Azobis 2-amidinopropane Dihydrochloride Research Articles

Monoclonal Antibody Aggregation Associated with Free Radical Induced Oxidation.

Oxidation is an important degradation pathway of protein drugs. The susceptibility to oxidation is a common concern for therapeutic proteins as it may impact product efficacy and patient safety. In this work, we used 2,2′-azobis (2-amidinopropane) dihydrochloride (AAPH) as an oxidative stress reagent to evaluate the oxidation of therapeutic antibodies. In addition to the oxidation of methionine (Met) and tryptophan (Trp) residues, we also observed an increase of protein aggregation. Size-exclusion chromatography and multi-angle light scattering showed that the soluble aggregates induced by AAPH consist of dimer, tetramer, and higher-order aggregate species. Sodium dodecyl sulfate polyacrylamide gel electrophoresis indicated that inter-molecular disulfide bonds contributed to the protein aggregation. Furthermore, intrinsic fluorescence spectra suggested that dimerization of tyrosine (Tyr) residues could account for the non-reducible cross-links. An excipient screening study demonstrated that Trp, pyridoxine, or Tyr could effectively reduce protein aggregation due to oxidative stress. This work provides valuable insight into the mechanisms of oxidative-stress induced protein aggregation, as well as strategies to minimize such aggregate formation during the development and storage of therapeutic proteins.

Effect of 2,2′-azobis(2-amidinopropane) dihydrochloride (AAPH) induced oxidation on the physicochemical properties, in vitro digestibility, and nutritional value of egg white protein

Protein oxidation can influence the quality of food during processing and storage. This study examined the changes in physicochemical properties and in vitro digestibility of egg white protein (EWP) oxidized with a peroxyl-radical-generating system (2,2′-azobis(2-amidinopropane) dihydrochloride (AAPH) simulating the oxidation environment of industrial processing. With the increasing AAPH concentration, all amino acid contents and protein solubility decreased, the carbonyl content almost doubled increased, free sulfhydryl content almost decreased by three quarters. The essential amino acids, such as phenylalanine, leucine, threonine, histidine was particularly sensitive towards oxidation, decreased by more than 10% after EWP oxidized by 5.0 mmol/L AAPH. Volume of larger soluble aggregates formed by AAPH increased, and the digestibility of EWP, decreased with the increase of oxidation degree. Molecular weight analysis showed that the content and antioxidant activity of low molecular weight peptides obtained by pepsin hydrolysis or trypsin hydrolysis was gradually reduced with the increase of the degree of oxidation, which indicated that the nutritional and biological activity of EWP was reduced by oxidation. These results may help to understand the changes in the functional and nutritional quality of egg-based foods that involve oxidation during processing.

Inhibition of Radioactive Depletion of Hemocytes and Antitumor Effects of Flavonoid

Natural products are able to inhibit radiation effects and exert an antitumor effect with fewer adverse reactions; however, their antitumor effects are less than those of widely-used synthetic drugs. Flavonoid is a natural material that has attracting attention, and we extracted this material with alcohol and investigated the effect of continuous flavonoid administration on radioactivity-induced reduction of hemocytes, in addition to the antioxidant and antitum or effects of flavonoid. Following a 1-week adjustment period, flavonoid was administered intraperitoneally to male ICR mice at a dose of 100 mg/kg every other day for 2 weeks. Following administration, 2 Gy whole-body irradiation was performed and the counts of leukocytes, lymphocytes, and granulocytes and monocytes in the peripheral blood were determined 1, 3, 7, 15 and 30 days after irradiation. These cells were considered since they are closely associated with immunity to radioactivity. In a second experiment, flavonoid was similarly administered to the mice for 2 weeks after a 1-week adjustment period, and 2 Gy whole-body irradiation was performed. The antioxidant effects in hemocytes were then investigated using 2,2'-azobis (2-amidinopropane) dihydrochloride (AAPH), a radical generator. In a third experiment, 1×106 Sarcoma-180 cells were inoculated into the right thigh of mice, which were divided into four groups: control, flavonoid-treated, 6 Gy irradiated and Flavonoid-treated + 6 Gy irradiated groups, and changes in tumor size were measured for 20 days. Statistical analysis was conducted using ANOVA for multiple groups. In the three experiments, administration of Flavonoid inhibited the reduction of hemocytes caused by whole-body irradiation, showed antioxidant effects against radioactivity, and inhibited tumor growth, respectively. In conclusion, our data suggest that the antioxidant effect of Flavonoid inhibits hemocyte reduction caused by whole-body irradiation and enhances immunological inhibition of tumor growth.

