as an Antiosteoporotic Agent via Receptor Activator of Nuclear Factor Kappa-B Ligand Signaling Disruption: Current Evidence and Other Potential Research Areas

Chin KY, Ima-Nirwana S

Evid Based Complement Alternat Med, 2012;2012:747020.
PMID: 22919420 DOI: 10.1155/2012/747020

Osteoporosis is a growing healthcare burden that affects the quality of life in the aging population. Vitamin E is a potential prophylactic agent that can impede the progression of osteoporosis. Various in vivo studies demonstrated the antiosteoporotic potential of vitamin E, but evidence on its molecular mechanism of action is limited. A few in vitro studies showed that various forms of vitamin E can affect the receptor activator of nuclear factor kappa-B ligand (RANKL) signaling and their molecular targets, thus preventing the formation of osteoclasts in the early stage of osteoclastogenesis. Various studies have also shown that the effects of the different isoforms of vitamin E differ. The effects of single isoforms and combinations of isoforms on bone metabolism are also different. Vitamin E may affect bone metabolism by disruption of free radical-mediated RANKL signaling, by its oestrogen-like effects, by its effects on the molecular mechanism of bone formation, by the anti-inflammatory effects of its long-chain metabolites on bone cells, and by the inhibition of 3-hydroxyl-3-methyglutaryl coenzyme A (HMG-CoA). In conclusion, the vitamin E isoforms have enormous potential to be used as prophylactic and therapeutic agents in preventing osteoporosis, but further studies should be conducted to elucidate their mechanisms of action.

Matched MeSH terms: Free Radicals
Fulltext In Vitro Wound Healing Potential of Stem Extract of Alternanthera sessilis

Muniandy K, Gothai S, Tan WS, Kumar SS, Mohd Esa N, Chandramohan G, et al.

Evid Based Complement Alternat Med, 2018;2018:3142073.
PMID: 29670658 DOI: 10.1155/2018/3142073

Impaired wound healing is one of the serious problems among the diabetic patients. Currently, available treatments are limited due to side effects and cost effectiveness. In line with that, we attempted to use a natural source to study its potential towards the wound healing process. Therefore, Alternanthera sessilis (A. sessilis), an edible and medicinal plant, was chosen as the target sample for the study. During this investigation, the wound closure properties using stem extract of A. sessilis were analyzed. Accordingly, we analyzed the extract on free radical scavenging capacity and the cell migration of two most prominent cell types on the skin, human dermal fibroblast (NHDF), keratinocytes (HaCaT), and diabetic human dermal fibroblast (HDF-D) to mimic the wound healing in diabetic patients. The bioactive compounds were identified using gas chromatography-mass spectrometry (GC-MS). We discovered that the analysis exhibited a remarkable antioxidant, proliferative, and migratory rate in NHDF, HaCaT, and HDF-D in dose-dependent manner, which supports wound healing process, due to the presence of wound healing associated phytocompounds such as Hexadecanoic acid. This study suggested that the stem extract of A. sessilis might be a potential therapeutic agent for skin wound healing, supporting its traditional medicinal uses.

Matched MeSH terms: Free Radicals
Fulltext Nigella sativa Fixed and Essential Oil Supplementation Modulates Hyperglycemia and Allied Complications in Streptozotocin-Induced Diabetes Mellitus

Sultan MT, Butt MS, Karim R, Zia-Ul-Haq M, Batool R, Ahmad S, et al.

Evid Based Complement Alternat Med, 2014;2014:826380.
PMID: 24511321 DOI: 10.1155/2014/826380

In the recent era, diabetes mellitus has emerged as one of the significant threats to public health and this situation demands the attention of the researchers and allied stakeholders. Dietary regimens using functional and nutraceutical foods are gaining wide range of acceptance and some traditional medicinal plants are of considerable importance. The main objective of this instant study was to explore the antidiabetic potential of Nigella sativa fixed oil (NSFO) and essential oil (NSEO). Three experimental groups of rats received diets during the entire study duration, that is, D1 (control), D2 (NSFO: 4.0%), and D3 (NSEO: 0.30%). Experimental diets (NSFO & NSEO) modulated the lipid profile, while decreasing the antioxidant damage. However, production of free radicals, that is, MDA, and conjugated dienes increased by 59.00 and 33.63%, respectively, in control. On the contrary, NSFO and NSEO reduced the MDA levels by 11.54 and 26.86% and the conjugated dienes levels by 32.53 and 38.39%, respectively. N. sativa oils improved the health and showed some promising anti-diabetic results.

