Displaying publications 21 - 40 of 144 in total

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  1. Roselle supplementation prevents nicotine-induced vascular endothelial dysfunction and remodelling in rats
    Si LY, Kamisah Y, Ramalingam A, Lim YC, Budin SB, Zainalabidin S
    Appl Physiol Nutr Metab, 2017 Jul;42(7):765-772.
    PMID: 28249121 DOI: 10.1139/apnm-2016-0506
    Vascular endothelial dysfunction (VED) plays an important role in the initiation of cardiovascular diseases. Roselle, enriched with antioxidants, demonstrates high potential in alleviating hypertension. This study was undertaken to investigate the effects of roselle supplementation of VED and remodelling in a rodent model with prolonged nicotine administration. Male Sprague-Dawley rats (n = 6 per group) were administered with 0.6 mg/kg nicotine for 28 days to induce VED. The rats were given either aqueous roselle (100 mg/kg) or normal saline orally 30 min prior to nicotine injection daily. One additional group of rats served as control. Thoracic aorta was isolated from rats to measure vascular reactivity, vascular remodelling and oxidative stress. Roselle significantly lowered aortic sensitivity to phenylephrine-induced vasoconstriction (Endo-(+) Cmax = 234.5 ± 3.9%, Endo-(-) Cmax = 247.6 ± 5.2%) compared with untreated nicotine group (Endo-(+) Cmax = 264.5 ± 6.9%, Endo-(-) Cmax = 276.5 ± 6.8%). Roselle also improved aortic response to endothelium-dependent vasodilator, acetylcholine (Endo-(+) Rmax = 73.2 ± 2.1%, Endo-(-) Rmax = 26.2 ± 0.8%) compared to nicotine group (Endo-(+) Rmax = 57.8 ± 1.7%, Endo-(-) Rmax = 20.9 ± 0.8%). In addition, roselle prevented an increase in intimal media thickness and elastic lamellae proliferation to preserve vascular architecture. Moreover, we also observed a significantly lowered degree of oxidative stress in parallel with increased antioxidant enzymes in aortic tissues of the roselle-treated group. This study demonstrated that roselle prevents VED and remodelling, and as such it has high nutraceutical value as supplement to prevent cardiovascular diseases.
    Matched MeSH terms: Antioxidants/analysis
  2. Fulltext A Comparative Characterization of Physicochemical and Antioxidants Properties of Processed Heterotrigona itama Honey from Different Origins and Classification by Chemometrics Analysis
    Shamsudin S, Selamat J, Sanny M, A R SB, Jambari NN, Khatib A
    Molecules, 2019 Oct 29;24(21).
    PMID: 31671885 DOI: 10.3390/molecules24213898
    Stingless bee honey produced by Heterotrigona itama from different botanical origins was characterised and discriminated. Three types of stingless bee honey collected from acacia, gelam, and starfruit nectars were analyzed and compared with Apis mellifera honey. The results showed that stingless bee honey samples from the three different botanical origins were significantly different in terms of their moisture content, pH, free acidity, total soluble solids, colour characteristics, sugar content, amino acid content and antioxidant properties. Stingless bee honey was significantly different from Apis mellifera honey in terms of physicochemical and antioxidant properties. The amino acid content was further used in the chemometrics analysis to evaluate the role of amino acid in discriminating honey according to botanical origin. Partial least squares-discriminant analysis (PLS-DA) revealed that the stingless bee honey was completely distinguishable from Apis mellifera honey. Notably, a clear distinction between the stingless bee honey types was also observed. The specific amino acids involved in the distinction of honey were cysteine for acacia and gelam, phenylalanine and 3-hydroxyproline for starfruit, and proline for Apis mellifera honey. The results showed that all honey samples were successfully classified based on amino acid content.
    Matched MeSH terms: Antioxidants/analysis*
  3. Fulltext Effect of the combination of gelam honey and ginger on oxidative stress and metabolic profile in streptozotocin-induced diabetic Sprague-Dawley rats
    Sani NF, Belani LK, Sin CP, Rahman SN, Das S, Chi TZ, et al.
