In vitro antioxidant activity and in vivo anti-fatigue effect of loach (Misgurnus anguillicaudatus) peptides prepared by papain digestion

Improving the activity of Lycium barbarum polysaccharide on sub-health mice

Anti-fatigue activity of Lycium barbarum polysaccharide on sub-health mice: LBP-4a exhibited anti-fatigue activity on sub-health mice, and the mechanism was closely correlated with the reduction of lipid peroxidation levels and an increase of antioxidant enzyme activities in skeletal muscle tissue, in addition to the improvement in intracellular calcium homeostasis imbalance of skeletal muscle and an increase in mitochondrial membrane potential.

Preparation and Characterization of Antioxidant Peptides from Fermented Goat Placenta

The goat placenta was fermented by Bacillus subtilis and the optimal fermentation parameters of strongest antioxidant capacity of peptides were obtained using response surface methodology (RSM). The effects of fermentation time, initial pH value and glucose content on the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging capacity of the goat peptides were well fitted to a quadric equation with high determination coefficients. According to the data analysis of design expert, the strongest DPPH radical scavenging capacity value was obtained with the following conditions: content of glucose was 2.23%, initial pH value was 7.00 and fermentation time was 32.15 h. The DPPH radical scavenging capacity commonly referring antioxidant activity showed a concentration dependency and increased with increasing peptide concentration. The effects of temperature and pH were assessed to determine the stability of antioxidant peptides prepared from goat placenta. Antioxidant peptides showed good stabilities when temperature was lower than 70℃. However, the antioxidant peptides lost antioxidant activities rapidly under alkaline and excessive acid condition. Ultrafiltration technique was performed to separate fermentation broth with different Mw (molecular weight). It was found that peptides in the range of < 3 KDa mainly accounted for the antioxidant activities.

Antioxidant and anti-fatigue activities of egg white peptides prepared by pepsin digestion

BACKGROUND

Some hydrolyzed peptides derived from food proteins possess antioxidant and anti-fatigue activities. In this study, egg white protein powder (EWPP) was hydrolyzed with pepsin for various times, and four peptide fractions were separated from the hydrolysates by ultrafiltration. The antioxidant activity of the four peptide fractions was determined. The peptide fraction with the strongest antioxidant activity was used to evaluate its anti-fatigue effect and probable mechanisms.

RESULTS

The egg white peptides (EWPs) fraction with molecular weight 2-5 kDa (named EWPs2) showed stronger antioxidant activity than the other peptide fractions (P < 0.05). The swimming time to exhaustion of mice administered EWPs2 was longer (P < 0.05) than that of the control group. EWPs2 increased the levels of blood glucose (by 28.4-42.2%), muscle glycogen (by 6.4-10.6%) and liver glycogen (by 10.7-23.8%) and significantly decreased the levels of lactic acid in muscle and urea nitrogen in blood (P < 0.05).

CONCLUSION

Among the four peptide fractions, EWPs2 possessed the strongest antioxidant activity and exhibited an anti-fatigue effect. The experimental data could clarify partially the anti-fatigue mechanisms of EWPs and provide an important basis for developing EWPs as safe and natural antioxidants and anti-fatigue agents for wide use.

In vitro antioxidant and anti-inflammatory activities of Radix Isatidis extract and bioaccessibility of six bioactive compounds after simulated gastro-intestinal digestion

ETHNOPHARMACOLOGICAL RELEVANCE

Radix Isatidis called "Ban-Lan-Gen" is one of the most commonly-used traditional Chinese medicines for antiviral, anti-inflammatory, antioxidant and antipyretic purposes. Investigate the bioaccessibility of uridine, epigoitrin, adenosine, clemastanin B, indigoticoside A and isolariciresinol as well as the antioxidant and anti-inflammatory activities during an in vitro gastro-intestinal digestion of the Radix Isatidis extract (RIE).

MATERIALS AND METHODS

High performance liquid chromatography (HPLC) technique was adopted to determine the bioaccessibility of six bioactive compounds in RIE. Antioxidant activities of RIE in different digestive stages were determined by 1,1-Diphenyl-2-picrylhydrazyl (DPPH), superoxide anion and hydroxyl radical scavenging abilities. Anti-inflammatory activity was assayed by the inhibitions of inflammatory cytokines such as nitrous oxide (NO), prostaglandin E2 (PGE2) and tumor necrosis factor α(TNF-α) producted by lipopolysaccharide (LPS) stimulated RAW264.7 cells.

