Antioxidant Properties Of Phenolic Compounds Research Articles

Cytotoxic and antioxidant properties of phenolic compounds from Tagetes patula flower

Context: Tagetes patula Linn. (Asteraceae) (French Marigold) flowers are used by local practitioners for cancer treatment; however, it lacks scientific justification.Objective: Identification of bioactive compounds in T. patula flower for cytotoxic and growth inhibition in human cancer cell lines along with its antioxidant properties using chemical and cell based systems.Materials and methods: The T. patula flower methanol extract, its seven fractions, and three phenolic compounds including methyl protocatechuate (1), patuletin (2), and patulitrin (3) were evaluated using sulforhodamine-B assay against HeLa, HT-144, NCI-H460, MCF-7, PC-3, and SF-268 human cancer cell lines. In parallel, antioxidant activity was evaluated using chemical (DPPH·, deoxyribose, and lipid peroxidation assays) and cell-based chemiluminescence systems (human neutrophils and mice macrophages).Results: The methanol extract and ethyl acetate insoluble fraction exhibited cytotoxic and growth inhibitory effects against HeLa in which 2 exhibited highest cell growth inhibition (GI50: 0.6 ± 0.1 µg/ml) and cytotoxicity (LC50: 2.5 ± 0.1 µg/ml). It also scavenged LOO· (IC50: 6.5 ± 0.7 µg/ml) and (IC50: 27.5 ± 1.3 μg/ml) in chemical systems and human neutrophils, respectively. However, 1 preferably scavenged H2O2–Cl− (IC50: 0.5 ± 0.01 μg/ml) in mice macrophages.Discussion and conclusion: Compound 2 from T. patula flower exhibited both growth inhibitory and cytotoxic properties while 1 and 3 were only growth inhibitory against HeLa. 1–3 also displayed antioxidant properties implying its probable role in growth inhibition/cytotoxic action. The present study provides scientific evidence for the use of T. patula flower in cancer treatment by traditional healer.

Importance of solvent association in the estimation of antioxidant properties of phenolic compounds by DPPH method.

The presented paper shows the influence of temperature increase in the range typically used during antioxidant measurements (15-35°C) on the estimation of antioxidant properties of phenolic compounds (caffeic acid, ferulic acid, gallic acid, trolox, butylhydroxyanisole, butylhydroxytoluene and 2,6-diisopropylphenol) in associating and non-associating solvents. A significant influence of temperature on the DPPH(•)/antioxidant reaction kinetic is observed for strongly associating solvents (e.g. methanol). This trend is less marked for non-associating solvents (e.g. dioxane, ethyl acetate). The performed experiments prove that the change of solvent structure, caused by temperature increase, influences the estimation of antioxidant properties of phenolic compounds much more than the increase of kinetic energy of reacting molecules and/or the increase of the dissociation degree of hydroxyl groups occurring in antioxidants.

Antioxidant Properties of Phenolic Compounds from Baccharis articulata and B. usterii

As a continuation of our research on the Baccharis genus, the evaluation of the antioxidant effect by TRAP and TBARS assays of three isolated compounds from n-butanol fractions of B. articulata and B. usterii is reported. The structures of these compounds were established as 4-O-beta-D-glucopyranosyl-3,5-dimethoxybenzyl-methanol (1), 5-O-[E]-dicaffeoylquinic acid (2), and 7-hydroxy-5,4'-dimethoxyflavone (3). In the TRAP assay it was possible to observe an antioxidant effect of both n-butanol fractions at 1.25 microg/mL. Among the isolated compounds, compound 2 displayed a remarkable contribution to the total antioxidant capacity of the n-butanol fraction of B. usterii. Moreover, the n-butanol fractions of both species, compounds 1 and 2 at 40.0 microg/mL were efficient in protection of lipid peroxidation in the TBARS experiment. They are promising lead compounds for use in medicinal chemistry studies.

