Carotenoid-containing unilamellar liposomes loaded with glutathione: a model to study hydrophobic-hydrophilic antioxidant interaction

Unilamellar liposomes are used as a simple two-compartment model to study the interaction of antioxidants. The vesicle membrane can be loaded with lipophilic compounds such as carotenoids or tocopherols, and the aqueous core space with hydrophilic substances like glutathione (GSH) or ascorbate, mimicking the interphase between an aqueous compartment of a cell and its surrounding membrane.

Unilamellar liposomes were used to investigate the interaction of GSH with the carotenoids lutein, β-carotene and lycopene in preventing lipid peroxidation. Lipid peroxidation was initiated with 2,2′-azo-bis-[2,4-dimethylvaleronitrile] (AMVN). Malondialdehyde (MDA) formation was measured as an indicator of oxidation; additionally, the loss of GSH was followed. In liposomes without added antioxidant, MDA levels of 119 ± 6 nmol/mg phospholipid were detected after incubation with AMVN for 2 h at 37°C. Considerably lower levels of 57 ± 8 nmol MDA/mg phospholipid were found when the liposomal vesicles had been loaded with GSH. Upon incorporation of β-carotene, lycopene or lutein, the resistance of unilamellar liposomes towards lipid peroxidation was further modified. An optimal further protection was observed with 0.02 nmol β-carotene/mg phospholipid or 0.06 nmol lycopene/mg phospholipid. At higher levels both these carotenoids exhibited prooxidant effects. Lutein inhibited lipid peroxidation in a dose-dependent manner between 0.02 and 2.6 nmol/mg phospholipid. With increasing levels of lycopene and lutein the consumption of encapsulated GSH decreased moderately, and high levels of β-carotene led to a more pronounced loss of GSH.

The data demonstrate that interactions between GSH and carotenoids may improve resistance of biological membranes towards lipid peroxidation. Different carotenoids exhibit specific properties, and the level for optimal protection varies between the carotenoids.     

顶羽菊抗氧化活性研究

目的:探讨顶羽菊提取物的抗氧化活性。方法:采用Folin-Ciocaheu法测定顶羽菊水提物和醇提物中的多酚含量,并以芦丁为标准品测定其黄酮含量;通过总还原力测定法、Fenton法、改良的邻苯三酚自氧化法、过氧化脂质测定、亚硝酸盐清除率测定和亚硝胺合成阻断率测定,分别对顶羽菊提取物的总还原力、超氧阴离子自由基和羟自由基清除能力、脂质过氧化抑制作用、清除亚硝酸盐自由基和亚硝胺阻断率进行测定。结果:顶羽菊水提物和醇提物中含有以黄酮类为主要成分的多酚类物质;具有较强的还原性和清除超氧阴离子自由基、羟自由基的活性,且醇提物的作用高于水提物;二者对脂质过氧化的抑制率达47%以上;顶羽菊提取物具有较强的清除亚硝酸钠和阻断亚硝胺合成的能力,水提物对亚硝酸盐的最大清除率为60.4%,醇提物对亚硝胺合成的阻断率为86.6%。结论:顶羽菊醇提物可作为抗氧化剂和防癌剂,用于清除机体内自由基、抗脂质氧化、延缓机体衰老、预防心血管系统疾病和癌症的发生。     

In vitro bioactivities and preparation of nanoemulsion from coconut oil loaded Curcuma aromatica extracts for cosmeceutical delivery systems

Curcuma aromatica (CA) is a herbaceous plant in the Zingiberaceae family. It has antioxidative activity and anti-inflammatory properties. The purpose of this study was to investigate the effect of solvents and extraction methods on CA rhizomes. The crude extracts were tested for phenolic and flavonoid contents, antioxidative activity by DPPH and lipid peroxidation assay, and protein denaturation inhibition. The crude extracts with 95% ethanol by maceration technique showed good results. It had phenolic content at 99.28 ± 1.09 mg GAE/g extract, flavonoid content at 397.00 ± 27.54 mg QE/g extract, antioxidative activity by DPPH assay and lipid peroxidation assay at IC₅₀ value of 0.55 ± 0.02 mg/ml and 0.60 ± 0.10 mg/ml, respectively. The percentage of protein denaturation inhibition was 65.97 ± 4.68%. The crude extract with 95% ethanol by maceration technique was selected to formulate nanoemulsion. Nanoemulsion formulation consisted of DI water, Tween 80, CA extract, coconut oil and Span 80 at 72.50, 12.93, 7.07, 5.00 and 2.5%w/w, respectively. Its appearance was an opaque yellow liquid with no precipitation and no phase separation at room temperature. The particle size, pH, and viscosity were 70.20 ± 0.38 nm, 5.87 ± 0.01 and 3.56 ± 0.24 cP, respectively. Nanoemulsion loaded CA extract had bioactivities and highly stable characteristics after heating–cooling test for 6 cycles. This study has demonstrated the potential of nanoemulsion from coconut oil loaded CA extract for further development to novel cosmetic products.     