RESULTS

The bioaccessibility of uridine, epigoitrin, adenosine, clemastanin B, indigoticoside A and isolariciresinol were 15.38%, 18.28%, 24.01%, 6.50%, 8.65% and 17.78%, respectively. Also, the digestion products still possessed certain antioxidant activities. The antioxidant activity was highly correlated with lignans (clemastanin B, indigoticoside A and isolariciresino). The anti-inflammation activity of the three samples decreased in the order: IN sample (the solution that had diffused into the dialysis tubing)>Nondigested sample (RIE solution)>Gastric sample (post-gastric digestion)>OUT sample (material that remained in the gastro-intestinal tract).

CONCLUSIONS

Results obtained in this research reveal the amount of bioactive compounds from RIE that could be available for absorption in vivo. The antioxidant activity decreased significantly but the anti-inflammatory activity was enhanced in serum-available fraction after gastro-intestinal digestion in vitro. This study could provide a scientific basis for a deeper pharmacological activity study of Radix Isatidis and a simple method for pharmacodynamic material basis research.

Identification of native angiotensin-I converting enzyme inhibitory peptides in commercial soybean based infant formulas using HPLC-Q-ToF-MS

This work evaluates, the presence of native antihypertensive peptides in five soybean-based infant formulas (SBIFs). SBIFs peptide extracts (<10 kDa) and their sub-fractions (5-10 kDa, 3-5 kDa, and <3 kDa) from a variety of samples were obtained by ultrafiltration and ACE inhibitory activity was determined. The highest activities were observed in the smaller (<5 kDa) peptide fractions. A set of peptides present in various SBIFs were studied, and identified using HPLC-Q-ToF-MS. Despite ACE inhibitory activity decreasing after in vitro gastrointestinal digestion, it still remained at a high value (IC50 values of 18.2±0.1 and 4.9±0.1 μg/mL). Peptides resisting the action of gastrointestinal enzymes were identified and compared to previously identified peptides, highlighting the presence of peptide RPSYT. This peptide was synthesised, its antihypertensive and antioxidant activity were evaluated, and its resistance to in vitro gastrointestinal digestion and to high processing temperatures were studied.

Antioxidant and functional properties of collagen hydrolysates from Spanish mackerel skin as influenced by average molecular weight

In the current study, the relationships between functional properties and average molecular weight (AMW) of collagen hydrolysates from Spanish mackerel (Scomberomorous niphonius) skin were researched. Seven hydrolysate fractions (5.04 ≤ AMW ≤ 47.82 kDa) from collagen of Spanish mackerel skin were obtained through the processes of acid extraction, proteolysis, and fractionation using gel filtration chromatography. The physicochemical properties of the collagen hydrolysate fractions were studied by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), gel filtration chromatography, scanning electron microscope (SEM) and Fourier transform infrared spectroscopy (FTIR). The results indicated that there was an inverse relationship between the antioxidant activities and the logarithm of the AMW of the hydrolysate fractions in the tested AMW range. However, the reduction of AMW significantly enhanced the solubility of the hydrolysate fractions, and a similar AMW decrease of the hydrolysate fractions negatively affected the emulsifying and foaming capacities. This presented as a positive correlation between the logarithm of AMW and emulsion stability index, emulsifying activity index, foam stability, and foam capacity. Therefore, these collagen hydrolysates with excellent antioxidant activities or good functionalities as emulsifiers could be obtained by controlling the effect of the digestion process on the AMW of the resultant hydrolysates.

Effects of intragastric administration of five oyster components on endurance exercise performance in mice

CONTEXT

Oysters [Crassostrea plicatula Gmelin (Ostreidae)] are widely used for food in coastal areas. It is reported to have several qualities such as improving sexual and immune function. They has been approved by Chinese Ministry of Health as a functional food.

OBJECTIVE

The effects of five types of oyster components (oyster meat, oyster glycogen, oyster protein, cooked liquid components, and water-insoluble components) on the swimming endurance of mice were investigated.

MATERIALS AND METHODS

First, the amino acid composition and sugar content of the five oyster components were analyzed by a physicochemical test. In the in vivo test, the control group was administered distilled water, and the five intervention groups were treated with various samples for 15 consecutive days [0.8 mg protein/(g BW·d) or 0.2 mg glycogen/(g BW·d)]. The swimming time was recorded through the exhaustive swimming test. The levels of serum lactic acid, blood urea nitrogen (BUN), liver glycogen, and gastrocnemius muscle glycogen were determined.

RESULTS

Oyster protein had a minimum F-value (the mole ratio of branched-chain amino acids to aromatic amino acids) (2.68), contained 1.85 mmol/mL taurine and no sugar. The components (except for oyster protein) significantly improved endurance capacity of mice and increased the liver and muscle glycogen contents (p<0.05), and reduced the lactic acid and BUN levels (p<0.05). Oyster protein had little effect.

