Displaying publications 101 - 120 of 127 in total

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  1. Anil Kumar, S., Saif, S.A., Oothuman, P., Mustafa, M.I.A.
    MyJurnal
    Introduction: Reduced cerebral blood fl ow is associated with neurodegenerative disorders and dementia, in particular. Experimental evidence has demonstrated the initiating role of chronic cerebral hypoperfusion in neuronal damage to the hippocampus, the cerebral cortex, the white matter areas and the visual system. Permanent, bilateral occlusion of the common carotid arteries of rats (two vessel occlusion - 2VO) has been introduced for the reproduction of chronic cerebral hypoperfusion as it occurs in Alzheimer’s disease and human aging. Increased generation of free radicals through lipid peroxidation can damage neuronal cell membrane. Markers of lipid peroxidation have been found to be elevated in brain tissues and body fl uids in neurodegenerative diseases, including Alzheimer’s disease, Parkinson disease and amyotrophic lateral sclerosis. Materials and Methods: Malondialdehyde (MDA), fi nal product of lipid peroxidation, was estimated by thiobarbituric acid-reactive substances (TBARS) assay kit at eight weeks after induction of 2VO in the rats and control group. Results: Our study revealed a highly signifi cant (p
    Matched MeSH terms: Free Radicals
  2. Arumugam K, Yip YC
    Fertil Steril, 1995 Jul;64(1):62-4.
    PMID: 7789581
    OBJECTIVE: To show that raised iron levels in the peritoneal fluid (PF) of patients with endometriosis catalyze free radical reactions that results in the tissue destruction and fibrosis seen in these patients.

    DESIGN: A case-controlled study of the iron levels (microgram/mL) in the pelvic PF of 12 patients with moderate-to-severe disease, 15 patients with minimal-to-mild disease and in 17 women with normal pelvises were compared. As an index of free radical reactions through lipid peroxidation, the levels of malondialdehyde levels (ng/mL) were assessed simultaneously in the same specimens.

    RESULTS: Controlling for the phase of the menstrual cycle, significantly higher levels of iron were seen in patients with endometriosis, the levels being correlated with the severity of the disease. However no such corresponding relationship was seen in the malondialdehyde levels in the PF.

    CONCLUSIONS: These results suggest that raised iron levels in the PF do not play a role in catalyzing free radical reactions as judged by the degree of lipid peroxidation.

    Matched MeSH terms: Free Radicals
  3. Alam I, Forid MS, Roney M, Aluwi MFFM, Huq AM
    Data Brief, 2021 Apr;35:106839.
    PMID: 33659597 DOI: 10.1016/j.dib.2021.106839
    The current data report describes the predictive identification of phytochemical constituents in the bioactive extract of Ipomoea mauritiana (IM) whole plant. For several formulations this plant was commonly used as 'Vidari' for Ayurvedic medicine. Traditionally, IM tubers are used to alleviate spinal cord pain, improve breast milk, as a tonic, increase sperm count and treating jaundice. The methanol extract can potentially scavenge free radicals and possess antibacterial activity that could be correlated with its chemical composition. So it is crucial to identify the major compounds of IM. An ultra-performance liquid chromatography coupled electrospray ionization quadrupole time-of-flight mass spectrometry (UPLC-ESI-QTOF/MS) method was adopted to detect the flavonoids, saponins, alkaloids, terpenoids in IM methanol extract. Data presented here is related to a published work Antioxidant and antibacterial activity of Ipomoea mauritiana Jacq.: A traditionally used medicinal plant in Bangladesh (Alam et al., 2020). Secondary metabolites were analyzed by the comparison of the mass fragmentation arrangements with Waters UNIFI library that enables for positive identification of the compounds based on the spectral match.
    Matched MeSH terms: Free Radicals
  4. Nur Syafiqah Martang, Nadia Majitol, Farnidah Jasnie, Lo Chor-Wai
    Borneo Akademika, 2020;4(4):15-20.