Method to Improve Azo-Compound (AAPH)-Induced Hemolysis of Erythrocytes for Assessing Antioxidant Activity of Lipophilic Compounds

We examined the method of oxidative hemolysis for assessment of antioxidant activity of various compounds, especially lipophilic compounds. 2,2'-Azobis(amidinopropane) dihydrochloride (AAPH) was used as the source of free radicals for the oxidative hemolysis of horse erythrocytes. We found that absorbance at 540 nm is not appropriate for monitoring AAPH-induced hemolysis. Instead, we should use absorbance at 523 nm (an isosbestic point), because AAPH oxidizes the oxygenated hemoglobin to methemoglobin and absorbance at 540 nm does not correctly reflect the amount of released hemoglobin by AAPH-induced hemolysis. The corrected method of AAPH-induced hemolysis was applicable to assess the antioxidant activity of various hydrophilic compounds such as ascorbic acid, (-)-epicatechin, and edaravone. For the assessment of antioxidant activity of lipophilic compounds, we need appropriate dispersing agents for these lipophilic compounds. Among several agents tested, 1,2-dimiristoyl-sn-glycero-3-phosphocholine (DMPC) liposome at a concentration of 0.34 mM was found to be useful. Exogenous α-tocopherol incorporated using DMPC liposome as a dispersing agent was shown to protect erythrocytes from AAPH-induced hemolysis in a concentration-dependent manner.

Effects of Cavitation Jet Treatment on the Structure and Emulsification Properties of Oxidized Soy Protein Isolate.

This study examined the ability of cavitation jet processing to regulate the oxidation concentrations with 2,2’-azobis (2-amidinopropane) dihydrochloride (AAPH) (0.2, 1, and 5 mmol/L) and the structure and emulsification of soy protein isolate (SPI). The tested properties included particle size distribution, hydrophobic properties (sulfhydryl group (SH) and disulfide bond (S-S) contents, surface hydrophobicity (H0)), emulsifying properties (particle size and ζ-potential of emulsions, emulsification activity index (EAI), and emulsification stability index (ESI)), as well as conformational characteristics. The high shear force of cavitation jet treatment reduced the particle size of oxidized SPI and distributed uniformly. Cavitation jet (90 MPa)-treated SPI (AAPH with 1 mmol/L) demonstrated a high H0 (4688.70 ± 84.60), high EAI (71.78 ± 1.52 m2/g), and high ESI (86.73 ± 0.97%). The ordered secondary structure (α-helix and β-turn content) of SPI was enhanced by the cavitation jet. Meanwhile, the distribution of SPI-oxidized aggregates was observed under an atomic force microscope. Therefore, cavitation jet processing combined with oxidation treatment is an effective method to improve the characteristics of SPI and has potential industrial application prospects.

Honeybee Pollen Extracts Reduce Oxidative Stress and Steatosis in Hepatic Cells.