Muscle physiology changes induced by every other day feeding and endurance exercise in mice: effects on physical performance

Every other day feeding (EOD) and exercise induce changes in cell metabolism. The aim of the present work was to know if both EOD and exercise produce similar effects on physical capacity, studying their physiological, biochemical and metabolic effects on muscle. Male OF-1 mice were fed either ad libitum (AL) or under EOD. After 18 weeks under EOD, animals were also trained by using a treadmill for another 6 weeks and then analyzed for physical activity. Both, EOD and endurance exercise increased the resistance of animals to extenuating activity and improved motor coordination. Among the groups that showed the highest performance, AL and EOD trained animals, ALT and EODT respectively, only the EODT group was able to increase glucose and triglycerides levels in plasma after extenuating exercise. No high effects on mitochondrial respiratory chain activities or protein levels neither on coenzyme Q levels were found in gastrocnemius muscle. However, exercise and EOD did increase β-oxidation activity in this muscle accompanied by increased CD36 levels in animals fed under EOD and by changes in shape and localization of mitochondria in muscle fibers. Furthermore, EOD and training decreased muscle damage after strenuous exercise. EOD also reduced the levels of lipid peroxidation in muscle. Our results indicate that EOD improves muscle performance and resistance by increasing lipid catabolism in muscle mitochondria at the same time that prevents lipid peroxidation and muscle damage.     

Antioxidant Properties of Selected <Emphasis Type="Italic">Boletus</Emphasis> Mushrooms

Considering the growing interest for mushrooms and the demand search of natural antioxidants sources, the aim of this study was to investigate the antioxidant properties of two edible widely used Boletus species, Boletus edulis, and Boletus auranticus, collected from Istra region in Croatia in late summer 2007. To evaluate the antioxidant properties and content of antioxidant compounds, scavenging capacity on DPPH˙, OH˙, and O₂˙⁻ radicals, reducing power and capacity to inhibit lipid peroxidation has been investigated. It is determined that content of total phenols (41.82 ± 0.08 mg gallic acid equivalent per gram of dry extract) was higher for B. edulis. Using high performance liquid chromatography/diode array detector analysis, the main antioxidant compound, variegatic acid, has been detected and quantified. 1,1-Diphenyl-2-picryl-hydrazyl-hydrate assay was used as a preliminary free radical–scavenging evaluation. By this assay, it has been found that B. edulis dry mushroom extract exhibits 50% of inhibition value at the extract concentration of 0.016 ± 0.0003 mg/ml. The extracts were capable of reducing iron(III) and, thus, are capable of donating electrons. Using electron paramagnetic resonance spin-trapping and spin-probing techniques, activity against relevant reactive species, ˙OH and O₂˙⁻ radical, was analyzed for both mushroom extracts. Both investigated extracts are determined as good inhibitors for ˙OH radical reduction, and both exhibited significant capacity for scavenging O₂˙⁻ radical and for that could help to prevent or meliorate oxidative damage. Only B. edulis extract prevents lipid peroxidation. Investigated mushroom extracts could represent easily accessible natural antioxidant resource.     