Analysis of the Fatty Acids and Phenolic Compounds in a Cereal-Based Fermented Food (Tarhana)

Tarhana is a Turkish home-made fermented food product. The mixture of wheat flour, yoghurt, yeast, cooked vegetables, salt, and spices is fermented for 1 - 7 days. Tarhana is sun dried and ground for preparation of instant Tarhana powder. Color, phenolic compounds and fatty acid composition were determined for home-made Tarhana, collected from 4 cities in the Thrace Region of Turkey. Color and phenolic content were significantly different (P < 0.05). These differences were due to the variation of ingredients used at different locations. The major unsaturated fatty acids were oleic (C18:1, 16.41% - 57.69%), and linoleic acids (C18:2, 9.74% - 56.31%). Palmitic (C16:0, 16.90% - 37.66%) and stearic acids (C18:0, 0.65% - 11.34%) were the main saturated fatty acids. This study suggested that Tarhana soup is a good source of unsaturated fatty acids. Antioxidant properties of phenolic compounds and their effect on peroxidation of lipids in Tarhana should be tested in future studies.

The importance of solvent type in estimating antioxidant properties of phenolic compounds by ABTS assay

ABTS assay belongs to the most popular methods employed for estimating antioxidant activity. However, researchers seldom pay attention to specific factors influencing the determination of antioxidant activity of the examined compounds and mixtures. The paper shows that the type of alcohol used significantly influences the estimation of antioxidant activity of phenolic compounds in ABTS assay, namely that their antioxidant activity increase with the lengthening of the aliphatic chain in alcohol. It results rather from the changes in ABTS •+ solvatation energy by the employed alcohols than from dissociation variations of phenolic compounds. The obtained results point to the difficulties in the correct estimation of the real antioxidant properties of plant and food extracts by ABTS assay. The presented results have also an ecological implication as they refer to the difference in estimation of antioxidant properties of compounds resulting from the replacement of toxic methanol by GRAS (Generally-Recognized-As Safe) solvents, ethanol and propanol.

Antioxidant Activities of Polyphenols Extracted from Olive (Olea europaea) of Chamlal Variety

The antioxidant properties of phenolic compounds from olive pulp (PCO) of chamlal variety and those of individual phenolic compounds were evaluated and compared with that of vitamin C (Vit C). The antioxidant activity was measured by the tests of iron reduction and scavenging hydrogen peroxide (H(2)O(2)). Results showed that all the substances tested exhibit a reducing power. The PCO present activities of iron reduction and H(2)O(2) scavenging higher than those of Vit C. The protective effect of PCO against oxidation of lipids and proteins from erythrocyte membranes was studied. The measurement of malondialdehyde generated under oxidative stress conditions induced by hydroxyl radicals generating system revealed that PCO have the most significant protective activity against lipid peroxidation (IC(50) = 49.27 ± 1.91 μg mL(-1)). Paradoxically, Vit C revealed a pro-oxidant effect. Proteins oxidation was evaluated using the H(2)O(2)/FeSO(4) system and electrophoresis. In the presence of PCO at 1 mg mL(-1), proteins of erythrocyte membranes were protected contrary to those treated with Vit C at the same concentration.

Role of Antioxidant Herbal Drugs in Renal Disorders: An Overview

Renal disorders have always remained a major area of concern for physicians since a long time. It is the 9th leading cause of death in United States. Incidence of kidney diseases leading to kidney failure is increasing day by day. A large number of chemicals in common use are potential renal toxins. The use of herbal drugs for the prevention and treatment of various diseases is constantly developing throughout the world. Many studies have been carried out that strongly support the contribution of antioxidants to the prevention of cardiovascular diseases, cancer, osteoporosis, neurodegenerative diseases, and diabetes mellitus, and suggest a role in the prevention of peptic ulcer. Polyphenols display a number of pharmacological properties in the renal area, acting as diuretic, anti inflammatory, antispasmodic, and antioxidant agents. The antioxidant properties of phenolic compounds have been widely studied, but it has become clear that their mechanisms of action go beyond the modulation of oxidative stress. Various polyphenolic compounds have been reported for their nephroprotective activity with a good level of renal protection. Therefore, considering the important role of polyphenolic compounds in the prevention or reduction of renal disorders induced by various nephrotoxic chemical agents, in this review, we have summarized the literature on some potent nephroprotective plants, such as, Achyrocline satureioides, Zingiber officinalis, Teminalia chebula etc having antioxidant properties.

