scholarly journals Molecular design of curcumin analogues with potent antioxidant properties and thermodynamic evaluation of their mechanism of free radical scavenge

2020 ◽  
Vol 44 (1) ◽  
Author(s):  
Ikechukwu Ogadimma Alisi ◽  
Adamu Uzairu ◽  
Stephen Eyije Abechi
2019 ◽  
Vol 16 (4) ◽  
pp. 377-391 ◽  
Author(s):  
B.S. Jayashree ◽  
H. Venkatachalam ◽  
Sanchari Basu Mallik

Flavonoids constitute a large group of polyphenolic compounds that are known to have antioxidant properties, through their free radical scavenging abilities. They possess a chromone (γ- benzopyrone) moiety, responsible for eliciting many pharmacological activities. Even though, natural flavonoids are highly potent, owing to their poor solubility, they are less used. Therefore, attempts have been made to improve their stability, solubility, efficacy and kinetics by introducing various substituents on the flavone ring. For nearly the last two decades, flavones were synthesized in our laboratory by simple, convenient and cost-effective methods, with the knowledge of both synthetic and semi-synthetic chemistry. In this direction, it was considered worthwhile to present an overview on the synthesized flavonoids. This review creates a platform for highlighting various modifications done on the flavone system along with their biological activity.


2015 ◽  
Vol 98 (4) ◽  
pp. 866-870 ◽  
Author(s):  
Violetta Kozik ◽  
Krystyna Jarzembek ◽  
Agnieszka Jędrzejowska ◽  
Andrzej Bąk ◽  
Justyna Polak ◽  
...  

Abstract Pomegranate fruit (Punica granatum L.) is a source of numerous phenolic compounds, and it contains flavonoids such as anthocyanins, anthocyanidins, cyanidins, catechins and other complexes of flavonoids, ellagitannins, and hydrolyzed tannins. Pomegranate juice shows antioxidant, antiproliferative, and anti-atherosclerotic properties. The antioxidant capacity (TEAC) of the pomegranate juices was measured using electron paramagnetic resonance (EPR) spectroscopy and 1,1-diphenyl-2-picrylhydrazyl (DPPH•) as a source of free radicals, and the total phenolic (TP) content was measured using UV-Vis spectroscopy. All the examined pomegranate juices exhibited relatively high antioxidant properties. The TEAC values determined by means of EPR spectroscopy using Trolox (TE) as a free radical scavenger were in the range of 463.12 to 1911.91 μmol TE/100 mL juice. The TP content measured by the Folin-Ciocalteu method, using gallic acid (GA) as a free radical scavenger, widely varied in the investigated pomegranate juice samples and ranged from 1673.62 to 5263.87 mg GA/1 L juice. The strongest antioxidant properties were observed with the fresh pomegranate juices obtained from the fruits originating from Israel, Lebanon, and Azerbaijan. Correlation analysis of numerical data obtained by means of EPR spectroscopy (TEAC) and UV-Vis spectroscopy (TP) gave correlation coefficient (r) = 0.90 and determination coefficient (r2) = 0.81 (P <0.05).


2000 ◽  
Vol 151 (1) ◽  
pp. 309
Author(s):  
R.S. Faustino ◽  
S. Sobrattee ◽  
T.A. Clark ◽  
G.N. Pierce

2008 ◽  
Vol 56 (22) ◽  
pp. 10646-10650 ◽  
Author(s):  
Francesco Puoci ◽  
Francesca Iemma ◽  
Manuela Curcio ◽  
Ortensia I. Parisi ◽  
Giuseppe Cirillo ◽  
...  

2021 ◽  
Vol 22 (13) ◽  
pp. 6946
Author(s):  
Weishun Tian ◽  
Suyoung Heo ◽  
Dae-Woon Kim ◽  
In-Shik Kim ◽  
Dongchoon Ahn ◽  
...  