Plasma and erythrocyte lipid peroxidation levels in patients with testis tumor after orchiectomy

Plasma and erythrocyte lipid peroxidation levels of 20 patients with histopathologically confirmed testis cancer and 20 healthy control individuals were studied between November 1995 and June 1997. The group with testis cancer had a mean age of 24.8±8.2 yr and the control group’s mean age was 28.3±6.9 yr. Stage distribution of the testis cancer cases were 4 of stage A, 10 of stage B, and 6 of stage C. Blood samples of the patients were drawn after orchiectomy and after 12 h fasting before chemotherapy. Mean plasma and erythrocyte lipid peroxidation levels were detected to be 14.51±5.30 nmol malondialdehide (MDA)/mL and 9.30±2.06 nmol MDA/g hemoglobin (Hb), respectively, in the testis cancer group, whereas the healthy control group had mean plasma and erythrocyte lipid peroxidation levels of 10.7±1.82 nmol MDA/mL and 6.18±1.68 nmol MDA/g Hb, respectively. Plasma and erythrocyte lipid peroxidation values of the testis cancer patients were determined to be statistically significantly higher than that of the health control group (p<0.001, p<0.001). No significant correlation was determined between plasma, erythrocyte lipid peroxidation levels and tumor markers. In conclusion, it can be said that an increase in the lipid peroxidation may play a role in the pathogenesis of testis carcinomas in addition to the other causes.     

痉挛型大鼠骨骼肌不同功能状态下表面肌电特征性变化的研究

目的:研究痉挛型瘫痪大鼠骨骼肌不同功能状态对其表面肌电特征性的影响。方法:选用健康5日龄新生wistar大鼠60只随机分为两组即:痉挛型瘫痪大鼠模型组和正常饲养组。复制痉挛型瘫痪大鼠模型成功后饲养30天,根据肌肉三种功能状态分为三组,分别为A组放松状态组、B向心性收缩状态组、C离心收缩状态组。每组包括痉挛型瘫痪大鼠10只,正常大鼠10只。检测工具采用Bio Trace+Software进行表面肌电的测试和分析;检测肌肉为伸膝肌群;检测指标为表面肌电均方根值(RMS);检测方式为电针刺激诱发不同收缩状态。结果采用SPSS17.0统计软件进行数据分析。结果:放松状态下痉挛大鼠RMS(2.76±0.09)v,正常大鼠RMS(2.82±0.07)v,独立样本的t检验P=0.1260.05;向心性收缩状态痉挛大鼠RMS(10.25±0.35)v,正常大鼠RMS(11.07±0.81)v,独立样本的t检验P=0.0120.05;离心性收缩状态痉挛大鼠RMS(3.32±0.27)v,正常大鼠RMS(4.0±3.045)v,独立样本的t检验P=0.0010.05。结论:痉挛型骨骼肌收缩时肌纤维的募集异于正常骨骼肌,表面肌电对鉴别肌痉挛有效。     

Concentric and eccentric isokinetic muscle activity separated by paired pattern classification of wavelet transformed mechanomyograms

It was hypothesized that concentric and eccentric isokinetic muscle actions should yield detectable differences in the mechanomyograms, which may reflect properties of the contraction and relaxation phases of the muscles. A paired pattern classification technique was adapted to determine whether wavelet transformed mechanomyograms from the three superficial quadriceps muscles were different during maximal concentric and eccentric isokinetic muscle actions. Mechanomyograms for this study were recorded from eleven healthy men (mean ± SD age = 20.1 ± 1.1 yrs) who performed maximal concentric and eccentric isokinetic muscle actions of the dominant leg extensors at a velocity of 30° s^?1. The results indicated that the paired pattern classification accurately classified the MMG intensity patterns in approximately 94% of the cases as being from a concentric or eccentric movement. Thus, it can be concluded that the differences in the intensity patterns recorded from concentric and eccentric muscle actions were significant. These findings indicated that the combined MMG wavelet analysis and pattern classification techniques could potentially be useful in situations where muscle activity during concentric muscle actions must be distinguished from that during eccentric muscle actions.     

