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Fulltext Risk factors for cataract: a case study at National University of Malaysia Hospital

Sharanjeet-Kaur, Arifah Nur Yahya, Che Muhaya Mohamad, McCarty, C.A.

Jurnal Sains Kesihatan Malaysia, 2006;4(1):85-98.
MyJurnal

The purpose of this study was to identify the most common forms of age-related cataracts and to estimate possible risk factors for age-related cataracts in a sample of cataract patients at the National University of Malaysia Hospital. Thirty five patients (17 males and 18 female) with cataracts were recruited from the ophthalmology ward and clinic at the hospital. The age range of the patients was between 39 to 93 years (mean 64.9 11.5 years). The Lens Opacities Classification System (Locs) III was used to grade nuclear, cortical and posterior subcapsular lens opacities. Grading of the cataract was carried out and the following information was collected: initial visual acuity and best-corrected visual acuity, demographic details, health history, dietary intake of antioxidants and lifetime ocular ultraviolet B exposure. Analyses were conducted using a standard case-control design. T-tests were used to assess the significance of continuous variables and chi-squared tests were used for categorical variables. The overall prevalence of cortical cataract was 34.4% (12 patients), nuclear cataract was 60.0% (21 patients), and posterior subcapsular cataract was 57.1% (20 patients). No significant potential risk factor was found for nuclear cataracts. In the case of posterior subcapsular cataract, hypertension was the only potential significant risk factor (x2 = 4.38, p = 0.036), and in the case of cortical cataract, cigarette smoking was the only significant risk factor. Although lifetime effective ocular UV-B exposure was found to be not a significant potential risk factor, but it was seen that for cortical cataracts, the mean difference of lifetime effective ocular UV-B exposure between those with cortical and those without cortical cataracts was larger compared to others with nuclear and posterior subcapsular cataracts. Hypertension was found to be a potential significant risk factor for posterior subcapsular cataract whereas cigarette smoking was a potentially significant risk factor for cortical cataract. Although not statistically significant, lifetime effective ocular UV-B exposure maybe a potential risk factor for cortical cataract.

Matched MeSH terms: Antioxidants
Fulltext Curcumin from turmeric (Curcuma longa) induced apoptosis in human mammary carcinoma cells (MDA-MB-231)

Latifah, S. Y., Faujan, H. A., Sze, L. P., Raha, A. R., Hisyam, A. H., Li, O. C.

Malaysian Journal of Medicine and Health Sciences, 2006;2(2):71-79.
MyJurnal

Introduction: Curcumin, a natural compound present in turmeric (Curcuma longa) has been known to possess both anti-inflammatory and antioxidant effects. Objectives: The objectives of the study were to evaluate the cytotoxic activities and to determine the mode of cell death induced by curcumin towards the human mammary carcinoma cells (MDAMB-231). Methodology: Cytotoxicity of curcumin and its effect on cell viability were determined by using MTT assay and trypan blue dye exclusion method, respectively. The mode of cell death was detected by viewing under a light microscope and through DNA fragmentation analysis. Results and discussion: Curcumin was cytotoxic to MDA-MB-231 cells with the IC50 of 17.25 ì g/ml. Cell viability treatment using curcumin at concentrations of 30 ì g/ml and 10 ì g/ml was significantly (p

Matched MeSH terms: Antioxidants
Fulltext Effects of vitamin E supplementation on bone metabolism in nicotine-treated rats

Norazlina M, Lee PL, Lukman HI, Nazrun AS, Ima-Nirwana S

Singapore Med J, 2007 Mar;48(3):195-9.
PMID: 17342286

Nicotine has been shown to exert negative effects on bone. This study determined whether vitamin E supplementation is able to repair the nicotine-induced adverse effects in bone.

