Lipid Peroxidation Inhibitory Effect Research Articles

Chemical characterization and antioxidative activity of four 3-hydroxyl-3-methylglutaroyl (HMG)-substituted flavonoid glycosides from Graptopetalum paraguayense E. Walther.

BackgroundGraptopetalum paraguayense E. Walther is a popular traditional Chinese herb and possesses several health benefits. In earlier studies, we demonstrated that G. paraguayense showed no genotoxicity and showed several biological activities. However, the constituents of G. paraguayense have not been studied yet. In this present study, we isolated and identified the constituents of the leaves of G. paraguayense E. Walther.ResultsA total of seven flavonoid compounds were isolated from the methanolic extract of G. paraguayense. The four major compounds isolated were flavonoid glucoside derivatives of quercetin (1, 3) and kampferol (2, 4), each presenting a 3-hydroxyl-3-methylglutaroyl (HMG) substituent; compounds 3 and 4—the 2´´-acetyl derivatives of 1 and 2, respectively—are novel compounds isolated from nature for the first time. High-performance liquid chromatography for the quantitative analyses of the four major HMG-substituted flavonoid glycosides in G. paraguayense E. Walther were accomplished to acquire the high yields of 1–4 in the methanolic extract (4.8, 5.7, 4.3, and 2.5 mg/g, respectively). Furthermore, the antioxidant activities, including radical-scavenging, reducing power and lipid peroxidation inhibitory effects of these isolated flavonoids were also evaluated. All seven of the isolated flavonoid compounds possessed antioxdative activity.ConclusionsIn this study of the constituents of the leaves of G. paraguayense E. Walther, we isolated four major components from its methanolic extract and determined their structures to be (acetylated) HMG-substituted flavonol glycosides, which are rare in nature. All seven of the isolated compounds possessed antioxdative activity, and those flavonoid compounds may be responsible for the functional ingredients in G. paraguayense. Further investigation of their bioactivities or pharmacological activities will be continued.Electronic supplementary materialThe online version of this article (doi:10.1186/s40529-015-0088-4) contains supplementary material, which is available to authorized users.

Chemical Composition, Antioxidant, Lipid Peroxidation Inhibition and Free Radical Scavenging Activities of Microwave Extracted Essential Oil from Allium sativum

Various chronicle diseases are associated with oxidative stress caused by free radicalsand reactive oxygen species in the living cell system. In the present study, the chemical composition and antioxidant capacity of Allium sativumessential oil (ASEO) were investigated using different scavenging models including 1,1-diphenyl-2-picryl hydrazyl (DPPH), nitric oxide, superoxide, and hydroxyl radicals. Also the ASEO was evaluated for its lipid peroxidation inhibition efficacy, reducing power ability and total phenolic contents. The ASEO was obtained by the hydrodistillation of the dried rhizomes of A. sativum using a microwave-assisted extraction technique. Gas chromatography-mass spectrometry analysis of the ASEO resulted in the determination of 17 different compounds, representing 92.46 % of the total oil. The major components in the ASEO were phenolics, saturated fatty acids, sugar alcohols, esters, hydrazine, quinoline and isoquinoline derivatives along with some other essential phytochemicals. The ASEO showed the antioxidant capacity as the inhibition of DPPH, nitric oxide, superoxide, and hydroxyl radicals by 72.06 %, 79.96 %, 72.66 %, and 71.21 %, respectively. Moreover, the ASEO displayed concentration-dependent reducing power ability and remarkable ferric ion-induced lipid peroxidation inhibitory effect in bovine brain extract. In addition, the ASEO yielded 5.75±0.21 mg/ g gallic acid equivalent phenolic content. The findings of the present study confirm the efficacy of A. sativumas a potential source of natural antioxidant.

Studies on phytochemical analysis, antioxidant and lipid peroxidation inhibitory effects of a medicinal plant, Coleus forskohlii

Oxidative stress caused by reactive oxygen species and free radicals generated in living cells may cause various chronic, non-communicable diseases. Current research is directed towards finding naturally occurring antioxidants of plant origin. This study investigated the phytochemistry, antioxidant and free radical scavenging potential of ethanolic root extract of Coleus forskohlii (ERECF) using different antioxidant models. The phytochemical analysis of ERECF revealed the presence of alkaloids, glycosides, terpenoids, saponins, phenols and steroids. ERECF showed antioxidant capacity with the inhibition of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical by 71.21%. ERECF also had a potent inhibitory effect on scavenging nitric oxide, superoxide and hydroxyl radicals, by 66.23%, 61.22% and 61.68%, respectively. Moreover, ERECF displayed a concentration-dependent reducing power ability and a remarkable ferric ion-induced lipid peroxidation inhibitory effect (69.24%) in bovine brain extract. These findings confirm the biological efficacy of C. forskohlii as a potential source of natural antioxidants.

