Ascorbate-induced Lipid Peroxidation Research Articles

Pharmacological study of original extracts of corn silk

Aim: the aim of the research is a pharmacological study of the original extracts of corn silk. Materials and methods. The object of the study were 4 original extracts of corn silk, obtained by extraction with water and ethanol of different concentrations, namely: aqueous extract of corn silk (ACSE), extract of corn silk, extracted with ethanol 30 % (ECSE 30 %) , extract of corn silk, extracted with ethanol 50 % (ЕCSЕ 50 %), extract of corn silk, extracted with ethanol 70 % (ЕCSЕ 70 %). A screening study of the antioxidant properties of corn silk extracts was carried out in vitro using models of spontaneous and ascorbate-induced lipid peroxidation (LPO) in rat liver homogenate. Results. As can be seen from the given data, ECSE 50 % at a dose of 20 mg/kg showed a pronounced protective effect on the hepatotoxicity of TСM. Its use led to a probable restoration of the bile-forming function of the liver against the background of tetrachloromethane hepatitis: in response to an increase in the cholesterol content (by 43 %, p<0.05), the content of bile acids increased 2 times (p<0.05), as a result of which cholate -cholesterol ratio approached the level of indicators of intact animals, the rate of bile secretion normalized. Based on the analysis of the results of the study, it can be concluded, that in terms of bile-forming and choleretic activity on the tetrachloromethane hepatitis model, ECSE 50 % was not inferior to silibor and superior to quercetin (р<0.05). Conclusions. Biologically active substances of corn silk affect not only the diffusion and filtration processes of the liver parenchyma, but also the biosynthesis and transport of its organic components, that is, they affect the bile-forming function

Effectiveness of food concentrate phenolic compounds of apples in experimental membrane pathologies

Apple fruits are an available source of phenolic compounds that exhibit a wide range of biological activities (antioxidant, anti-inflammatory, membrane stabilizing, etc.). The antioxidant properties of food concentrate phenolic compounds of apples (Concentrate) were studied in vitro in models of spontaneous and ascorbate induced lipid peroxidation (LPO) in rat liver homogenate, and acute carbon tetrachloromethane hepatitis was chosen as in vivo model in rats. Membrane stabilizing activity was evaluated by the degree of hemolysis in blood samples from the tail vein. The effect of Concentrate on vascular permeability was studied considering the time of animal skin papules staining at the site of injection of phlogogenic substances. Hepatoprotective activity in the model of acute carbon tetrachloride hepatitis was assessed by changes in prooxidant-antioxidant status in liver homogenate and liver enzymes activity in serum. Significant antioxidant effect of Concentrate was fixed in models of spontaneous and ascorbate induced LPO (TBA reactants’ content was 3.12 times and 2.25 times lower than control for spontaneous LPO and ascorbate induced LPO, respectively) and under tetrachloride hepatitis (Concentrate antioxidant activity was 47.8%). The membrane-protective activity of the studied Concentrate was also high and reached 50.1%. Also, Concentrate demonstrated capillary-strengthening properties, reducing the permeability of the vascular wall, which was caused by three different chlorogens, most notably by zymosan (Concentrate significantly delayed the stain utilization from the bloodstream by 2.14 times compared to control). Newly developed concentrate showed complex hepatoprotective activity, improving the indices of antioxidant-prooxidant status and activity of liver cytolysis enzymes in rats with tetrachloromethane hepatitis. The transparent corrective effects of Concentrate are the result of synergism and additivity of its multiple components and indicate the prospects of its further research in order to develop medications for the prophylaxis and treatment of diseases associated with membrane damage.