Matched MeSH terms: Antioxidants/therapeutic use*
Quercetin, a flavonoid antioxidant, modulates endothelium-derived nitric oxide bioavailability in diabetic rat aortas

Machha A, Achike FI, Mustafa AM, Mustafa MR

Nitric Oxide, 2007 Jun;16(4):442-7.
PMID: 17513143 DOI: 10.1016/j.niox.2007.04.001

The present work examined the effect of chronic oral administration of quercetin, a flavonoid antioxidant, on blood glucose, vascular function and oxidative stress in STZ-induced diabetic rats. Male Wistar-Kyoto (WKY) rats were randomized into euglycemic, untreated diabetic, vehicle (1% w/v methylcellulose)-treated diabetic, which served as control, or quercetin (10mgkg(-1) body weight)-treated diabetic groups and treated orally for 6 weeks. Quercetin treatment reduced blood glucose level in diabetic rats. Impaired relaxations to endothelium-dependent vasodilator acetylcholine (ACh) and enhanced vasoconstriction responses to alpha(1)-adrenoceptor agonist phenylephrine (PE) in diabetic rat aortic rings were restored to euglycemic levels by quercetin treatment. Pretreatment with N(omega)-nitro-l-arginine methyl ester (l-NAME, 10microM) or methylene blue (10microM) completely blocked but indomethacin (10microM) did not affect relaxations to ACh in aortic rings from vehicle- or quercetin-treated diabetic rats. PE-induced vasoconstriction with an essentially similar magnitude in vehicle- or quercetin-treated diabetic rat aortic rings pretreated with l-NAME (10microM) plus indomethacin (10microM). Quercetin treatment reduced plasma malonaldehyde (MDA) plus 4-hydroxyalkenals (4-HNE) content as well as increased superoxide dismutase activity and total antioxidant capacity in diabetic rats. From the present study, it can be concluded that quercetin administration to diabetic rats restores vascular function, probably through enhancement in the bioavailability of endothelium-derived nitric oxide coupled to reduced blood glucose level and oxidative stress.

Matched MeSH terms: Antioxidants/therapeutic use
Time-relative changes in the erythrocyte antioxidant enzyme activities and their relationship with Glasgow Coma Scale scores in severe head injury patients in the 21-day posttraumatic study period

Nayak CD, Nayak DM, Raja A, Rao A

Indian J Med Sci, 2007 Jul;61(7):381-9.
PMID: 17611343

BACKGROUND: Reactive oxygen species are indicated to play a prime role in the pathophysiology of brain damage following a severe head injury (SHI).
AIM: The current study was designed to understand the time-relative changes and relationship between erythrocyte antioxidant enzyme activities and Glasgow Coma Scale (GCS) scores of SHI patients in the 21-day posttraumatic study period.
SETTINGS AND DESIGN: The study included 24 SHI patients and 25 age- and sex-matched normal controls (NC). Activities of superoxide dismutase (SOD), glutathione reductase (GR) and glutathione peroxidase (GSH-Px) were assayed in these patients and controls. The GCS scores of these patients were also recorded for the comparative study.
MATERIALS AND METHODS: Venous blood samples were collected on day 7 (D7) and D21 from SHI patients and NC for the assay of SOD, GR and GSH-Px activities. These changes were correlated with age and changes in GCS scores of patients.
STATISTICAL ANALYSIS: A one-way analysis of variance (ANOVA) was used to compare mean values of each parameter between group 1 (NC), group 2 (D7 changes in SHI patients) and group 3 (D21 changes in SHI patients). ANOVA was followed by Bonferroni post hoc tests. The Pearson correlation was applied to correlate between the antioxidant parameters and age and GCS scores of these patients.
RESULTS: A significant increase in erythrocyte SOD and GSH-Px activities was observed in group 3 as compared to groups 1 and 2. The increase in GSH-Px activity was significant in group 2 as compared to group 1. Although not significant, there was an increase in mean GR activity in groups 2 and 3 as compared to group 1.
CONCLUSION: These findings indicate that SHI patients have shown significantly enhanced erythrocyte SOD and GSH-Px activities during the 21-day posttraumatic study period.