Matched MeSH terms: Free Radicals
Fulltext Virgin coconut oil supplementation prevents bone loss in osteoporosis rat model

Hayatullina Z, Muhammad N, Mohamed N, Soelaiman IN

Evid Based Complement Alternat Med, 2012;2012:237236.
PMID: 23024690

Oxidative stress and free radicals have been implicated in the pathogenesis of osteoporosis. Therefore, antioxidant compounds have the potential to be used in the prevention and treatment of the disease. In this study, we investigated the effects of virgin coconut oil (VCO) on bone microarchitecture in a postmenopausal osteoporosis rat model. VCO is a different form of coconut oil as it is rich with antioxidants. Three-month-old female rats were randomly grouped into baseline, sham-operated, ovariectomized control (Ovx), and ovariectomized rats fed with 8% VCO in their diet for six weeks (Ovx+VCO). Bone histomorphometry of the right femora was carried out at the end of the study. Rats supplemented with VCO had a significantly greater bone volume and trabecular number while trabecular separation was lower than the Ovx group. In conclusion, VCO was effective in maintaining bone structure and preventing bone loss in estrogen-deficient rat model.

Matched MeSH terms: Free Radicals
Fulltext Ameliorative Effects of Aquilaria malaccensis Leaves Aqueous Extract on Reproductive Toxicity Induced by Cyclophosphamide in Male Rats

Razak RNHA, Ismail F, Isa MLM, Wahab AYA, Muhammad H, Ramli R, et al.

Malays J Med Sci, 2019 Jan;26(1):44-57.
PMID: 30914892 MyJurnal DOI: 10.21315/mjms2019.26.1.4

Background: Cyclophosphamide (CP) is a widely used anti-neoplastic and immunosuppressive agent that is associated with adverse side effects including reproductive toxicity. Aquilaria malaccensis (AM) is a traditional medicinal plant which was reported to exhibit high anti-oxidant and free radical scavenging properties. The present study was aimed to evaluate the protective effects of AM leaves extract on sperm quality following toxic exposure to CP.
Methods: Forty-eight male Sprague Dawley rats were allocated into eight groups of six rats (n = 6): control, CP only (200 mg kg-1), AM only (100 mg kg-1, 300 mg kg-1 and 500 mg kg-1) and CP + AM (100 mg kg-1, 300 mg kg-1 and 500 mg kg-1). Animals were sacrificed after 63 days of treatment and the sperm from the caudal epididymis was taken for sperm analysis.
Results: The body and the reproductive organs weight, sperm count and motility did not differ between CP and other groups (P > 0.05). A significant increase (P < 0.05) in percentage of the dead and abnormal sperm were seen in the CP alone treated group compared to the control group. Co-administration of AM to the CP exposed rats significantly reduced the (P < 0.05) percentage of abnormal sperm as compared to the CP only group.
Conclusion: Overall, the present results represent the potential of AM to protect against CP induced reproductive toxicity.

Matched MeSH terms: Free Radicals
Fulltext Production of defatted palm kernel cake protein hydrolysate as a valuable source of natural antioxidants

Zarei M, Ebrahimpour A, Abdul-Hamid A, Anwar F, Saari N

Int J Mol Sci, 2012;13(7):8097-111.
PMID: 22942692 DOI: 10.3390/ijms13078097

The aim of this study was to produce a valuable protein hydrolysate from palm kernel cake (PKC) for the development of natural antioxidants. Extracted PKC protein was hydrolyzed using different proteases (alcalase, chymotrypsin, papain, pepsin, trypsin, flavourzyme, and bromelain). Subsequently, antioxidant activity and degree of hydrolysis (DH) of each hydrolysate were evaluated using DPPH• radical scavenging activity and O-phthaldialdehyde spectrophotometric assay, respectively. The results revealed a strong correlation between DH and radical scavenging activity of the hydrolysates, where among these, protein hydrolysates produced by papain after 38 h hydrolysis exhibited the highest DH (91 ± 0.1%) and DPPH• radical scavenging activity (73.5 ± 0.25%) compared to the other hydrolysates. In addition, fractionation of the most effective (potent) hydrolysate by reverse phase high performance liquid chromatography indicated a direct association between hydrophobicity and radical scavenging activity of the hydrolysates. Isoelectric focusing tests also revealed that protein hydrolysates with basic and neutral isoelectric point (pI) have the highest radical scavenging activity, although few fractions in the acidic range also exhibited good antioxidant potential.