    MyJurnal
    Most of the plants in the ginger family Zingeberaceae are well-known for their medicinal properties. However, the genus Hornstedtia found in Sabah is less reported. This research aims to investigate the phytochemical constituent and vitamin C content of a fruit, locally known as the Tolidus fruit in Sabah. The dried fruit sample was extracted using three solvents which were water, ethanol and methanol. The phytochemical constituents were determined using standard Colour Test for the presence of alkaloid, flavonoid, saponin and tannin. Then, the content of Vitamin C was determined using the standard Colorimetric Titration and ascorbic acid as standard. The phytochemical evaluation revealed that all three targeted constituents were present in all extracts except for the alkaloid. The vitamin C content was determined in both dried and fresh sample of fruits, where 52.84 mg was quantified in the fresh fruit aqueous extract and 23.93 mg in the dried fruit aqueous extract respectively. These results are comparable to the content of vitamin C in orange and lime fruits. The phytochemical evaluation and vitamin C content of Tolidus suggested the potential of this underutilised fruit to be the natural and affordable source of vitamin C. Additionally, may protect the body against harmful free radicals. However, further analysis is needed to determine other constructive natural contents and evaluate the efficacy of this fruit as a natural source of antioxidant
    Matched MeSH terms: Free Radicals
  5. Rehman U, Sarfraz RM, Mahmood A, Hussain Z, Thu HE, Zafar N, et al.
    Curr Drug Deliv, 2021 Feb 11.
    PMID: 33583374 DOI: 10.2174/1567201818666210212085912
    BACKGROUND: Despite exhibiting promising anticancer potential, the clinical significance of capecitabine (a potent prodrug of 5-fluorouracil used for treatment of colorectal cancer) is limited owing to its acidic and enzymatic hydrolysis, lower absorption following the oral administration, poor bioavailability, short plasma half-life and poor patient compliance.

    OBJECTIVES: The present study was aimed to fabricate the capecitabine as smart pH-responsive hydrogel network to efficiently facilitate its oral delivery while shielding its stability in the gastric media.

    METHODS: The smart pH sensitive HP-β-CD/agarose-g-poly(MAA) hydrogel network was developed using an aqueous free radical polymerization technique. The developed hydrogels were characterized for drug-loading efficiency, structural and compositional features, thermal stability, swelling behaviour, morphology, physical form, and release kinetics. The pH-responsive behaviour of developed hydrogels was established by conducting the swelling and release behaviour at different pH values (1.2 and 7.4), demonstrating significantly higher swelling and release at pH 7.4 as compared with pH 1.2. The capecitabine-loaded hydrogels were also screened for acute oral toxicity in animals by analysing the body weight, water and food intake, dermal toxicity, ocular toxicity, biochemical analysis, and histological examination.

    RESULTS: The characteristic evaluations revealed that capecitabine (anticancer agent) was successfully loaded into the hydrogel network. Capecitabine loading was ranged from 71.22% to 90.12%. An interesting feature of hydrogel was its pH-responsive behaviour which triggers release at basic pH (94.25%). Optimum swelling (95%) was seen at pH 7.4. Based upon regression coefficient R2 (0.96 - 0.99) best fit model was zero order. The extensive toxicity evaluations evidenced good safety profile with no signs of oral, dermal or ocular toxicities, as well as no variations in blood parameters and histology of vital organs.

    CONCLUSION: Our findings conclusively evinced that the developed hydrogel exhibited excellent pharmaceutical and therapeutic potential and thus can be employed as pH-responsive system for controlled delivery of anticancer agents.

    Matched MeSH terms: Free Radicals
  6. Sivasothy Y, Leong KH, Loo KY, Adbul Wahab SM, Othman MA, Awang K
    Nat Prod Res, 2021 Feb 16.