Hepatoprotective Potentials of Onion and Garlic Extracts on Cadmium-Induced Oxidative Damage in Rats

The hepatoprotective effect of onion and garlic extracts on cadmium (Cd)-induced oxidative damage in rats is reported. Control group received double-distilled water alone. Cd group was challenged with 3CdSO₄·8H₂O (as Cd; 1.5 mg/kg bw per day per oral) alone, while extract-treated groups were pretreated with varied doses of onion and/or garlic extract (0.5 and 1.0 ml/100 g bw per day per oral) for a week and thereafter co-treated with Cd (1.5 mg/kg bw per day per oral) for 3 weeks. Cd caused a marked (p?<?0.001) increase in the levels of lipid peroxidation and glutathione S-transferase, whereas glutathione, superoxide dismutase, and catalase levels were decreased in the liver. We also observed a decrease in hepatic activities of alanine transaminase (ALT), aspartate transaminase (AST), and alkaline phosphatase and a concomitant increase in the plasma activities of ALT and AST. Onion and garlic extracts significantly attenuated these adverse effects of Cd. Onion extract proffered a dose-dependent hepatoprotection. Our study showed that Cd-induced oxidative damage in rat liver is amenable to attenuation by high dose of onion and moderate dose of garlic extracts possibly via reduced lipid peroxidation and enhanced antioxidant defense system that is insufficient to prevent and protect Cd-induced hepatotoxicity.     

Preventive role of Gynandropsis gynandra L., against aflatoxin B1 induced lipid peroxidation and antioxidant defense mechanism in rat

G. gynandra extract was found to potentially diminish the rate of lipid peroxidation, with a significant increase in the levels of enzymatic (superoxide dismutase, catalase and glutathione peroxidase) and non-enzymatic (reduced glutathione vitamins E and C, and uric acid) antioxidants, which were found, altered during aflatoxin B1 (AFB1) injection. The result confirmed that G. gynandra extract exerts its chemopreventive efficacy by preventing the rate of lipid peroxidation and influenced the enzymatic and non-enzymatic antioxidants in AFB1 induced male albino rats.     

Modulation of glutathione and antioxidant enzymes by Ocimum sanctum and its role in protection against radiation injury

Aqueous extract (OE) of the leaves of Ocimum sanctum, the Indian holy basil, has been found to protect mouse against radiation lethality and chromosome damage and to possess significant antioxidant activity in vitro. Therefore a study was conducted to see if OE protects against radiation induced lipid peroxidation in liver and to determine the role, if any, of the inherent antioxidant system in radioprotection by OE. Adult Swiss mice were injected intraperitoneally (i.p.) with 10 mg/kg of OE for 5 consecutive days and exposed to 4.5 Gy of gamma radiation 30 min after the last injection. Glutathione (GSH) and the antioxidant enzymes glutathione transferase (GST), reductase (GSRx), peroxidase (GSPx) and superoxide dismutase (SOD), as well as lipid peroxide (LPx) activity were estimated in the liver at 15 min, 30 min, 1, 2, 4 and 8 hr post-treatment. LPx was also studied after treatment with a single dose of 50 mg/kg of OE with/without irradiation. OE itself increased the GSH and enzymes significantly above normal levels whereas radiation significantly reduced all the values. The maximum decline was at 30-60 min for GSH and related enzymes and at 2 hr for SOD. Pretreatment with the extract checked the radiation induced depletion of GSH and all the enzymes and maintained their levels within or above the control range. Radiation significantly increased the lipid peroxidation rate, reaching a maximum value at 2 hr after exposure (approximately 3.5 times that of control). OE pretreatment significantly (P < 0.0001) reduced the lipid peroxidation and accelerated recovery to normal levels. The results indicate that Ocimum extract protects against radiation induced lipid peroxidation and that GSH and the antioxidant enzymes appear to have an important role in the protection.     

The antioxidant properties of polypore mushroom <Emphasis Type="Italic">Daedaleopsis confragosa</Emphasis>

Daedaleopsis confragosa belong to a large and remarkable group of mushrooms called polypores. This type of mushroom could be easily said to be quite unexplored and unused when it comes to its antioxidant properties. Thus, in order to evaluate its antioxidant activity, the investigation had to include the total phenolics and flavonoide content, the content of Selenium, the content of Zinc, the scavenging capacity on DPPH^· and OH^· radicals, reducing power and capacity to remove lipid peroxidation. The investigated mushroom extract contained 54.17 mg GAE/g of total phenols and 48.46 mg CE/g of total flavonoides. Zinc and Selenium were detected and quantified by using inductively coupled plasma mass spectroscopy. The scavenging activity of the radicals was found to exhibit 50% of the inhibition value (IC₅₀ value) at the extract concentration of 0.015±0.007 mg/ml for the investigated D. confragosa extract. By using electron paramagnetic resonant spectroscopy it was found that the investigated extract does not have a significant role in the prevention of lipid peroxidation. It was effective in scavenging on ^·OH radical, RI was 56±2%.     

