Inhibition of lipid oxidation in foods and feeds and hydroxyl radical-treated fish erythrocytes: A comparative study of Ginkgo biloba leaves extracts and synthetic antioxidants

Effects of oxidized soybean oil on the performance of sows and jejunum health of suckling piglets

Oils provide a considerable amount of energy to the swine diet, but they are prone to lipid oxidation if not properly preserved. Consumption of oxidized oils can adversely affect the animal organism and even the offspring. This study investigated the impact of oxidized soybean oil in the diets of sows from 107 days gestation to 21 days of lactation on the performance of sows and jejunum health of suckling piglets. Sixteen sows were randomly allocated into two groups: one group (n = 8) was fed with the fresh soybean oil (FSO) diet, and another group (n = 8) was treated with the oxidized soybean oil (OSO) diet. Dietary oxidized soybean oil does not affect sow performance. Antioxidant enzyme activity in the milk was reduced significantly in the OSO group, such as the superoxide dismutase (SOD), total antioxidant capacity (T-AOC), and catalase (CAT) activities (p < 0.05). On Day 21, oxidized soybean oil increased tumor necrosis factor-α (TNF-α), interleukin 6 (IL-6), and interleukin 8 (IL-8) levels in sow milk and the concentrations of TNF-α and IL-8 cytokines in plasma (p < 0.05). Suckling piglets from sows fed on OSO showed a trend towards increased IL-6 and TNF-α in plasma (p < 0.1). The mRNA expression of interleukin 1β (IL-1β) was augmented, whereas interleukin 10 (IL-10) was decreased, and zonula occludens-1 (ZO-1) had a tendency to be down-regulated in OSO treatment. This study revealed that the OSO of feed decreased the antioxidant capacity of milk, further contributing to the inflammatory response in the jejunum of suckling piglets.

Improving the Stability of Red Blood Cells in Rainbow Trout (Oncorhynchus mykiss) and Herring (Clupea harengus): Potential Solutions for Post-mortem Fish Handling to Minimize Lipid Oxidation

This study aimed at limiting hemolysis of fish red blood cells (RBCs) as a strategy to limit hemoglobin (Hb)-induced lipid oxidation during post-mortem handling and processing. Effects of varying temperature, salinity, and mechanical impact were studied using washed resuspended RBCs (wr-RBCs) and whole blood (WB) from rainbow trout (Oncorhynchus mykiss) and herring (Clupea harengus). The wr-RBCs were most stable avoiding mechanical stress, keeping isotonic conditions (0.9–1.3% NaCl) and low temperature 0–6 °C, with predicted minimum at 2.5 °C. When compared at the same salinity, it was found that hemolysis was more pronounced in herring than trout wr-RBCs. Furthermore, WB was more stable than wr-RBCs, showing protecting the effects of blood plasma. Studying individual plasma components, stabilizing effects were found from glucose, proteins, and ascorbic acid. This study indicates that small adjustments in the early handling and processing of fish such as changing salinity of storage and rinsing solutions could minimize Hb contamination of the fish muscle and thereby improve quality.

Dietary Ginkgo biloba leaf extract alters immune-related gene expression and disease resistance to Aeromonas hydrophila in common carp Cyprinus carpio

Ginkgo biloba leaf is widely used in traditional medicine in China. The present study aimed to illustrate the effects of dietary Ginkgo biloba leaf extract (GBLE) on growth performance and immune responses in common carp infected by Aeromonas hydrophila. Six different diets either not treated (control) or treated with 0.5, 1, 2, 5 and 10 g/kg of GBLE were designed to feed the fishes for 8 weeks. The results indicated that, compared to the control groups, 10 g/kg dietary GBLE significantly increased body growth and feed utilization. In GBLE dietary groups, red blood cell levels, white blood cells, hematocrit, hemoglobin, total protein, albumin and globulin were significantly increased relative to the control groups. Dietary supplementation with 5 g/kg GBLE increased the phagocytic ratio, and phagocytic indexes increased in the 2, 5 and 10 g/kg groups relative to the control groups. Moreover, 2, 5 and 10 g/kg GBLE diets increased O₂^- production compared to the control groups. Additionally, GBLE diets stimulated lysozyme activity (in 10 g/kg group) and inhibited bactericidal activity (in 0.5, 2, 5 and 10 g/kg group). Quantitative real-time PCR showed that IL1β, IL8, TNF-α, IL10, TGFβ, and inducible enzyme genes were prone to decrease while SAA, hepcidin and GPX1 were increased due to the GBLE diet in the intestine. In the head-kidney, the GBLE treatment decreased IL1β, IL8, TNF-α, IL10, TGFβ, INOS and arginase gene expressions, whereas SOD upregulation was found in the GBLE condition. The mRNA expressions of IL1β, IL8, TNF-α, IL10 and INOS were decreased, but SAA, hepcidin, GPX1 and SOD mRNA levels were increased in the spleen in the GBLE diet compared to the control. Additionally, diet supplemented with GBLE improved the survival rate infected with A. hydrophila. Our observations suggest that GBLE effectively enhanced growth performance, modulated immune-related gene expression. It improved survival rate of common carp after A. hydrophila infection and the optimum concentration we recommend is 10 g/kg of GBLE.