Studies on Phytochemicals, Antioxidant, Free Radical Scavenging and Lipid Peroxidation Inhibitory effects of Trachyspermum ammi seeds

Abstract: Objective: Reactive oxygen species and free radicals generate oxidative stress in the living cells associated with number of chronic diseases. Current research is directed towards finding naturally occurring antioxidants of plant origin. Hence, this study was aimed to determine phytochemical analysis, antioxidant and free radical scavenging potential of ethanolic seed extract of Trachyspermum ammi (ESETA). Methods: A preliminary phytochemical screening was carried out for the analysis of important phytochemicals present in ESETA. Antioxidant potential of ESETA was evaluated by various scavenging models including DPPH, nitric oxide, superoxide, and hydroxyl radical as well as its lipid peroxidation ability in bovine brain extract. Results: The phytochemical analysis of ESETA revealed the presence of various phytoconstituents including alkaloids, glycosides, terpenoids, saponins, phenols and steroids. The ESETA showed the antioxidant capacity as the inhibition of DPPH radical by 73.41%. Also the ESETA had potent inhibitory effect on scavenging nitric oxide, superoxide, and hydroxyl radicals by 67.33%, 63.22% and 62.48% respectively. Moreover, the ESETA displayed concentration-dependent reducing power ability and remarkable ferric ion-induced lipid peroxidation inhibitory effect (69.22%) in bovine brain extract. Conclusion: These findings confirm the pharmacological efficacy of T. ammi as a potential source of natural antioxidant. Key words: Trachyspermum ammi, Phytochemicals, Reactive oxygen species, Free radicals, Antioxidant activity.

Phytochemicals, Antioxidant and Anti-Lipid Peroxidation Activities of Ethanolic Extract of a Medicinal Plant, A ndrographis paniculata

Various human diseases are associated with oxidative stress caused by reactive oxygen species and free radicals generated in the living cells. Current research is directed toward finding naturally occurring antioxidant components of plant origin. This study was outlined to probe phytochemical analysis, antioxidant and anti-lipid peroxidation potential of ethanolic whole plant extract of Andrographis paniculata (EWPEAP) using different antioxidant and free radical scavenging models. The phytochemical analysis of EWPEAP revealed the presence of alkaloids, glycosides, terpenoids, saponins, phenols and steroids. The EWPEAP showed the antioxidant capacity as the inhibition of 1,1-diphenyl-2-picrylhydrazyl radical by 72.4%. The EWPEAP also had potent inhibitory effect on scavenging nitric oxide, superoxide and hydroxyl radicals by 66.5%, 62.2% and 62.5%, respectively. Moreover, the EWPEAP displayed concentration-dependent reducing power ability and significant (P < 0.05) ferric ion-induced lipid peroxidation inhibitory effect in bovine brain extract. These findings confirm the biological efficacy of A. paniculata as a potential source of natural antioxidant. Practical Applications Andrographis paniculata plant is widely used in Southeast Asia as febrifuge, tonic, stomachic and anthelmintic. It is also used as a principal ingredient of several pharmaceutical preparations in various forms as well as household medicine. Although it is being used in traditional practices, A. paniculata has been found to possess several biological properties including hepatoprotective, antithrombotic, anti-inflammatory, immunostimulant, antimalarial, antihyperglycemic and cardioprotective effect. Because oxidative stress has been implicated as one of the inducing factors for the generation of various metabolic disorders, the present study has evaluated the antioxidant potential of whole plant of A. paniculata, which may prove to be beneficial against free radical generated disorders.

Evaluation of antioxidant activities of zein protein fractions.