Prognostic value of lipid peroxidation changes in acute poisoning with household drugs “bath salts”

Aim. To study the state of lipid peroxidation processes in case of psychodisleptic poisoning of the “bath salt” type and to determine the clinical and biochemical markers of a favorable and complicated course of the acute period of poisoning.
 Methods. In 347 patients with acute household poisoning (“bath salts”) admitted to the toxicology department of the Chelyabinsk Regional Clinical Hospital №3, the clinical and biochemical features of the acute period of psychodisleptic poisoning (“bath salts”) were studied in a favorable and unfavorable course. Blood and urine samples were taken from all patients, which later underwent chemical and toxicological studies by gas chromatography-mass spectrometry. Also, lipid peroxidation and antioxidant activity were determined in selected blood samples. Lipid peroxidation products were detected in heptane-isopropanol extracts of biological material by spectrophotometry. The intensity of Fe2+-ascorbate-induced lipid peroxidation was determined in E.I. L'vovskaya's modification. The study of patients' samples was carried out in the biochemical laboratory of the regional clinical hospital №3, at the Department of Biochemistry of the Ural state university of physical culture and the South Ural state medical university of Chelyabinsk.
 Results. Patients with “bath salts” poisoning in the acute period showed an elevated content of all categories of peroxidation products in the blood serum — by 1.51–1.70 times more than in the control group of healthy people. A decrease in antioxidant activity values I and II by 1.13–1.31 times was also found. With favorable outcomes of poisoning, the level of activation of lipid peroxidation processes decreased with an adequate increase in the activity of the antioxidant system by 1.5–1.6 times. The activation of lipid peroxidation processes in the blood serum accompanied by a decrease in the activity of antioxidant system led to an unfavorable course of the disease and the development of cerebral edema in 18 patients which was fatal.
 Conclusion. The clinical and biochemical features of the course of the acute period of poisoning with “bath salts” revealed by us suggest adverse outcomes of the disease with a tendency to an increase in the content of serum lipid peroxidation products in the course of the disease (instead of reducing them) along with a reduction of antioxidant activity; these indicators should be compensated by the use of antioxidant therapy.

Annona muricata Linn. leaf as a source of antioxidant compounds with in vitro antidiabetic and inhibitory potential against α-amylase, α-glucosidase, lipase, non-enzymatic glycation and lipid peroxidation

Annona muricata leaves are used in traditional medicine to manage diabetes mellitus and its complications. The aim of this study was to evaluate the potential in vitro antidiabetic properties of Annona muricata leaf by identifying its main phytochemical constituents and characterizing the phenolic-enriched fractions for their in vitro antioxidant capacity and inhibitory activities against glycoside and lipid hydrolases, advanced glycation end-product formation and lipid peroxidation. Ethanol extract of A. muricata leaf was subjected to a liquid-liquid partitioning and its fractions were used in enzymatic assays to evaluate their inhibitory potential against α-amylase, α-glucosidase and lipase, as well as their antioxidant (DPPH, ORAC, FRAP and Fe2+-ascorbate-induced lipid peroxidation assays) and anti-glycation (BSA-fructose, BSA-methylglyoxal and arginine-methylglyoxal models) capacities. In addition, identification of the main bioactive compounds of A. muricata leaf by HPLC-ESI-MS/MS analysis was carried out. Ethyl acetate (EtOAc) and n-butanol (BuOH) fractions showed, respectively, antioxidant properties (ORAC 3964 ± 53 and 2707 ± 519 μmol trolox eq g−1, FRAP 705 ± 35 and 289 ± 18 μmol trolox eq g−1, and DPPH IC50 4.3 ± 0.7 and 9.3 ± 0.8 μg mL−1) and capacity to reduce liver lipid peroxidation (p < .01). Also, EtOAc and BuOH, respectively, inhibited glycation in BSA-fructose (IC50 45.7 ± 13.5 and 61.9 ± 18.2 μg mL−1), BSA-methylglyoxal (IC50 166.1 ± 21.6 and 413.2 ± 49.5 μg mL−1) and arginine-methylglyoxal (IC50 437.9 ± 89.0 and 1191.0 ± 199.0 μg mL−1) assays, α-amylase (IC50 9.2 ± 2.3 and 6.1 ± 1.6 μg mL−1), α-glucosidase (IC50 413.1 ± 121.1 and 817.4 ± 87.9 μg mL−1) and lipase (IC50 74.2 ± 30.1 and 120.3 ± 50.5 μg.mL−1), and presented lower cytotoxicity, when compared to the other fractions and crude extract. Various biomolecules known as potent antioxidants were identified in these fractions, such as chlorogenic and caffeic acids, procyanidins B2 and C1, (epi)catechin, quercetin, quercetin-hexosides and kaempferol. This study presents new biological activities not yet described for A. muricata, which contributes to the understanding of the potential effectiveness in the use of the A. muricata leaf, especially its polyphenols-enriched fractions, for the management of diabetes mellitus and its complications.