    Biomed Res Int, 2014;2014:160695.
    PMID: 24822178 DOI: 10.1155/2014/160695
    Diabetic complications occur as a result of increased reactive oxygen species (ROS) due to long term hyperglycaemia. Honey and ginger have been shown to exhibit antioxidant activity which can scavenge ROS. The main aim of this study was to evaluate the antioxidant and antidiabetic effects of gelam honey, ginger, and their combination. Sprague-Dawley rats were divided into 2 major groups which consisted of diabetic and nondiabetic rats. Diabetes was induced with streptozotocin intramuscularly (55 mg/kg body weight). Each group was further divided into 4 smaller groups according to the supplements administered: distilled water, honey (2 g/kg body weight), ginger (60 mg/kg body weight), and honey + ginger. Body weight and glucose levels were recorded weekly, while blood from the orbital sinus was obtained after 3 weeks of supplementation for the estimation of metabolic profile: glucose, triglyceride (TG), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), reduced glutathione (GSH): oxidized glutathione (GSSG), and malondialdehyde (MDA). The combination of gelam honey and ginger did not show hypoglycaemic potential; however, the combination treatment reduced significantly (P < 0.05) SOD and CAT activities as well as MDA level, while GSH level and GSH/GSSG ratio were significantly elevated (P < 0.05) in STZ-induced diabetic rats compared to diabetic control rats.
    Matched MeSH terms: Antioxidants/analysis
  4. Fulltext Oil palm vegetation liquor: a new source of phenolic bioactives
    Sambanthamurthi R, Tan Y, Sundram K, Abeywardena M, Sambandan TG, Rha C, et al.
    Br J Nutr, 2011 Dec;106(11):1655-63.
    PMID: 21736792 DOI: 10.1017/S0007114511002121
    Waste from agricultural products represents a disposal liability, which needs to be addressed. Palm oil is the most widely traded edible oil globally, and its production generates 85 million tons of aqueous by-products annually. This aqueous stream is rich in phenolic antioxidants, which were investigated for their composition and potential in vitro biological activity. We have identified three isomers of caffeoylshikimic acid as major components of oil palm phenolics (OPP). The 2,2-diphenyl-1-picrylhydrazyl assay confirmed potent free radical scavenging activity. To test for possible cardioprotective effects of OPP, we carried out in vitro LDL oxidation studies as well as ex vivo aortic ring and mesenteric vascular bed relaxation measurements. We found that OPP inhibited the Cu-mediated oxidation of human LDL. OPP also promoted vascular relaxation in both isolated aortic rings and perfused mesenteric vascular beds pre-contracted with noradrenaline. To rule out developmental toxicity, we performed teratological studies on rats up to the third generation and did not find any congenital anomalies. Thus, these initial studies suggest that OPP is safe and may have a protective role against free radical damage, LDL oxidation and its attendant negative effects, as well as vascular constriction in mitigating atherosclerosis. Oil palm vegetation liquor thus represents a new source of phenolic bioactives.
    Matched MeSH terms: Antioxidants/analysis
  5. Fulltext Chemical compositions, antioxidant and antimicrobial activities of essential oils of Piper caninum Blume
    Salleh WM, Ahmad F, Yen KH, Sirat HM
    Int J Mol Sci, 2011;12(11):7720-31.
    PMID: 22174627 DOI: 10.3390/ijms12117720
    Chemical composition, antioxidant and antimicrobial activities of the fresh leaves and stems oils of Piper caninum were investigated. A total of forty eight constituents were identified in the leaves (77.9%) and stems (87.0%) oil which were characterized by high proportions of phenylpropanoid, safrole with 17.1% for leaves and 25.5% for stems oil. Antioxidant activities were evaluated by using β-carotene/linoleic acid bleaching, DPPH radical scavenging and total phenolic content. Stems oil showed the highest inhibitory activity towards lipid peroxidation (114.9 ± 0.9%), compared to BHT (95.5 ± 0.5%), while leaves oil showed significant total phenolic content (27.4 ± 0.5 mg GA/g) equivalent to gallic acid. However, the essential oils showed weak activity towards DPPH free-radical scavenging. Evaluation of antimicrobial activity revealed that both oils exhibited strong activity against all bacteria strains with MIC values in the range 62.5 to 250 μg/mL, but weak activity against fungal strains. These findings suggest that the essential oils can be used as antioxidant and antimicrobial agents for therapeutic, nutraceutical industries and food manufactures.
