Review: Antioxidant therapeutic advances in COPD

Rahman, Irfan

doi:10.1177/1753465808098224

Cited by 118 publications

(76 citation statements)

References 192 publications

(251 reference statements)

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“…Curcumin has been reported to exert antioxidant, anti-inflammatory, anticancer and hepatoprotective effects (18). Furthermore, curcumin functions as an exogenous Nrf2 agonist, and can promote the nuclear translocation and biological effects of Nrf2 (19). Therefore, the present study used curcumin to upregulate Nrf2, and subsequently investigated the effects of Nrf2 on HSCs.…”

Section: Introductionmentioning

confidence: 99%

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Curcumin upregulates Nrf2 nuclear translocation and protects rat hepatic stellate cells against oxidative stress

Liu

Dou

Zheng

et al. 2015

Molecular Medicine Reports

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Abstract. The present study aimed to investigate the protective role of curcumin against oxidative stress in rat hepatic stellate cells (HSCs)-T6, and to determine the possible underlying mechanisms. HSC-T6 cells were divided into three groups: Negative control group, oxidant-treated group and curcumin-treated group. Flow cytometry and spectrophotometry were used to measure the production of reactive oxygen species (ROS), and the levels of malondialdehyde (MDA) and glutathione (GSH). Immunocytochemistry and a radioimmunoassay were used to determine the expression of smooth muscle α-actin (α-SMA) and the secretion of extracellular matrix (ECM) molecules. In addition, western blotting and immunocytochemistry were used to determine the expression levels of nuclear factor-erythroid 2-related factor (Nrf2). Treatment with glucose oxidase (GO) significantly stimulated the formation of ROS and increased the production of MDA, as compared with the control cells; however, the production of GSH was only slightly increased. In addition, treatment with GO significantly promoted the expression of α-SMA and the secretion of ECM molecules. Conversely, treatment with curcumin significantly decreased the levels of ROS and MDA, and significantly increased the levels of GSH. Curcumin significantly inhibited the expression of α-SMA and decreased the secretion of ECM molecules. Furthermore, treatment with curcumin significantly increased the nuclear expression levels of Nrf2. These results indicated that curcumin may protect rat HSCs against oxidative stress and inhibit the GO-induced activation and secretion of ECM molecules in vitro. These effects were mediated by the upregulation of Nrf2 nuclear translocation. IntroductionPrevious studies have demonstrated that oxidative stress has a significant role in the occurrence and progression of hepatitis and hepatic fibrosis (1-4). Oxidative stress results from the excessive production of reactive oxygen species (ROS), and the inability of an organism to eliminate them. Excessive ROS lead to lipid peroxidation, protein and DNA damage, and injury to cellular structure and function (5). Numerous studies have reported the important role of ROS in various types of hepatic injury (6-10). In addition to ROS-induced inflammation, ROS may lead to loss of normal regulatory functions, resulting in tissue injury and excessive repair, and the development of hepatitis and hepatic fibrosis (11,12). It has previously been demonstrated that activation of hepatic stellate cells (HSCs) has a key role in the progression of hepatic fibrosis; therefore, HSCs are considered important target cells in hepatic fibrosis research (13). Furthermore, HSCs can be activated by oxidative stress and transformed into myofibroblasts. Myofibroblasts synthesize abundant extracellular matrix (ECM) molecules, which may lead to hepatic fibrosis (14); therefore, how to inhibit the activation of HSCs exposed to oxidative stress requires further investigation. Nuclear factor-erythroid 2-related factor (Nrf2) is a transcription fa...

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Section: Introductionmentioning

confidence: 99%

“…Notably, curcumin has been shown to function as an exogenous agonist of Nrf2 (19). A previous study suggested that curcumin may alter the conformation of Keap1, and promote the dissociation of Nrf2 from Keap1 and its subsequent nuclear translocation (36).…”

mentioning

confidence: 99%

Curcumin upregulates Nrf2 nuclear translocation and protects rat hepatic stellate cells against oxidative stress

Liu

Dou

Zheng

et al. 2015

Molecular Medicine Reports

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“…Among the properties behind these virtues, the antioxidant activity holds a place of first order [1][2] . Many of the medicinal plants contain a broad spectrum of phytochemical substances which are sources of natural antioxidants such as α-tochopherol, phenolic acids, flavonoids and tannins.…”

Section: Introductionmentioning

confidence: 99%

Study on the antioxidant activities of root extracts of Zizyphus lotus from the western region of Algeria

Ghalem¹,

Merghache²,

Belarbi³

2014

Phcog J.

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Objective: To find a new natural source of antioxidant, the phenolic contents and antioxidant activities of some secondary metabolites extracted from roots of Ziziphus lotus were evaluated. Methods: The total polyphenol contents were determined spectrophotometrically. Pyrrocatechol, catechin and cyanidin equivalents were used for these parameters. The antioxidant activities of the extracts were determined by several in vitro systems of assays, namely DPPH radical scavenging activity method, b-Carotene Bleaching assay (BCB), Ferric Reducing Antioxidant Power assay (FRAP) and Total Antioxidant capacity test (TAC). Results: The quantitative estimation showed that the roots of Z. lotus were rich in polyphenols (20.09 mg PE/g DW) and proanthocyannidins (1.56%) and they contained a small amount of flavonoids (0.02 mg CE/g DW). The most fractions exhibited high antioxidant activities, and some even showed higher potency than the standard synthetic antioxidants in some instances. In DPPH assay, all extracts had shown significant inhibition (58.535 -94.730% at 1 mg/mL). In addition, the IC 50 values ranged from 0.211 to 0.816 mg/mL, compared to 0.110, 0.214, 0.214 and 0.413 mg/mL for gallic acid, tannic acid, butylated-hydroxyanisol and ascorbic acid respectively. In (BCB) assay, the extracts showed strong inhibition (55.55 -100.00% at 1 mg/mL) and the IC 50 values ranging from 0.123 to 0.850 mg/mL compared to 0.433 mg/mL for gallic acid. A dose dependant curve was obtained for all extracts in the FRAP assay. However, the antioxidant potencies of ascorbic acid and extracts were comparable at low concentrations. The majority of extracts showed the highest value of antioxidant activity, based on TAC test (0.073 -0.398 mg ascorbic acid / mg extract). Conclusion: The results indicate that Z. lotus roots could be an important sources of natural antioxidants.

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“…В на-стоящее время известны миметики таких фермен-тов, как СОД, каталаза и глутатионпероксидаза. Большинство из них являются миметиками СОД [30].…”

Section: миметики ферментовunclassified

“…Первая группа миметиков СОД включает в себя ряд макроциклических соеди-нений на основе марганца: M40401, M40403 и M40419 [31,32,33]. Второй класс представляет со-бой марганец-соединения на основе металлопорфи-ринов: AEOL-10113 и AEOL-10150 [30,33]. Третий класс миметиков СОД -это, как правило, ароматиче-ские соединения с этилен-и диамин-замес тителями, образующие комплексы с марганцем.…”

Section: № 31'2014unclassified