Nonalcoholic fatty liver disease (NAFLD) is a major cause of morbidity and mortality worldwide. Additional therapies using functional foods and dietary supplements have been investigated and used in clinical practice, showing them to be beneficial. Honeybee pollen from Chile has shown a large concentration of phenolic compounds and high antioxidant activity. In this work, we characterized twenty-eight bee pollen extracts from the central zone of Chile according to botanical origin, phenolic profile, quercetin concentration, and antioxidant activity (FRAP and ORAC-FL). Our results show a statistically significant positive correlation between total phenolic content and antioxidant capacity. Selected samples were evaluated on the ability to reverse the steatosis in an in vitro cell model using Hepa1-6 cells. The pollen extracts protected Hepa1-6 cells against oxidative damage triggered by 2,2′-azo-bis(2-amidinopropane) dihydrochloride (AAPH)derived free radicals. This effect can be credited to the ability of the phenolic compounds present in the extract to protect the liver cells from chemical-induced injury, which might be correlated to their free radical scavenging potential. Additionally, bee pollen extracts reduce lipid accumulation in a cellular model of steatosis. In summary, our results support the antioxidant, hepatoprotective, and anti-steatosis effect of bee pollen in an in vitro model.

Glutathione peroxidase-like functions of 1,2-diselenane-4,5-diol and its amphiphilic derivatives: Switchable catalytic cycles depending on peroxide substrates

Amphiphilic derivatives of (±)-trans-1,2-diselenane-4,5-diol (DSTox) decorated with long alkyl chains or aromatic substituents via ester linkages were applied as glutathione peroxidase (GPx)-like catalysts. The reduction of H2O2 with the diselenide catalysts was accelerated through a GPx-like catalytic cycle, in which the diselenide (Se–Se) bond was reduced to the diselenolate form ([Se-,Se-]) by coexisting dithiothreitol, and the generated highly active [Se-,Se-] subsequently reduced H2O2 to H2O retrieving the original Se–Se form. In the lipid peroxidation of lecithin/cholesterol liposomes induced by 2,2′-azobis(2-amidinopropane) dihydrochloride (AAPH), on the other hand, the Se–Se form directly reduced lipid peroxide (LOOH) to the corresponding alcohol (LOH), inhibiting the radical chain reaction, to exert the antioxidative effect. Thus, the two GPx-like catalytic cycles can be switched depending on the peroxide substrates. Furthermore, hydrophilic compounds with no or short alkyl groups (C3) showed high antioxidative activities for the catalytic reduction of H2O2, while lipophilic compounds with long alkyl chains (C6-C14) or aromatic substituents were more effective antioxidants against lipid peroxidation. In addition, these compounds showed low cytotoxicity in cultured HeLa cells and exhibited sufficient anti-lipid peroxidative activities, suggesting their potentials as selenium-based antioxidative drugs.

Hepatoprotective species from the Chilean medicinal flora: Junellia spathulata (Verbenaceae)

Ethnopharmacological relevanceChilean population relies on medicinal plants for treating a wide range of illnesses, especially those of the gastrointestinal system. Junellia spathulata (Gillies & Hook.) Moldenke var. spathulata (Verbenaceae), called as “verbena-azul-de-cordilleira”, is a medicinal plant native to Argentina and Chile traditionally used for treating digestive disorders. Although the species of the genus are important as therapeutic resources for the Andean population, the plants are very scarcely studied. Aims of the studyThe purpose of the present study was to find out the main constituents and investigate the protective effect of J. spathulata against oxidative stress induced by the potent oxidant 2,2′-azobis (2-amidinopropane) dihydrochloride (AAPH) in human hepatoblastoma cells. Materials and methodsThe crude methanol extract of J. spathulata and an iridoid obtained by chromatographic processes were tested to access the hepatoprotective effect and cytotoxicity in HepG2 cell. In addition, the reducing power of the samples and their ability to scavenge free radicals were evaluated using FRAP and ORAC assay systems. ResultsThe iridoid asperuloside, the main compound of the crude methanol extract of J. spathulata, was isolated and identified by means of NMR analysis. The crude methanol extract of J. spathulata and asperuloside protected HepG2 cells against oxidative damage triggered by AAPH-derived free radicals. This effect can be credited to the ability of the extract and asperuloside to protect the liver cells from chemical-induced injury, which might be correlated to their free radical scavenging potential. ConclusionsThis study experimentally evidenced the ethnopharmacological usefulness of J. spathulata as a treatment of digestive disorders. Our result could stimulate further investigations of hepatoprotective agents in other Chilean Junellia species.