Matched MeSH terms: Antioxidants/metabolism*
Probucol modulates iron nitrilotriacetate (Fe-NTA)-dependent renal carcinogenesis and hyperproliferative response: diminution of oxidative stress

Iqbal M, Okazaki Y, Okada S

Mol Cell Biochem, 2007 Oct;304(1-2):61-9.
PMID: 17487455

Probucol is a clinically used cholesterol-lowering drug, with pronounced antioxidant properties. We have reported previously, that dietary supplementation of probucol enhances NAD(P)H:quinone reductase (Iqbal M, Okada S (2003) Pharmacol Toxicol 93:259-263) and inhibits Fe-NTA induced lipid peroxidation and DNA damage in vitro (Iqbal M, Sharma SD, Oakada (2004) Redox Rep 9:167-172). Further to this, in the present study, we evaluated the modulatory effect of probucol on iron nitrilotriacetae (Fe-NTA) dependent renal carcinogenesis, hyperproliferative response and oxidative stress. In Fe-NTA alone treated group, a 20% renal cell tumor incidence was recorded whereas, in N-diethylnitrosamine (DEN)-initiated and Fe-NTA promoted animals, the percentage tumor incidence was increased to 70% as compared with untreated controls. No tumor incidence was recorded in DEN-initiated, nonpromoted group. Diet supplemented with 1.0% probucol fed prior to, during and after Fe-NTA treatment in DEN-initiated animals afforded >65% protection in renal cell tumor incidence. Probucol fed diet pretreatment also resulted a significant and dose dependent inhibition of Fe-NTA induced renal ornithine decarboxylase (ODC) activity. In oxidative stress studies, Fe-NTA alone treatment enhanced lipid peroxidation, accompanied by a decrease in the level of GSH, activities of antioxidants and phase II metabolizing enzymes in kidney concomitant with histolopathological changes. These changes were significantly and dose-dependently alleviated by probucol fed diet. From this data, it can be concluded that probucol can modulates toxic and tumor promoting effects of Fe-NTA and can serve as a potent chemopreventive agent to suppress oxidant induced tissue injury and carcinogenesis, in addition to being a cholesterol lowering and anti-atherogenic drug.

Matched MeSH terms: Antioxidants/pharmacology; Antioxidants/therapeutic use
Mulberry leaves protect rat tissues from immobilization stress-induced inflammation

Lee CY, Cheng HM, Sim SM

Biofactors, 2007;31(1):25-33.
PMID: 18806306

The ability of the antioxidants in the mulberry leaves to protect Sprague-Dawley rats from injuries caused by immobilization stress was studied as an indicator of the tissue bioavailability of antioxidants. Nitrite level, lipid peroxidation and total antioxidant activity (TAA) in the plasma and tissues were measured. There were hypertrophy of the adrenal glands and kidneys, significant increased levels of nitrite in the plasma and adrenal glands, elevated thiobarbituric acid reactive substances (TBARS) in the plasma, kidneys and spleen, and a reduction of TAA in the plasma, liver, adrenal glands, kidneys and spleen of the immobilized rats. Antioxidants in the mulberry leaf extract suppressed the increase of nitrite and TBARS. Adrenal glands appeared to be the target organ of the antioxidants in the leaf extract. The low dose mulberry antioxidants were more effective than pure rutin (4 mg/day) to protect the cells against inflammation and peroxidation induced by stress.

Matched MeSH terms: Antioxidants/metabolism
Relationship between neurological outcome and early oxidative changes in erythrocytes in head injury patients

Nayak C, Nayak D, Bhat S, Raja A, Rao A

Clin Chem Lab Med, 2007;45(5):629-33.
PMID: 17484625

Experimental data indicate that destructive oxidative events reach their peak within the first 24 h after trauma in head injury (HI) and that brain damage occurring due to this impact can be the cause of death or irreversible permanent disabilities in affected patients.

Matched MeSH terms: Antioxidants/analysis
Fulltext Antioxidative activities of water extracts of some Malaysian herbs

Huda-Faujan, N., Noriham, A., Norrakiah, A.S., Babji, A.S.