Evaluation of antioxidant effect of various Extracts ofleucasaspera in vitro

Lamiaceae herbs known for their culinary properties are a rich source of potentially health-beneficial antioxidant polyphenols. The objective of this investigation was to evaluate and prove the in vitro antioxidant activity of five different extracts of aerial parts of the plant Leucas aspera, belonging to the family Lamiaceae on different models namely the DPPH free radical scavenging assay, Fe 2+ - ascorbate induced lipid peroxidation, Nitric oxide scavenging activity, Total antioxidant equivalence and Hydroxyl radical scavenging activity by standardized methods. The results showed the ethanolic and hydroalcoholic extracts of Leucas aspera (EELA and HAELA) to exhibit maximum inhibition of free radical formation followed by EAELA, the ethyl acetate extract. The least antioxidant potential was exhibited by HELA and CELA, the n-hexane and chloroform extracts of Leucas aspera. The potential antioxidant activities in vitro may indicate their therapeutic and related beneficial properties in oxidative stress, a condition underlying many disorders.

&lt;i&gt;In vitro&lt;/i&gt; evaluation of inhibitory effect of &lt;i&gt;Phoenix dactylifera&lt;/i&gt; bark extract on rat lipid peroxidation and blood hemolysis

Purpose: To determine the polyphenolic content of P. dactylifera L. (date palm) bark extract and to investigate its in vitro inhibitory effects on lipid peroxidation in the brain, liver, and kidney tissues of rat, as well as on blood hemolysis in rats. Methods: P. dactylifera L. barks were collected from Ahvaz, (Khuzestan, Iran). Methanolic extract of the P. dactylifera barks were prepared using maceration method. Total phenolic, flavonoid and proanthocyanidin contents were determined by colorimetric methods. The effects of the extract were investigated on thiobarbituric acid reactive substances formation in Fe 2+ /ascorbate induced-lipid peroxidation in brain, liver and kidney tissues of rats. Furthermore, the inhibitory effects of the extracts on erythrocyte hemolysis caused by 2,2'-Azobis (2-amidinopropane) dihydrochloride (AAPH) were evaluated. Results: Total phenolic, flavonoids and proanthocyanidins contents per each g dry extract of P. dactylifera L. were 50.7 mg tannic acid, 10.38 mg rutin, and 5.45 mg cyanidin, respectively, while halfmaximal inhibitory concentration (IC 50 ) for inhibition of lipid peroxidation in brain, liver, and kidney tissues of rats was 3150.71, 1941.45, and 1546.01 μg/mL, respectively, and for the inhibition of erythrocyte hemolysis, it was 472.41 μg/mL. Conclusion: The findings of this study indicate significant anti-lipid peroxidation and anti-hemolytic effects of the bark extract. Therefore, the extract can potentially be used for the in vivo treatment of diseases associated with lipid peroxidation such as cancers and Alzheimer's disease, but further studies are required. Keywords: Phoenix dactylifera , Date palm, Lipid peroxidation, Antioxidant, Erythrocyte hemolysis

A Comparative In Vitro Study on the Antioxidant and Anti-acetylcholinesterase Properties of Aerial Parts of Strophanthus preusii Engl & Pax.

