Antioxidant Pathways and Chemical Mechanism of Curcumin

2011 ◽  
Vol 236-238 ◽  
pp. 2311-2314 ◽  
Author(s):  
Yuan Liang Guo ◽  
Xiang Zhou Li ◽  
Chun Tao Kuang

Curcumin, a hydrophobic polyphenol derived from rhizome (turmeric) of the herbCurcuma longa, have been shown to exhibit antioxidant, anticarcinogenic anti-inflammatory, antimicrobial and nephroprotective activities,et al. Among these, its potent antioxidant activity is worthwhile of special attention, because oxidative stress is involved in the pathogenesis of cancer, neurodegenerative diseases,et al. This review focuses on the ways that curcumin exerts its antioxidant activity, including direct chemical reaction with free radicals, chelation with metals ions which results in oxidative stress, regulation of antioxidant-related enzyme activity and gene expression. Meanwhile the disputed chemical antioxidant mechanism is also discussed.

2020 ◽  
Vol 5 (2) ◽  
pp. 250-257
Author(s):  
Nurul Fatimah ◽  
◽  
Reksi Sundu

Free radicals and reactive species are widely believed to contribute to the development of several diseases by causing oxidative stress and eventually oxidative. Vernonia amygdalina (Astereacea) is a small shrub or tree between 1 and 5m high growing throughout tropical Africa. Plants are generally known as bitter leaves is well cultivated and is a general market for merchandise in several countries. The purpose of this study was to determine the antioxidant activity of hexane fraction from ethanol extract od Frican leaves (Vernonia amygdalina Del.). The method used in this study was the DPPH (1,1-Diphenil-2-Picrylhydrazyl) method. The result of phytochemical screening showed that ethanolic extract of African leaves contained a composition of secondary metabolites of alkaloids, flavonoids, tannins, steroids/triterpenoids and saponins. The antioxidant activity of the extract of n-hexane fraction was classified as very weak with an IC50 value of 317.98 ppm.


2017 ◽  
Vol 2017 ◽  
pp. 1-15 ◽  
Author(s):  
Krzysztof Michalak ◽  
Aleksandra Sobolewska-Włodarczyk ◽  
Marcin Włodarczyk ◽  
Justyna Sobolewska ◽  
Piotr Woźniak ◽  
...  

Long-term fluoroquinolone-associated disability (FQAD) after fluoroquinolone (FQ) antibiotic therapy appears in recent years as a significant medical and social problem, because patients suffer for many years after prescribed antimicrobial FQ treatment from tiredness, concentration problems, neuropathies, tendinopathies, and other symptoms. The knowledge about the molecular activity of FQs in the cells remains unclear in many details. The effective treatment of this chronic state remains difficult and not effective. The current paper reviews the pathobiochemical properties of FQs, hints the directions for further research, and reviews the research concerning the proposed treatment of patients. Based on the analysis of literature, the main directions of possible effective treatment of FQAD are proposed: (a) reduction of the oxidative stress, (b) restoring reduced mitochondrion potential ΔΨm, (c) supplementation of uni- and bivalent cations that are chelated by FQs and probably ineffectively transported to the cell (caution must be paid to Fe and Cu because they may generate Fenton reaction), (d) stimulating the mitochondrial proliferation, (e) removing FQs permanently accumulated in the cells (if this phenomenon takes place), and (f) regulating the disturbed gene expression and enzyme activity.


Author(s):  
Shahida Perveen ◽  
Syed Muhammad Saad ◽  
Khalid Mohammed Khan ◽  
Muhammad Iqbal Choudhary

Background: Antioxidants are small molecules that prevent or delay the process of oxidations caused by highly reactive free radicals. These molecules are known for their ability to protect various cellular architecture and other biomolecules from oxidative stress and free radicals. Thus, antioxidants play a key role in the prevention of oxidative damages caused by highly reactive free radicals. Method: In the present study, a series of previously synthesized heterocyclic 2-aryl-4(3H)-quinazolinone derivatives 1-25 was screened for antioxidant activity by employing in vitro DPPH and superoxide anion radical scavenging activities. ROS inhibitory activities were also evaluated by serum-opsonized zymosan activated whole blood phagocytes and isolated neutrophils. Cytotoxicity studies were carried out by employing an MTT assay against the 3T3 cell line. Results: Most of the 2-aryl-4(3H)-quinazolinone derivatives showed potent antioxidant activities in superoxide anion radical scavenging assay with IC50 value ranging between 0.57 µM – 48.93 µM, as compared to positive control quercetin dihydrate (IC50 = 94.1± 1.1 µM ). Compounds 5, 6, and 14 showed excellent activity in DPPH assay. Compounds 5-8, 12-15, 17, and 20 showed promising activities in the ROS inhibition assay. All compounds were found to be non-cytotoxic against the 3T3 cell line. Structure antioxidant activity has been established. Conclusion: It can be concluded that most of the heterocyclic 2-aryl-4(3H)-quinazolinone derivatives 1-25 are identified as promising antioxidant agents that are capable of fighting against free radicals and oxidative stress. Thus, they can serve as a lead towards treating oxidative stress and related pathologies.