DISCUSSION AND CONCLUSION

The effects of oyster components on the swimming endurance of mice may be attributed to the high ratio of the branched-chain amino acid composition, bioactivity of taurine, and glycogen.

Cornu cervi pantotrichum supplementation improves exercise performance and protects against physical fatigue in mice

Cornu cervi pantotrichum (CCP) is a well-known yang-invigorating agent used in traditional Chinese medicine that can nourish the blood, tonify qi, and invigorate bones and tendons with multifunctional bioactivities. However, evidence on the effects of CCP on exercise performance and physical fatigue is limited. We evaluated the potential beneficial effects of ethanolic extract from CCP on ergogenic and antifatigue functions following a physiological challenge. Male ICR mice from four groups (n=8 per group) were orally administered CCP for 14 days at 0, 2054, and 4108 mg/kg/day, and were respectively designated as the vehicle, CCP-1X, and CCP-2X groups. The physical performance and antifatigue function were evaluated using forelimb grip strength and exhaustive swimming time as well as serum levels of lactate, ammonia, glucose, and creatine kinase after a 15-min swimming exercise. The results indicated that CCP-1X supplementation significantly improved grip strength; reduced fatigue-associated biochemical indices, including lactate and ammonia levels; and ameliorated skeletal muscle injury induced by acute exercise challenge. A trend analysis revealed that CCP supplementation significantly increased grip strength and dose-dependently reduced serum alkaline phosphatase, uric acid, triacylglycerol, and glucose levels in healthy mice. Therefore, CCP is a potential agent with an antifatigue pharmacological effect.

Evaluation of hypocholesterolemic effect and antioxidant activity of Boops boops proteins in cholesterol-fed rats

Dietary proteins affect blood cholesterol concentrations and antioxidant status, which are related to several diseases, including cardiovascular disease. The present study attempts to investigate the potential of Boops boops proteins (Bb-NHP) and its hydrolysate (Bb-HP) in the prevention of hypercholesterolemia and oxidative stress in rats fed a high cholesterol diet (HCD). After four weeks' treatment, serum lipid profiles (total cholesterol, triglycerides, HDL-cholesterol and LDL-cholesterol), the activities of alanine aminotransferase (ALT) and aspartate aminotransferase (AST), the level of malonaldehyde (MDA) and the activities of antioxidant enzymes [catalase (CAT) and glutathione peroxidase (GPx)] in liver were determined. Compared with those fed a standard diet, high cholesterol diet induced dyslipidemia, oxidative stress, and aortic structure alterations. Interestingly, supplementing the HCD with Boops boops proteins attenuated these anomalies in a dose-dependent manner. These observations suggested that B. boops proteins might provide health benefits by helping to reduce the deleterious effects of increased intake of cholesterol that characterize modern diets.

Isolation and identification of antioxidant peptides from commercial soybean-based infant formulas

Soybean-based infant formulas (SBIFs) based on soybean protein isolate (90% of proteins) are an interesting alternative to cow's milk infant formulas. Different works have demonstrated the presence of bioactive peptides in different soybean-based foodstuffs. The aim of this work was the evaluation, for the first time, of antioxidant peptides in five different commercially available SBIFs. Ultrafiltration through 10 kDa molecular weight cut-off filters was the most suitable extraction method. Despite peptide concentrations ranging between 1.19 and 2.27 mg/mL, similar antioxidant capacities were detected in all SBIF extracts. Extracts were further fractionated according to their molecular weight by ultrafiltration, and fractions from 5 to 10 kDa, 3 to 5 kDa, and below 3 kDa were obtained. The most active fraction was further fractionated by off-gel isoelectrofocusing and reversed-phase chromatography. Antioxidant fractions were also submitted to simulated gastrointestinal digestion (GI) with pepsin and pancreatin to evaluate their antioxidant capacity after digestion. Peptides were identified by HPLC-ESI-Q-ToF-MS/MS. At least 120 peptides were identified in every antioxidant fraction, with 42 peptides common to all SBIFs.