Effects of Angelica sinensis extracts on lipid oxidation in fish feeds and growth performance of juvenile Jian carp (Cyprinus carpio var. Jian)

The study was to explore the effect of the extracts of Angelica sinensis (EAs) on lipid oxidation in fish feeds compared with ethoxyquin (EQ) and the effect of dietary EAs on growth performance of carp (Cyprinus carpio var. Jian). Firstly, fish feeds were respectively added with EQ, and ethyl ether extract, ethyl acetate extract (EAE), acetone extract, ethanol extract (EE) and aqueous extract (AQE) of Angelica sinensis, except for the control. The results showed that EAs and EQ inhibited lipid oxidation in fish feeds (P < 0.05). Of all of the examined EAs, EAE showed the strongest protective effects against lipid oxidation (P < 0.05). Moreover, EAE at high concentrations showed a stronger effect on lipid oxidation compared with EQ (P < 0.05). Then, 7 experimental diets respectively supplemented with 0.0, 1.0, 2.0, 3.0, 4.0, 5.0 and 6.0 g/kg of EAE were fed to the respective treatment groups for 30 d. Four replicates were performed for each treatment group; 20 carp (mean weight: 12.10 ± 0.13 g) were in each replicate. The results indicated that dietary EAE improved the growth performance in carp (P < 0.05). The appropriate concentration of EAE for carp growth was estimated to be 3.643 g/kg diet. Thus, EAE could be used as a natural antioxidant in feeds for Jian carp.

The effects of ethoxyquin and Angelica sinensis extracts on lipid oxidation in fish feeds and growth, digestive and absorptive capacities and antioxidant status in juvenile red carp (Cyprinus carpio var. xingguonensis): a comparative study

Firstly, a linoleic and linolenic acid emulsion and fish feeds were incubated with graded levels of ethoxyquin (EQ) and petroleum ether extract, ethyl acetate extract (EAE), ethanol extract and aqueous extract of Angelica sinensis. The results showed that EQ and extracts of Angelica sinensis (EAs) inhibited lipid oxidation in material above. Of all of the examined EAs, EAE showed the strongest protective effects against the lipid oxidation. Moreover, EAE at high concentrations showed a stronger inhibitory effect on lipid oxidation than that of EQ. Next, 7 experimental diets that respectively supplemented 0.0, 0.2, 0.8 and 3.2 g kg^-1 of EQ and EAE were fed to 280 juvenile red carp (Cyprinus carpio var. xingguonensis) with seven treatment groups for 30 days. The results indicated that dietary EAE improved growth performance in carp. Moreover, dietary EAE increased the activities of trypsin, lipase, alpha-amylase, alkaline phosphatase, glutamate-oxaloacetate transaminase and glutamate-pyruvate transaminase (GPT) and decreased plasma ammonia content in carp. Meanwhile, dietary EAE reduced the levels of malondialdehyde and raised the activities of anti-superoxide anion, anti-hydroxyl radical, superoxide dismutase, catalase, glutathione peroxidase and glutathione reductase and the content of reduced glutathione in the hepatopancreas and intestine of carp. However, with the exception of GPT, dietary EQ got the opposite results to dietary EAE in carp. These results revealed that dietary EAE improved the digestive, absorptive and antioxidant capacities in fish. However, dietary EQ inhibited the digestive, absorptive and antioxidant capacities in fish. So, EAE could be used as a natural antioxidant for replacing EQ in fish feeds.

