Flavonoids as antioxidants evaluated by in vitro and in situ liver chemiluminescence

Fraga, César G.; Martino, Virginia; Ferraro, Graciela; Coussio, J.; Boveris, Alberto

doi:10.1016/0006-2952(87)90724-6

Cited by 217 publications

(100 citation statements)

References 22 publications

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“…Some investigators recognized that the antioxidative and lipid peroxidation-inhibiting potential of flavonoids predominantly resided in the radical-scavenging capacity rather than the chelation of metals. 22,23 Other reports demonstrated that the presence of transition metals caused flavonoids to act as prooxidants instead of antioxidants. 16 Thus, irrespective of the iron-chelating parameter, the chemical characteristics in terms of ease of oxidation for flavonoids could be used as an index of 602 ANALYTICAL SCIENCES MAY 2001, VOL.…”

Section: Determination Of the Antioxidant Activitymentioning

confidence: 99%

Estimation of the Antioxidant Activities of Flavonoids from Their Oxidation Potentials

Yang

Kotani²,

Arai³

et al. 2001

ANAL. SCI.

262

171

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A simple electrochemical method for estimating the antioxidant activity (AA) of flavonoids has been developed. The proposed method is based on a measurement of the half-wave potential (E1/2) of the first oxidation wave of flavonoids by using flow-through column electrolysis. At the same time, the lipid peroxidation (LPO) inhibiting effects of these flavonoids were determined. A quantitative structure-activity relationship was obtained to describe the AA of flavonoids: IC50(µM) = 30.36 + 151.50E1/2 (V) -12.63log P (r = 0.852), where IC50 represents the concentration for 50% inhibition of LPO, and P represents the octanol/water partition coefficient. This method is expected to be useful for the quick screening of flavonoid antioxidants, and evaluating the AA of flavonoid-containing foods and medicinal plants.

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Section: Determination Of the Antioxidant Activitymentioning

confidence: 99%

Estimation of the Antioxidant Activities of Flavonoids from Their Oxidation Potentials

Yang

Kotani²,

Arai³

et al. 2001

ANAL. SCI.

262

171

View full text Add to dashboard Cite

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“…Most of its biological actions, such as lowering of plasma lipid levels, anti-inflammatory effects, and antimicrobial, anticancer, and antioxidant activities, are related to the polyphenol fraction, namely, tea catechins (3,8,11,12,24). These compounds, which belong to the flavan-3-ols family, have recently received considerable attention because of their potential therapeutic effects.…”

mentioning

confidence: 99%

Anti- Trypanosoma cruzi Activity of Green Tea ( Camellia sinensis ) Catechins

Paveto

Güida

Esteva

et al. 2004

Antimicrob Agents Chemother

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The trypanocidal action of green tea catechins against two different developmental stages of Trypanosoma cruzi is reported for the first time. This activity was assayed with the nonproliferative bloodstream trypomastigote and with the intracellular replicative amastigote parasite forms. An ethyl acetate fraction from Camellia sinensis green tea leaves, which contains most of the polyphenolic compounds and the maximal trypanocidal activity, was obtained by fractionation of the aqueous extract with organic solvents. The active compounds present in this extract were further purified by LH-20 column chromatography and were identified by highperformance liquid chromatography analysis with a photo diode array detector and gas chromatography coupled to mass spectroscopy. The following flavan-3-ols derivatives, known as catechins, were identified: catechin, epicatechin, gallocatechin, epigallocatechin, catechin gallate, epicatechin gallate, gallocatechin gallate, and epigallocatechin gallate. The purified compounds lysed more than 50% of the parasites present in the blood of infected BALB/c mice at concentrations as low as 0.12 to 85 pM. The most active compounds were gallocatechin gallate and epigallocatechin gallate, with minimal bactericidal concentrations that inhibited 50% of isolates tested of 0.12 and 0.53 pM, respectively. The number of amastigotes in infected Vero cells decreased by 50% in the presence of each of these compounds at 100 nM. The effects of the catechins on the recombinant T. cruzi arginine kinase, a key enzyme in the energy metabolism of the parasite, were assayed. The activity of this enzyme was inhibited by about 50% by nanomolar concentrations of catechin gallate or gallocatechin gallate, whereas the other members of the group were less effective. On the basis of these results, we suggest that these compounds could be used to sterilize blood and, eventually, as therapeutic agents for Chagas' disease.Trypanosoma cruzi is the causative agent of Chagas' disease, which is a major endemic disease in South and Central America (29). Human hosts are infected either by the triatomide insect vector bite, by blood transfusion, or by congenital transmission. The chronic phase of the disease occurs several years after infection, with cardiac and gastrointestinal pathologies being the typical clinical manifestations (6).The main approach to the elimination of Chagas' disease in areas of endemicity is the control of transmission by the insect vector (28). On the other hand, crystal violet is the only effective chemoprotective agent for banked blood. However, the high level of toxicity of this drug has imposed severe restrictions on its use (7,19,21,22).Treatment of patients with Chagas' disease relies on two chemotherapeutic agents: benznidazole and nifurtimox. These two drugs have several limitations because they are effective but highly toxic during the acute phase of the disease and scarcely beneficial in the chronic phase (23, 25). The undesirable side effects associated with these classical trypanocidal...