Angelica sinensis improves exercise performance and protects against physical fatigue in trained mice

Angelica sinensis (AS) is a well-known medicinal herb and food material with antioxidative and multifunctional pharmacological activities. However, we lack evidence of the effect of AS on exercise performance and physical fatigue. We aimed to evaluate the potential beneficial effect of AS on ergogenic and anti-fatigue functions after physiological challenge. Male ICR strain mice were randomly assigned to four groups (n=10 per group) for treatment: (1) sedentary control and vehicle treatment (vehicle control); (2) exercise training with vehicle treatment (exercise control); (3) exercise training with AS treatment at 0.41 g/kg/day (Ex-AS1); and (4) 2.05 g/kg/day (Ex-AS5); both the vehicle and AS were orally administered for 6 weeks. Exercise performance and anti-fatigue function were evaluated by forelimb grip strength, exhaustive swimming time, and levels of serum lactate, ammonia, glucose, and creatine kinase (CK) after a 15-min swimming exercise. Trend analysis revealed that AS treatments significantly increased endurance swimming time and blood glucose level, and decreased serum lactate, ammonia and CK levels. Liver and muscle glycogen contents were higher for Ex-AS1 and Ex-AS5 groups than the exercise control. Therefore, AS supplementation improved exercise performance and had anti-fatigue properties in mice and may be an effective ergogenic aid in exercise training.

Astragalus membranaceus improves exercise performance and ameliorates exercise-induced fatigue in trained mice

Astragalus membranaceus (AM) is a popular "Qi-tonifying" herb with a long history of use as a Traditional Chinese Medicine with multiple biological functions. However, evidence for the effects of AM on exercise performance and physical fatigue is limited. We evaluated the potential beneficial effects of AM on ergogenic and anti-fatigue functions following physiological challenge. Male ICR strain mice were randomly assigned to four groups (n = 10 per group) for treatment: (1) sedentary control and vehicle treatment (vehicle control); (2) exercise training with vehicle treatment (exercise control); and (3) exercise training with AM treatment at 0.615 g/kg/day (Ex-AM1) or (4) 3.075 g/kg/day (Ex-AM5). Both the vehicle and AM were orally administered for 6 weeks. Exercise performance and anti-fatigue function were evaluated by forelimb grip strength, exhaustive swimming time, and levels of serum lactate, ammonia, glucose, and creatine kinase after 15-min swimming exercise. Exercise training combined with AM supplementation increased endurance exercise capacity and increased hepatic and muscle glycogen content. AM reduced exercise-induced accumulation of the byproducts blood lactate and ammonia with acute exercise challenge. Moreover, we found no deleterious effects from AM treatment. Therefore, AM supplementation improved exercise performance and had anti-fatigue effects in mice. It may be an effective ergogenic aid in exercise training.

Deer Antler Extract Improves Fatigue Effect through Altering the Expression of Genes Related to Muscle Strength in Skeletal Muscle of Mice

Deer antler is a well-known traditional Chinese medicine used in Asian countries for the tonic and the improvement of aging symptoms. The present study was designed to investigate the antifatigue effect and mechanism of Formosan sambar deer tip antler extract (FSDTAE). The swimming times to exhaustion of mice administered FSDTAE (8.2 mg/day) for 28 days were apparently longer than those of the vehicle-treated mice in forced swim test. However, the indicators of fatigue, such as the reduction in glucose level and the increases in blood urea nitrogen and lactic acid levels, were not significantly inhibited by FSDTAE. Therefore, microarray analysis was further used to examine the anti-fatigue mechanism of FSDTAE. We selected genes with fold changes >2 or <-2 in skeletal muscle for pathway analysis. FSDTAE-affected genes were involved in 9 different signaling pathways, such as GnRH signaling pathway and insulin signaling pathway. All of the significantly expressed genes were classified into 8 different categories by their functions. The most enriched category was muscular system, and 6 upregulated genes, such as troponin I, troponin T1, cysteine and glycine-rich protein 2, myosin heavy polypeptide 7, tropomyosin 2, and myomesin family member 3, were responsible for the development and contraction of muscle. Real-time PCR analysis indicated that FSDTAE increased troponins mRNA expression in skeletal muscle. In conclusion, our findings suggested that FSDTAE might increase the muscle strength through the upregulation of genes responsible for muscle contraction and consequently exhibited the anti-fatigue effect in mice.

Effect of whey protein hydrolysates with different molecular weight on fatigue induced by swimming exercise in mice

BACKGROUND

In order to improve the antioxidant and anti-fatigue capacities of whey protein for wider utilization, it was hydrolyzed by chymotrypsin (EC 3.4.21.1) to produce whey protein hydrolysate (WPH). Fractions of WPH with different molecular weight (MW) were separated by ultrafiltration. Kunming mice in various treatment groups were orally administered (1.5 g kg(-1) body weight) whey protein isolate (WPI), WPH or WPHs with different MW (<5, 5-10, 10-30 or >30 kDa) for 6 weeks to explore whether different MW fractions of WPH affected mice fatigue.