The Free Radical Scavenging and Anti-Isolated Human LDL Oxidation Activities of Pluchea indica (L.) Less. Tea Compared to Green Tea (Camellia sinensis).

Tea is one of the most popular beverages in the world. Camellia sinensis tea (CST) or green tea is widely regarded as a potent antioxidant. In Thailand, Pluchea indica (L.) Less. tea (PIT) has been commercially available as a health-promoting drink. This study focused on free radical scavenging activities of PIT, and its ability to protect isolated human low-density lipoproteins (LDL) from oxidation by chemical agents. A preliminary study to investigate the antioxidant nature of PIT was undertaken. These included common antioxidant assays involving 2,2-Diphenyl-1-picrylhydrazyl (DPPH), 2,2-azinobis-(3-ethylbenzothiazoline)-6-sulfonic acid (ABTS), hypochlorous acid (HOCl), and its potential to scavenge peroxynitrite. In separated experiments, isolated human LDL was challenged with either 2,2′-azobis(2-amidinopropane) dihydrochloride (AAPH), copper (Cu2+), or 3-Morpholinosydnonimine hydrochloride (SIN-1) to induce LDL oxidation. PIT exhibited antioxidant activity in all test systems and performed significantly better than CST in both DPPH (P < 0.05; IC50PIT = 245.85 ± 15.83 and CST = 315.41 ± 24.18 μg/ml) and peroxynitrite scavenging assays. PIT at 75 μg/ml almost fully prevented the peroxynitrite over a 5 h period. Moreover, it displayed similar properties to CST during the antioxidation of isolated human LDL using AAPH, Cu2+, SIN-1, and hypochlorous acid scavenging assays. However, it revealed a significantly lower ABTS scavenging activity than CST (P < 0.05; IC50PIT = 30.47 ± 2.20 and CST = 21.59 ± 0.67 μg/ml). The main constituents of the PIT were identified using LC-MS/MS. It contained 4-O-caffeoylquinic acid (4-CQ), 5-O-caffeoylquinic acid (5-CQ), 3,4-O-dicaffeoylquinic acid (3,4-CQ), 3,5-O-dicaffeoylquinic acid (3,5-CQ), and 4,5-O-dicaffeoylquinic acid (4,5-CQ). In conclusion, caffeoyl derivatives in PIT could play an important role in potent antioxidant properties. So, it may be further developed to be antioxidant beverages for preventing atherosclerosis and cardiovascular diseases associated with oxidative stress.

Effect of AAPH oxidation on digestion characteristics of seed watermelon (Citrullus lanatus var) kernels protein isolates

Seed watermelon kernel is a typical complex food with high fat and protein contents. During storage and processing, it is often affected by various factors to undergo interactions between components, which lead to its quality change. In this experiment, seed watermelon kernels were used as research objects, and the effects of 2′-Azobis (2-amidinopropane) dihydrochloride (AAPH) on seed watermelon kernel protein isolates (WMP) were investigated. The structure and digestion characteristics of WMP after oxidation were studied. The results showed that with the increase of AAPH concentration (0.05−5 mol/L), WMP showed obvious aggregation, and its solubility decreased from 6.76 mg/mL to 9.59 mg/mL. The free sulfhydryl content of WMP was 18.24 mmol/g decreased to 11.25 mmol/g, α-helix decreased and β-sheet decreased in secondary structure, and its disulfide bond increased by 43.06 mmol/g from 39.57 mmol/g, enthalpy (ΔH) and denaturation temperature increased (Td) (P < 0.05). By mass spectrometry results of simulated gastric digestion products, it was found that oxidation adversely affected the digestion characteristics of WMP. It can be seen that the lipid oxidation product APPH of seed watermelon kernel can significantly affect the structure and function of the protein extracted from the seed kernel.

Comparison of Antioxidants: The Limited Correlation between Various Assays of Antioxidant Activity.