Liquid Chromatography Analysis of Common Nutritional Components, in Feed and Food

Food and feed laboratories share several similarities when facing the implementation of liquid-chromatographic analysis. Using the experience acquired over the years, through application chemistry in food and feed research, selected analytes of relevance for both areas were discussed. This review focused on the common obstacles and peculiarities that each analyte offers (during the sample treatment or the chromatographic separation) throughout the implementation of said methods. A brief description of the techniques which we considered to be more pertinent, commonly used to assay such analytes is provided, including approaches using commonly available detectors (especially in starter labs) as well as mass detection. This manuscript consists of three sections: feed analysis (as the start of the food chain); food destined for human consumption determinations (the end of the food chain); and finally, assays shared by either matrices or laboratories. Analytes discussed consist of both those considered undesirable substances, contaminants, additives, and those related to nutritional quality. Our review is comprised of the examination of polyphenols, capsaicinoids, theobromine and caffeine, cholesterol, mycotoxins, antibiotics, amino acids, triphenylmethane dyes, nitrates/nitrites, ethanol soluble carbohydrates/sugars, organic acids, carotenoids, hydro and liposoluble vitamins. All analytes are currently assayed in our laboratories.

Active polyphenolic compounds, nutrient contents and antioxidant capacity of extruded fish feed containing purple coneflower (Echinacea purpurea (L.) Moench.)

The growth of fish is directly dependent on feed composition and quality. Medicinal plants can be added to fish feed as adjuvant therapy for the prevention of fish diseases. The purple coneflower (Echinacea purpurea (L.) Moench.) has been reported to have multiple biological effects, including immunomodulatory and antioxidant activity. The most active compounds of E. purpurea are polyphenols - caffeic acid derivatives: caftaric acid, chlorogenic acid, cynarin, echinacoside and cichoric acid.

Due to a relatively limited number of studies on the use of the purple coneflower as a nutritional supplement for fish feeding, extruded fish feed with addition of Echinacea roots was produced. In the feed total phenolic content, selected polyphenol contents, the energetic value, nutrient contents and antioxidant capacity were examined.

The results indicate that fish feed with addition of the Echinacea has a great potential to be a good source of natural radical scavengers, for example polyphenols, and nutritive ingredients. Antioxidant properties of feed were well correlated with the coneflower content. The study findings confirmed that high-temperature extrusion-cooking process does not deactivate phenolic antioxidant compounds, which are present both in the Echinacea roots and in the final product. Fish feed with addition of E. purpurea can be used as a nutritional supplement in the prevention of fish diseases caused by oxidative stress.

The cytotoxicity and protective effects of Astragalus membranaceus extracts and butylated hydroxyanisole on hydroxyl radical-induced apoptosis in fish erythrocytes

Erythrocytes play an essential role in transporting O₂ and CO₂ for respiration in fish. However, erythrocytes continuously suffer from reactive oxygen species (ROS) -induced oxidative stress and apoptosis. Thus, it is essential to expand our knowledge of how to protect erythrocytes against ROS-induced oxidative stress and apoptosis in fish. In this study, we explored the cytotoxicity and the effects of butylated hydroxyanisole (BHA), ethyl ether extracts, ethyl acetate extracts, acetone extracts (AE), ethanol extracts, and aqueous extracts of Astragalus membranaceus (EAm) on hydroxyl radical (•OH)-induced apoptosis in carp erythrocytes. The rat hepatocytes and carp erythrocytes were incubated with different concentrations of BHA or EAm(0.125 to 1 mg/mL). The toxicity in rat hepatocytes and carp erythrocytes was then measured using a 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay and a haemolysis assay, respectively. The carp erythrocytes were treated with BHA or EAm in the presence of 40 μmol/L FeSO₄ and 20 μmol/L H₂O₂ at 37 °C, except for the control group. Oxidative stress and apoptosis parameters in the carp erythrocytes were then evaluated using the commercial kit. The results indicated that at high concentrations, BHA and EAm could induce toxicity in rat hepatocytes and fish erythrocytes. However, BHA was more toxic than EAm at the same concentrations. Moreover, the toxicity order of BHA and EAm in the fish erythrocytes approximately agreed with that for the rat hepatocytes. Butylated hydroxyanisole and EAm suppressed the •OH-induced phosphatidylserine exposure and DNA fragmentation (the biomarkers of apoptosis) by decreasing the generation of ROS, inhibiting the oxidation of cellular components, and restoring the activities of antioxidants in carp erythrocytes. Of all of the examined EAm, the AE showed the strongest effects. The effects of AE on superoxide anion, H₂O₂, met-haemoglobin and reduced glutathione levels, as well as glutathione reductase activity and apoptosis were equivalent to or stronger than those of BHA. These results revealed that the AE of Astragalus membranaceus could be used as a potential natural antioxidant or apoptosis inhibitor in fish erythrocytes.