International Food Research Journal, 2007;14(1):61-68.
MyJurnal

This study was conducted on selected local herbs such as ulam raja (Cosmos caudatus), kesum (Polygonum minus), selom (Oenanthe javanica), pegaga (Centella asiatica) and curry leaves (Murraya koenigii) to investigate their antioxidative activities. The water extracts of the herbs were analysed for total phenolic content, reducing antioxidant power, ferric thiocyanate (FTC) and the thiobarbituric acid (TBA) test was also accried out. Polygonum minus showed the highest total phenolic content and reducing power among the herbs. Increasing the concentration of the extracts resulted in increased Fe3+ reducing antioxidant power for all the herbs. FTC and TBA tests on the extracts during seven days of storage showed that all the herbs extracts had the ability to reduce oxidation compared to the control (P < 0.05). From the FTC analysis, Murraya koenigii leaves was best in reducing the oxidation rate (67.67%) compared to the other herbs studied. Analysis of TBA showed that Centella asiatica extract had the highest antioxidant effect. However, both TBA and FTC analysis for these two herbs showed no significant difference (P >0.05) from Polygonum minus and butylated hydroxyanisole (BHT) a synthetic antioxidant. Correlation analysis showed positive correlations between amount of total phenolic content and reducing power (r = 0.75) and antioxidative activities (r = 0.58) in linoleic acid emulsion system. This shows that antioxidative activities of these Malaysian herbal plants especially Polygonum minus may be a potential source of natural antioxidants with similar characteristics to the synthetic antioxidant, BHT.

Matched MeSH terms: Antioxidants
Fulltext The effect of 5-week exercise program on oxidative stress and response to acute exercise among sedentary subjects

Farah Fauzi, Siti Balkis Budin, Shahrul Azwan, Leong, Kok Yuen

Jurnal Sains Kesihatan Malaysia, 2007;5(2):39-52.
MyJurnal

Physical training is associated with oxidative stress and improvement in blood antioxidant status. In this study, we investigated the effects of training on plasma malondialdehyde (MDA) and 4-hydroxynonenal (4-HNE) as markers of lipid peroxidation, superoxide dismutase (SOD) activity, and ascorbic acid (AA) after a single bout of acute exercise. Twelve healthy, untrained young adult men were recruited for 5 weeks of aerobic training period. They were subjected to a rope-skipping exercise for 20 minutes at the intensity of 65-80% of heart rate reserve, thrice weekly. They also had to perform a single, acute bout of the same exercise protocol prior to and after training period. Venous blood samples were collected at resting condition (BL), immediately (0 h) and 24 hours (24 h) post acute exercise on both single bout sessions. Results showed that the pattern changes of oxidative stress response are quite similar on both acute sessions. The acute bouts of rope-skipping is associated with a significant increased (p = 0.001) in lipid peroxidation markers immediately after cessation of exercise, with a concomitant increases in antioxidant levels, albeit higher when compared to pre-training values (p = 0.001). These changes were followed by a significant decreased (p = 0.001) in all parameters, toward resting values, 24 hours thereafter. The training program seemed to induce a significant increase in MDA and 4-1-INE but also enhanced the antioxidant defense system namely SOD and AA among the untrained subjects.

Matched MeSH terms: Antioxidants
Fulltext Tocotrienol levels in adipose tissue of benign and malignant breast lumps in patients in Malaysia