The inhibitory effects a range of synthetic and natural antioxidants on lipid peroxidation of egg yolk and erythrocyte membranes induced by a free radical generator 2,2′-azobis(2-amidinopropane) dihydrochloride (AAPH) was compared, with significant differences being found between both systems. When the protection by selected antioxidants against the effects of AAPH on erythrocytes (hemolysis, oxidation of hemoglobin and glutathione (GSH) and generation of reactive oxygen species (ROS)) was studied, most antioxidants were protective, but in some tests (oxidation of hemoglobin and GSH) some acted as prooxidants, inducing oxidation in the absence of AAPH and enhancing the AAPH-induced oxidation. These results demonstrate a diversified action of antioxidants in different systems and point to a need for careful extrapolation of any conclusions drawn from one parameter or experimental system to another.

Antioxidant efficacy of (−)-loliolide isolated from Sargassum horneri against AAPH-induced oxidative damage in Vero cells and zebrafish models in vivo

Seaweed-derived compounds are known to possess various biological activities. The present study evaluated the antioxidant potential of (−)-loliolide, a monoterpenoid isolated from Sargassum horneri in Vero cells and zebrafish models. (−)-Loliolide was purified from the chloroform fraction of an S. horneri methanol extract using high-performance centrifugal partition chromatography (HPCPC). HPCPC was found to be an effective method to isolate (−)-loliolide, yielding a high purity product. Electron spin resonance evaluation demonstrated that (−)-loliolide had significant alkyl radical scavenging activity (IC50: 0.043 ± 0.005 mg mL−1). In addition, our study showed that (−)-loliolide demonstrated dose-dependent protective effects for Vero cell viability against 2,2′-azobis(2-amidinopropane) dihydrochloride (AAPH)-induced intracellular reactive oxygen species (ROS). Moreover, (−)-loliolide reduced lipid peroxidation in AAPH-induced zebrafish embryos, while ameliorating the survival rate and cell death in a dose-dependent manner. These results reveal the antioxidant potential of (−)-loliolide. Future studies highlighting the potential applications of S. horneri in manufacturing functional food ingredients are required.

Fucoidan from acid-processed Hizikia fusiforme attenuates oxidative damage and regulate apoptosis

We had observed in our previous study that the active fucoidan (JHCF4), isolated from the crude fucoidan in acid-processed Hizikia fusiforme, possessed an anticancer effect. In this study, the antioxidant effect of JHCF4 was evaluated. Among the fractions, JHCF4 showed the highest scavenging activity against 2, 2-diphenyl-1-picrylhydrazyl (DPPH), alkyl, and hydroxyl radicals, as well as protective effect against reactive oxygen species (ROS) in 2, 2′-azobis (2-amidinopropane) dihydrochloride (AAPH)-treated Vero cells. Furthermore, JHCF4 showed a protective activity against AAPH-induced apoptosis, as observed by nuclear staining with Hoechst 33342. Our results showed that JHCF4 can up-regulate Bcl-xL, down-regulate Bax and cleave caspase-3 with increased concentrations in AAPH-induced Vero cells. JHCF4 induced anti-apoptosis via a mitochondria-mediated pathway. Additionally, JHCF4 was selected for further in vivo screening in a zebrafish model, which markedly decreased ROS generation and lipid peroxidation. Thus, JHCF4 showed a potential protective activity against AAPH-induced ROS both in vitro and in the zebrafish model.

Effect of Peroxyl‐Radicals‐Induced Oxidative Modification in the Physicochemical and Emulsifying Properties of Walnut Protein

AbstractIn this paper, the effects of peroxyl radical oxidation on the physicochemical and functional properties of walnut protein were investigated. Walnut protein isolate (WPI) containing 2,2′‐azobis(2‐amidinopropane) dihydrochloride (AAPH) was oxidatively stressed under aerobic conditions in peroxyl radical‐generating media. Incubation of walnut protein with increasing concentration of AAPH resulted in gradual carbonyl generation and free sulfhydryl group degradation. The results of surface hydrophobicity implied that oxidation leads to protein aggregation thus decreasing protein solubility in an AAPH concentration‐dependent manner (P &lt; 0.05). Emulsifying properties exhibited a significant increase (P &lt; 0.05) at AAPH concentrations up to 0.2 mM and higher AAPH concentrations reduced the emulsifying capacity of WPI. These results indicate that appropriate oxidation is helpful to improve the emulsifying properties of protein, and with an increase of oxidation degree, emulsifying functional will damage.