2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Dejene Disasa ◽  
Lihong Cheng ◽  
Majid Manzoor ◽  
Qian Liu ◽  
Ying Wang ◽  
...  

In the present study, the replicative lifespan assay of yeast was used to guide the isolation of antiaging substance from Gentiana rigescens Franch, a traditional Chinese medicine. A compound with antiaging effect was isolated, and the chemical structure of this molecule as amarogentin was identified by spectral analysis and compared with the reported data. It significantly extended the replicative lifespan of K6001 yeast at doses of 1, 3, and 10 μM. Furthermore, amarogentin improved the survival rate of yeast under oxidative stress by increasing the activities of catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx), and these enzymes’ gene expression. In addition, this compound did not extend the replicative lifespan of sod1, sod2, uth1, and skn7 mutants with K6001 background. These results suggested that amarogentin exhibited antiaging effect on yeast via increase of SOD2, CAT, GPx gene expression, enzyme activity, and antioxidative stress. Moreover, we evaluated antioxidant activity of this natural products using PC12 cell system, a useful model for studying the nervous system at the cellular level. Amarogentin significantly improved the survival rate of PC12 cells under H2O2-induced oxidative stress and increased the activities of SOD and SOD2, and gene expression of SOD2, CAT, GPx, Nrf2, and Bcl-x1. Meanwhile, the levels of reactive oxygen species (ROS) and malondialdehyde (MDA) of PC12 cells were significantly reduced after treatment of the amarogentin. These results indicated that antioxidative stress play an important role for antiaging and neuroprotection of amarogentin. Interestingly, amarogentin exhibited neuritogenic activity in PC12 cells. Therefore, the natural products, amarogentin from G. rigescens with antioxidant activity could be a good candidate molecule to develop drug for treating neurodegenerative diseases.


Author(s):  
Pradeesh S ◽  
Swapna T S

Objective: The main aim of this study was to evaluate the antioxidants present in Sesbania grandiflora (L.) Pers. belongs to the family Fabaceae.Methods: Fresh samples were used for the analysis of antioxidants such as total phenol, carotenoids, Vitamin-A, Vitamin-C, Vitamin-E, peroxidase (POD), catalase (CAT), superoxide dismutase (SOD), ascorbate peroxidase, monodehydroascorbate reductase, and glutathione reductase by standard estimation methods.Results: Present studies revealed that this wild leafy plant has numerous antioxidant factors that destroying the free radicals that damage the cells.Conclusion: S. grandiflora contain many enzymatic and non-enzymatic antioxidants and could be a good source of dietary antioxidants which play an important role in the prevention of diseases associated with oxidative stress.


InterConf ◽  
2021 ◽  
pp. 264-280
Author(s):  
Ala Fulga ◽  
Valeriana Pantea ◽  
Lilia Andronache ◽  
Olga Tagadiuc ◽  
Mihail Todiras ◽  
...  

Background. The oxygen is the ultimate electron acceptor in the electron flow system that produces energy. Problems appears when the electron flow becomes uncoupled thus, generating free radicals. While the majority of processes require oxygen, the last is a highly reactive molecule that can damage cells by producing reactive oxygen species, such as hydroxyl radical, superoxide radical, hydrogen peroxide and hypochlorous acid, all together defined as triggers of oxidative stress. The last is involved in many types of pathologies, such as cancer, atherosclerosis and rheumatic arthritis. Antioxidants can stop formation of free radical by giving hydrogen atoms or scavenging them. The antioxidant can be defined any molecule capable of preventing or blocking oxidation of lipids, proteins and nucleic acids. The reduced glutathione (GSH), as well enzymes, glutathione peroxidase (GPO), glutathione reductase (GR) and glutathione S-transferase (GST) represent antioxidants which prevent the formation of new free radicals, converting them into less harmful molecules. The present study was conducted to assess the antioxidant activity of Taraxacum officinale (TO) ethanolic extracts with different bioactive contents. This experiment was conducted with extracts prepared from dandelion (Taraxacum officinale F. H. Wigg) leaves. A series (10%, 20%, 25%, 40%, 50% and 80%) of ethanolic extracts were made. The influence of TO extracts on RBC’s GPO, GR, GST, glutathione (GSSG, GSH and total-GSH) and thiols (native and total) was evaluated by measuring absorbance spectrophotometrically. Conclusions. Taraxacum officinale ethanolic extracts exhibit a strong antioxidant activity. This plant is capable of preventing damage of cells during oxidative stress process, by using different targets of glutathione system. But, this activity depends of ethanol concentrations, maybe due to different bioactive content.