Nesaretnam K, Gomez PA, Selvaduray KR, Razak GA

Asia Pac J Clin Nutr, 2007;16(3):498-504.
PMID: 17704032

Data on dietary exposure to vitamin E by plasma or adipose tissue concentrations of alpha-tocopherol (alpha-T) in observational studies have failed to provide consistent support for the idea that alpha-T provides women with any protection from breast cancer. In contrast, studies indicate that alpha, gamma, and delta-tocotrienols but not alpha-T have potent anti-proliferative effects in human breast cancer cells. Our aim was to investigate whether there was a difference in tocopherol and tocotrienol concentrations in malignant and benign adipose tissue, in a Malaysian population consuming predominantly a palm oil diet. The study was undertaken using fatty acid levels in breast adipose tissue as a biomarker of qualitative dietary intake of fatty acids. The major fatty acids in breast adipose tissue of patients (benign and malignant) were oleic acid (45-46%), palmitic (28-29%) and linoleic (11-12%). No differences were evident in the fatty acid composition of the two groups. There was a significant difference (p=0.006) in the total tocotrienol levels between malignant (13.7 +/- 6.0 microg/g) and benign (20+/-6.0 microg/g) adipose tissue samples. However, no significant differences were seen in the total tocopherol levels (p=0.42) in the two groups. The study reveals that dietary intake influences adipose tissue fatty acid levels and that adipose tissue is a dynamic reservoir of fat soluble nutrients. The higher adipose tissue concentrations of tocotrienols in benign patients provide support for the idea that tocotrienols may provide protection against breast cancer.

Matched MeSH terms: Antioxidants/analysis*
Antioxidant and hepatoprotective effects of Orthosiphon stamineus Benth. standardized extract

Yam MF, Basir R, Asmawi MZ, Ismail Z

Am J Chin Med, 2007;35(1):115-26.
PMID: 17265556

Orthosiphon stamineus (OS), Benth. (Lamiaceae) is widely used in Malaysia for treatments of various kidney and liver ailments. In the experiment, DPPH* radicals scavenging, Fe(3+)-induced lipid peroxidation inhibiting activities and trolox equivalent antioxidant capacity (TEAC) of methanol/water extract of Orthosiphon stamineus (SEOS) were determined. The results indicated that SEOS exhibited antioxidant, lipid peroxidation inhibition and free radical scavenging activities. The hepatoprotective activity of the SEOS was studied using CCl(4)-induced liver toxicity in rats. The activity was assessed by monitoring liver function tests through the measurement of alanine transaminase (ALT) and aspartate transaminase (AST). Furthermore, hepatic tissues were also subjected to histopathological studies. Pretreatment of SEOS (125, 250, 500 and 1000 mg/kg p.o.) dose-dependently reduced the necrotic changes in rat liver and inhibited the increase of serum ALT and AST activities. The results of the present study indicated that the hepatoprotective effect of Orthosiphon stamineus might be ascribable to its antioxidant and free radical scavenging property.

Matched MeSH terms: Antioxidants/metabolism*
Reduction of DNA damage in older healthy adults by Tri E Tocotrienol supplementation

Chin SF, Hamid NA, Latiff AA, Zakaria Z, Mazlan M, Yusof YA, et al.

Nutrition, 2008 Jan;24(1):1-10.
PMID: 17884341

The free radical theory of aging (FRTA) suggests that free radicals are the leading cause of deteriorating physiologic function during senescence. Free radicals attack cellular structures or molecules such as DNA resulting in various modifications to the DNA structures. Accumulation of unrepaired DNA contributes to a variety of disorders associated with the aging process.

Matched MeSH terms: Antioxidants/pharmacology*
Antioxidant profiles of a prepared extract of Chinese herbs for the treatment of atopic eczema

Chung LY

Phytother Res, 2008 Apr;22(4):493-9.
PMID: 18338748 DOI: 10.1002/ptr.2350

A standardized mixture of Chinese herbs, Zemaphyte taken orally as a daily decoction has been shown to be effective in the treatment of atopic eczema. This study showed that Zemaphyte is an efficient antioxidant, being capable of scavenging both superoxide and hydroxyl, and preventing peroxidation of biological membranes. It does not degrade hydrogen peroxide directly, but instead most likely forms a Zemaphyte-hydrogen peroxide complex. The complexed hydrogen peroxide can then be degraded in the presence of catalase to form oxygen and water. It is conceivable that Zemaphyte may contribute to the down-regulation of the activities of cells implicated in atopic eczema through its antioxidant activities.