Matched MeSH terms: Free Radicals/chemistry
A new prenylated dihydrochalcone from the leaves of Artocarpus lowii

Jamil S, Sirat HM, Jantan I, Aimi N, Kitajima M

J Nat Med, 2008 Jul;62(3):321-4.
PMID: 18404311 DOI: 10.1007/s11418-008-0226-3

A new prenylated dihydrochalcone, 2',4'-dihydroxy-4-methoxy-3'-prenyldihydrochalcone (1), along with two known compounds, 2',4',4-trihydroxy-3'-prenylchalcone (2) and 2',4-dihydroxy-3',4'-(2,2-dimethylchromene)chalcone (3) were isolated from the leaves of Artocarpus lowii. The structures of 1-3 were elucidated by spectroscopic methods and by comparison with data reported in the literature. Compounds 1-3 showed strong free radical scavenging activity towards 2,2-diphenyl-1-picrylhydrazyl (DPPH) measured by electron spin resonance (ESR) spectrometry.

Matched MeSH terms: Free Radicals/metabolism
Flavonoids and linderone from Lindera oxyphylla and their bioactivities

Hosseinzadeh M, Hadi AH, Mohamad J, Khalilzadeh MA, Cheahd SC, Fadaeinasab M

Comb Chem High Throughput Screen, 2013 Feb;16(2):160-6.
PMID: 23173924

A new linderone A, namely 2-cinnamoyl-3-hydroxy-4, 5-dimethoxycyclopenta-2, 4-dienone (5), together with three known flavonoids (1-3) and one linderone (4), were isolated from the bark of Lindera oxyphylla. Extensive spectroscopic analysis including 1D and 2D-NMR spectra determined their sturctures. In addition, the antioxidant activity of all the compounds has been determined using 2, 2-diphenyl-1-picrylhydrazyl radical scavenging (DPPH), ferric reducing antioxidant power (FRAP) and ferrous ion chelating (FIC) methods. Compound 3 showed excellent DPPH scavenging activity with IC50% value of 8.5 ± 0.004% (μg/mL) which is comparable with vitamin C. This compound, also showed an absorbance value of 1.00 ± 0.06% through FRAP test when compared with Butyl Hydroxy Aniline (BHA). However, FIC showed low activity for all the isolated compounds (chelating activity less than 50%) in comparison with ethylene diamine tetra acetic acid (EDTA). Anticancer activity for all compounds has also been measured on A375 human melanoma, HT-29 colon adenocarcinoma, MCF-7 human breast adenocarcinoma cells, WRL-68 normal hepatic cells, A549 non-small cell lung cancer cells and PC-3 prostate adenocarcinoma cell line. Compound 1 showed A549=65.03%, PC-3=30.12%, MCF-7=47.67, compound 2 showed PC-3=90.13%, compound 3 showed MCF-7=79.57 and for compound 5 MCF-7 is 96.33.

Matched MeSH terms: Free Radicals/chemistry
alpha-Tocopherol increased nitric oxide synthase activity in blood vessels of spontaneously hypertensive rats

