Dietary chestnut bee pollen as an immunostimulant for rainbow trout (Oncorhynchus mykiss): Effects on the growth, haematological values, immune response, oxidant/antioxidant status, and survival against Aeromonas salmonicida subsp. achromogenes.

The present study was designed to assess the influence of dietary supplementation with chestnut bee pollen at various levels in rainbow trout, Oncorhynchus mykiss. For two weeks feeding period, a total of 300 fish were allocated into 12 fiberglass tanks and divided into four equal groups, three replicates each, with chestnut bee pollen (BP) dietary inclusion as follows; the fish group was given a basal diet (C); fish group fed a diet supplemented with BP 1% (BP-1); fish group fed a diet supplemented with BP 2% (BP-2); and fish group fed a diet supplemented with BP 4% (BP-3). At the end of the experiment, growth, haematological values, immune status, antioxidant status, and survival rate against Aeromonas salmonicida subsp. achromogenes were evaluated. Dietary supplementation with chestnut bee pollen significantly improves growth performance. Fish fed the diets containing chestnut bee pollen had higher the haematological values than those fed the control diet. The results showed that all the immunological parameters in the groups fed with chestnut bee pollen were significantly higher when compared to the control group. Moreover, dietary chestnut bee pollen increased disease resistance against Aeromonas salmonicida subsp. achromogenes compared to the control group. The tissue SOD, CAT and GSH-Px activities of groups fed with chestnut bee pollen significantly enhanced when compared with the control groups. In contrast, the tissue MDA levels in all groups fed with chestnut bee pollen were significantly decreased. The best values for the antioxidant parameters were determined in the groups fed with 2 and 4% of chestnut bee pollen. Overall, these findings suggest that dietary chestnut bee pollen enhances the growth, the haematological values, the immune and antioxidant response and increases disease resistance against rainbow trout.

Effect of chlorpyrifos on some biochemical changes in Cyprinus carpio: the protective effect of ellagic acid.

In this study, ameliorative effects of ellagic acid (EA) on oxidative stress induced by chlorpyrifos (CPF) in carp, Cyprinus carpio, were investigated. Fish were divided into six groups: C (no treatment), EA (100 mg kg fish-1), CPF-1 (0.040 mg L-1), CPF-2 (0.080 mg L-1), CPF-1 + EA, and CPF-2 + EA. CPF and EA were applied simultaneously for 14 days and, at the end of the study, liver, kidney, and gill samples were collected from fish. On the taken tissue samples, malondialdehyde (MDA) level and some antioxidant enzyme (superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and glutathione-S-transferase (GST)) activities were evaluated. The results demonstrated statistically significant increases in the MDA levels of the CPF-1 and CPF-2 groups. On the other hand, the MDA levels were significantly decreased by EA administration. Also, CPF exposure caused statistically significant increases in the SOD and GST activities and statistically significant decreases in the CAT and GPx activities. However, treatment with EA reversed negative alterations in the SOD, CAT, GPx, and GST activities. Therefore, the results of this study results showed that simultaneous treatment with EA alleviates CPF-induced oxidative stress in fish.

Ameliorative effect of Fennel (Foeniculum vulgare) essential oil on chlorpyrifos toxicity in Cyprinus carpio.

Chlorpyrifos (CPF) is an organophosphate pesticide that is frequently and widely used to control both agricultural and domestic pests worldwide. In this study, the protective effect of Fennel (Foeniculum vulgare) essential oil (FEO) was investigated in carp (Cyprinus carpio) exposed to CPF. The fish were divided into six groups that one control group (no treatment) and five experimental groups (FEO (3ml/100g diet) group, CPF1 (0.023 mg/l) group CPF2 (0.046 mg/l) group, CPF1 (0.023 mg/l) plus FEO (3ml/100g diet) group, CPF2 (0.046 mg/l) plus FEO (3ml/100g diet) group). Blood and tissue (liver, kidney, gill, and brain) samples were taken from the fish at the end of 14 days of application. Hemoglobin (Hb) level, nitoblue tetrazolium (NBT) activity, and total immunoglobulin (TI) level were measured in blood samples of fish. Acetylcholinesterase (AChE) activity was determined in brain tissue while malondialdehyde (MDA) level, reduced glutathione (GSH) level, catalase (CAT), and glutathione peroxidase (GPx) activity were determined in liver, kidney, and gill tissues. The results showed that there was a significant decrease in Hb level, NBT activity, and TI levels in CPF-treated fish compared to the control group. In addition, increased in MDA levels and significant decreases in GSH level, AChE, CAT, and GPx activities were observed in CPF-treated groups. However, FEO-treated was showed a significant improvement in all parameters except AChE activity compared to CPF groups. These study findings showed that FEO could improve CPF-induced toxicity in C. carpio, except inhibition of AChE activity.