Comparative Antioxidant Properties of Some Gabaergic Phenols and Related Compounds, Determined for Homogeneous and Membrane Systems

Some phenols, like propofol, thymol and related compounds, have been shown to act on the GABA(A) receptor. Several compounds with GABAergic activity have displayed neuroprotective effects attributed mainly to the potentiation of GABA(A)-mediated inhibition of synaptic transmission. It has also been found that compounds containing a phenolic OH group can scavenge reactive oxygen species, as in the case of propofol, among others. Thus, the neuroprotective action mechanism of GABAergic phenols would involve both effects, their pharmacological activity on GABA(A) and their intrinsic antioxidant ability. In this context, the study of the antioxidant properties of phenolic compounds included in the present work will enable these capacities to be correlated with their eventual pharmacological activities. The assays chosen in this study included determination of antioxidant ability in homogeneous isotropic systems (DPPH reduction, FRAP and hydrogen peroxide scavenging) and in heterogeneous membrane systems (inhibition of lipid peroxidation of phospholipid SUVs). The comparative evaluation of the results showed some differences between the relative order of antioxidant potency among all assayed compounds determined by using both types of systems. This analysis supports the conclusion that the antioxidant values obtained in homogeneous non-membrane systems, for phenols or other lipophilic compounds, should be revised according to their capacity of interaction with membranes (i.e. Log P in membrane-buffer system) in order to obtain antioxidant potency values more approximate to those actually occurring in biological systems. These results are essential to understand the actual neuroprotective action mechanism exerted by phenolic compounds involving a pharmacological activity, an antioxidant effect or both actions exerted mutually.

Antioxidant properties of phenolic compounds occurring in edible mushrooms

Total phenolic and flavonoid contents occurring in eight types of edible mushrooms ( Agaricus bisporus, Boletus edulis, Calocybe gambosa, Cantharellus cibarius, Craterellus cornucopioides, Hygrophorus marzuolus, Lactarius deliciosus and Pleurotus ostreatus) have been respectively evaluated by the Folin–Ciocalteau assay and by the colorimetric reaction with NaNO 2 and AlCl 3 in a basic media. Generally, the assayed mushrooms contained between 1 and 6 mg of phenolics per gram of dried mushroom, depending on the species, while the flavonoid concentrations ranged between 0.9 and 3.0 mg per gram of dried matter. The profile and concentration of individual phenolics was determined by means of high performance liquid chromatography. Homogentisic acid was the free phenolic acid significantly present in all mushrooms although the content varied considerably among the analysed species. Flavonoids, such as myricetin and catechin were also detected in the mushrooms studied. The antioxidant properties of the methanolic extracts from mushrooms were evaluated by monitoring the linoleic acid autoxidation, and all the mushrooms species showed inhibition, with C. cibarius being the most effective against lipid oxidation (74% of inhibition) and A. bisporus the species with lowest antioxidant activity (10% of inhibition).

Role of phenolic compounds in peptic ulcer: An overview

Peptic ulcer is the most common gastrointestinal tract (GIT) disorder in clinical practice, which affects approximately 5-10% of the people during their life. The use of herbal drugs for the prevention and treatment of various diseases is constantly developing throughout the world. This is particularly true with regard to phenolic compounds that probably constitute the largest group of plants secondary metabolites. Phenolic compounds have attracted special attention due to their health-promoting characteristics. In the past ten years a large number of the studies have been carried out on the effects of phenolic compounds on human health. Many studies have been carried out that strongly support the contribution of polyphenols to the prevention of cardiovascular diseases, cancer, osteoporosis, neurodegenerative diseases, and diabetes mellitus, and suggest a role in the prevention of peptic ulcer. Polyphenols display a number of pharmacological properties in the GIT area, acting as antisecretory, cytoprotective, and antioxidant agents. The antioxidant properties of phenolic compounds have been widely studied, but it has become clear that their mechanisms of action go beyond the modulation of oxidative stress. Various polyphenolic compounds have been reported for their anti-ulcerogenic activity with a good level of gastric protection. Besides their action as gastroprotective, these phenolic compounds can be an alternative for the treatment of gastric ulcers. Therefore, considering the important role of polyphenolic compounds in the prevention or reduction of gastric lesions induced by different ulcerogenic agents, in this review, we have summarized the literature on some potent antiulcer plants, such as, Oroxylum indicum, Zingiber officinale, Olea europaea L., Foeniculum vulgare, Alchornea glandulosa, Tephrosia purpurea, and so on, containing phenolic compounds, namely, baicalein, cinnamic acid, oleuropein, rutin, quercetin, and tephrosin, respectively, as active constituents.