    PMID: 33593208 DOI: 10.1080/14786419.2021.1885405
    The use of antidiabetic agents which control glycemic levels in the blood and simultaneously inhibit oxidative stress is an important strategy in the prevention of Diabetes Mellitus and its complications. In our previous study, malabaricone C (3) and its dimer, giganteone A (5) exhibited significant DPPH free radical scavenging activities which were lower than the activity of the positive control, ascorbic acid. These compounds were evaluated for their α-glucosidase inhibitory activities at different concentrations (0.02-2.5 mM) in the present study. Compounds 3 (IC50 59.61 µM) and 5 (IC50 39.52 µM) were identified as active alpha-glucosidase inhibitors, each respectively being 24 and 37 folds more potent than the standard inhibitor, acarbose. Based on the molecular docking studies, compounds 3 and 5 docked into the active site of the α-glucosidase enzyme, forming mainly hydrogen bonds in the active site.
    Matched MeSH terms: Free Radicals
  7. Rahman ML, Wong ZJ, Sarjadi MS, Joseph CG, Arshad SE, Musta B, et al.
    Polymers (Basel), 2021 May 06;13(9).
    PMID: 34066308 DOI: 10.3390/polym13091486
    Toxic metals in the industrial wastewaters have been liable for drastic pollution hence a powerful and economical treatment technology is needed for water purification. For this reason, some pure cellulosic materials were derived from waste fiber to obtain an economical adsorbent for wastewater treatment. Conversion of cellulose into grafting materials such as poly(methyl acrylate)-grafted cellulose was performed by free radical grafting process. Consequently, poly(hydroxamic acid) ligand was produced from the grafted cellulose. The intermediate products and poly(hydroxamic acid) ligand were analyzed by FT-IR, FE-SEM, TEM, EDX, and XPS spectroscopy. The adsorption capacity (qe) of some toxic metals ions by the polymer ligand was found to be excellent, e.g., copper capacity (qe) was 346.7 mg·g-1 at pH 6. On the other hand, several metal ions such as cobalt chromium and nickel also demonstrated noteworthy sorption capacity at pH 6. The adsorption mechanism obeyed the pseudo second-order rate kinetic model due to the satisfactory correlated experimental sorption values (qe). Langmuir model isotherm study showed the significant correlation coefficient with all metal ions (R2 > 0.99), indicating that the single or monolayer adsorption was the dominant mode on the surface of the adsorbent. This polymer ligand showed good properties on reusability. The result shows that the adsorbent may be recycled for 6 cycles without any dropping of starting sorption capabilities. This polymeric ligand showed outstanding toxic metals removal magnitude, up to 90-99% of toxic metal ions can be removed from industrial wastewater.
    Matched MeSH terms: Free Radicals
  8. Leong XF, Salimon J, Mustafa MR, Jaarin K
    Malays J Med Sci, 2012 Jan;19(1):20-9.
    PMID: 22977371
    BACKGROUND: Oxidative stress is associated with the pathogenesis of cardiovascular diseases. The process of deep-fat frying in dietary cooking oil plays a role in the generation of free radicals. In this study, palm olein heated to 180 °C was tested for its effect on the activity of blood pressure-regulating enzymes and lipid peroxidation.

    METHODS: Forty-two adult male Sprague-Dawley rats were equally assigned into 6 groups.The first group was fed with normal rat chow as the control group, and the subsequent groups were fed with rat chow fortified with 15% weight/weight of the following: fresh palm olein, palm olein heated once, palm olein heated twice, palm olein heated 5 times, or palm olein heated 10 times. The duration of feeding was 6 months. Fatty acid analyses of oil were performed using gas chromatography. Peroxide values were determined using standard titration. Plasma was collected for biochemical analyses.

    RESULTS: Repeatedly heated palm olein increased the levels of peroxide, angiotensin-converting enzyme, and lipid peroxidation as well as reduced the level of heme oxygenase. Fresh palm olein and palm olein heated once had lesser effects on lipid peroxidation and a better effect on the activity of blood pressure-regulating enzymes than repeatedly heated palm olein.

    CONCLUSION: Repeatedly heated palm olein may negatively affect the activity of blood pressure-regulating enzymes and increase lipid peroxidation.