Reaction targets of antioxidants in azo-initiator or lipid hydroperoxide induced lipid peroxidation

Lipid peroxidation (LPO) is reported to be involved in the pathogenesis of several oxidative diseases, and several therapeutic approaches using antioxidants have been proposed. LPO is thought to progress via a complicated series of multistep reactions suggesting that the activity of each antioxidant may be different, and depends on the reacting molecules. Hence, in this study, we evaluated the inhibitory mechanisms of several antioxidants toward arachidonic acid (AA) peroxidation induced by the azo initiator 2,2’-azobis(2-amidinopropane) dihydrochloride (AAPH) or a lipid hydroperoxide, hydroperoxyoctadecadienoic acid (HpODE)/hemin. Edaravone, ferrostatin-1, TEMPO and trolox effectively inhibited the production of malondialdehyde (MDA) and several oxidised AAs generated in the AAPH-induced LPO because of their scavenging ability toward lipid peroxyl radicals. In contrast, ebselen and ferrostatin-1 showed strong antioxidative activity in the HpODE/hemin-induced peroxidation. Under this condition, ebselen and ferrostatin-1 were thought to reduce HpODE and its derived alkoxyl radicals to the corresponding lipid alcohols. In conclusion, we found that each antioxidant had different antioxidative activities that prevented the progression of LPO. We expect that these findings will contribute to the design of novel therapeutic strategies using an appropriate antioxidant targeted to each step of the development of oxidative stress diseases.

Recovery and identification bioactive peptides from protein isolate of Spirulina platensis and their in vitro effectiveness against oxidative stress-induced erythrocyte hemolysis.

Spirulina platensis is recognized as one of the most nutritious foods, containing a high protein content of up to 70%. Meanwhile, he interest in using natural protein resources to develop bioactive peptides is steadily increasing. Therefore, this study released the bioactive peptides from S. platensis by enzymatic hydrolysis using pepsin (1:3000 U g-1 ), and their amino acid sequences were determined by de novo sequencing. On this basis, the antioxidant activities of synthesized bioactive peptides were comprehensively evaluated by 2,2'-azinobis-3-ethylbenzothiazolin-6-sulfonic acid assay, 1,1-diphenyl-2-picryhydrazyl assay, and cell hemolysis assay induced by 2,2'-azobis-(2-amidino-propane) dihydrochloride (AAPH). The degree of hydrolysis and recovery percentage of pepsin hydrolysis were 172 and 825 g kg-1 respectively, and FFEFF (P1: m/z 736.4, 8%), EYFDALA (P2: m/z 828.4, relative intensity 18.5%), and VTAPAASVAL (P3: m/z 899.5, relative intensity 17.3%) were purified and identified. P2 possessed an excellent radical scavenging activity compared with P1, P3, and vitamin C, which was contributed to by its high β-sheet conformation and specific amino acid compositions. Moreover, P2 significantly attenuated AAPH-induced oxidative hemolysis of erythrocytes and protected the erythrocytes, because it reduced the formation of malondialdehyde and increased the enzyme activities of superoxide dismutase, catalase, and glutathione peroxidase in erythrocytes. This study provided insights into the potential antioxidant function of the synthesized peptides originated from the bioactive peptides of S. platensis proteins, which would contribute to the development of natural antioxidant from new protein resources. © 2020 Society of Chemical Industry.

Daily Consumption of an Anthocyanin-Rich Extract Made From New Zealand Blackcurrants for 5 Weeks Supports Exercise Recovery Through the Management of Oxidative Stress and Inflammation: A Randomized Placebo Controlled Pilot Study.