    Matched MeSH terms: Antioxidants/analysis*
  6. Effects of preharvest applications of methyl jasmonate and chitosan on postharvest decay, quality and chemical attributes of Fragaria chiloensis fruit
    Saavedra GM, Figueroa NE, Poblete LA, Cherian S, Figueroa CR
    Food Chem, 2016 Jan 1;190:448-53.
    PMID: 26212995 DOI: 10.1016/j.foodchem.2015.05.107
    Fragaria chiloensis fruit has a short postharvest life mainly due to its rapid softening. In order to improve its postharvest life, preharvest applications of methyl jasmonate (MeJA) and chitosan were evaluated during postharvest storage at room temperature. The quality and chemical parameters, and protection against decay were evaluated at 0, 24, 48 and 72 h of storage from fruits of two subsequent picks (termed as first harvest and second harvest). In general, fruits treated with MeJA and chitosan maintained higher levels of fruit firmness, anthocyanin, and showed significant delays in decay incidence compared to control fruit. MeJA-treated fruits exhibited a greater lignin content and SSC/TA ratio, and delayed decay incidences. Instead, chitosan-treated fruits presented higher antioxidant capacity and total phenol content. In short, both the elicitors were able to increase the shelf life of fruits as evidenced by the increased levels of lignin and anthocyanin, especially of the second harvest.
    Matched MeSH terms: Antioxidants/analysis
  7. Fulltext Polyphenol Rich Ajuga bracteosa Transgenic Regenerants Display Better Pharmacological Potential
    Rubnawaz S, Kayani WK, Akhtar N, Mahmood R, Khan A, Okla MK, et al.
    Molecules, 2021 Aug 11;26(16).
    PMID: 34443462 DOI: 10.3390/molecules26164874
    Ajuga bracteosa Wall. ex Benth. is an endangered medicinal herb traditionally used against different ailments. The present study aimed to create new insight into the fundamental mechanisms of genetic transformation and the biological activities of this plant. We transformed the A. bracteosa plant with rol genes of Agrobacterium rhizogenes and raised the regenerants from the hairy roots. These transgenic regenerants were screened for in vitro antioxidant activities, a range of in vivo assays, elemental analysis, polyphenol content, and different phytochemicals found through HPLC. Among 18 polyphenolic standards, kaempferol was most abundant in all transgenic lines. Furthermore, transgenic line 3 (ABRL3) showed maximum phenolics and flavonoids content among all tested plant extracts. ABRL3 also demonstrated the highest total antioxidant capacity (8.16 ± 1 μg AAE/mg), total reducing power, (6.60 ± 1.17 μg AAE/mg), DPPH activity (IC50 = 59.5 ± 0.8 μg/mL), hydroxyl ion scavenging (IC50 = 122.5 ± 0.90 μg/mL), and iron-chelating power (IC50 = 154.8 ± 2 μg/mL). Moreover, transformed plant extracts produced significant analgesic, anti-inflammatory, anticoagulant, and antidepressant activities in BALB/c mice models. In conclusion, transgenic regenerants of A. bracteosa pose better antioxidant and pharmacological properties under the effect of rol genes as compared to wild-type plants.
    Matched MeSH terms: Antioxidants/analysis
  8. Fulltext Phenolic content, antioxidant effect and cytotoxic activity of Leea indica leaves
    Reddy NS, Navanesan S, Sinniah SK, Wahab NA, Sim KS
    BMC Complement Altern Med, 2012;12:128.