    Matched MeSH terms: Free Radicals
  9. Leong XF, Rais Mustafa M, Jaarin K
    PMID: 23533459 DOI: 10.1155/2013/120732
    Hypertension increases the risk for a variety of cardiovascular diseases, including stroke, coronary artery disease, heart failure, and peripheral vascular disease. The increase in oxidative stress has been associated with the pathogenesis of hypertension. Increase of blood pressure is due to an imbalance between antioxidants defence mechanisms and free radical productions. Excessive production of reactive oxygen species reduces nitric oxide bioavailability leading to an endothelial dysfunction and a subsequent increase in total peripheral resistance. Hypertension can cause few symptoms until it reaches the advanced stage and poses serious health problems with lifelong consequences. Hypertensive patients are required to take drugs for life to control the hypertension and prevent complications. Some of these drugs are expensive and may have adverse reactions. Hence, it is timely to examine scientifically, complimentary therapies that are more effective and with minimal undesirable effects. Nigella sativa (NS) and its active constituents have been documented to exhibit antioxidant, hypotensive, calcium channel blockade and diuretic properties which may contribute to reduce blood pressure. This suggests a potential role of NS in the management of hypertension, and thus more studies should be conducted to evaluate its effectiveness.
    Matched MeSH terms: Free Radicals
  10. Muhammad N, Luke DA, Shuid AN, Mohamed N, Soelaiman IN
    PMID: 23118785 DOI: 10.1155/2012/161527
    Postmenopausal osteoporotic bone loss occurs mainly due to cessation of ovarian function, a condition associated with increased free radicals. Vitamin E, a lipid-soluble vitamin, is a potent antioxidant which can scavenge free radicals in the body. In this study, we investigated the effects of alpha-tocopherol and pure tocotrienol on bone microarchitecture and cellular parameters in ovariectomized rats. Three-month-old female Wistar rats were randomly divided into ovariectomized control, sham-operated, and ovariectomized rats treated with either alpha-tocopherol or tocotrienol. Their femurs were taken at the end of the four-week study period for bone histomorphometric analysis. Ovariectomy causes bone loss in the control group as shown by reduction in both trabecular volume (BV/TV) and trabecular number (Tb.N) and an increase in trabecular separation (Tb.S). The increase in osteoclast surface (Oc.S) and osteoblast surface (Ob.S) in ovariectomy indicates an increase in bone turnover rate. Treatment with either alpha-tocopherol or tocotrienol prevents the reduction in BV/TV and Tb.N as well as the increase in Tb.S, while reducing the Oc.S and increasing the Ob.S. In conclusion, the two forms of vitamin E were able to prevent bone loss due to ovariectomy. Both tocotrienol and alpha-tocopherol exert similar effects in preserving bone microarchitecture in estrogen-deficient rat model.
    Matched MeSH terms: Free Radicals
  11. Swamy MK, Akhtar MS, Mohanty SK, Sinniah UR
    PMID: 26186612 DOI: 10.1016/j.saa.2015.07.009
    Plant mediated synthesis of nanoparticles has been considered as green route and a reliable technique for the synthesis of nanoparticles due to its eco-friendly approach. In this study, we report a simple and eco-friendly approach for the synthesis of silver nanoparticles (AgNPs) using methanolic Momordica cymbalaria fruit extract as reducing agent. The fruit extract of M. cymbalaria exposed to AgNO3 solution showed the change in color from green to light yellow at room temperature within 1h of incubation confirms the synthesis of AgNPs. UV-vis spectra analysis revealed that the synthesized AgNPs had a sharp surface plasmon resonance at around 450 nm, while, the X-ray Diffraction (XRD) patterns confirmed distinctive peaks indices to the crystalline planes of the face centered cubic silver. The Atomic Force Microscopy (AFM) and Scanning Electron Microscopy (SEM) analysis results confirmed the presence of spherical shaped AgNPs by a huge disparity in the particle size distribution with an average size of 15.5 nm. The synthesized AgNPs showed strong antibacterial activity against all the tested multidrug resistant human pathogenic bacterial strains and also exhibited highest free radical scavenging activity (74.2%) compared to fruit extract (60.4%). Moreover, both fruit extract and the synthesized AgNPs showed the cytotoxicity towards Rat L6 skeletal muscle cell line at different concentrations, but the highest inhibition percentage was recorded for AgNPs at concentration of 100 μg/ml.