Background: Regular exercise is essential to a healthy lifestyle but evokes an oxidative and inflammatory stress. Depending upon its intensity and duration this can result in either beneficial adaptive changes or underlying tissue damage that impacts upon long-term health and individual sporting training schedules. Functional foods containing plant bioactives have potential to support exercise through management of the detrimental aspects of exercise and complement ergonomic adaptive benefits.Aim: Previously we reported that a single consumption of a 3.2 mg/kg New Zealand blackcurrant anthocyanin-rich extract (BAE) 1 h before a 30 min rowing exercise attenuated moderate exercise-mediated oxidative stress and supported innate immunity. Here we evaluate whether the efficacy of a single consumption of BAE 1 h prior to exercise is changed after extended daily BAE consumption for 5 weeks.Results: On week 1, a single consumption of BAE 1 h before a 30 min row mediated a significant (p < 0.05) 46% reduction in post-exercise-induced malondialdehyde (MDA) by 2 h compared to a 30% reduction in the placebo group. Similar efficacy was observed 5 weeks later after daily consumption of BAE. In addition, daily BAE consumption for 5 weeks improved the efficacy to (a) resolve acute inflammation, and (b) increased plasma IL-10, salivary beta-defensin 2 (BD2) and secretory IgA. Although no change in plasma antioxidant capacity was detected, a significant (p < 0.009) positive correlation between plasma IL-10 and plasma antioxidant capacity (R2 = 0.35) was observed on week 6 after 5 week BAE consumption suggesting IL-10 influences antioxidant properties. Using a differentiated myotubule cell-line revealed that whilst IL-10 had no direct antioxidant neutralizing action, longer-term exposure (24 h) attenuated 2,2′-Azobis(2-amidinopropane) dihydrochloride (AAPH)-induced myotubule oxidative stress, supporting a putative role for IL-10 in the modulation of cellular antioxidant systems.Conclusions: Daily consumption of BAE for 5 weeks serves to enhance the exercise recovery effectiveness of a single consumption of BAE and promotes beneficial/protective antioxidant/anti-inflammatory cellular events that facilitate exercise recovery.

Antihyperglycaemic and antioxidant activities of Crataeva adansonii DC. ssp. adansonii leaves extract on ICR mice

Crataeva adansonii DC. ssp. adansonii is a medicinal plant belong to Capparidaceae family, used traditionally by Togolese to treat diabetes mellitus. The aim of this study was to evaluate the antihyperglycaemic and antioxidant activities of the plant leaves. The effect of hydroethanolic extract of C. adansonii ssp. adansonii leaves was assessed in vivo on blood glucose levels in fasting normal and glucose loaded hyperglycemic (oral glucose tolerance test) mice. The phytochemical screening has been done by coloring tests in chemistry. In vitro antioxidants assays had been performed by 2, 2'-azobis 2 amidinopropane dihydrochloride (AAPH) free radical scavenging assay, Ferric reducing antioxidant power (FRAP) assay, Fe2+ chelating assay and total antioxidant capacity (TAC) quantification. After 30 min glucose loading (4 g/kg), the extract 500 mg/kg was showed a significant (p &lt; 0.001) decreased of the peak of blood glucose compared to the hyperglycemic control. The two doses of extract (250 and 500 mg/kg) did not act on the basic blood glucose compared to the normoglycemic control. Phytochemical screening revealed a presence of flavonoids, tannins, alkaloids and sterols. AAPH free radical scavenging activity, reducing power, Fe2+ chelating activity and total antioxidant capacity have shown dose-dependent antioxidant capacity and reducing power of extract compared to ascorbic acid and Butylated hydroxyl Toluene used as reference drug. These finding prove that C. adansonii ssp. adansonii leaves can be used in the treatment of diabetes mellitus and its complications related to oxidative stress and support the use of the plant in traditional medicine in diabetes treatment. &#x0D; Keywords: Crataeva adansonii, antihyperglycaemic, phytochemical, antioxidant.