RESULTS

Compared with the control group (orally administered 9 g kg(-1) saline) or the WPI group, low-MW (<10 kDa) WPH groups showed prolonged swimming time (P < 0.05) and had higher concentrations (P < 0.05) of glucose, non-esterfied fatty acid, liver glycogen, superoxide dismutase and glutathione peroxidase and lower concentration of lactate. Low-MW (<10 kDa) WPHs had higher hydroxyl- and α,α-diphenyl-β-picrylhydrazyl-scavenging abilities and ferrous-chelating capacity than WPI.

CONCLUSION

The results proved that low-MW (<10 kDa) WPHs with higher anti-fatigue capacity showed higher free radical-scavenging and ferrous-chelating activities.

Comparison of in vitro digestion characteristics and antioxidant activity of hot- and cold-pressed peanut meals

Due to the poor protein solubility, hot-pressed peanut meal (HPM) has less value than cold-pressed peanut meal (CPM) in the food industry. The objective of this study was to determine whether the denatured proteins in HPM were suitable for hydrolysis by digestive enzymes. The hydrolysis characteristics and antioxidant activity of HPM and CPM during in vitro digestion were compared. The results showed that HPM was hydrolysed more extensively than CPM. There were more free amino acids and small peptides with MW<5 kDa in HPM hydrolysates. In addition, HPM hydrolysates displayed stronger 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,20-azinobis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical-scavenging activities, ORAC value and reducing power than CPM hydrolysates, which could be due to the higher content of small peptides, antioxidative amino acids and melanoidins in HPM hydrolysates. The above results indicated that HPM was a potential source of protein supplement for human consumption.

An endurance-enhancing effect of peanut meal protein hydrolysate in mice: possible involvement of a specific peanut peptide

To improve the functional properties of peanut meal protein for wide utilization, hydrolysis was conducted by alcalase. Compared with saline and peanut meal protein, intragastric administration of low molecular weight (<1 kD) peanut meal peptide (PPH I) could significantly prolong swimming time, increase levels of blood sugar, non-esterified fatty acids (NEFA) and liver glycogen and decrease blood lactate content in mice. Levels of Pro, Leu, Val and His in low molecular weight peanut meal peptides were higher significantly than those in other peanut meal protein hydrolysates. Hydrophobic amino acids, such as Pro, Tyr and His, could perhaps capture free radical and increase antioxidant capacity of peanut peptide and retard fatigue induced by free radical. After separation by HPLC, a primary peptide P1, Pro-Glu-Ile-Glu-Val, was sequenced. Its N-terminal was Val, and it was rich in antioxidant amino acid, Pro and Ile. Levels of plasma glucose, NEFA and liver glycogen in PPH I group were higher than those in mice intragastric administration with peptide P1, and the swimming time is longer in PPH I group than in P1 group. So, the high content of P1 was one of the reason why PPH I had high endurance-enhancing capacity.

Antioxidant and anti-fatigue activities of phenolic extract from the seed coat of Euryale ferox Salisb. and identification of three phenolic compounds by LC-ESI-MS/MS

This study investigated the antioxidant potential and anti-fatigue effects of phenolics extracted from the seed coat of Euryale ferox Salisb. The in vitro antioxidant potentials, including scavenging DPPH, hydroxyl radical activities and reducing power were evaluated. Antioxidant status in vivo was analyzed by SOD, CAT, GSH-Px activities and the MDA content in liver and kidneys of D-galactose-induced aging mice. The anti-fatigue effect was evaluated using an exhaustive swimming test, along with the determination of LDH, BUN and HG content. The phenolic extract possessed notable antioxidant effects on DPPH, hydroxyl radical scavenging and reducing power. The mice which received the phenolic extract showed significant increases of SOD, CAT (except for in the kidney), GSH-Px activities, and a decrease of MDA content. The average exhaustive swimming time was obviously prolonged. Meanwhile, increase of LDH content and decrease of BUN content were observed after mice had been swimming for 15 min. The HG storage of mice was improved in the high and middle dose extract groups compared with the normal group. The contents of total phenols and gallic acid of the extract were determined. Three compounds in the extract were identified as 5,7-dihydroxy-2-(3,4,5-trihydroxyphenyl)-chroman-4-one, 5,7,4-trihydroxyflavanone and buddlenol E. These results suggest that the extract of E. ferox is a promising source of natural antioxidants and anti-fatigue material for use in functional foods and medicines.