To evaluate and compare the antioxidant and acetylcholinestrase (AChE)-inhibitory properties of aerial parts of Strophanthus preussii (leaves, stem and root named as SPL, SPS and SPR, respectively) while catechin served as standard. The antioxidant and AchE-inhibitory properties of the methanol extracts of SP were evaluated by standard in vitro methods viz: DPPH (2,2-diphenyl-1-picrylhydrazine), nitric oxide (NO), hydroxyl radical (OH-) and hydrogen peroxide (H2O2) radical scavenging assays as well as reducing power, Fe2+/ascorbate-induced lipid peroxidation (LPO) and AChE inhibition assays. The total phenolic and flavonoid contents of the extracts were also estimated. High phenolic and flavonoid contents were found in the aerial parts of Strophanthus preussii. The amount of phenolic and flavonoids contents followed the order SPL > SPR > SPS at 250─1000 µg/ml. The results revealed that all the extracts showed antioxidant activities in vitro. However, SPL had the highest DPPH, H2O2 and OH radical scavenging abilitie, while the reducing power of the extracts followed the order SPR > SPL > SPS at 1000 µg/ml. In addition, SPL, SPS and SPR significantly inhibited LPO in rat liver by 42%, 23%, 35% and in rat brain by 68%, 31% and 51%, respectively. The LPO inhibitory activities of SPL were statistically similar to the standard. Only SPS produced significant NO scavenging effects among the extracts. The percentage inhibition of AChE activity was significant for SPL and SPR at 750 and 1000 µg/ml. The leaves and root of Strophanthus preusii proved to be potent natural antioxidants and could justify their traditional use in the management of stress-related diseases.

In vitro studies to assess the antioxidative, radical scavenging and arginase inhibitory potentials of extracts from Artocarpus altilis, Ficus exasperate and Kigelia africana

To justify the use of Artocarpus altilis (A. altilis), Ficus exasperata (F. exasperata) and Kigelia africana (K. africana) in ethnomedicine for the treatment of several ailments and to evaluate the in vitro antioxidant, radical scavenging and arginase inhibitory potentials of these herbs and compared with catechin (Standard). Antioxidant activities were determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH), nitric oxide, hydrogen peroxide (H2O2) and hydroxyl (OH) radicals scavenging methods. The flavonoids and phenolics content, inhibition of arginase activity, Fe(2+)/ascorbate-induced lipid peroxidation (LPO) and reducing power were also determined. The A. altilis, F. exasperata and K. africana showed dose-dependent and significant scavenging of DPPH, H2O2 and OH radicals in vitro relative to catechin. The A. altilis and F. exasperata effectively scavenged DPPH radical with IC50 of 593 and 635 µg/mL and, OH radical with IC50 of 487 and 514 µg/mL, respectively. The DPPH and OH radicals scavenging activities followed the order A. altilis>F. exasperata>K. africana. In addition, A. altilis and F. exasperata significantly (P<0.05) inhibited LPO in a dose-dependent manner. The A. altilis extract had the most potent inhibitory activity against LPO with 79% relative to catechin (28%) at 750 µg/mL. The reducing power followed the order: A. altilis>Catechin>F. exasperata>K. africana at 1 000 µg/mL. The A. altilis at 500 and 750 µg/mL significantly (P<0.05) inhibited arginase activity by 63% and 67%, respectively. The flavonoids contents were found to be highest in A. altilis. Extracts of A. altilis and F. exasperata are potent antioxidative agents with strong radical scavenging activity and inhibition of lipid peroxidation.

The Protective Effect of Glycyrrhetinic Acid on Carbon Tetrachloride-Induced Chronic Liver Fibrosis in Mice via Upregulation of Nrf2

This study was designed to investigate the potentially protective effects of glycyrrhetinic acid (GA) and the role of transcription factor nuclear factor-erythroid 2(NF-E2)-related factor 2 (Nrf2) signaling in the regulation of Carbon Tetrachloride (CCl4)-induced chronic liver fibrosis in mice. The potentially protective effects of GA on CCl4-induced chronic liver fibrosis in mice were depicted histologically and biochemically. Firstly, histopathological changes including regenerative nodules, inflammatory cell infiltration and fibrosis were induced by CCl4.Then, CCl4 administration caused a marked increase in the levels of serum aminotransferases (GOT, GPT), serum monoamine oxidase (MAO) and lipid peroxidation (MDA) as well as MAO in the mice liver homogenates. Also, decreased nuclear Nrf2 expression, mRNA levels of its target genes such as superoxide dismutase 3 (SOD3), catalase (CAT), glutathione peroxidase 2 (GPX2), and activity of cellular antioxidant enzymes were found after CCl4 exposure. All of these phenotypes were markedly reversed by the treatment of the mice with GA. In addition, GA exhibited the antioxidant effects in vitro by on FeCl2-ascorbate induced lipid peroxidation in mouse liver homogenates, and on DPPH scavenging activity. Taken together, these results suggested that GA can protect the liver from oxidative stress in mice, presumably through activating the nuclear translocation of Nrf2, enhancing the expression of its target genes and increasing the activity of the antioxidant enzymes. Therefore, GA may be an effective hepatoprotective agent and viable candidate for treating liver fibrosis and other oxidative stress-related diseases.