Isolation of a powerful antioxidant from Olea europaea fruit-mill waste: 3,4-Dihydroxyphenylglycol

Nutritional and antioxidant properties of phenolic compounds are important in relation to human health and palatability of products. 3,4-Dihydroxyphenylglycol (DHPG) is a strong antioxidant found in small amounts in virgin olive oil and table olives, with an antioxidant activity even higher than that of the powerful hydroxytyrosol. The origin of this antioxidant is completely unclear since has never been reported as a free plant metabolite. In this respect possible precursors of DHPG have also been discussed in this study. The presence of soluble compounds that either contain DHPG in their molecular structure or act as substrates for its synthesis has been showed for the first time. The quantities of DHPG recovered in olive drupe tissue by thermal treatment exceed widely the values indicated in the literature, showing the release or formation of additional DHPG from precursors after heating. In addition, DHPG obtained under certain extraction conditions from fresh solid waste of two-phase olive oil extraction systems (alperujo) is its most important phenolic compound. Therefore, the solid olive waste is a good source of this simple monomer phenol. The chemical structure, purity and racemic nature of isolated DHPG were also analysed for the first time by NMR experiments.

Effect of phenolic compounds and quinones on radiation-induced oxidation processes of hexane and ethanol

The radiation-chemical yields were determined for the products of γ-radiation induced oxidation of hexane and ethanol in the presence of natural and synthetic phenolic compounds and quinones. It was found that the commercial antioxidants ionol and bisphenol 2246 more effectively inhibit the hexane oxidation process while α-tocopherol and quinones are superior to other test compounds in the suppression of ethanol oxidation. The results indicate that the antioxidant properties of phenolic compounds and quinones depend not only on their structure but also on the nature of the oxidation substrate. The cause of this phenomenon is discussed.

Trans-3-Phenyl-2-Propenoic Acid (Cinnamic Acid) Derivatives: Structure-Activity Relationship as Hepatoprotective Agents

Among various phenolic compounds, caffeic acid (3,4-dihydroxycinnamic acid) exhibited pharmacological antioxidant, anticancer and antimutagenic activities. The antioxidant properties of phenolic compounds depend on their chemical structure, however, the role of the ethylenic side chain in the radical scavenging activity remains controversial. Thus, the aim of this study consisted to test cinnamic acid and 15 cinnamic acid derivatives in the well known CCl(4)-induced acute liver damage model, which is dependent on oxidative stress mechanisms. Cinnamic acid and 15 cinnamic acid derivatives (50 mg/kg, p.o.) were administered to male Wistar rats intoxicated with CCl(4) (4 g/kg, p.o.). The activities of gamma-glutamyl transpeptidase, alkaline phosphatase and alanine aminotransferase were measured in serum. The lipid peroxidation products were determined in liver. Compounds with a methoxy group at position 3 or 4, or a 3,4-methylenedioxy moiety were the most active ones. Also, we observed that the monosubstituted 3 or 4 hydroxy, or the bulky 3,4 dibenzyloxy substituted compounds showed lower activity. The poorest activity was displayed by disubstituted 3,4-dihydroxy, dimethoxy or diacetyl cinnamic acid derivatives, the ester derived from cinnamic acid with an 8 carbon chain and N-dimethyl substituted compound. Thus, the methoxy substituted group at positions 3 or 4 or the 3,4-methylenedioxy moiety in the caffeic acid derivatives; seem to be the main features required for the hepatoprotection in this model.