Interaction of physical trainings and coffee intakes in fuel utilization during exercise in rats

This study investigates the impact of exercises, coffee intakes, and physical trainings on fuel utilization in rats. Ninety-six rats were fed a control diet with either water (C) or coffee (CF; 0.12 g freeze-dried instant coffee/100 g body weight/d). Additionally, the animals go through physical training (TC and TCF) or no training (NTC and NTCF) for 4 weeks. For physical training, animals have to exercise on treadmills for 30 minutes (5 d per week, 15° incline, 0.5-0.8 km/h). At the end of week 4, the animals in each group were subdivided into three exercise groups: before exercise (BE), during exercise (DE), and after exercise (AE). The DE rats exercised on treadmills for 1 hour immediately before being sacrificed. Hemoglobin, hematocrit, glucose, glycogen, protein, triglyceride (TG), and free fatty acid (FFA) levels in the plasma, liver, and skeletal muscle of the rats were compared accordingly. Organ weights were also measured. Coffee-training interaction had a significant impact on heart weight, visceral fat, hemoglobin, hematocrit, liver glycogen in DE and AE, and liver triglyceride in DE and AE. Exercise (meaning exercised on a treadmill for 1 hour immediately before being sacrificed) training interaction was significant in liver glycogen, muscle glycogen in control diet and control diet with coffee, FFA and muscle TG levels at control diet with coffee group. Exercise-coffee interactions significantly influenced the FFA with no training groups. Exercise-coffee-training interaction significantly effects on FFA, Liver TG and Muscle TG. Coffee intakes can increase lipolysis during exercising but coffee consumptions delay the recovery of liver glycogen levels in trained rats after exercising. Coffee intakes can increase lipolysis during exercising but coffee consumptions delay the recovery of liver glycogen levels in trained rats after exercising. Coffee can be an effective ergogenic aid during exercise for physically trained rats.

Antioxidant and anti-fatigue effects of anthocyanins of mulberry juice purification (MJP) and mulberry marc purification (MMP) from different varieties mulberry fruit in China

Anthocyanins, copiously distributed in a variety of colored fruits and vegetables, are probably the most important group of visible plant pigments besides chlorophyll. And the mulberry fruit is one of the anthocyanins-rich fruits. Total flavonols, total phenolic acids and anthocyanins contents of ten varieties mulberry juice purification (MJP) and mulberry marc purification (MMP) were determined. The highest content was 965.63±4.90 mg RE/g, 690.83±7.38 mg GAE/g and 272.00±1.20 mg cyanidin-3-glucoside/g FW, respectively. Moreover, MJP and MMP exhibited high antioxidant activity, including total force reduction (TRP), Fe³⁺ reducing power (FRAP) and DPPH • radical scavenging capacity. In addition, the anti-fatigue activity of MJP and MMP was determined through mice-burden swimming experiments. Interestingly, the antioxidant and anti-fatigue capacities of MMP were much higher than those of MJP. The experimental results suggested that the generally discarded mulberry marc had greater value of development and utilization as food processing waste.

Resveratrol protects against physical fatigue and improves exercise performance in mice

Resveratrol (RES) is a well-known phytocompound and food component which has antioxidative and multifunctional bioactivities. However, there is limited evidence for the effects of RES on physical fatigue and exercise performance. The purpose of this study was to evaluate the potential beneficial effects of trans-RES on fatigue and ergogenic functions following physiological challenge. Male ICR mice from four groups (n = 8 per group) were orally administered RES for 21 days at 0, 25, 50, and 125 mg/kg/day, which were respectively designated the vehicle, RES-25, RES-50, and RES-125 groups. The anti-fatigue activity and exercise performance were evaluated using forelimb grip strength, exhaustive swimming time, and levels of serum lactate, ammonia, glucose, and creatine kinase (CK) after a 15-min swimming exercise. The exhaustive swimming time of the RES-25 group (24.72 ± 7.35 min) was significantly (p = 0.0179) longer than that of vehicle group (10.83 ± 1.15 min). A trend analysis revealed that RES treatments increased the grip strength. RES supplementation also produced dose-dependent decreases in serum lactate and ammonia levels and CK activity and also an increase in glucose levels in dose-dependent manners after the 15-min swimming test. The mechanism was related to the increased energy utilization (as blood glucose), and decreased serum levels of lactate, ammonia, and CK. Therefore, RES could be a potential agent with an anti-fatigue pharmacological effect.