    Matched MeSH terms: Free Radicals
  12. Wasman SQ, Mahmood AA, Chua LS, Alshawsh MA, Hamdan S
    Indian J Exp Biol, 2011 Oct;49(10):767-72.
    PMID: 22013743
    Antioxidant and gastroprotective activities of aqueous and ethanolic extract of Andrographis paniculata leaves in rats have been reported. Sprague Dawley rats, 6 per group were used and rats in groups 1 to 6 were pretreated with (0.25% w/v) carboxymethyl cellulose (negative control, 5 ml/kg), 20 mg/kg omeprazole (positive control), (250 mg/kg and 500 mg/kg) of aqueous leaf extracts (APLAE) and (250 and 500 mg/kg) of ethanol leaf extracts (APLEE) respectively. Animals were orally administered with 95% ethanol (5 ml/kg) 60 min after their pretreatments. Rats were sacrificed 1 h after treatment and gastric contents were collected to measure pH and mucous weight. Stomach was analyzed for gross and histological changes. Ulcer control group showed extensive lesions of gastric mucosal layer, whereas rats pretreated with omeprazole, 250 and 500 mg/kg of APLAE showed significant and dose dependent reduction in gastric lesions with increased pH and mucus content of stomach. Rats pretreated with 250 or 500 mg/kg of APLEE showed significantly better inhibition of gastric mucosal lesions. Further, the in vitro antioxidant studies using 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay showed that ethanol extracts have superior free radical scavenging activity with IC50 value = 10.9 than aqueous extracts with IC50 value = 24.65. Results of this study showed that pretreatment with ethonolic extract of A. paniculata ethanolic provided significant protection against gastric ulcer by regulating of pH, mucous production and antioxidant property.
    Matched MeSH terms: Free Radicals/chemistry
  13. Muhammad N, Din LB, Sahidin I, Hashim SF, Ibrahim N, Zakaria Z, et al.
    Molecules, 2012 Jul 30;17(8):9043-55.
    PMID: 22847143 DOI: 10.3390/molecules17089043
    A new resveratrol dimer, acuminatol (1), was isolated along with five known compounds from the acetone extract of the stem bark of Shorea acuminata. Their structures and stereochemistry were determined by spectroscopic methods, which included the extensive use of 2D NMR techniques. All isolated compounds were evaluated for their antioxidant activity using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity (RSA) and the β-carotene-linoleic acid (BCLA) assays, and compared with those of the standards of ascorbic acid (AscA) and butylated hydroxytoluene (BHT). All compounds tested exhibited good to moderate antioxidant activity in the DPPH assay (IC₅₀s 0.84 to 10.06 mM) and displayed strong inhibition of β-carotene oxidation (IC₅₀s 0.10 to 0.22 mM). The isolated compounds were evaluated on the Vero cell line and were found to be non-cytotoxic with LC₅₀ values between 161 to 830 µM.
    Matched MeSH terms: Free Radicals/chemistry
  14. Alshawsh MA, Abdulla MA, Ismail S, Amin ZA, Qader SW, Hadi HA, et al.
    Molecules, 2012;17(5):5385-95.