Free radical generation and oxidative stress push forward an immense influence on the pathogenesis of neurodegenerative diseases such as Alzheimer’s disease and Parkinson’s disease. Maclura tricuspidata fruit (MT) contains many biologically active substances, including compounds with antioxidant properties. The current study aimed to investigate the neuroprotective effects of MT fruit on hydrogen peroxide (H2O2)-induced neurotoxicity in SH-SY5Y cells. SH-SY5Y cells were pretreated with MT, and cell damage was induced by H2O2. First, the chemical composition and free radical scavenging properties of MT were analyzed. MT attenuated oxidative stress-induced damage in cells based on the assessment of cell viability. The H2O2-induced toxicity caused by ROS production and lactate dehydrogenase (LDH) release was ameliorated by MT pretreatment. MT also promoted an increase in the expression of genes encoding the antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT). MT pretreatment was associated with an increase in the expression of neuronal genes downregulated by H2O2. Mechanistically, MT dramatically suppressed H2O2-induced Bcl-2 downregulation, Bax upregulation, apoptotic factor caspase-3 activation, Mitogen-activated protein kinase (MAPK) (JNK, ERK, and p38), and Nuclear factor-κB (NF-κB) activation, thereby preventing H2O2-induced neurotoxicity. These results indicate that MT has protective effects against H2O2-induced oxidative damage in SH-SY5Y cells and can be used to prevent and protect against neurodegeneration.


2021 ◽  
Vol 17 ◽  
Author(s):  
Brahim Asseli ◽  
Reguia Mahfoudi ◽  
Amar Djeridane ◽  
Mohamed Yousfi

Background: Research on medicinal plant antioxidants has emerged as a potential therapeutic to prevent free radical generated damage in the human body. Hammada elegans Botsch (popularly known as “Ajram”) is a xerophytic plant widely found in Laghouat region, but there are only a few reports about the biological or chemical properties of these species. Hence, the aim of this study is to investigate the antioxidant and the antihemolytic activities of hexanic, acetonic, methanolic and aqueous extracts of aerial parts of Algerian Hammada elegans Botsch by employing different in vitro assay systems. Methods: The total phenolic content, the flavonoid content and the condensed tannin amount were analyzed using Folin-Ciocalteu, aluminum chloride and vanillin assays, respectively. The in vitro antioxidant capacity of extracts was assessed by CUPRAC, iron chelating, ABTS•+and antihemolytic assays, and was expressed as EC50 values. Results: Among the analyzed extracts, the aqueous extract had the highest phenolic, flavonoid and tannin contents. Also, this extract displayed the highest antioxidant capacities compared to the other extracts and standards. Its EC50 value for ABTS radical-scavenging activity was 0.265 ± 0.003 mg/L. Moreover, this extract showed high iron (II) chelating ability (EC50 = 0.958 ± 0.001 mg/L), and good antioxidant activity in the cupric ion reducing activity (CUPRAC) in a concentration dependent manner (EC50 were 0.709 ± 0.002 mg/L). Additionally, this extract had the best antihemolytic activity against AAPH-induced hemolysis (EC50=0.090 ± 0.004 mg/L). Conclusion: Our study revealed that the aqueous extract of Hammada elegans Botsch, is a potential source of antioxidants which possess a high protective effect of membrane against free radical.


2021 ◽  
Vol 10 (4) ◽  
pp. 408-414
Author(s):  
Oluwaseun Ruth Olasehinde ◽  
Olakunle Bamikole Afolabi ◽  
Benjamin Olusola Omiyale ◽  
Oyindamola Adeniyi Olaoye