Effects of salidroside on exhaustive exercise‑induced oxidative stress in rats

Intense exercise increases oxygen consumption and may produce an imbalance between reactive oxygen species (ROS) and antioxidants, inducing oxidative stress as a result of increased ROS production. Exogenous antioxidants may prevent oxidative damages since they are able to detoxify certain peroxides by scavenging the ROS produced during exercise. The aim of this study was to evaluate the effects of salidroside on exhaustive exercise-induced oxidative stress in rats. A total of 40 animals were randomly divided into four groups of ten rats each: control (C), low-dose salidroside‑treated (LT), middle-dose salidroside-treated (MT) and high-dose salidroside-treated (HT) groups. The rats in the treated groups received salidroside (25, 50 and 100 mg/kg, respectively) intragastrically (ig) and the rats in the control group received drinking water ig for 4 weeks. After 4 weeks, the rats performed an exhaustive swimming exercise and exhaustive swimming times were recorded. The malondialdehyde (MDA), catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and glycogen levels in the liver tissues of the rats were measured. The data revealed that salidroside was able to elevate the exercise tolerance and increase the liver glycogen levels of the rats following exhaustive exercise. Salidroside was also able to reduce MDA levels and enhance the activities of antioxidant enzymes (CAT, SOD and GSH-Px) in the liver tissues of the rats. The results from this study indicate that salidroside is effective in the prevention of oxidative stress following exhaustive exercise.

Ultrasonic-assisted enzymolysis to improve the antioxidant activities of peanut (Arachin conarachin L.) antioxidant hydrolysate

The objective of this work is to provide a theoretical basis for preparing peanut antioxidant hydrolysate in order to improve its antioxidant activities. Therefore, response surface methodology (RSM) based on the Box-Behnken design was used to optimize ultrasonic-assisted enzymolysis for the purpose of preparing peanut antioxidant hydrolysate. Results indicated that the DPPH free radical scavenging activity of peanut hydrolysate could reach 90.06% under the following optimum conditions: ultrasonic power of 150.0 w, reaction temperature of 62.0 °C, incubation time of 25.0 min, and initial pH value of 8.5. The DPPH free radical scavenging rate of peanut hydrolysate from ultrasonic-assisted enzymolysis improved comparing with that of peanut hydrolysate from protease hydrolysis alone. The peanut antioxidant hydrolysate was found to display eight improved kinds of antioxidant activities. In conclusion, the optimal ultrasonic-assisted enzymolysis technology conditions described in this paper, appear to be beneficial for preparing peanut antioxidant hydrolysate.

Triterpenoid-Rich Extract from Antrodia camphorata Improves Physical Fatigue and Exercise Performance in Mice

Antrodia camphorata (AC) is an endemic mushroom that grows in Taiwan. We investigated the fatigue-alleviating effects of AC on endurance capacity in swim-exercised and weight-loading mice. Male Institute of Cancer Research (ICR) strain mice from 3 groups (n = 10 per group in each test) were orally administered AC fruiting body extract for 7 days at 0, 50, and 200 mg/kg/day, designated vehicle, AC-50, and AC-200, respectively. Trend analysis revealed that AC treatments increased grip strength. AC dose-dependently increased swim time, blood glucose, and muscular and hepatic glycogen levels and dose-dependently decreased plasma lactate and ammonia levels and creatine kinase activity. The increase in swimming endurance with AC administration was caused by an increase in liver and muscle glycogen deposition. A. camphorata may have potential for use in ergogenic and antifatigue activities.

Optimisation of hydrolysis of purple sea urchin (Strongylocentrotus nudus) gonad by response surface methodology and evaluation of in vitro antioxidant activity of the hydrolysate

BACKGROUND

Hydrolysates prepared from sea urchin (Strongylocentrotus nudus) gonad by enzymatic treatment showed strong 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity and reducing power.

RESULTS

Hydrolysis of S. nudus gonad by the commercial protease papain was optimised for maximum degree of hydrolysis (DH) and trichloroacetic acid-soluble peptide index (TCA-SPI) using response surface methodology. Results showed that the optimal conditions were the following: temperature of 48.83 °C, pH of 6.92, enzyme-to-substrate ratio of 3143 U g(-1), and substrate concentration of 83.5 g L(-1). Under these conditions, a DH of 27.96 ± 0.54% and a TCA-SPI of 57.32 ± 0.63% were obtained. The hydrolysate prepared in the optimal conditions was fractionated by an ultra-filtration system and the resultant fraction below 10 kDa was found to effectively scavenge hydroxyl radical (EC(50) = 13.29 ± 0.33 mg mL(-1)) and hydrogen peroxide (EC(50) = 16.40 ± 0.37 mg mL(-1)), inhibit lipid peroxidation (EC(50) = 11.05 ± 0.62 mg mL(-1)), chelate Fe(2+) (EC(50) = 7.26 ± 0.44 mg mL(-1)), and protect mice macrophages against death induced by tert-butyl hydroperoxide.