Adding iron to green tea may decrease its antioxidant capacity in rats after an oral dose of the mixture

We tested in rats the hypothesis that adding iron to green tea diminishes the increase in antioxidant properties in plasma and red blood cells after tea ingestion. Thirty-two rats were divided randomly into 4 groups of 8 rats each. Rats were administered, by gavage, an infusion of green tea, iron citrate, a mixture of iron citrate and green tea infusion, or water. Blood was drawn under anesthesia from the jugular vein at 10, 30, 45, and 60 minutes after gavage. Antioxidant capacity was measured in plasma with the ferric-reducing ability of plasma and total radical trapping antioxidant parameter assays and in red blood cells (diacetyldichlorofluorescein assay). Phenolic compounds were determined in plasma with the modified Folin-Ciocalteau assay. The antioxidant capacity of plasma, measured with the total radical trapping antioxidant parameter assay, and the polyphenol content of plasma in rats that received tea increased at 30 minutes after gavage ( P < .05) and subsequently dropped. When iron was introduced together with tea, the polyphenol content and the antioxidant capacity of plasma did not rise ( P > .05), showing a similar profile with plasma of rats that received iron only or water. Results from the ferric-reducing ability of plasma assay in plasma and the diacetyldichlorofluorescein assay in red blood cells were not as clear. This study suggests that iron may modify the antioxidant properties of phenolic compounds. Further studies on the effect of iron on the bioavailability and the antioxidant capacity of phenolic compounds are required.

Comparative study of radical scavenger and antioxidant properties of phenolic compounds from Vitis vinifera cell cultures using in vitro tests

Vitis vinifera cell suspensions were used to isolate and characterize the flavonoids (anthocyanins, catechins) and non-flavonoids (stilbenes) found in red wine. Furthermore, we showed that astringin is produced although this stilbene has not previously been reported to be a constituent of V. vinifera or wine. The ability of these compounds to act as radical scavengers was investigated using 1,1-diphenyl-2-picryl-hydrazyl (DPPH), a stable free radical. Antioxidant activities were assessed by their capacity to prevent Fe 2+-induced lipid peroxidation in microsomes and their action on Cu 2+-induced lipid peroxidation in low-density lipoproteins. The results showed that astringin has an important antioxidant effect similar to that of rans-resveratrol, and a higher radical scavenger activity than the latter. Astringinin appeared to be more active. These data indicate that phenolic compounds (stilbenes, catechins, anthocyanins) exhibit interesting properties which may account in part for the so-called “French paradox,” i.e. that moderate drinking of red wine over a long period of time can protect against coronary heart disease.

Antioxidant properties of phenolic compounds in macadamia nuts

AbstractPhenolic compounds in macadamia nuts and shells were identified, and their antioxidant activities were evaluated in refined macadamia nut oil. Thin‐layer chromatography of oil extracted from macadamia nut kernels and shells indicated the possible presence of catechol, phrogallol, and 3,4,5‐trihydroxy phenolic compounds. Four phenolic compounds were tentatively identified as 2,6‐dihydroxybenzoic acid, 2′‐hydroxy‐4′‐methoxyacetophenone, 3′,5′‐dimethoxy‐4′‐hydroxyacetophenone, and 3,5‐dimethoxy‐4‐hydroxycinnamic acid. Adding 0.01% of 2′‐hydroxy‐4′‐methoxyacetophenone, 3′,5′‐dimethoxy‐4′‐hydroxyacetophenone, or 3,5‐dimethoxy‐4‐hydroxycinnamic acid to the oil significantly increased the Rancimat induction time against the control (P&lt;0.0001). At this concentration, 3′,5′‐dimethoxy‐4′‐hydroxyacetophenone was the most effective compound added. Although induction times of oils with 0.01%, 2,6‐dihydroxybenzoic acid were not significantly different from the control, at 0.1% there was a significant difference from the control (P&lt;0.0001). The activity was the same as that of 2′‐hydroxy‐4′‐methoxyacetophenone at 0.1%.