2020 ◽  
Vol 27 (7) ◽  
pp. 614-622
Author(s):  
Ahmet Savcı ◽  
Enver Fehim Koçpınar ◽  
Harun Budak ◽  
Mehmet Çiftci ◽  
Melda Şişecioğlu

Background: Free radicals lead to destruction in various organs of the organism. The improper use of antibiotics increases the formation of free radicals and causes oxidative stress. Objective: In this study, it was aimed to determine the effects of gentamicin, amoxicillin, and cefazolin antibiotics on the mouse heart. Methods: 20 male mice were divided into 4 groups (1st control, 2nd amoxicillin, 3rd cefazolin, and 4th gentamicin groups). The mice in the experimental groups were administered antibiotics intraperitoneally at a dose of 100 mg / kg for 6 days. The control group received normal saline in the same way. The gene expression levels and enzyme activities of SOD, CAT, GPx, GR, GST, and G6PD antioxidant enzymes were investigated. Results : GSH levels decreased in both the amoxicillin and cefazolin groups, while GR, CAT, and SOD enzyme activities increased. In the amoxicillin group, Gr, Gst, Cat, and Sod gene expression levels increased. Conclusion: As a result, it was concluded that amoxicillin and cefazolin caused oxidative stress in the heart, however, gentamicin did not cause any effects.


2020 ◽  
Vol 10 (1) ◽  
pp. 90
Author(s):  
Nur Ariska Nugrahani

Radikal bebas yang berbahaya jika konsentrasi ROS akan meningkat sehingga akan mengakibatkan stress oksidatif. Stress oksidatif biasanya disebabkan oleh konsentrasi tinggi dari radikal bebas dalam sel dan jaringan yang dapat diinduksi oleh beberapa faktor negatif seperti gamma, UV, radiasi sinar-X, tekanan psiko-emosional dan makanan yang tercemar.Untuk meminimalisir radikal bebas dalam tubuh diperlukan antioksidan alami seperti ekstrak buah kiwi dan ekstrak buah apel. Uji aktivitas antioksidan pada masing- masing ekstrak dilakukan dengan metode DPPH (1,1- difenil-2-pikrihidazil). Hasil menunjukkan bahwa nilai IC50 dari ekstrak buah kiwi lebih rendah daripada IC50 ekstrak buah apel. Hal ini menunjukkan bahwa ekstrak buah kiwi mempunyai aktivitas antioksidan lebih kuat dari ekstrak buah apel. Keyword : Radikal bebas, DPPH, Ekstrak buah kiwi, Ekstrak buah apel Free radicals will be dangerous if the ROS concentration will increase and causes oxidative stress. Oxidative stress is usually caused by high concentrations of free radicals in cells and tissues which can be induced by several negative factors such as gamma, UV, X-ray radiation, psycho-emotional pressure and contaminated food. To minimize free radicals in the body natural antioxidants such as kiwi fruit extract and apple extract. The antioxidant activity test on each extract was carried out by the DPPH method (1,1-diphenyl-2-picrihydazyl). The results showed that IC50 value of kiwi fruit extract was lower than IC50 of apple fruit extract. This shows that kiwi fruit extract has stronger antioxidant activity than apple extract. Keyword : free radicals, DPPH, kiwi fruit extract, apple fruit extract


2016 ◽  
Vol 9 (2) ◽  
pp. 130-135 ◽  
Author(s):  
Silvia Mošovská ◽  
Patrícia Petáková ◽  
Michal Kaliňák ◽  
Anna Mikulajová

Abstract The evaluation of antioxidant potential of food has received much attention in recent years. Antioxidant compounds can scavenge free radicals and thereby can protect the human body from free radicals. This study was focused on the isolation of curcuminoids from the dried turmeric rhizome, and studying their antioxidant activity. The presence of curcuminoids was identified in turmeric sample by Nuclear Magnetic Resonance (NMR) analysis. Since neutral curcumin is known to be poorly soluble, the synthesis of curcumin-cyclodextrin and curcumin-phospholipid complexes was also performed. The antioxidant activity of isolated curcuminoids was assessed by two methods (ABTS and FRAP assay) and their scavenging activities were compared with those of prepared complexes. The ability to reduce ABTS radical cation decreased as follows: quercetin > trolox > curcuminoids > curcumin-cyclodextrin complex > curcumin-phospholipid complex. The reducing potential of tested samples in descending order was quercetin > trolox > curcumin-cyclodextrin complex > curcuminoids > curcumin-phospholipid complex.


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