Phytic Acid Inhibits Lipid PeroxidationIn Vitro

Phytic acid (PA) has been recognized as a potent antioxidant and inhibitor of iron-catalyzed hydroxyl radical formation under in vitro and in vivo conditions. Therefore, the aim of the present study was to investigate, with the use of HPLC/MS/MS, whether PA is capable of inhibiting linoleic acid autoxidation and Fe(II)/ascorbate-induced peroxidation, as well as Fe(II)/ascorbate-induced lipid peroxidation in human colonic epithelial cells. PA at 100 μM and 500 μM effectively inhibited the decay of linoleic acid, both in the absence and presence of Fe(II)/ascorbate. The observed inhibitory effect of PA on Fe(II)/ascorbate-induced lipid peroxidation was lower (10–20%) compared to that of autoxidation. PA did not change linoleic acid hydroperoxides concentration levels after 24 hours of Fe(II)/ascorbate-induced peroxidation. In the absence of Fe(II)/ascorbate, PA at 100 μM and 500 μM significantly suppressed decomposition of linoleic acid hydroperoxides. Moreover, PA at the tested nontoxic concentrations (100 μM and 500 μM) significantly decreased 4-hydroxyalkenal levels in Caco-2 cells which structurally and functionally resemble the small intestinal epithelium. It is concluded that PA inhibits linoleic acid oxidation and reduces the formation of 4-hydroxyalkenals. Acting as an antioxidant it may help to prevent intestinal diseases induced by oxygen radicals and lipid peroxidation products.

Moderate intermittent hypoxia/hyperoxia: implication for correction of mitochondrial dysfunction

Abstract The purpose of this study was to appreciate the acute hypoxia-induced mitochondrial oxidative damage development and the role of adaptation to hypoxia/hyperoxia (H/H) in correction of mitochondrial dysfunction. It was demonstrated that long-term sessions of moderate H/H [5 cycles of 5 min hypoxia (10% O2 in N2) alternated with 5 min hyperoxia (30% O2 in N2) daily for two weeks]_attenuated basal and Fe2+/ascorbate-induced lipid peroxidation (LPO) as well as production of carbonyl proteins and H2O2 in liver mitochondria of rats exposed to acute severe hypoxia (7% O2 in N2, 60 min) in comparison with untreated animals. It was shown that H/H increases the activity of glutathione peroxidase (GPx), reduces hyperactivation of Mn-SOD, and decreases Cu,Zn-SOD activity as compared with untreated rats. It has been suggested that the induction of Mn-SOD protein expression and the coordinated action of Mn-SOD and GPx could be the mechanisms underlying protective effects of H/H, which promote the correction of the acute hypoxia-induced mitochondrial dysfunction. The increase in Mn-SOD protein synthesis without changes in Mn-SOD mRNA level under H/H pretreatment indicates that the Mn-SOD activity is most likely dependent on its posttranslational modification or on the redox state of liver mitochondria.