Zein protein was extracted from the by-product corn gluten meal. The obtained zein protein was 1st hydrolyzed by 4 different proteases. The antioxidant activities of the hydrolysates or peptides were evaluated by free radical scavenging activity, metal ion chelating activity, and lipid peroxidation inhibitory capacity. Among hydrolysates produced, alkaline protease hydrolysates exhibited the highest antioxidant activity. A regression model was established by uniform design to optimize the alkaline protease hydrolysis conditions. The hydrolysates with molecular weight < 3 kDa obtained from ultrafiltration showed the highest antioxidant activities in all relevant assays. The hydrolysates with molecular weight <3 kDa were subsequently purified by gel filtration chromatography, and fraction F3 exhibited the highest antioxidant activities. Two peptides were identified from fraction F3 using LC-ESI-Q-TOF MS/MS as Pro-Phe (263.13 Da) and Leu-Pro-Phe (375.46 Da). These peptides exhibited good free radical scavenging activity and lipid peroxidation inhibitory effect. The results clearly indicated that zein protein fractions are good sources for the development of natural antioxidants for the food industry.

Antioxidant and protective effect of inulin and catechin grafted inulin against CCl4-induced liver injury

In this study, the antioxidant activity and hepatoprotective effect of inulin and catechin grafted inulin (catechin-g-inulin) against carbon tetrachloride (CCl4)-induced acute liver injury were investigated. Results showed that both inulin and catechin-g-inulin had moderate scavenging activity on superoxide radical, hydroxyl radical and H2O2, as well as lipid peroxidation inhibition effect. The antioxidant activity decreased in the order of Vc>catechin>catechin-g-inulin>inulin. Administration of inulin and catechin-g-inulin could significantly reduce the elevated levels of serum aspartate transaminase, alanine transaminase and alkaline phosphatase as compared to CCl4 treatment group. Moreover, inulin and catechin-g-inulin significantly increased the levels of hepatic superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, glutathione and total antioxidant capacity, whereas markedly decreased the malondialdehyde level when compared with CCl4 treatment group. Notably, catechin-g-inulin showed higher hepatoprotective effect than inulin. In addition, the hepatoprotective effect of catechin-g-inulin was comparable to positive standard of silymarin. Our results suggested that catechin-g-inulin had potent antioxidant activity and potential protective effect against CCl4-induced acute liver injury.

Evaluation of antioxidant activity and total phenol in different varieties of Lantana camara leaves.

BackgroundPhytochemicals like carotenoids, tocopherols, ascorbates and phenols present in the plants are strong antioxidants and have an important role in the health care system. There is growing interest in correlating the phytochemical constituents of a plant with its pharmacological activity. Therefore, the present study investigates the content of total phenolics, flavonoids and the antioxidant activity of four different varieties of Lantana camara L. (Verbenaceae) leaves by using in vitro antioxidant models.MethodsThe leaves of Chandigarh purple variety (CPV), Palampur red variety (PRV), Chandigarh yellow turning pink variety (YTPV) and Chandigarh yellow variety (CYV) Lantana camara were collected and the total phenolic, flavonoid content, antioxidant and free radical scavenging activities were determined in their methanolic extracts.ResultsThe phenolic content was found to be highest in the CYV extract (232.99 ± 15.97 mg GAE/ g extract). The content of the flavonoids are in the order of YTPV, PRV, CPV and CYV. The IC50 values for the 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging test were in the order of CYV (33.30 ± 2.39) < PRV (40.32 ± 2.94) < YTPV (475.33 ± 5.20) < CPV (927.16 ± 2.88 μg/mL). The highest total antioxidant capacity was observed in CYV (222.20 ± 5.05 mg AAE/ g). The Ferric ion reducing antioxidant potential (FRAP) value of the extracts were in the order of CYV > PRV > YTPV > CPV. The IC50 values of 2, 2'-azino-bis-(3-ethylbenzothiazoline-6-sulfonate) (ABTS) scavenging assay for CYV, PRV, YTPV, CPV were 18.25 ± 0.19, 18.24 ± 1.82, 50.43 ± 9.49, 52.84 ± 1.82 μg/mL respectively. PRV extract showed the maximum in vitro lipid peroxidation inhibition effect with an IC50 value of 68.50 μg/mL which is even stronger as compared to the standard Rutin (79.69 μg/mL). The extracts showed a strong correlation between the phenolic content and their antioxidant activities. The highest correlation (r = 0.998, R2 = 0.997) was found between total phenolic content and ABTS scavenging assay.ConclusionAmong the four varieties investigated, CYV and PRV extracts showed strong antioxidant activities and may be used as a potential source of natural antioxidant against free radical associated diseases.