Newaz MA, Nawal NN, Rohaizan CH, Muslim N, Gapor A

Am J Hypertens, 1999 Aug;12(8 Pt 1):839-44.
PMID: 10480480

Antioxidant protection provided by different doses of alpha-tocopherol was compared by determining nitric oxide synthase (NOS) activity in blood vessels of spontaneously hypertensive rats (SHR) treated with alpha-tocopherol. SHR were divided into four groups namely hypertensive control (C), treatment with 17 mg of alpha-tocopherol/kg diet (alpha1), 34 mg of alpha-tocopherol/kg diet (alpha2), and 170 mg of alpha-tocopherol/kg diet (alpha3). Wister Kyoto (WKY) rats were used as normal control (N). Blood pressure were recorded from the tail by physiography every other night for the duration of the study period of 3 months. At the end of the trial, animals were sacrificed. The NOS activity in blood vessels was measured by [3H]arginine radioactive assay and the nitrite concentration in plasma by spectrophotometry at wavelength 554 nm using Greiss reagent. Analysis of data was done using Student's t test and Pearson's correlation. The computer program Statistica was used for all analysis. Results of our study showed that for all the three alpha-tocopherol-treated groups, blood pressure was significantly (P < .001) reduced compared to the hypertensive control and maximum reduction of blood pressure was shown by the dosage of 34 mg of alpha-tocopherol/kg diet (C: 209.56 +/- 8.47 mm Hg; alpha2: 128.83 +/- 17.13 mm Hg). Also, NOS activity in blood vessels of SHR was significantly lower than WKY rats (N: 1.54 +/- 0.26 pmol/mg protein, C: 0.87 +/- 0.23 pmol/mg protein; P < .001). Although alpha-tocopherol in doses of alpha1, alpha2, and alpha3 increased the NOS activity in blood vessels, after treatment only that of alpha2 showed a statistical significance (P < .01). Plasma nitrite concentration was significantly reduced in SHR compared to normal WKY rats (N: 54.62 +/- 2.96 mol/mL, C: 26.24 +/- 2.14 mol/mL; P < .001) and accordingly all three groups showed significant improvement in their respective nitrite level (P < .001). For all groups, NOS activity and nitrite level showed negative correlation with blood pressure. It was significant for NOS activity in hypertensive control (r = -0.735, P = .038), alpha1 (r = -0.833, P = .001), and alpha2 (r = -0.899, P = .000) groups. For plasma nitrite, significant correlation was observed only in group alpha1 (r = -0.673, P = .016) and alpha2 (r = -0.643, P = .024). Only the alpha2 group showed significant positive correlation (r = 0.777, P = .003) between NOS activity and nitrite level. In conclusion it was found that compared to WKY rats, SHR have lower NOS activity in blood vessels, which upon treatment with antioxidant alpha-tocopherol increased the NOS activity and concomitantly reduced the blood pressure. There was correlation of lipid peroxide in blood vessels with NOS and nitric oxide, which implies that free radicals may be involved in the pathogenesis of hypertension.

Matched MeSH terms: Free Radicals/metabolism
Effects of copper overload on hepatic lipid peroxidation and antioxidant defense in rats

Zhang SS, Noordin MM, Rahman SO, Haron J

Vet Hum Toxicol, 2000 Oct;42(5):261-4.
PMID: 11003114

The influence of copper (Cu) overload on hepatic lipid peroxidation and antioxidation defense capacity was studied by overloading rats with copper sulphate orally (500 mg Cu/kg bw) 5 d/w for 8 w. Malondialdehyde (MDA), Cu-Zn superoxide dismutase (SOD), and Se-glutathione peroxidase (GSH-Px) were measured in serum and liver homogenate at 2, 4 and 8 w of dosing. Liver Cu concentration and alanine aminotransferase (ALT) activity were also determined. As Cu loading progressed, there were multiparameter changes with significant ALT elevation, increased MDA concentrations in serum and liver homogenate, and dramatic declines of SOD and GSH-Px activities in erythrocytes and whole blood respectively, along with marked elevation of hepatic Cu in the Cu-dosed group. Excessive Cu accumulation in the liver depressed SOD and GSH-Px activities and resulted in high MDA in serum and liver homogenate due to the lipid peroxidation induced by the Cu overload.

Matched MeSH terms: Free Radicals/metabolism
Proteomics, oxidative stress and male infertility

Agarwal A, Durairajanayagam D, Halabi J, Peng J, Vazquez-Levin M

Reprod Biomed Online, 2014 Jul;29(1):32-58.
PMID: 24813754 DOI: 10.1016/j.rbmo.2014.02.013