Antioxidant and antihepatotoxic efficacy of methanolic extract of Elephantopus scaber Linn in Wistar rats

ObjectiveTo determine the in vitro and in vivo antioxidant and hepatoprotective activity of methanolic extract of Elephantopus scaber root against CCl4 induced liver damage in rats. MethodsIn vitro antioxidant activity was studied by determining superoxide scavenging, hydroxyl scavenging and Fe2+ ascorbate induced lipid peroxidation inhibiting activity of methanolic extract. The in vivo hepatoprotective activity was studied by estimating AST, ALT, ALP, GGT, total protein, albumin levels and by histopathological examination in CCl4 toxicity induced experimental rats. The peroxidative hepatic damage was studied by assessing TBARS, CD, SOD, CAT and GSH in liver. ResultsMethanolic extract of Elephantopus scaber root at doses of 75mg and 150mg/kg body weight significantly reduced the levels of AST, ALT, ALP & GGT and increased the level of TP and Albumin. The levels of TBARS and CD were decreased and the level of GSH increased. The levels of SOD and CAT were decreased. Histopathological changes induced by CCl4 were reduced by the treatment of methanolic extract of Elephantopus scaber root. The effect was compared with reference drug curcumin. ConclusionsThe antioxidant and antihepatotoxic activities of methanolic extract of Elephantopus scaber root was probably due to free radical scavenging activity.

Chlorella vulgaris extract ameliorates carbon tetrachloride-induced acute hepatic injury in mice

The possible protective effects of Chlorella vulgaris extract (CVE) on carbon tetrachloride (CCl(4))-induced acute hepatic injury in mice and the mechanism underlying these effects was investigated. CCl(4) administration caused a marked increase in the levels of serum aminotransferases, lipid peroxidation and cytochrome P450-2E1 (CYP450) expression. Also, decreased glutathione (GSH) content and activities of cellular antioxidant defense enzymes such as superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), catalase and glutathione-S-transferase (GST) were found after CCl(4) exposure. All of these phenotypes were markedly reversed by preadministration of the mice with CVE. In addition, CVE exhibited antioxidant effects on FeCl(2)-ascorbate induced lipid peroxidation in mouse liver homogenates, and on superoxide radical scavenging activity. Taken together, these results suggest that CVE produced a protective action on CCl(4)-induced acute hepatic injury in mice, presumably through blocking CYP-mediated CCl(4) bioactivation, inducing the GSH levels, antioxidant enzyme activities and free radical scavenging effect. Therefore, CVE may be an effective hepatoprotective agent and viable candidate for treating hepatic disorders and other oxidative stress-related diseases.

Evaluation of the antioxidant activity of five endemic Ligustrum species leaves from Taiwan flora in vitro

Leaves from the plant species belonging to the genus Ligustrum are widely used as tea or herbal medicine in Europe, China, and Japan. The antioxidant properties of five Ligustrum species from Taiwan were compared using in vitro antioxidant methods such as DPPH radical scavenging, TEAC, and FRAP assays. Cell-based antioxidant methods were used, including Fe2+/ascorbate-induced lipid peroxidation on brain homogenate and AAPH-induced erythrocyte haemolysis. The amounts of major phenolic compounds from the Ligustrum species, including phenylpropanoids, flavonoids, and iridoids, were determined by spectrophotometric methods. The results showed that all Ligustrum species exhibited antioxidant, radical-scavenging, anti-haemolytic, and lipid peroxidation-inhibiting activities at different magnitudes of potency. A significant correlation was found between antioxidant activity and the amount of antioxidant components, in particular, total phenolics and phenylpropanoids. Among all Ligustrum species from Taiwan, Ligustrum morrisonense is presented as potential source of natural antioxidants.

Antioxidant Activity of Newly Synthesized 2,7‐Diazaphenothiazines

A series of 19 derivatives of 2,7-diazaphenothiazine was synthesized and evaluated for their antioxidant activity bearing in mind the structural similarity with "classical" phenothiazines several of which are considered powerful antioxidants. Among the new derivatives that inhibited in vitro Fe(2+)/ascorbate-induced lipid peroxidation of rat liver microsomal membranes, several exhibited significant antioxidant activity with IC(50 )values in the range of 64-125 microM. Although N-substitution led to a variable degree of antioxidant activity, the latter appears to correlate with the lipophilicity (expressed as clogP values) of the substituted derivatives. Reduced lipophilicity may also explain the relatively lower protection offered by these derivatives against lipid peroxidation when compared to their "classical" phenothiazine counterparts. Thus, modification of the phenothiazine structure by a substitution of two benzene rings with pyridine rings to form this new type of azaphenothiazines does not enhance antioxidant activity, although it retains it.