    PMID: 22898370 DOI: 10.1186/1472-6882-12-128
    The leaves of Leea indica (Vitaceae), commonly known as 'Huo Tong Shu' in Malaysia, have been traditionally used as natural remedy in folk medicine by the locals. The current study reports the outcome of antioxidant and cytotoxic investigation of L. indica leaves. To the best of our knowledge, this is the first report of L. indica leaf crude ethanol and its fractionated extracts (hexane, ethyl acetate and water) for evaluation of total phenolic content, antioxidant effect and cytotoxic activity against colon cancer cell lines.
    Matched MeSH terms: Antioxidants/analysis
  9. Vitamin E and its effect on arterial stiffness in postmenopausal women--a randomized controlled trial
    Rasool AH, Rehman A, Wan Yusuf WN, Rahman AR
    Int J Clin Pharmacol Ther, 2003 Dec;41(12):587-92.
    PMID: 14692708
    INTRODUCTION: Arterial stiffness is emerging as a useful index of vascular health. Postmenopausal women have been shown to have stiffer arteries. Hormone replacement therapy and soy isoflavones improve arterial stiffness in these women. The aim of this study is to establish whether vitamin E improves arterial stiffness in postmenopausal women after 10 weeks of supplementation.

    METHODS: Twenty postmenopausal women with a mean age of 54.59 +/- 1.22 years participated in this randomized, crossover, double-blind, placebo-controlled clinical trial. All women received 400 IU of tocopherol daily for 10 weeks or a placebo capsule, before being crossed over for treatment. At intervals of 5 weeks, subjects attended sessions where measurements of arterial stiffness, blood pressure and plasma vitamin E level were taken. Pulse wave velocity measurement, using the automated Complior machine, was used as an index of arterial stiffness.

    RESULTS: Plasma vitamin E level was 30.38 +/- 1.56 micromol/l at baseline, after treatment it was 59.01 +/- 3.30 micromol/l and 31.17 +/- 1.37 micromol/l with vitamin E and placebo, respectively (p < 0.001). There was no significant difference in pulse wave velocity after 10-week treatment with placebo and vitamin E (9.14 +/- 0.29 versus 9.04 +/- 0.29 m/s, respectively). Similarly, no difference in systolic and diastolic blood pressure was seen between placebo and vitamin E at the end of 10 weeks.

    CONCLUSION: Supplementary vitamin E for 10 weeks at 400 IU daily has no effect on arterial stiffness in healthy postmenopausal women.

    Matched MeSH terms: Antioxidants/analysis
  10. Fulltext Antioxidant, total phenolic content and cytotoxicity evaluation of selected Malaysian plants
    Qader SW, Abdulla MA, Chua LS, Najim N, Zain MM, Hamdan S
    Molecules, 2011 Apr 21;16(4):3433-43.
    PMID: 21512451 DOI: 10.3390/molecules16043433
    Aqueous and ethanol extracts of different traditional Malaysian plants (Polygonum minus, Andrographis paniculata, Curcuma xanthorrhiza, Momordica charantia and Strobilanthes crispus) were evaluated for their antioxidant properties, total phenolic content and cytotoxic activity. Antioxidant activity was evaluated by using 1,1-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) assays. The results showed that ethanol extracts contain high antioxidant activities compared to aqueous extracts. The findings exhibited a strong correlation between antioxidant activity and the total phenol contents. In addition, all the plant extracts showed non-toxic effects against a normal human lung fibroblast cell line (Hs888Lu). Although traditionally aqueous extracts are used, we determined that ethanol extracts usually achieved better activity in the assays.
    Matched MeSH terms: Antioxidants/analysis
  11. Fulltext What are the antioxidant status predictors' factors among male chronic obstructive pulmonary disease (COPD) patients?
    Pirabbasi E, Najafiyan M, Cheraghi M, Shahar S, Abdul Manaf Z, Rajab N, et al.
    Glob J Health Sci, 2013 Jan;5(1):70-8.