Matched MeSH terms: Antioxidants/pharmacology*
Tyrisonase inhibition and melanin reduction of human melanocytes (HEMn-MP) using Anacardium occidentale L extract

Abdul Gaffar R, Abdul Majid FA, Sarmidi MR

Med J Malaysia, 2008 Jul;63 Suppl A:100-1.
PMID: 19025004

Cashew (Anacardium occindentale L) leaves extract (CLE) has potential as tyrosinase inhibitor that can be used for therapeutic in pigmentation problem. This study investigates the real potential of CLE to inhibit tyrosinase and melanin reduction using human epidermal melanocytes. The extracts were exposed to the human melanocytes for more than 24 hours. The CLE extract exhibited potential as tyrosinase inhibitor, reduced melanin and high in antioxidant activity relative to commercial extract of Emblica sp.

Matched MeSH terms: Antioxidants/pharmacology
Protective antioxidant effect of Centella asiatica bioflavonoids on lead acetate induced neurotoxicity

Ponnusamy K, Mohan M, Nagaraja HS

Med J Malaysia, 2008 Jul;63 Suppl A:102.
PMID: 19025005

Lead (Pb) is a neurotoxic heavy metal and children in the developmental stage are particularly susceptible to toxic effects of lead exposure. The brain is the key organ involved in interpreting and responding to potential stressors. Epidemiological investigations have established the relationship between chronic lead exposure and cognitive impairments in young children. Excessive production of radical species plays an important role in neuronal pathology resulting from excitotoxic insults, therefore one plausible neuroprotective mechanism of bioflavonoids is partly relevant to their metal chelating and antioxidant properties. Centella asiatica (CA) is a tropical medicinal plant enriched with bioflavonoids and triterpenes and selenium, reported to rejuvenate the cells and promote physical and mental health. Bioflavonoids are claimed to be exert antimutagenic, neurotrophic and xenobiotics ameliorating and membrane molecular stabilizing effects. The objective of the present work is to study the protective antioxidant effect of pretreatment of CA extract (CAE) on lead acetate induced changes in oxidative biomarkers in the central nervous system (CNS) of mice.

Matched MeSH terms: Antioxidants/pharmacology*
GAPDH as housekeeping gene for human skin fibroblast senescent model

Zainuddin A, Makpol S, Chua KH, Abdul Rahim N, Yusof YA, Ngah WZ

Med J Malaysia, 2008 Jul;63 Suppl A:73-4.
PMID: 19024990

Validation of housekeeping gene is important for accurate quantitation of RNA in real time RT-PCR technique. The purpose of this study was to determine the validity of glyceraldehyde 3-phosphate dehydrogenase (GAPDH) as a housekeeping gene for quantitative real time RT-PCR assessment in human skin fibroblast senescent model. The cells were divided into different treatment groups; young (passage 4), senescent (passage 30), treatment with H2O2 and treatment with A-tocotrienol prior to H2O2 treatment. Our results showed that the expression level of GAPDH was constant with different treatment groups. Therefore, we concluded that GAPDH was suitable to be used as housekeeping gene in human skin fibroblast senescent model.

Matched MeSH terms: Antioxidants/metabolism*
Fulltext Palm tocotrienol exerted better antioxidant activities in bone than alpha-tocopherol

Maniam S, Mohamed N, Shuid AN, Soelaiman IN

Basic Clin Pharmacol Toxicol, 2008 Jul;103(1):55-60.
PMID: 18598299 DOI: 10.1111/j.1742-7843.2008.00241.x