    PMID: 22569417 DOI: 10.3390/molecules17055385
    Orthosiphon stamineus is considered an important traditional folk medicine. In this study ethanol and aqueous extracts of O. stamineus were evaluated in vitro for their antioxidant, antimicrobial as well as for their immunomodulatory properties on human peripheral blood mononuclear cells (PBMCs). The DPPH radical scavenging method was used for the determination of antioxidant activity, while the antibacterial efficacy was investigated by both disc diffusion method and Minimum Inhibitory Concentration (MIC) against four bacterial strains (Gram-positive and Gram-negative). Furthermore, the immunomodulatory potential of the extracts was investigated through the MTT assay. Aqueous extract of O. stamineus exhibited significant free radical scavenging activity with IC₅₀ 50 9.6 µg/mL, whereas the IC₅₀ for the ethanol extract was 21.4 µg/mL. The best antimicrobial activity was shown by the aqueous extract of O. stamineus against Staphylococcus aureus, with inhibition zone of 10.5 mm and MIC value 1.56 mg/mL. Moreover, the results observed from the MTT assay showed that both plant extracts stimulated the PBMCs proliferation in vitro in a concentration-dependent manner, but the aqueous extract has remarkable activity against PBMCs. These findings indicate that O. stamineus showed high antioxidant activity and may be considered as an immunomodulatory agent.
    Matched MeSH terms: Free Radicals/antagonists & inhibitors
  15. Jamila N, Khairuddean M, Yaacob NS, Kamal NN, Osman H, Khan SN, et al.
    Bioorg Chem, 2014 Jun;54:60-7.
    PMID: 24813683 DOI: 10.1016/j.bioorg.2014.04.003
    Garcinia hombroniana (seashore mangosteen) in Malaysia is used to treat itching and as a protective medicine after child birth. This study was aimed to investigate the bioactive chemical constituents of the bark of G. hombroniana. Ethyl acetate and dichloromethane extracts of G. hombroniana yielded two new (1, 9) and thirteen known compounds which were characterized by the spectral techniques of NMR, UV, IR and EI/ESI-MS, and identified as; 2,3',4,5'-tetrahydroxy-6-methoxybenzophenone(1), 2,3',4,4'-tetrahydroxy-6-methoxybenzophenone (2), 2,3',4,6-tetrahydroxybenzophenone (3), 1,3,6,7-tetrahydroxyxanthone (4), 3,3',4',5,7-pentahydroxyflavone (5),3,3',5,5',7-pentahydroxyflavanone (6), 3,3',4',5,5',7-hexahydroxyflavone (7), 4',5,7-trihydroxyflavanone-7-rutinoside (8), 18(13→17)-abeo-3β-acetoxy-9α,13β-lanost-24E-en-26-oic acid (9), garcihombronane B (10), garcihombronane D (11), friedelan-3-one (12), lupeol (13), stigmasterol (14) and stigmasterol glucoside (15). In the in vitro cytotoxicity against MCF-7, DBTRG, U2OS and PC-3 cell lines, compounds 1 and 9 displayed good cytotoxic effects against DBTRG cancer cell lines. Compounds 1-8 were also found to possess significant antioxidant activities. Owing to these properties, this study can be further extended to explore more significant bioactive components of this plant.
    Matched MeSH terms: Free Radicals/antagonists & inhibitors
  16. Yusri NM, Chan KW, Iqbal S, Ismail M
    Molecules, 2012 Oct 25;17(11):12612-21.
    PMID: 23099617 DOI: 10.3390/molecules171112612
    A sequential solvent extraction scheme was employed for the extraction of antioxidant compounds from kenaf (Hibiscus cannabinus L.) seeds. Yield of extracts varied widely among the solvents and was the highest for hexane extract (16.6% based on dry weight basis), while water extract exhibited the highest total phenolic content (18.78 mg GAE/g extract), total flavonoid content (2.49 mg RE/g extract), and antioxidant activities (p < 0.05). DPPH and hydroxyl radical scavenging, β-carotene bleaching, metal chelating activity, ferric thiocyanate and thiobarbituric acid reactive substances assays were employed to comprehensively assess the antioxidant potential of different solvent extracts prepared sequentially. Besides water, methanolic extract also exhibited high retardation towards the formation of hydroperoxides and thiobarbituric acid reactive substances in the total antioxidant activity tests (p < 0.05). As conclusion, water and methanol extracts of kenaf seed may potentially serve as new sources of antioxidants for food and nutraceutical applications.