    PMID: 23283038 DOI: 10.5539/gjhs.v5n1p70
    Imbalance between antioxidant and oxidative stress is a major risk factor for pathogenesis of some chronic diseases such as chronic obstructive pulmonary disease (COPD). This study aimed to determine antioxidant and oxidative stress status, and also theirs association with respiratory function of male COPD patients to find the antioxidant predictors' factors. A total of 149 subjects were involved in a cross-sectional study. The study was conducted at two medical centers in Kuala Lumpur, Malaysia. Results of the study showed that plasma vitamin C was low in most of the subjects (86.6%). Total antioxidant capacity was the lowest in COPD stage IV compare to other stages (p < 0.05). Level of plasma vitamin A (p= 0.012) and vitamin C (p= 0.007) were low in malnourished subjects. The predictors for total antioxidant capacity were forced vital capacity (FVC) % predicted and intake of ?-carotene (R2= 0.104, p= 0.002). Number of cigarette (pack/ year) and smoking index (number/ year) were not associated with total antioxidant capacity of this COPD population. Plasma oxidative stress as assessed plasma lipid peroxidation (LPO) was only positively correlated with plasma glutathione (p= 0.002). It might be a need to evaluate antioxidant status especially in older COPD patients to treat antioxidant deficiency which is leading to prevent COPD progression.
    Study site: Outpatient clinics, Pusat Perubatan Universiti Kebangsaan Malaysia (PPUKM) and Institute of Respiratory Medicine, Kuala Lumpur, Malaysia
    Matched MeSH terms: Antioxidants/analysis*
  12. Fulltext Efficacy of Ascorbic Acid (Vitamin C) and/N-Acetylcysteine (NAC) Supplementation on Nutritional and Antioxidant Status of Male Chronic Obstructive Pulmonary Disease (COPD) Patients
    Pirabbasi E, Shahar S, Manaf ZA, Rajab NF, Manap RA
    J Nutr Sci Vitaminol (Tokyo), 2016;62(1):54-61.
    PMID: 27117852 DOI: 10.3177/jnsv.62.54
    Antioxidant therapy has a potential to be introduced as therapeutic modality for chronic obstructive pulmonary disease (COPD) patients. This study aimed to determine the effect of antioxidant supplementation [ascorbic acid and N-Acetylcysteine (NAC)] on nutritional and antioxidant status in male COPD patients. A parallel and single blind randomised controlled clinical trial (RCT) was conducted at two medical centers in Kuala Lumpur, Malaysia. Seventy-nine subjects were recruited and randomly divided into four trial arms (i.e., NAC, vitamin C, NAC+vitamin C and control groups) for six mo. The primary outcome was changes in body mass index by estimating power of 90% and significance level of p<0.05. Repeated Measure ANOVA showed that there was a significant interaction effect on BMI (p=0.046) and carbohydrate intake (p=0.030), especially in the NAC group. Plasma glutathione (GSH) increased significantly in all intervention groups, especially in vitamin C (p=0.005). A single supplementation of NAC or vitamin C improved nutritional and antioxidant status of subjects.
    Matched MeSH terms: Antioxidants/analysis*
  13. Chemical composition, antioxidant and cytotoxicity activities of the essential oils of Myristica fragrans and Morinda citrifolia
    Piaru SP, Mahmud R, Abdul Majid AM, Ismail S, Man CN
    J Sci Food Agric, 2012 Feb;92(3):593-7.
    PMID: 25520982
    In this study the chemical composition, antioxidant activities and cytotoxic effect of the essential oils of Myristica fragrans (nutmeg) and Morinda citrifolia (mengkudu) were determined.
    Matched MeSH terms: Antioxidants/analysis
  14. Fulltext Intrastrain comparison of the chemical composition and antioxidant activity of an edible mushroom, Pleurotus giganteus, and its potent neuritogenic properties
    Phan CW, David P, Tan YS, Naidu M, Wong KH, Kuppusamy UR, et al.
    ScientificWorldJournal, 2014;2014:378651.