Growth performance, haematological changes, immune response, antioxidant activity and disease resistance in rainbow trout (Oncorhynchus mykiss) fed diet supplemented with ellagic acid.

The present study was performed to investigate the effects of various levels of dietary ellagic acid (EA) on growth performance, haematological values, immune response, protection against Yersinia ruckeri infection, and oxidant/antioxidant status in rainbow trout, Oncorhynchus mykiss. Fish were fed with the control diet and three different experimental diets containing three graded levels of EA (50, 100 and 200 mg kg-1 diet) for 8 weeks. At the end of the experiment, the growth performance [weight gain (WG), specific growth rate (SGR) and feed conversion ratio (FCR)], haematological values [the red blood cell (RBC) count, haemoglobin (Hb) concentration, haematocrit (Ht) level and erythrocyte indices: mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH) and mean corpuscular haemoglobin concentration (MCHC)], immune response [white blood cell (WBC) count, oxidative radical production (nitroblue tetrazolium (NBT) assay), phagocytic activity (PA) and phagocytic index (PI), total protein (TP) and immunoglobulin M (IgM) levels, serum bactericidal activity (BA), lysozyme (LYZ) and myeloperoxidase (MPO) activities] and oxidant/antioxidant status [tissue malondialdehyde (MDA) levels and superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) activities] were analysed. In addition, fish were challenged by Y. ruckeri and survival rate was recorded for 14 days. In the groups fed with EA the growth parameters such as WG, SGR, and FCR did not vary significantly. The RBC count, Hb concentration, and Ht level increased in the groups fed with EA when compared with the control group. However, there were no significant differences in the MCV, MCH and MCHC values among the groups. The results demonstrated enhancement in all the immunological parameters in the groups fed with EA compared to the control group. The results obtained from challenge with Y. ruckeri revealed reduction in the mortalities in the groups fed with EA. The dietary EA stimulated the SOD, CAT and GSH-Px activities in liver, head kidney and spleen as compared to the control group; however, a reverse trend was observed in the MDA levels of tissues. The present study suggest that EA can effectively enhance the haematological values, immune response, antioxidant capacity, and disease resistance in rainbow trout.

Effects of curcumin on haematological values, immunity, antioxidant status and resistance of rainbow trout (Oncorhynchus mykiss) against Aeromonas salmonicida subsp. achromogenes.

The present study was conducted to evaluate the effects of various levels of dietary curcumin on growth performance, haematological values, immunity and protection against Aeromonas salmonicida subsp. achromogenes infection in rainbow trout, Oncorhynchus mykiss. Fish were fed with diets containing different levels of curcumin; 0% (C), %1 (E1), %2 (E2) and %4 (E3), as treatment groups. After 8 weeks of feeding, the growth performance [weight gain (WG), specific growth rate (SGR) and feed conversion ratio (FCR)], haematological values [the red blood cell (RBC) count, haemoglobin (Hb) concentration, haematocrit (Ht) level and erythrocyte indices: mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH) and mean corpuscular haemoglobin concentration (MCHC)], various immune parameters [white blood cell (WBC) count, oxidative radical production (nitroblue tetrazolium (NBT) assay), phagocytic activity (PA) and phagocytic index (PI), total protein (TP) and immunoglobulin M (IgM) levels, serum bactericidal (BA), lysozyme (LYZ) and myeloperoxidase (MPO) activities] and antioxidant capacity [tissue malondialdehyde (MDA) levels and superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) activities] were analysed. In addition, fish were challenged by Aeromonas salmonicida subsp. achromogenes and survival rate was recorded for 14 days. The results indicated that the growth performance was significantly influenced by the dietary curcumin levels, the maximal WG and SGR occurred at fish fed the diet containing 2% curcumin. Fish fed the diet containing curcumin had lower FCR than those fed the control diet. The RBC count, Hb concentration, and Ht level increased in the groups fed with curcumin when compared with the control group. However, there were no significant differences in the MCV, MCH and MCHC values among experimental groups. All the chosen immune parameters were enhanced in the groups fed diets containing curcumin. Also, the relative percentage survivals were higher in the groups fed with curcumin, especially in the E2 group, compared to the control. The dietary curcumin stimulated the SOD, CAT and GSH-Px activities in liver, head kidney and spleen as compared to the control group; however, a reverse trend was observed in the MDA levels of tissues. The highest values for haematological, immunological (except TP level of E3 group) and antioxidant parameters were found in the E2 group. These results collectively suggest that curcumin can be used in aquaculture to improve the growth, haematological values, immune responses, antioxidant capacity and disease resistance of rainbow trout, O. mykiss.