Introduction: Diabetes mellitus (DM) has been recognized as the seventh leading cause of global mortality; however, researchers seek alternative means to manage the menace. The current study sought to investigate antioxidant potentials, α-amylase, and α-glucosidase inhibitory activities of ethanolic extract of Moringa oleifera flower in vitro. Methods: Antioxidant properties of the extract were appraised by assessing its inhibition against 1,1-diphenyl-2-picrylhydrazyl (DPPH), hydroxyl (OH•), and hydrogen peroxide (H2O2) free radicals, as well as ferric reducing antioxidant power (FRAP), the antidiabetic activity was evaluated by α-amylase and α-glucosidase inhibition.Results: In this study, ethanolic extract of M. oleifera flower demonstrated a significant (P < 0.05) inhibition against DPPH free radical (43.57–83.56%) in a concentration-dependent manner, while FRAP (101.76 ± 1.63 mg/100 g), OH• scavenging ability (71.62 ± 0.95 mg/100 g), and H2O2 free radical scavenging capacity (15.33 ± 1.20 mg/100 g) were also observed. In the same manner, ethanolic extract of M. oleifera flower revealed a significant (P < 0.05) inhibition against α-amylase (IC50= 37.63 mg/mL) and α-glucosidase activities (IC50= 38.30 mg/mL) in the presence of their respective substrates in a concentration-dependent manner in comparison with acarbose. Conclusion: Ethanoic extract of M. oleifera flower could be useful as an alternative phytotherapy in the management of DM, having shown a strong antioxidative capacity and substantial inhibition against the activities of key enzymes involved in carbohydrate hydrolysis in vitro.


2016 ◽  
Vol 19 (4) ◽  
pp. 76-83
Author(s):  
Trang Thi Xuan Dai ◽  
Anh Thi Tu Vo

This study was subjected to investigate antimicrobial and antioxidant properties of Eclipta alba extracts (methanol, hexane, chloroform and ethyl acetate extracts). The antioxidant property of the extract was assessed by 2,2- diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging method. Kirby-Bauer method was used to determine the antibacterial activity against Enterobacter cloacae of the extracts. The extracts of Eclipta alba were tested against E. cloacae. The highest antibacterial potentiality was exhibited by the ethyl acetate extract of E. alba leaves, means of zones of bacterial growth inhibition are 26.3 mm at a concentration of 32 μg/mL. DPPH free radical scavenging effect of the extracts was compared with standard antioxidant vitamin C. The highest antioxidant activity was exhibited by the ethyl acetate extract of E. alba leaves. The result also showed that the DPPH scavenging activity of ethyl acetate extract from leaves of E. alba was high (EC50 = 419.38 μg/mL). However, this result was 18.99 times lower than that of vitamin C (EC50 = 22.08 μg/mL).


2005 ◽  
Vol 153 (1-3) ◽  
pp. 153-156 ◽  
Author(s):  
P.A. Kilmartin ◽  
M. Gizdavic-Nikolaidis ◽  
Z. Zujovic ◽  
J. Travas-Sejdic ◽  
G.A. Bowmaker ◽  
...  

2021 ◽  
Vol 4 (2) ◽  
pp. 64-71
Author(s):  
O. Ya. Ivanushun ◽  
◽  
O. S. Yaremkevych ◽  
I.V. Semeniuk ◽  
O.V. Karpenko ◽  
...  

The antioxidant properties of humic acids of various origins have been investigated (from bio-humus, black soil from Ternopil region, and peat from different regions, such as: Velykyi Liubin, Drohobych and Belarus Republic). Titrimetric analysis has been shown the quantitative composition of the acidic functional groups of the obtained humic acids. According to the data of thermogravimetric analysis, the values of parameters, showing the ratio of their aliphatic to the cyclic part were determined. It was found that all obtained humic acids are characterized by high antioxidant activity: the formation of thiobarbituractive products and carbonyl groups of proteins in liver hepatocytes were decreased. The inhibition of the products of free radical formation of lipid components and proteins was better inhibited by 1% solutions of humates from vermicompost and humic acids from peat. The results indicate prospects of the humic acids for creating the means of restoring the physiological functions of biological objects in pathological conditions under conditions of free radical stress for application in cosmetic pharmaceutical products.


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