    PMID: 25121118 DOI: 10.1155/2014/378651
    Two strains of Pleurotus giganteus (commercial and wild) were tested for their ability to induce neurite outgrowth in rat pheochromocytoma (PC12) and mouse neuroblastoma-2a (N2a) cells. Treatment with the mushroom extracts resulted in neuronal differentiation and neuronal elongation, but not nerve growth factor (NGF) production. Linoleic acid (4.5-5.0%, w/w) which is a major fatty acid present in the ethanol extract promoted NGF biosynthesis when augmented with low concentration of NGF (5 ng/mL). The two strains of mushroom were found to be high in protein (154-192 g kg(-1)), total polysaccharides, phenolics, and flavonoids as well as vitamins B1, B2, and B3. The total phenolics present in the mushroom extracts were positively correlated to the antioxidant activity (free radical scavenging, ferric reducing power, and lipid peroxidation inhibition). To conclude, P. giganteus could potentially be used in well-balanced diet and as a source of dietary antioxidant to promote neuronal health.
    Matched MeSH terms: Antioxidants/analysis*
  15. Fulltext Antioxidant activity and phenolic content of Paederia foetida and Syzygium aqueum
    Osman H, Rahim AA, Isa NM, Bakhir NM
    Molecules, 2009;14(3):970-8.
    PMID: 19305354 DOI: 10.3390/molecules14030970
    The antioxidant activity of fresh and dried plant extracts of Paederia foetida and Syzygium aqueum were studied using beta-carotene bleaching and the 2,2'-azinobis(3-ethyl-benzothiazoline-6-sulfonic acid) (ABTS) radical cation assay. The percentage of antioxidant activity for all extract samples using both assays was between 58 and 80%. The fresh samples of both plants had higher antioxidant activity than the dried samples. The results of the beta-carotene bleaching assay were correlated (R(2) = 0.9849) with those of the ABTS assay.
    Matched MeSH terms: Antioxidants/analysis*
  16. Fulltext Bioactive compounds, antioxidant, xanthine oxidase inhibitory, tyrosinase inhibitory and anti-inflammatory activities of selected agro-industrial by-products
    Oskoueian E, Abdullah N, Hendra R, Karimi E
    Int J Mol Sci, 2011;12(12):8610-25.
    PMID: 22272095 DOI: 10.3390/ijms12128610
    Evaluation of abundantly available agro-industrial by-products for their bioactive compounds and biological activities is beneficial in particular for the food and pharmaceutical industries. In this study, rapeseed meal, cottonseed meal and soybean meal were investigated for the presence of bioactive compounds and antioxidant, anti-inflammatory, xanthine oxidase and tyrosinase inhibitory activities. Methanolic extracts of rapeseed meal showed significantly (P < 0.01) higher phenolics and flavonoids contents; and significantly (P < 0.01) higher DPPH and nitric oxide free radical scavenging activities when compared to that of cottonseed meal and soybean meal extracts. Ferric thiocyanate and thiobarbituric acid tests results showed rapeseed meal with the highest antioxidant activity (P < 0.01) followed by BHT, cotton seed meal and soybean meal. Rapeseed meal extract in xanthine oxidase and tyrosinase inhibitory assays showed the lowest IC(50) values followed by cottonseed and soybean meals. Anti-inflammatory assay using IFN-γ/LPS stimulated RAW 264.7 cells indicated rapeseed meal is a potent source of anti-inflammatory agent. Correlation analysis showed that phenolics and flavonoids were highly correlated to both antioxidant and anti-inflammatory activities. Rapeseed meal was found to be promising as a natural source of bioactive compounds with high antioxidant, anti-inflammatory, xanthine oxidase and tyrosinase inhibitory activities in contrast to cotton and soybean meals.
    Matched MeSH terms: Antioxidants/analysis*
  17. Identification of proanthocyanidin dimers and trimers, flavone C-Glycosides, and antioxidants in Ficus deltoidea , a malaysian herbal tea
    Omar MH, Mullen W, Crozier A
    J Agric Food Chem, 2011 Feb 23;59(4):1363-9.