    Matched MeSH terms: Free Radicals/chemistry
  17. Srinivasan V, Pandi-Perumal SR, Maestroni GJ, Esquifino AI, Hardeland R, Cardinali DP
    Neurotox Res, 2005;7(4):293-318.
    PMID: 16179266
    The pineal product melatonin has remarkable antioxidant properties. It scavenges hydroxyl, carbonate and various organic radicals, peroxynitrite and other reactive nitrogen species. Melatonyl radicals formed by scavenging combine with and, thereby, detoxify superoxide anions in processes terminating the radical reaction chains. Melatonin also enhances the antioxidant potential of the cell by stimulating the synthesis of antioxidant enzymes like superoxide dismutase, glutathione peroxidase and glutathione reductase, and by augmenting glutathione levels. The decline in melatonin production in aged individuals has been suggested as one of the primary contributing factors for the development of age-associated neurodegenerative diseases, e.g., Alzheimer's disease. Melatonin has been shown to be effective in arresting neurodegenerative phenomena seen in experimental models of Alzheimer's disease, Parkinsonism and ischemic stroke. Melatonin preserves mitochondrial homeostasis, reduces free radical generation, e.g., by enhancing mitochondrial glutathione levels, and safeguards proton potential and ATP synthesis by stimulating complex I and IV activities. Therapeutic trials with melatonin have been effective in slowing the progression of Alzheimer's disease but not of Parkinson's disease. Melatonin's efficacy in combating free radical damage in the brain suggests that it may be a valuable therapeutic agent in the treatment of cerebral edema after traumatic brain injury.
    Matched MeSH terms: Free Radicals/metabolism
  18. Rati Selvaraju T, Khaza'ai H, Vidyadaran S, Sokhini Abd Mutalib M, Ramachandran V, Hamdan Y
    Int J Vitam Nutr Res, 2014;84(3-4):140-51.
    PMID: 26098478 DOI: 10.1024/0300-9831/a000201
    Glutamate is the major mediator of excitatory signals in the mammalian central nervous system. Extreme amounts of glutamate in the extracellular spaces can lead to numerous neurodegenerative diseases. We aimed to clarify the potential of the following vitamin E isomers, tocotrienol-rich fraction (TRF) and α-tocopherol (α-TCP), as potent neuroprotective agents against glutamate-induced injury in neuronal SK-N-SH cells. Cells were treated before and after glutamate injury (pre- and post-treatment, respectively) with 100-300 ng/ml TRF/α-TCP. Exposure to 120 mM glutamate significantly reduced cell viability to 76% and 79% in the pre- and post-treatment studies, respectively; however, pre- and post-treatment with TRF/α-TCP attenuated the cytotoxic effect of glutamate. Compared to the positive control (glutamate-injured cells not treated with TRF/α-TCP), pre-treatment with 100, 200, and 300 ng/ml TRF significantly improved cell viability following glutamate injury to 95.2%, 95.0%, and 95.6%, respectively (p<0.05).The isomers not only conferred neuroprotection by enhancing mitochondrial activity and depleting free radical production, but also increased cell viability and recovery upon glutamate insult. Our results suggest that vitamin E has potent antioxidant potential for protecting against glutamate injury and recovering glutamate-injured neuronal cells. Our findings also indicate that both TRF and α-TCP could play key roles as anti-apoptotic agents with neuroprotective properties.
    Matched MeSH terms: Free Radicals/antagonists & inhibitors
  19. Khor SC, Razak AM, Wan Ngah WZ, Mohd Yusof YA, Abdul Karim N, Makpol S
    PLoS One, 2016;11(2):e0149265.