Oxidative stress has been established as one of the main causes of male infertility and has been implicated in many diseases associated with infertile men. It results from high concentrations of free radicals and suppressed antioxidant potential, which may alter protein expression in seminal plasma and/or spermatozoa. In recent years, proteomic analyses have been performed to characterize the protein profiles of seminal ejaculate from men with different clinical conditions, such as high oxidative stress. The aim of the present review is to summarize current findings on proteomic studies performed in men with high oxidative stress compared with those with physiological concentrations of free radicals, to better understand the aetiology of oxidative stress-induced male infertility. Each of these studies has suggested candidate biomarkers of oxidative stress, among them are DJ-1, PIP, lactotransferrin and peroxiredoxin. Changes in protein concentrations in seminal plasma samples with oxidative stress conditions were related to stress responses and to regulatory pathways, while alterations in sperm proteins were mostly associated to metabolic responses (carbohydrate metabolism) and stress responses. Future studies should include assessment of post-translational modifications in the spermatozoa as well as in seminal plasma proteomes of men diagnosed with idiopathic infertility. Oxidative stress, which occurs due to a state of imbalance between free radicals and antioxidants, has been implicated in most cases of male infertility. Cells that are in a state of oxidative stress are more likely to have altered protein expression. The aim of this review is to better understand the causes of oxidative stress-induced male infertility. To achieve this, we assessed proteomic studies performed on the seminal plasma and spermatozoa of men with high levels of oxidative stress due to various clinical conditions and compared them with men who had physiological concentrations of free radicals. A variety of sperm and seminal plasma proteins were found to be expressed either in abundance (over-expressed) or in a lesser amount (underexpressed), while other proteins were found to be unique either to men with oxidative stress or to men with a balanced ratio of antioxidants/free radicals. Each study included in this review suggested several proteins that could possibly act as biomarkers of oxidative stress-induced male infertility, such as protein DJ-1, PIP, lactotransferrin and peroxiredoxin. Pathway analysis performed in these studies revealed that the changes in seminal plasma proteins in men with oxidative stress could be attributed to stress responses and regulatory pathways, while changes in sperm proteins were linked to stress responses and metabolic responses. Subsequent studies could look into post-translational modifications in the protein profile of men with idiopathic infertility. We hope that the information in this review will contribute to a better understanding of the main causes of idiopathic male infertility.

Matched MeSH terms: Free Radicals/metabolism
Fulltext Tocotrienol-Rich Fraction Ameliorates Antioxidant Defense Mechanisms and Improves Replicative Senescence-Associated Oxidative Stress in Human Myoblasts

Khor SC, Wan Ngah WZ, Mohd Yusof YA, Abdul Karim N, Makpol S

Oxid Med Cell Longev, 2017;2017:3868305.
PMID: 28243354 DOI: 10.1155/2017/3868305

During aging, oxidative stress affects the normal function of satellite cells, with consequent regeneration defects that lead to sarcopenia. This study aimed to evaluate tocotrienol-rich fraction (TRF) modulation in reestablishing the oxidative status of myoblasts during replicative senescence and to compare the effects of TRF with other antioxidants (α-tocopherol (ATF) and N-acetyl-cysteine (NAC)). Primary human myoblasts were cultured to young, presenescent, and senescent phases. The cells were treated with antioxidants for 24 h, followed by the assessment of free radical generation, lipid peroxidation, antioxidant enzyme mRNA expression and activities, and the ratio of reduced to oxidized glutathione. Our data showed that replicative senescence increased reactive oxygen species (ROS) generation and lipid peroxidation in myoblasts. Treatment with TRF significantly diminished ROS production and decreased lipid peroxidation in senescent myoblasts. Moreover, the gene expression of superoxide dismutase (SOD2), catalase (CAT), and glutathione peroxidase (GPX1) was modulated by TRF treatment, with increased activity of superoxide dismutase and catalase and reduced glutathione peroxidase in senescent myoblasts. In comparison to ATF and NAC, TRF was more efficient in heightening the antioxidant capacity and reducing free radical insults. These results suggested that TRF is able to ameliorate antioxidant defense mechanisms and improves replicative senescence-associated oxidative stress in myoblasts.

Matched MeSH terms: Free Radicals/metabolism
Fulltext Cosmos caudatus as a potential source of polyphenolic compounds: optimisation of oven drying conditions and characterisation of its functional properties

Mediani A, Abas F, Khatib A, Tan CP

Molecules, 2013 Aug 29;18(9):10452-64.
PMID: 23994970 DOI: 10.3390/molecules180910452

The aim of the study was to analyze the influence of oven thermal processing of Cosmos caudatus on the total polyphenolic content (TPC) and antioxidant capacity (DPPH) of two different solvent extracts (80% methanol, and 80% ethanol). Sonication was used to extract bioactive compounds from this herb. The results showed that the optimised conditions for the oven drying method for 80% methanol and 80% ethanol were 44.5 °C for 4 h with an IC₅₀ of 0.045 mg/mL and 43.12 °C for 4.05 h with an IC₅₀ of 0.055 mg/mL, respectively. The predicted values for TPC under the optimised conditions for 80% methanol and 80% ethanol were 16.5 and 15.8 mg GAE/100 g DW, respectively. The results obtained from this study demonstrate that Cosmos caudatus can be used as a potential source of antioxidants for food and medicinal applications.

Matched MeSH terms: Free Radicals/chemistry

Filters

Please provide feedback to Administrator ([email protected])

External Links