Characterization of polysaccharides with antioxidant and hepatoprotective activities from the wild edible mushroom Russula vinosa Lindblad.

The aim of the present study was to investigate the antioxidant and hepatoprotective effects of water-soluble polysaccharides (RVLWP) and alkali-soluble polysaccharides (RVLAP) from Russula vinosa on carbon tetrachloride (CCl4)-induced acute liver damage in mice. For the in vitro antioxidant activities, RVLWP and RVLAP exhibited potent 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity (IC50 = 1.55 ± 0.04 and 3.37 ± 0.21 mg/mL, respectively), hydrogen peroxide scavenging activity (IC50 = 6.07 ± 0.24 and 9.23 ± 0.54 mg/mL, respectively), lipid peroxidation inhibitory effect (IC50 = 0.52 ± 0.095 and 0.86 ± 0.043 mg/mL, respectively), and moderate reducing power and Fe(2+) chelating activity (IC50 = 1.86 ± 0.0036 and 0.22 ± 0.0057 mg/mL, respectively). Ascorbic acid was employed as the standard antioxidant in the present study. For the in vivo hepatoprotective activity, administration of RVLWP and RVLAP (200 mg/kg) significantly prevented the elevation in serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities in acute liver damage induced by CCl4 and suppressed hepatic malondialdehyde (MDA) formation. Mice treated with RVLWP and RVLAP demonstrated a better profile of antioxidants with augmented activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) in the liver. The results suggest that RVLWP and RVLAP protect the liver from CCl4-induced hepatic damage via antioxidant mechanisms.

Nonallergenic urushiol derivatives inhibit the oxidation of unilamellar vesicles and of rat plasma induced by various radical generators

Urushiols consist of an o-dihydroxybenzene (catechol) structure and an alkyl chain of 15 or 17 carbons in the 3-position of a benzene ring and are allergens found in the family Anacardiaceae. We synthesized various veratrole (1,2-dimethoxybenzene)-type and catechol-type urushiol derivatives that contained alkyl chains of various carbon atom lengths, including –H, –C1H3, –C5H11, –C10H21, –C15H31, and –C20H41, and investigated their contact hypersensitivities and antioxidative activities. 3-Decylcatechol and 3-pentadecylcatechol displayed contact hypersensitivity, but the other compounds did not induce an allergic reaction, when the ears of rats were sensitized by treatment with the compounds every day for 20 days. Catechol-type urushiol derivatives (CTUDs) exerted very high radical-scavenging activity on the 1,1-diphenyl-2-picrylhydrazyl radical and inhibited lipid peroxidation in a methyl linoleate solution induced by 2,2′-azobis(2,4-dimethylvaleronitrile) (AMVN). However, veratrole-type urushiol derivatives did not scavenge or inhibit lipid peroxidation. CTUDs also acted as effective inhibitors of lipid peroxidation of the egg yolk phosphatidylcholine large unilamellar vesicle (PC LUV) liposome system induced by various radical generators such as AMVN, 2,2′-azobis(2-amidino-propane) dihydrochloride, and copper ions, although their efficiencies differed slightly. In addition, CTUDs suppressed formation of cholesteryl ester hydroperoxides in rat blood plasma induced with copper ions. CTUDs containing more than five carbon atoms in the alkyl chain showed excellent lipophilicity in a n-octanol/water partition experiment. These compounds also exhibited high affinities to the liposome membrane using the ultrafiltration method of the PC LUV liposome system. Therefore, CTUDs seem to act as efficient antioxidative compounds against membranous lipid peroxidation owing to their localization in the phospholipid bilayer. These results suggest that nonallergenic CTUDs act as antioxidants to protect against oxidative damage of cellular and subcellular membranes.

2-Amino-5-alkylidenethiazol-4-ones as promising lipid peroxidation inhibitors

2-Amino-5-alkylidenethiazol-4-one represents a promising scaffold in medicinal chemistry and drug discovery. In the present study the antioxidant activity of 30 diverse 2-amino-5-alkylidenethiazol-4-ones was screened using a lipid peroxidation (LP) method. All compounds under study showed activity regardless of the substituent nature. However, several compounds exhibited a significant LP inhibition effect, which was in the range of that obtained with standard antioxidants. Compounds containing an (indol-3-yl)methylene group at position 5 of thiazol-4-one moiety and a six-membered ring as the 2-amino substituent showed inhibitory effects higher than 60 %. The most active compound, 5-benzylidene-2-morpholinothiazol-4(5H)-one, was investigated by means of ab initio calculations in order to clarify the most probable mechanism of antioxidant action. These calculations imply that electron transfer from the 2-amino-5-alkylidenethiazol-4-ones to the lipid alkoxyl, lipid peroxyl, or hydroxyl radicals could produce radical cations able to scavenge the lipid radicals and produce adducts, and ultimately terminate the reaction by proton transfer. Thus we propose the electron transfer (SET) mechanism as the most probable one that explains the observed inhibition of LP.