The aim of this study was to investigate the effects of vitamin E on the levels of lipid peroxidation and antioxidant enzymes in rat bones. Fifty-six normal male Sprague-Dawley rats, aged 3 months, were randomly divided into seven groups with eight rats in each group. The age-matched control group was given the vehicle olive oil, by oral gavage daily. Six of the treatment groups received either palm tocotrienol or pure alpha-tocopherol at the dose of 30, 60 or 100 mg/kg body weight, by oral gavage daily, 6 days a week for 4 months. Thiobarbituric acid-reactive substance (TBARS) that is an index to measure the level of lipid peroxidation and the antioxidant enzymes, glutathione peroxidase and superoxide dismutase levels were measured in the femur at the end of the study. Palm tocotrienol at the dose of 100 mg/kg body weight significantly reduced the TBARS level in the femur with a significant increase in glutathione peroxidase activity compared to the age-matched control group. These were not observed in the alpha-tocopherol groups. Palm tocotrienol was more effective than pure alpha-tocopherol acetate in suppressing lipid peroxidation in bone. Palm tocotrienol showed better protective effect against free radical damage in the femur compared to alpha-tocopherol. This study suggests that palm tocotrienol plays an important role in preventing imbalance in bone metabolism due to free radicals.

Matched MeSH terms: Antioxidants/administration & dosage; Antioxidants/pharmacology*
Phenylacetic acids were detected in the plasma and urine of rats administered with low-dose mulberry leaf extract

Lee CY, Sim SM, Cheng HM

Nutr Res, 2008 Aug;28(8):555-63.
PMID: 19083460 DOI: 10.1016/j.nutres.2008.05.001

The use of a high quercetin dose to demonstrate its absorption and bioavailability does not reflect the real dietary situation because quercetin glycosides are usually present in small amounts in the human diet. This study aimed to demonstrate the absorption and bioavailability of quercetin in mulberry leaves that represents a more physiologic dietary situation. Mulberry leaf ethanol extract was prepared similar to tea infusion, which is the way the tea leaves are generally prepared for consumption. Accordingly, rats were fed by oral intubation the mulberry leaf ethanol extract (15 g%/rat per day) or pure rutin (135 microg/rat per day) for 2 weeks. The control group received a similar volume of the vehicle, 10% ethanol. There was a significant increase in total antioxidant activity (TAA) in the urine and feces of the antioxidants-fed rats. Phenylacetic acid, a microbial metabolite of quercetin, was detected in the urine of the test animals, and quercetin was present in the fecal samples. By using an in situ intestinal preparation, 3-hydroxyphenylacetic acid, another microbial metabolite of quercetin, was detected in the plasma when the duodenal segment was instilled with 2 mg of rutin. This microbial metabolite retained 50% of the TAA of quercetin. The results of this study indicate that in a more realistic dietary situation, an increase in TAA in the body after consumption of quercetin-containing foods is contributed mainly by the microbial metabolites.

Matched MeSH terms: Antioxidants/analysis
A study of the antioxidant effect of alpha lipoic acids on sperm quality

Ibrahim SF, Osman K, Das S, Othman AM, Majid NA, Rahman MP

Clinics (Sao Paulo), 2008 Aug;63(4):545-50.
PMID: 18719769

OBJECTIVE: Assisted reproductive techniques are useful in helping infertile couples achieve successful conception. Initial studies have shown that sperm cryopreservation, one step in assisted reproduction, causes a dramatic reduction in sperm quality. This has been attributed to, among other things, free radical activities. The aim of the present study was to minimize this oxidative attack by adding an antioxidant into the sperm microenvironment. Alpha lipoic acids were selected for this purpose for their efficient free radical scavenging properties and solubility in lipid and aqueous phases.
METHODS: For this investigation, semen from six Boer bucks was pooled. Seminal analysis of the baseline prior to incubation of samples with different concentrations of Alpha lipoic acids (0.00625, 0.0125, 0.025, 0.05, 0.1 mmol/ml) was performed, and post-seminal analysis was conducted after a one-hour incubation. The comet assay was used to observe the effect of Alpha lipoic acids on sperm DNA integrity. Statistical analysis using an unpaired t-test with a significance level of p<0.05 was then performed.
RESULTS: Our results indicate that the sperm motility rate was improved after incubation with Alpha lipoic acids at a concentration of 0.02 mmol/ml. This concentration was also capable of reducing DNA damage.
CONCLUSION: In conclusion, Alpha lipoic acids renders cryoprotection to sperm, thereby improving sperm quality.

Matched MeSH terms: Antioxidants/therapeutic use*

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