Supplementation with green tea and oregano extracts on productive characteristics,blood metabolites,and antioxidant status of Jersey cows during the transition period

Plant extracts have been recognized as beneficial to human health and have been evaluated as feed additive for domestic and companion animals. This study evaluated oregano and green tea extracts fed to Jersey cows from approximately 21 d before calving to 21 d after calving on milk production, milk composition, and blood metabolites as well as investigated immunological and antioxidant attributes. Twenty-four Jersey cows with 441 ± 27 kg of BW, 3.5 ± 0.3 of body condition score (BCS), and 2.7 ± 1.8 lactations were selected at approximately 28 d before the expected parturition date and were randomly assigned to three treatments with eight cows each: without plant extracts in diet (control – CON), addition of 10 g per day of oregano extract (OR), and addition of 5 g per day of green tea extract (GT). Feed intake, BW, BCS, blood metabolites, hemogram as well as oxidative stress biomarkers were evaluated from approximately 3 weeks prepartum to 3 weeks postpartum (transition period) while milk production and composition were evaluated during the first 3 weeks of lactation. Plant extracts did not change BW, BCS, and DM intake (DMI) throughout the transition period, but OR increased in approximately 20% total digestive nutrients and metabolizable energy intake on days 15 and 16 postpartum compared with CON. In the prepartum, OR increased in 48% platelets count compared to the CON, while GT augmented in 142% eosinophils compared with CON. Oregano extract reduced the levels of reactive species in the erythrocytes in 40% during prepartum and postpartum compared with CON, while GT reduced its levels in 24 and 29% during prepartum and postpartum, respectively, when compared with CON. In the postpartum period, OR increased in 60% the carbonylated protein content compared with CON, while GT reduced in 45% the levels of reactive species in plasma compared with CON. During the postpartum, both extracts increased in 33% the concentration of reduced glutathione when compared with CON. Moreover, GT tended to decrease feed efficiency in 11% when compared with CON; OE reduced milk pH and somatic cell count when compared with CON. In conclusion, OE and GT did not expressively affect immunological attributes in blood but reduce some oxidative stress biomarkers without compromising productive traits of Jersey cows during the transition period.     

Antioxidant activity of dioscorea and dehydroepiandrosterone (DHEA) in older humans

Dioscorea is a yam steroid extract used in commercial steroid synthesis and consumed by people. DHEA is a steroid which declines with age, but without known activity. This study was designed to determine whether dioscorea supplementation could increase serum dehydroepiandrosterone sulfate (DHEAS) in humans and modulate lipid levels in older people. The subjects were selected volunteers aged 65–82 years. The serum DHEAS level, lipid peroxidation and lipid profile were assessed. Three weeks of dioscorea supplementation had no affect on serum DHEAS level. However DHEA intake of 85 mg/day increased serum DHEA levels 100.3 %. DHEA and dioscorea significantly reduced serum lipid peroxidation, lowered serum triglycerides, phospholipid and increased HDL levels. Both DHEA and the steroid yam extract, dioscorea, have significant activities as antioxidant to modify serum lipid levels.     

Whole-body cryostimulation as an effective way of reducing exercise-induced inflammation and blood cholesterol in young men

Inflammation may accompany obesity and a variety of diseases, or result from excessive exercise. The aim of this study was to investigate the anti-inflammatory effect of whole-body cryostimulation on the inflammatory response induced by eccentric exercise under laboratory conditions. The study also sought to establish if cold treatment changes the lipid profile and modifies energy expenditure in young people. Eighteen healthy and physically active, college-aged men volunteered to participate in the experiment. They were divided into two subgroups: CRYsubmitted to whole-body cryostimulation, and CONT- a control group. Both groups performed eccentric work to induce muscle damage. Blood samples were collected before and 24 h after the exercise. Over the five days that followed, the CRY group was exposed to a series of 10 sessions in a cryogenic chamber (twice a day, for 3 min, at a temperature of ?110°C). After this period of rest, both groups repeated a similar eccentric work session, following the same schedule of blood collection. The perceived pain was noted 24h after each session of eccentric workout. A 30-minute step up/down work-out induced delayed-onset muscle soreness in both groups. The five-day recovery period accompanied by exposure to cold significantly enhanced the concentration of the anti-inflammatory cytokine IL-10. It also led to a pronounced reduction in levels of the pro-inflammatory cytokine IL-1β, and reduced muscle damage. The values for IL-10 before the second bout of eccentric exercise in the CRY group were 2.0-fold higher in comparison to baseline, whereas in the CONT group, the concentration remained unchanged. Furthermore, blood concentrations of the pro-inflammatory cytokine IL-1β fell significantly in the CRY group. The main finding of this study was that a series of 10 sessions of whole body cryostimulation significantly reduced the inflammatory response induced by eccentric exercise. The lipid profile was also improved, but there was no effect on energy expenditure during the exercise.     