Production of nigragillin and dihydrophaseic acid by biotransformation of litchi pericarp with Aspergillus awamori and their antioxidant activities

Biotransformation with Aspergillus awamori could degrade the bound bioactive compounds of plant tissues into free form and induce the biosynthesis of novel chemicals. In this work, two bioactive compounds with high levels were produced from litchi pericarp via A. awamori fermentation. They were purified and identified to be nigragillin and dihydrophaseic acid by nuclear magnetic resonance spectroscopy and mass spectrometry. The anticancer activity, DNA protection effect and antioxidant activity of these two compounds were evaluated. Dihydrophaseic acid had significantly inhibitory effect against HepG2 and HeLa cells with IC50 values of 41.92±6.15 and 79.37±9.78μg/mL, respectively. Nigragillin showed a better DPPH radical scavenging activity than dihydrophaseic acid. Dihydrophaseic acid possessed good lipid peroxidation inhibition effect, hydroxyl radical scavenging activity, and DNA protection effect even at a low dosage. The results indicated that biotransformation with A. awamori was a good way to produce bioactive compounds.

Lipid peroxidation-inhibitory effects of perioperatively used drugs associated with their membrane interactions

Objective: Oxidative/nitrative stress, an imbalance between oxidant production and antioxidant defense in the biological system, is induced not only by various diseases but also by anesthesia and surgical trauma. Since the choice of drugs is expected to reduce oxidative/nitrative stress in the perioperative period, the lipid peroxidation inhibition by different drugs associated with surgery was studied together with investigating one of their possible mechanisms. Methods: Lipid peroxidation-inhibitory effects were fluorometrically determined using the liposomes of diphenyl-1-pyrenylphosphine-incorporated lipid bilayers which were treated with 10-200 μM drugs and reference antioxidants, and then peroxidized with 20 μM peroxynitrite. Membrane interactions were evaluated by the drug- and antioxidant-induced changes in membrane fluidity which were determined by measuring the fluorescence polarization of 1,6-diphenyl-1,3,5-hexatriene-labeled biomimetic membranes after treating with drugs and antioxidants at 1-200 μM. Results: All of the tested drugs concentration-dependently inhibited peroxynitrite-induced lipid peroxidation as well as antioxidant α-tocopherol, quercetin and (–)-epigallocatechin-3-gallate. The inhibition at 10 μM was greatest in propofol, followed by guaiacol, thiopental, thymol, phenol, midazolam, diazepam, lidocaine, eugenol, procaine, bupivacaine, ropivacaine, sevoflurane, ketamine, mepivacaine and prilocaine. Antioxidant drugs including propofol, local anesthetics and phenol derivatives, and reference antioxidants interacted with biomimetic membranes consisting of phospholipids and cholesterol to modify the membrane fluidity, while their membrane-interacting potencies did not necessarily correlate to their lipid peroxidation-inhibiting ones, suggesting that the interaction between drugs and membrane lipid bilayers, at least in part, underlies the lipid peroxidation inhibition. Conclusion: In addition to their inherent effects, propofol and other drugs to inhibit lipid peroxidation may be protective against perioperative oxidative/nitrative stress. The membrane interaction could be a guide for discovering novel antioxidant drugs.