    PMID: 26885980 DOI: 10.1371/journal.pone.0149265
    Aging results in a loss of muscle mass and strength. Myoblasts play an important role in maintaining muscle mass through regenerative processes, which are impaired during aging. Vitamin E potentially ameliorates age-related phenotypes. Hence, this study aimed to determine the effects of the tocotrienol-rich fraction (TRF) and α-tocopherol (ATF) in protecting myoblasts from replicative senescence and promoting myogenic differentiation. Primary human myoblasts were cultured into young and senescent stages and were then treated with TRF or ATF for 24 h, followed by an analysis of cell proliferation, senescence biomarkers, cellular morphology and differentiation. Our data showed that replicative senescence impaired the normal regenerative processes of myoblasts, resulting in changes in cellular morphology, cell proliferation, senescence-associated β-galactosidase (SA-β-gal) expression, myogenic differentiation and myogenic regulatory factors (MRFs) expression. Treatment with both TRF and ATF was beneficial to senescent myoblasts in reclaiming the morphology of young cells, improved cell viability and decreased SA-β-gal expression. However, only TRF treatment increased BrdU incorporation in senescent myoblasts, as well as promoted myogenic differentiation through the modulation of MRFs at the mRNA and protein levels. MYOD1 and MYOG gene expression and myogenin protein expression were modulated in the early phases of myogenic differentiation. In conclusion, the tocotrienol-rich fraction is superior to α-tocopherol in ameliorating replicative senescence-related aberration and promoting differentiation via modulation of MRFs expression, indicating vitamin E potential in modulating replicative senescence of myoblasts.
    Matched MeSH terms: Free Radicals/metabolism
  20. Selvaraja M, Chin VK, Abdullah M, Arip M, Amin-Nordin S
    Front Med (Lausanne), 2020;7:598665.
    PMID: 33644084 DOI: 10.3389/fmed.2020.598665
    Systemic lupus erythematosus (SLE) is a chronic autoimmune disease afflicting multiple organs. Lupus nephritis (LN) is a serious complication of SLE and remains a major cause of mortality and morbidity. Curative therapy remains unavailable as etiology from genetic and environmental factors is still unclear. The present study was conducted to elucidate the link between HLA-DRB1 gene polymorphisms with SLE and LN through clinical and laboratory/biological presentations in a population of Malaysian Malay females with SLE. A total of 100 Malay female SLE patients inclusive of 70 SLE patients without LN and 30 patients with LN were included in this study. HLA-DRB1 allele examination in SLE patients was performed using PCR-SSO, and the alleles' frequencies were compared with 951 publicly available datasets representing Malay healthy controls in Malaysia. Cytokines and free radical levels were detected by ELISA and bead-based multiplexed Luminex assays. The association between HLA-DRB1 alleles with clinical and serological manifestations and immune mediators was analyzed using different statistical approaches whenever applicable. Our study showed that HLA-DRB1*0405, HLA-DRB1*1502, and HLA-DRB1*1602 were associated with the increased risk of SLE while HLA-DRB1*1201 and HLADRB1*1202 alleles were associated with a lower risk of SLE development. Furthermore, HLA-DRB1*04 showed significant association to LN and arthritis while HLA-DRB1*15 was significantly associated with oral ulcer in Malay SLE patients. Association analysis of HLA-DRB1*04 with clinical and biological factors revealed that HLA-DRB1*04 was significantly associated with Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) scores, anti-nuclear antibody (ANA), C-reactive protein (CRP) in the blood, and total protein in the urine. SLE carriers with the HLA-DRB1*04 allele were significantly correlated to the increased levels of cytokines (IFN-y, GM-CSF, IL-17F, IL-18, IL-21, and VEGF) and were significantly showing negative correlation to IL-5 and free radicals (LPO and catalase enzyme) levels compared to SLE carriers without HLA-DRB1*04 allele. The results suggested that disease severity in SLE may be determined by HLA-DRB1 alleles. The risk of HLA-DRB1*04 allele with LN was supported by the demonstration of an intense inflammatory response in Malay SLE patients in Malaysia. More studies inclusive of a larger and multiple SLE cohorts in the future are warranted to validate these findings.
    Matched MeSH terms: Free Radicals
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