Ischemic post-conditioning protects brain and reduces inflammation in a rat model of focal cerebral ischemia/reperfusion

Ischemic post-conditioning (Post-cond) is a phenomenon in which intermittent interruptions of blood flow in the early phase of reperfusion can protect organ from ischemia/reperfusion (I/R) injury. Recent studies demonstrated ischemic Post-cond reduced infarct size in cerebral I/R injury. However, the molecular mechanisms underlying this phenomenon are not completely understood. As inflammation is known to be detrimental to the neurological outcome during the acute phase after stroke, we investigated whether ischemic Post-cond played its protective role in preventing post-ischemic inflammation in the rat middle cerebral artery occlusion model. Rats were treated with ischemic Post-cond after 60 min of occlusion (beginning of reperfusion). The infarct volume and myeloperoxidase activity were assessed at 24 h. The lipid peroxidation levels was evaluated by malondialdehyde assay and the expressions of interleukin-1β, tumor necrosis factor-α, and intercellular adhesion molecule 1 were studied by RT-PCR or western blotting. Ischemic Post-cond decreased myeloperoxidase activity and expressions of interleukin-1β, tumor necrosis factor-α, and intercellular adhesion molecule 1. Ischemic Post-cond also reduced infarct volume and lipid peroxidation levels. These findings indicated that ischemic Post-cond may be a promising neuroprotective approach for focal cerebral I/R injury and it is achieved, at least in part, by the inhibition of inflammation.     

β-Glucan extracts inhibit the in vitro intestinal uptake of long-chain fatty acids and cholesterol and down-regulate genes involved in lipogenesis and lipid transport in rats

BackgroundDietary fiber reduces the intestinal absorption of nutrients and the blood concentrations of cholesterol and triglycerides.AimWe wished to test the hypothesis that high-viscosity (HV) and low-viscosity preparations of barley and oat β-glucan modify the expression of selected genes of lipid-binding proteins in the intestinal mucosa and reduce the intestinal in vitro uptake of lipids.MethodsFive different β-glucan extracts were separately added to test solutions at concentrations of 0.1–0.5% (wt/wt), and the in vitro intestinal uptake of lipids into the intestine of rats was assessed. An intestinal cell line was used to determine the effect of β-glucan extracts on the expression of intestinal genes involved in lipid metabolism and fatty acid transport.ResultsAll extracts reduced the uptake of 18:2 when the effective resistance of the unstirred water layer was high. When the unstirred layer resistance was low, the HV oat β-glucan extract reduced jejunal 18:2 uptake, while most extracts reduced ileal 18:2 uptake. Ileal 18:0 uptake was reduced by the HV barley extract, while both jejunal and ileal cholesterol uptakes were reduced by the medium-purity HV barley extract. The inhibitory effect of HV barley β-glucan on 18:0 and 18:2 uptake was more pronounced at higher fatty acid concentrations. The expression of genes involved in fatty acid synthesis and cholesterol metabolism was down-regulated with the HV β-glucan extracts. β-Glucan extracts also reduced intestinal fatty-acid-binding protein and fatty acid transport protein 4 mRNA.ConclusionsThe reduced intestinal fatty acid uptake observed with β-glucan is associated with inhibition of genes regulating intestinal uptake and synthesis of lipids. The inhibitory effect of β-glucan on intestinal lipid uptake raises the possibility of their selective use to reduce their intestinal absorption.     

Antioxidant activities of different parts of Gnetum gnemon L.