Antioxidant, lipid peroxidation inhibition and free radical scavenging efficacy of a diterpenoid compound sugiol isolated from Metasequoia glyptostroboides

ObjectiveTo investigate the antioxidant efficacy of a biologically active diterpenoid compound sugiol isolated from Metasequoia glyptostroboides (M. glyptostroboides) in various antioxidant models. MethodsAn abietane type diterpenoid sugiol, isolated from ethyl acetate extract of M. glyptostroboides cones, was analyzed for its antioxidant efficacy as reducing power ability and lipid peroxidation inhibition as well as its ability to scavenge free radicals such as 1,1-diphenyl-2-picryl hydrazyl, nitric oxide, superoxide and hydroxyl radicals. ResultsThe sugiol showed significant and concentration-dependent antioxidant and free radical scavenging activities. Consequently, the sugiol exerted lipid peroxidation inhibitory effect by 76.5% as compared to α-tocopherol (80.13%) and butylated hydroxyanisole (76.59%). In addition, the sugiol had significant scavenging activities of 1,1-diphenyl-2-picryl hydrazyl, nitric oxide, superoxide and hydroxyl free radicals in a concentration-dependent manner by 78.83%, 72.42%, 72.99% and 85.04%, when compared to the standard compound ascorbic acid (81.69%, 74.62%, 73.00% and 73.79%) and α-tocopherol/butylated hydroxyanisole (84.09%, 78.61%, 74.45% and 70.02%), respectively. ConclusionsThese findings justify the biological and traditional uses of M. glyptostroboides or its secondary metabolites as confirmed by its promising antioxidant efficacy.

In vitro antioxidant activities and antioxidant enzyme activities in HepG2 cells and main active compounds of endophytic fungus from pigeon pea [Cajanus cajan (L.) Millsp.

This study evaluated the antioxidant activity of the main active compound of an endophytic fungus MD-R-1 from pigeon pea. This fungus was identified as Aspergillus fumigates by ITS sequence. The antioxidant capacity was evaluated by DPPH, hydroxyl radical scavenging, reducing power, lipid peroxidation and XOD inhibitory effect assays. Among the four fractions, the EtOAc fraction showed the best antioxidant activity (IC50 values were 16.38, 35.20, 19.69, 22.64 and 193.24μg/mL, respectively) and the highest phenolic and flavonoid content. Furthermore, it possessed good protective activity from oxidative DNA damage. The activities of superoxide dismutase (SOD), catalase (CAT) and glutathione reductase (GR) in HepG2 cells treated with MD-R-1 EtOAc extracts were also determined. The results showed that EtOAc extracts significantly increased the activities of SOD, CAT and GR in HepG2 cells in a dose-dependent manner. The LC–MS/MS was used to analyze EtOAc fraction and the result pointed to a notable antioxidant compound, luteolin. The present investigation suggests that MD-R-1 represents a valuable natural antioxidant source and may be applicable in health food industry potentially.

Comparison of antioxidant capacity, protein profile and carbohydrate content of whey protein fractions

Whey is used as an additive in food industry and a dietary supplement in nutrition. Here we report a comparative analysis of antioxidant potential of whey and its fractions. Fractions were obtained by size exclusion chromatography, before and after enzymatic digestion with pepsin or trypsin. Superoxide radical scavenging, lipid peroxidation inhibition and cupric ion reducing activities of different fractions were checked. Peptides were detected by SDS–PAGE and GC–MS was used to determine carbohydrate content of the fractions. All samples showed antioxidant activity and the second fraction of the trypsin hydrolysate showed the highest superoxide radical scavenging activity. CUPRAC value of this fraction was two-times higher than that of whey filtrate. The first fraction of the pepsin hydrolysate was the most effective inhibitor of lipid peroxidation. Each sample exhibited a different polypeptide profile. Different percentages of carbohydrates were identified in whey filtrate and in all second fractions, where galactose was the major component.

Purification and identification of antioxidant peptides from corn gluten meal

Corn gluten meal was hydrolyzed by alkaline protease and Flavourzyme to obtain the antioxidant peptides. The antioxidant activities of the hydrolysates or peptides were evaluated by free radical scavenging capacity (1,1-diphenyl-2-picrylhydrazyl/2,2-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt/hydroxyl radical/superoxide radical anion), metal ion (Fe2+/Cu2+) chelating activity and lipid peroxidation inhibitory capacity. The hydrolysates were separated by ultrafiltration, and those with molecular weight <10kDa exhibited highest antioxidant activity in all relevant assays. The hydrolysates were subsequently purified by gel filtration chromatography, and fraction F3 showed the highest antioxidant activity. Three peptides were identified from fraction F3 using LC–ESI–Q–TOF MS/MS as Leu-Pro-Phe (375.46Da), Leu-Leu-Pro-Phe (488.64Da) and Phe-Leu-Pro-Phe (522.64Da). These peptides exhibited good free radical scavenging activity and lipid peroxidation inhibitory effect. Thus, corn gluten meal may be used as a potential source of antioxidant peptides for food and nutraceutical applications.