GLYCOSIDASE INHIBITORY ACTIVITY AND ANTIOXIDANT PROPERTIES OF A POLYSACCHARIDE FROM THE MUSHROOM INONOTUS OBLIQUUS

ABSTRACT A water-soluble polysaccharide from Inonotus obliquus (IOPS) was isolated from the mushroom Inonotus obliquus (Fr.) Pilat. The chemical compositions, molecular weight and inhibitory activities on glycosidase and antioxidant properties of IOPS were investigated. The results indicated that IOPS was an acid protein-bound polysaccharide, with a molecular weight of 1.7 × 104 Da and the contents of neutral sugar, protein and uronic acids being 42.5, 18.5 and 6.1%, respectively. IOPS exhibited an inhibitory activity against α-glucosidase with the IC50 value of 93.3 µg/mL, whereas it had no effective inhibition on α-amylase. Results of antioxidant activity assays revealed that IOPS had inhibitory activity on the concentration-dependent quenching of 1,1-Diphenyl-2-picrylhydrazyl and hydroxyl radicals. Furthermore, IOPS inhibited the formation of thiobarbituric acid-reactive substances in Fe2+/ascorbate-induced lipid peroxidation in rat liver tissue. These results clearly demonstrated that IOPS was one of the main bioactive components of I. obliquus that contributed to hypoglycemic activity and antioxidant activity. PRACTICAL APPLICATIONS Diabetes mellitus is one of the primary threats to human health because of its increasing prevalence, chronic course and disabling complications. Postprandial hyperglycemia plays an important role in the development of type 2 diabetes mellitus and complications associated with the disease. One therapeutic approach to decrease postprandial hyperglycemia is to retard the absorption of glucose through inhibition of carbohydrate-hydrolyzing enzymes in the digestive organs. In this study, a polysaccharide isolated from the mushroom Inonotus obliquus (IOPS) was shown to have notable glycosidase inhibitory effects and antioxidant activities. This research will benefit for the investigation of effective and safe α-glucosidase inhibitors from natural materials. IOPS could be a good candidate for application in food and medicinal fields. It might be developed for functional food or lead compounds for use in antidiabetes.

Modulatory effect of Morus indica against two-stage skin carcinogenesis in Swiss albino mice: possible mechanism by inhibiting aryl hydrocarbon hydroxylase.

The modulatory effect of the methanolic extract of Morus indica on 12-O-tetradecanoyl-phorbol-13-acetate (TPA) induced oxidative stress and 7,12-dimethylbenz(a)anthracene induced and croton oil (0.5% per mouse/0.2 mL acetone, v/v) promoted skin tumourigenesis in Swiss albino mice was studied. The efficacy of the M. indica extract was also evaluated in-vitro by studying the inhibition of the activity and level of aryl hydrocarbon hydroxylase, cytochrome P450, DNA sugar damage in calf thymus DNA and Fe(++)/ascorbate-induced lipid peroxidation in microsomes of mice. Significant increases in the activity of antioxidant enzymes (P <0.001) and a concomitant decrease (P <0.001) in the cutaneous malondialdehyde level were observed at three doses of plant extract (2.5, 5.0 and 7.5 mg kg(-1)). Application of M. indica 1 h before each application of croton oil showed inhibitory effects on tumour promotion in terms of a reduction in the number of tumours/mouse and percentage of mice with tumours. It was also accompanied by an extension of the tumour latency period. TPA, which resulted in a rapid and transient stimulation of mouse epidermal ornithine decarboxylase activity (P <0.001), was inhibited dose dependently by pre-treatment with M. indica extract (P <0.001). The results suggest that M. indica extract may be useful as a therapeutic agent for cancer control as it blocks or suppresses events associated with chemical carcinogenesis.