Effects of dietary propolis on the number and size of pleopadal egg, oxidative stress and antioxidant status of freshwater crayfish (Astacus leptodactylus Eschscholtz).

Four different crayfish diets; control, E1, E2 and E3, respectively containing 0, 1, 2 and 4% propolis, were tested to determine the effects of dietary propolis on the number and size of pleopadal egg, and malondialdehyde (MDA) level, superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) activities in the freshwater crayfish (Astacus leptodactylus). The crayfish were kept at 9.6±5.3°C water temperature and fed three times daily during a six month period The pleopodal egg number (from 7 to 9) produced per gram of the body weight and total pleopodal egg number (from 201 to 263) significantly increased (P<0.05) with the dietary propolis supplemantation. However, an increase in the dietary propolis led to a significant decrease (P<0.05) in the pleopodal egg size (from 3.22mm to 2.76mm). MDA level significantly (P<0.05) decreased in the hepatopancreas (from 4.78 to 3.04 nmol/g protein) and ovarium (from 3.52 to 1.98 nmol/g protein) of the crayfish fed with the increased dietary propolis level. On the other hand, an increase in the dietary propolis led to a significant increase (P<0.05) in SOD activities in hepatopancreas (from 21.8 to 41.1U/g protein) and ovarium (from 16.8 to 26.8U/g protein). However, CAT activities significantly decreased (P<0.05) in the hepatopancreas (from 23.8 to 18.9 nmol/g protein) and ovarium (from 21.8 to 17.5 nmol/g protein) of the crayfish fed with the increased dietary propolis level. Similarly, an increase in the dietary propolis caused a significant decrease (P<0.05) in GSH-Px activities in the hepatopancreas (from 21.8 to 41.1U/g protein) and ovarium (from 16.8 to 26.8U/g protein) with the formation of the pleopodal egg. The dietary propolis improves reproductive efficiency in the crayfish and decreases the oxidative stress under controlled hatchery conditions.

Protective effect of propolis against oxidative stress and immunosuppression induced by oxytetracycline in rainbow trout (Oncorhynchus mykiss, W.).

The aim of this study was to investigate the effects of propolis on oxytetracycline (OTC)-induced oxidative stress and immunosuppression in fish. OTC (100 mg per kg⁻¹ body weight) was orally administered to fish for 14 days. A significant elevation in the level of malondialdehyde, as an index of lipid peroxidation, and reductions in antioxidant enzyme activities (superoxide dismutase, catalase, and glutathione peroxidase) and low molecular weight antioxidant (reduced glutathione) levels were observed in the blood, liver, kidney, spleen, and heart tissues of OTC-treated fish. OTC also had a suppressive effect on specific and non-specific immune system parameters, such as leucocyte counts, oxidative radical production (nitrobluetetrazolium activity), total plasma protein and immunoglobulin levels, and phagocytic activity. Pre-treatment, post-treatment, and simultaneous treatment with propolis (50 mg per kg⁻¹ body weight, orally) attenuated the OTC-induced oxidative stress by significantly decreasing the levels of malondialdehyde in tissues. In addition, propolis significantly increased the level of reduced glutathione and the catalase, glutathione peroxidase, and superoxide dismutase activities. Upon the administration of propolis, the suppressed immune system parameters were significantly increased in fish treated with OTC. The present results suggest that pre-treatment, post-treatment, and simultaneous administration of propolis might alleviate OTC-induced oxidative stress and immunosuppression.