Preliminary characterization and potential hepatoprotective effect of polysaccharides from Cipangopaludina chinensis

In the present study, we investigated the preliminary characterization, in vitro antioxidant and in vivo heptoprotective activities of polysaccharides from Cipangopaludina chinensis (CCPS). The results of chemical and gas chromatography analysis indicated that CCPS was mostly composed of glucose with high contents of uronic acid and sulfate. For antioxidant activities in vitro, CCPS showed medium lipid peroxidation inhibition effect and high Fe²⁺ chelating and hydroxyl radical scavenging activities. For hepatoprotective activity in vivo, the administration of CCPS significantly decreased the serum levels of alanine aminotransferase and aspartate aminotransferase, inhibited the formation of malondialdehyde in liver and tumor necrosis factor-alpha (TNF-α) in serum and restored the liver activities of superoxide dismutase, glutathione peroxidase in BCG/LPS-induced immunological liver injury mice. The results suggested that CCPS had a significant protective effect against BCG/LPS-induced immunological liver injury. The hepatoprotective effect of CSPS might be partly due to its immunoregulatory effect by inhibiting TNF-α production and antioxidant activities to protect biological systems against the oxidative stress, which were dependent on the chemical and structural properties of CCPS. Further work on the structure of CCPS is in progress.

Anti-inflammatory, analgesic, and antioxidant activities of Pisonia aculeata: Folk medicinal use to scientific approach

Context: Pisonia aculeata leaves (Nyctagenaceae), a Folk medicinal plant used in the treatment of several inflammation, pain, and oxidative stress associated diseases.Objective: To evaluate anti-inflammatory, analgesic, and antioxidant potential of crude methanol extract of P. aculeata leaves (MEPA).Materials and methods: Analgesic and anti-inflammatory activities of MEPA (250 and 500 mg/kg) were evaluated using writhing, formalin, hot plate, tail flick, carrageenan-induced paw edema test, and membrane stabilizing activity. Free radical scavenging activity, total phenolic and flavonoid contents of MEPA were also determined using standard methods.Results: Oral administration of MEPA showed significant (p < 0.001) inhibition of paw edema, pronounced at 4 h and 5 h after carrageenan injection, and at 200 µg/mL exerts 77.67 and 38.51% protective effect against hypotonic solution and heat induced hemolysis, respectively. MEPA (250 and 500 mg/kg) produced 35.21 and 79.14% inhibition of acetic acid-induced writhing. Furthermore, MEPA (500 mg/kg) inhibited 49.19% early and 73.14% late phase of formalin-induced hypernociception. In contrast, a lower dose of MEPA did not prevent hot plate induced nociception, while in the tail immersion method, pronounced analgesic activity was observed between 1 and 4 h postdosing. The extract possesses significant in vitro antioxidant activity and a lipid peroxidation inhibition effect. Total phenolic and total flavonoid content in MEPA were 87.99 ± 0.87 mg GAE/g and 58.98 ± 0.01 mg QE/g, respectively.Discussion and conclusion: Our findings confirmed the analgesic, anti-inflammatory and antioxidant activities of Pisonia aculeata leaves. Contents of flavonoids and phenolic compounds in extract could be correlated with its observed biological activities.

Antioxidant activity and potential hepatoprotective effect of polysaccharides from Cyclina sinensis

In the present study, we investigated the preliminary structure, in vitro antioxidant and in vivo hepatoprotective activities of polysaccharides from Cyclina sinensis (CSPS). The analytic results of Fourier transform-infrared spectroscopy indicated the presence of α-type glycosidic linkages in CSPS-1 or CSPS-2, and the average molecular weights for CSPS-1, CSPS-2 and CSPS-3 were 69, 81 and 101kDa, respectively. For antioxidant activities in vitro, crude CSPS, CSPS-1, CSPS-2 and CSPS-3 showed moderate H2O2 scavenging activity, lipid peroxidation inhibition effect and strong Fe2+ chelating activity. For hepatoprotective activity in vivo, the administration of CSPS significantly decreased serum levels of alanine aminotransferase and aspartate aminotransferase, inhibited the formation of malondialdehyde and enhanced the activities of liver superoxide dismutase and glutathione peroxidase in carbon tetrachloride-induced liver injury mice. These results suggested that CSPS had potent antioxidant and hepatoprotective activities.