Potent hepatoprotective effect in CCl4-induced hepatic injury in mice of phloroacetophenone from Myrcia multiflora

Background: This study investigated the hepatoprotective effect and antioxidant properties of phloroacetophenone (2′,4′,6′-trihydroxyacetophenone – THA), an acetophenone derived from the plant Myrcia multiflora.Material & Method: The free radical scavenging activity in vitro and induction of oxidative hepatic damage by carbon tetrachloride (CCl4) (0.5 ml/kg, i.p.) were tested in male Swiss mice (25±5 g).Results: This compound exhibited in vitro antioxidant effects on FeCl2–ascorbate-induced lipid peroxidation (LPO) in mouse liver homogenate, scavenging hydroxyl and superoxide radicals, and 2,2-diphenyl-1-picrylhydrazyl. The in vivo assays showed that THA significantly (p<0.01) prevented the increases of hepatic LPO as measured by the levels of thiobarbituric acid-reactive substances, mitochondrial swelling. It also protected hepatocytes against protein carbonylation and oxidative DNA damage. Consistent with these observations, THA pre-treatment normalized the activities of antioxidant enzymes, such as catalase, glutathione peroxidase, and superoxide dismutase, and increased the levels of reduced glutathione (GSH) in CCl4-treated mice. In addition, THA treatment significantly prevented the elevation of serum enzymatic activities of alanine amino transferase, aspartate amino transferase, and lactate dehydrogenase, as well as histological alterations induced by CCl4. Silymarin (SIL) (24 mg/kg), a known hepatoprotective drug used for comparison, led to a significant decrease (p<0.01) in activities of theses enzymes in way very similar to that observed in pre-treatment with THA.Conclusion: These results suggest that the protective effects are due to reduction of oxidative damage induced by CCl4 resulting from the antioxidant properties of THA.

Effects of Athamanta turbith fruit essential oils on CCl4‐induced hepatic failure in mice and their antioxidant properties

The effects of essential oils isolated from mature fruits of Athamanta turbith ssp. hungarica (Borbás) Tutin and A. turbith ssp. haynaldii (Borbás & Uechtr.) Tutin (Umbelliferae) on some liver biochemical parameters in mice intoxicated with carbon tetrachloride were investigated. Pretreatment with both essential oils extenuated the effects caused by carbon tetrachloride. In order to investigate in vitro antioxidant properties of the oils, three methods were applied: scavenging of both 2,2-diphenyl-1-picrylhydrazyl (DPPH) and OH radicals, as well as a test of inhibition of Fe(2+)/ascorbic-induced lipid peroxidation. Investigated essential oils exhibited modest antioxidant capacity. Therefore, their influence on biochemical parameters in intoxicated animals might be linked to the inhibition of enzymes (cytochrome P450 2E1) involved in metabolic activation of halomethanes.

Plantain (Plantago L.) Species as Novel Sources of Flavonoid Antioxidants

To examine the antioxidant properties of methanol extracts of selected Plantago species (P. argentea Chaix., P. holosteum Scop., P. major L., P. maritima L., and P. media L.), various assays that measure free radical scavenging ability were carried out: DPPH, hydroxyl radical, superoxide anion, and nitric oxide scavenger capacity tests, reducing power (FRAP) assay, and Fe(2+)/ascorbate induced lipid peroxidation. In all of the tests extracts showed a potent antioxidant effect compared with BHT, a well-known synthetic antioxidant, and the extract of P. major, accepted as an official remedy. Besides, in examined extracts the total phenolic amount (ranging from 38.43 to 70.97 mg of GAE/g of dw) and the total flavonoid content (5.31-13.10 mg of QE/g of dw) were determined. Furthermore, the presence and content of selected flavonoids (luteolin-7-O-glucoside, apigenin-7-O-glucoside, luteolin, apigenin, rutin, and quercetin) were studied using LC-MS/MS technique. LC-MS/MS analysis showed noticeable qualitative and quantitative differences between the species according to which the examined Plantago species could be regarded as a possible new source of natural antioxidants. In this study three of the species examined, P. maritima, P. argentea, and P. holosteum, have been analyzed for the first time.