Dietary supplementation with annatto food-coloring extracts increases the resistance of human erythrocytes to hemolysis

Erythrocytes exhibit high susceptibility to hemolysis in several pathologies due to the oxidation of cellular components. We hypothesized that annatto carotenoids improve the redox status of erythrocyte plasma membranes and promote a consequent increase in human erythrocyte resistance to hemolysis. The objective of this study was to evaluate whether food-grade annatto carotenoids can increase human erythrocyte resistance to hemolysis in vitro and ex vivo. For the in vitro experiment, erythrocytes from healthy volunteers were isolated and coincubated with bixin (BIX) or norbixin (NBIX) and 2,2′-azobis(2-amidinopropane) dihydrochloride (AAPH), glucose, or sodium nitrite (NaNO2) as hemolysis inducers. In the ex vivo study, healthy volunteers consumed a capsule containing BIX or NBIX (0.05 mg/kg body weight per day) or placebo for 7 days before blood sample collection. Their erythrocytes were isolated and incubated with AAPH, glucose, or NaNO2. In both the ex vivo and in vitro studies, erythrocytes were subjected to osmotic fragility tests. The activity of antioxidant enzymes, and reduced glutathione and lipid peroxidation levels in erythrocytes were also evaluated ex vivo. In vitro BIX and NBIX not only reduced erythrocyte membrane fragility induced by AAPH, glucose, or NaNO2 but also improved basal osmotic resistance in the micromole-per-liter range (P < .05). BIX and NBIX supplementation increased erythrocyte membrane resistance (P < .05), with BIX being more effective. Also, BIX and NBIX protected erythrocytes from lipid peroxidation and improved the cellular redox environment (P < .05). These results support the hypothesis that annatto carotenoids supplementation exerts antihemolytic properties by preventing the oxidative damage of human erythrocytes.

Antioxidant and anti-melanogenic activities of ultrasonic extract from Stichopus japonicus

Objective: To investigate the antioxidant and anti-melanogenesis activities of an ultrasonic extract of red sea cucumber, Stichopus japonicus, collected from Jeju Island. Methods: Antioxidant activity experiments were assessed by an electron spin resonance system and a cellular model of immortalized human keratinocytes (HaCaT) to determine its radical scavenging activity and protective effects against 2,2’-azobis (2-amidinopropane) dihydrochloride (AAPH)-induced oxidative stress. Anti-melanogenic activity of the ultrasonic extract of red sea cucumber was also examined using the melanoma cell model B16F10 and mushroom tyrosinase. Following the induction by α-melanocyte-stimulating hormone, the effects of the ultrasonic extract of red sea cucumber on intracellular tyrosinase activity, melanin content and the melanogenic protein expression of microphthalmia-associated transcription factor, tyrosinase, and tyrosinase-related proteins (TRP-1, and TRP-2) were examined. Results: The ultrasonic extract of red sea cucumber significantly scavenged 2,2-diphenyl-1-picrylhydrazyl and alkyl radicals [IC50: (0.924±0.035) and (0.327±0.006) mg/mL, respectively], as well as showed a protective effect against oxidative stress and attenuated generation of intracellular reactive oxygen species on AAPH- induced HaCaT cells, with no cytotoxicity (12.5-400 μg/mL). The ultrasonic extract of red sea cucumber also exhibited a tyrosinase inhibitory effect [IC50: (2.750±0.006) mg/mL]. On α-melanocyte-stimulating hormone-stimulated B16F10 melanoma cells, the ultrasonic extract of red sea cucumber (25-200 μg/mL) significantly inhibited not only melanin synthesis and tyrosinase activity, but also protein expressions of microphthalmia-associated transcriptional factor, tyrosinase, TRP-1, and TRP-2. Conclusions: The ultrasonic extract of red sea cucumber shows antioxidant and anti-melanogenic potential and may be a natural candidate for anti-aging as well as a whitening agent in the cosmeceuticals industry.