Analyses on biological activities of Gnetum gnemon were done to determine the total phenolic and antioxidants of the plant. Four parts of G. gnemon were used in this study, which were leaf, bark, twig, and seeds of the plant. All parts were extracted in methanol, ethanol, hexane, chloroform and hot water using reflux. The total phenolic content of the plant extracts were determined by using Folin-Ciocalteu method. The results demonstrated that the bark from hot water extract showed the highest total phenolic at 10.71?±?0.01 mg GAE/ FDW, while the lowest was chloroform extract of seed at 2.15?±?0.01 mg GAE/ FDW. The antioxidant activity of the plant extracts were determined by using DPPH and FRAP assays, respectively. The DPPH results showed that all plant extracts demonstrated weak free radical scavenging activity tested at the final concentration of 300 μg/ml. In contrast, the methanolic twig extract showed strong reducing power activity (FRAP) at 83.55?±?1.05%, while the hot water seed extract showed the least activity at 41.86?±?4.22% tested at the final concentration of 300 μg/ml. However, there were no correlation between total phenolics and both antioxidant assays tested.     

In Vitro α-Glucosidase Inhibition and Antioxidative Potential of an Endophyte Species (Streptomyces sp. Loyola UGC) Isolated from Datura stramonium L

Endophytic actinomycetes isolated from Datura stramonium L. was evaluated for its effects against in vitro α-glucosidase inhibition, antioxidant, and free radical scavenging activities. Based on microbial cultural characteristic and 16S rRNA sequencing, it was identified as Streptomyces sp. loyola UGC. The methanolic extract of endophytic actinomycetes (MeEA) shows remarkable inhibition of α-glucosidase (IC₅₀ 730.21 ± 1.33 μg/ml), scavenging activity on 2,2-diphenyl-picrylhydrazyl (DPPH) (IC₅₀ 435.31 ± 1.79 μg/ml), hydroxyl radical (IC₅₀ 350.21 ± 1.02 μg/ml), nitric oxide scavenging (IC₅₀ 800.12 ± 1.05 μg/ml), superoxide anion radical (IC₅₀ 220.31 ± 1.47 μg/ml), as well as a high and dose-dependent reducing power. The MeEA also showed a strong suppressive effect on rat liver lipid peroxidation. Antioxidants of β-carotene linoleate model system revels significantly lower than BHA. The total phenolic content of the extract was 176 mg of catechol equivalents/gram extract. Perusal of this study indicates MeEA can be used as natural resource of α-glucosidase inhibitor and antioxidants.     

Indices of free-radical-mediated damage following maximum voluntary eccentric and concentric muscular work

This study monitored plasma and skeletal muscle markers of free-radical-mediated damage following maximum eccentric and concentric exercise, to examine the potential role of free radicals in exercise-induced muscle damage. Fourteen male volunteers performed either (1) a bout of 70 maximum eccentric and a bout of 70 maximum concentric muscle actions of the forearm flexors (the bouts being separated by 4 weeks; n = 8) or (2) a bout of 80 maximum eccentric and a bout of 80 maximum concentric muscle actions of the knee extensors (the bouts being separated by 1 week; n=6). Plasma markers of lipid peroxidation, thiobarbituric acid-reactive substances (TBARS) and diene-conjugated compounds (DCC) were monitored in the arm protocol and skeletal muscle markers of oxidative lipid and protein damage, malondialdehyde (MDA) and protein carbonyl derivatives (PCD) respectively, were monitored in the leg protocol. In both protocols, the contralateral limb was used for the second bout and the order of the bouts was randomised between limbs. Repeated measures ANOVA indicated significant changes from baseline following eccentric arm work on the measures of serum creatine kinase activity (P < 0.05), maximum voluntary torque production (P < 0.01) and relaxed arm angle (P < 0.01). Subjective muscle soreness peaked 2 days after eccentric arm work (P < 0.05, Wilcoxon test). However, there were no changes in the plasma levels of TBARS or DCC following the eccentric or concentric arm exercise. Immediately after concentric leg exercise, skeletal muscle PCD concentrations was significantly higher than that observed immediately after eccentric work (P < 0.05). However, no significant difference between the eccentric and concentric knee extensor bouts was observed on the measure of skeletal muscle MDA concentration. The results of this study offer no support for the involvement of oxygen free radicals in exercise-induced muscle damage.