CONCLUSION

Hydrolysates prepared from S. nudus gonad have the potential to be applied as natural antioxidant agents.

Chemical composition and antioxidant activities of Broussonetia papyrifera fruits

Fruits of Broussonetia papyrifera from South China were analyzed for their total chemical composition, and antioxidant activities in ethanol and aqueous extracts. In the fruit of this plant, the crude protein, crude fat and carbohydrates was 7.08%, 3.72% and 64.73% of dry weight, respectively. The crude protein, crude fat and carbohydrates were 15.71%, 20.51% and 36.09% of dry weight, respectively. Fatty acid and amino acid composition of the fruit were analyzed. Unsaturated fatty acid concentration was 70.6% of the total fatty acids. The percentage of the essential amino acids (EAAs) was 40.60% of the total amino acids. Furthermore, B. papyrifera fruit are rich in many mineral elements and vitamins. Total phenolic content was assessed using the Folin-Ciocalteau assay, whereas antioxidant activities were assessed by measuring the ability of the two extracts to scavenge DPPH radicals, inhibit peroxidation, and chelate ferric ions. Their reducing power was also assessed. Results indicated that the aqueous extract of B. papyrifera was a more potent reducing agent and radical-scavenger than the ethanol extract. GC-MS analysis of the ethanol extract showed the presence of some acid-containing compounds. The changes in total phenolic content and antioxidant capacity in B. papyrifera from four different regions grown under normal conditions were assessed. The antioxidant activity of different extracts was positively associated with their total phenolic content. These results suggest that the fruit of B. papyrifera could be used in dietary supplement preparations, or as a food additive, for nutritional gain, or to prevent oxidation in food products.

Antioxidant and antiproliferative activities of loach ( Misgurnus anguillicaudatus ) peptides prepared by papain digestion

Loach protein hydrolysates (LPH) prepared by papain digestion were fractionated into four fractions, LPH-I (MW > 10 kDa), LPH-II (MW = 5-10 kDa), LPH-III (MW = 3-5 kDa), LPH-IV (MW < 3 kDa), and the in vitro antioxidant and antiproliferative (anticancer) activities of all fractions were determined. LPH-IV showed the lowest IC(50) value (16.9 ± 0.21 mg/mL) for hydroxyl radical scavenging activity and the highest oxygen radical scavenging capacity (ORAC) value (reaching 215 ± 5.9 mM Trolox/100 g loach peptide when the concentration was 60 μg/mL). Compared with other fractions, LPH-IV also exhibited stronger antiproliferative activity for human liver (HepG2), breast (MCF-7), and colon (Caco-2) cancer cell lines in a dose-dependent manner. When the protein concentration was 40 mg/mL, the HepG2 and MCF-7 cell proliferation of LPH-IV reached 7 and 4%, respectively, with no significant difference from those of LPH (8 and 7%, p > 0.05), with significantly less growth than those of LPH-I, LPH-II, and LPH-III, respectively (p < 0.05). The Caco-2 colon cell proliferation of LPH-IV was 12.8- and 8.7-fold smaller than those of LPH-I and LPH-II, respectively (p < 0.05). All of the fractions had a greater ability to inhibit Caco-2 colon cancer cell proliferation than to inhibit HepG2 liver cancer and MCF-7 breast cancer cell proliferation. The ORAC values of most of the fractions correlated (R(2) > 0.86, p < 0.01) with the antiproliferative activity of the three cancer cell lines, suggesting that higher antioxidant activity leads to better antiproliferative activity. However, further mechanistic and human clinical studies of the anticancer activity of loach protein hydrolysate fractions are needed.

Anti-fatigue properties of tartary buckwheat extracts in mice

Anti-fatigue properties of tartary buckwheat extracts (TBE) was investigated in male Kunming mice. The animals were divided into four groups. The first group, designated as the control group (control), was administered with distilled water by gavage every day for 28 days. The other three groups, designated as TBE treatment groups, were administered with TBE of 60, 120 and 240 mg/kg body weight, respectively, by gavage every day for 28 days. Exhaustive swimming time, blood lactic acid (BLA), blood urea nitrogen (BUN), tissue glycogen, glutathione peroxidase (GPx) and superoxide dismutase (SOD) of mice after swimming were determined. The results showed that tartary buckwheat extracts had anti-fatigue properties, which extended the exhaustive swimming time of mice, effectively inhibiting the increase of BLA, decreasing the level of BUN, increasing the tissue glycogen content and the activities of SOD and GPx of mice. However, further study is needed to elucidate the exact mechanism of the effect of TBE on fatigue.