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“…However, reduction in the serum bicarbonate level indicates the tendency of chronic HU use to be associated with metabolic acidosis. The presence of flavonoids and alkaloids in HU could account for these protective effects since these phytocomponents have been documented to confer protection on the liver and kidneys through prevention of tissue lipid peroxidation which is mediated their anti-oxidant and free-radical scavenging activities (Fraga et al, 1987;Laughton et al, 1989;Sanz et al, 1994).…”

Section: Discussionmentioning

confidence: 99%

Evaluation of the toxicity and reversibility profile of the aqueous seed extract of <i>Hunteria umbellata</i> (K.Schum) Hallier F. in rodents

Adeneye¹,

Adeyemi²,

Agbaje³

et al. 2010

Afr. J. Trad. Compl. Alt. Med.

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Hunteria umbellata (K. Schum.) Hallier f. (family: Apocynaceae) is reputed for the folkloric management of labour, pain and swellings, stomach ulcers, diabetes, obesity, and anaemia, with no scientific report of its toxicity and reversibility profile. The present study was, therefore, aimed at investigating the in vivo toxicity and reversibility profile of the aqueous seed extract of Hunteria umbellata (HU). The acute oral and intraperitoneal toxicity studies of HU were determined in Swiss albino mice while its 90-day oral toxicity and toxicity reversibility profile on anthropometric, biochemical, haematological and histopathological parameters were also assessed using standard procedures. Results showed that the LD 50 values for the acute oral and intraperitoneal toxicity studies for HU were estimated to be 1000 mg/kg and 459.3 mg/kg, respectively. Visible signs of immediate and delayed toxicities including starry hair coat, respiratory distress, and dyskinesia were observed. For the chronic oral toxicity study, HU administered for 90 days produced significant (p<0.001) reductions in the weight gain pattern and significant (p<0.001) and dose related increases in the relative weights of liver, stomach, spleen, testis, lungs and heart, at the 100 and 500 mg/kg of HU. Chronic HU treatment also produced significant (p<0.05, p<0.001) dose related reductions in the serum levels of fasting blood glucose, bicarbonate, urea and creatinine while causing non-significant (p>0.05) alterations in the serum levels of sodium, potassium, alaninine transaminase, aspartate transaminase, alkaline phosphatase, total and conjugated bilirubin, total protein and albumin. Also, chronic oral treatment with HU produced significant (p<0.05, p<0.01, p<0.001) and dose-related increases in the red cell count, packed cell volume, haemoglobin concentration, platelet count, total leucocyte count and lymphocyte differential while producing significant (p<0.05) reductions in neutrophil and granulocyte differentials. HU also produced histological features of proliferations of the stomach epithelia, lung tissues, splenic white and red pulps, and testicular spermatogenic series. Following 14 days of oral toxicity reversibility test, there was no significant (p>0.05) reversal in the serum levels of the biochemical and haematological parameters investigated, including the HU-induced histological lesions.Overall, results of this study showed that HU has a relatively low oral toxicity profile but its prolonged use, particularly, at high doses should be with great caution.

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Flavonoids as antioxidants evaluated by in vitro and in situ liver chemiluminescence

Cited by 217 publications

References 22 publications

Estimation of the Antioxidant Activities of Flavonoids from Their Oxidation Potentials

Estimation of the Antioxidant Activities of Flavonoids from Their Oxidation Potentials

Anti- Trypanosoma cruzi Activity of Green Tea ( Camellia sinensis ) Catechins

Evaluation of the toxicity and reversibility profile of the aqueous seed extract of <i>Hunteria umbellata</i> (K.Schum) Hallier F. in rodents

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