    PMID: 21261251 DOI: 10.1021/jf1032729
    Phenolic compounds in an aqueous infusion of leaves of Ficus deltoidea (Moraceae), a well-known herbal tea in Malaysia, were analyzed by HPLC coupled to photodiode array and fluorescence detectors and an electrospray ionization tandem mass spectrometer. Following chromatography of extracts on a reversed phase C(12) column, 25 flavonoids were characterized and/or tentatively identified with the main constituents being flavan-3-ol monomers, proanthocyanidins, and C-linked flavone glycosides. The proanthocyanidins were dimers and trimers comprising (epi)catechin and (epi)afzelechin units. No higher molecular weight proanthocyanidin polymers were detected. The antioxidant activity of F. deltoidea extract was analyzed using HPLC with online antioxidant detection. This revealed that 85% of the total antioxidant activity of the aqueous F. deltoidea infusion was attributable to the flavan-3-ol monomers and the proanthocyanidins.
    Matched MeSH terms: Antioxidants/analysis*
  18. Approach to preserve phenolics in Thunbergia laurifolia leaves by different drying treatments
    Oh HKF, Siow LF, Lim YY
    J Food Biochem, 2019 07;43(7):e12856.
    PMID: 31353691 DOI: 10.1111/jfbc.12856
    Different drying methods and blanching were investigated as to their effects on antioxidant and oxidase activities of Thunbergia laurifolia leaves. Results showed that oven-drying had the highest degradation of total phenolic content (TPC) and antioxidant activity at >85%, while freeze-drying had the lowest at <20%. However, inactivation of oxidase enzymes by blanching at 100°C resulted in a lesser decrease in TPC for oven-drying at 50 and 100°C (51% and 65%, respectively), indicating the importance of inactivating the oxidase enzymes for lower degradation of phenolics on drying. The high-performance liquid chromatography analysis showed that its major antioxidant, rosmarinic acid, degraded tremendously in the presence of oxidase enzymes, but only degraded slightly upon inactivation of oxidase enzymes. Hence, this work showed that by controlling the enzymatic activity, the preservation of phenolics with specific bioactivity in herbal tea leaves can be achieved. PRACTICAL APPLICATIONS: Thunbergia laurifolia leaves have been frequently consumed in the form of a tea or pill due to its medicinal properties. Processing of fresh herbal plant leaves by drying is required to preserve antioxidant phenolic compounds and quality of the plant leaves. Although the drying effects on the antioxidant properties have been studied, the factors that cause the change in properties have not been investigated in-depth. Controlling the factors that affect the phenolic content can help to preserve the beneficial antioxidants when processing the leaves by drying. The result of this study will be of relevance and beneficial to the herbal tea industry.
    Matched MeSH terms: Antioxidants/analysis*
  19. Fulltext In vitro antioxidant activities of extract and oil from roselle (Hibiscus sabdariffa L.) seed against sunflower oil autoxidation
    Nyam KL, Teh YN, Tan CP, Kamariah L
    Malays J Nutr, 2012 Aug;18(2):265-74.
    PMID: 24575672 MyJurnal
    In order to overcome the stability problems of oils and fats, synthetic antioxidants such as butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT) and tert-butyl hydroquinone (TBHQ) have widespread use as food additives in many countries. Recent reports reveal that these compounds may be implicated in many health risks, including cancer and carcinogenesis. Hence, there is a move towards the use of natural antioxidants of plant origin to replace these synthetic antioxidants.
    Matched MeSH terms: Antioxidants/analysis*
  20. Fulltext Nutritional content and in vitro antioxidant potential of Garcinia atroviridis (Asam gelugor) leaves and fruits
    Nursakinah I, Zulkhairi HA, Norhafizah M, Hasnah B, Zamree MS, Farrah SI, et al.
    Malays J Nutr, 2012 Dec;18(3):363-71.
    PMID: 24568077 MyJurnal
    The objective of this study was to determine antioxidant potential of Garcinia atroviridis leaves and fruits extracts in vitro.
    Matched MeSH terms: Antioxidants/analysis*
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