l-Citrulline (l-Cit) is a non-essential amino acid that stimulates nitric oxide (NO) production and improves exercise performance by reducing muscle damage indices; however, the direct benefits of l-Cit on antioxidant markers are unclear. The aim of this study was to examine antioxidant responses to high-intensity interval exercise following acute l-Cit supplementation. Nine young men (21 (sd 1) years) participated in a double-blind crossover study in which they received 12 g of l-Cit and placebo (PL) an hour prior to high-intensity interval exercise on two occasions, separated by a 7-d washout period. Blood samples were obtained before (PRE), immediately after (IP), 10 (10P) and 30 min after exercise (30P) from the cubital vein using standard procedures. Serum concentrations of superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT) and NO metabolites (NOx) were measured. The exercise protocol significantly elevated SOD (P = 0·01) and GPx (P = 0·048) from PRE to 10P in the l-Cit group with greater changes than the PL group. CAT concentrations increased IP (P = 0·014) and remained elevated at 10P (P = 0·03) and 30P (P = 0·015) in both the l-Cit and PL conditions. NOx concentrations increased IP (P = 0·05) in the l-Cit group with greater changes than PL group in PRE to IP, PRE to 10P and PRE to 30P (P < 0·05). Our data indicate that l-Cit supplementation (single 12 g dose pre-exercise) induces improvements in antioxidant markers following a session of high-intensity interval exercise in young men.

Many factors, including pathogens, environmental change and breeding techniques, affect honeybee immunity/resistance, so substances and natural supplements that enhance it are desired. To eliminate the impact of unknown external factors, in 2016 a cage experiment was conducted under constant laboratory conditions (35 °C, 65% relative humidity). Bees in the control group were fed with sugar dissolved in water at ratio 1:1 ad libitum with no additives, while the other group was fed with sugar syrup (1:1) supplemented with piperine (3 µg/ml) ad libitum. The piperine-treated workers lived 9 days longer compared to the control group. In the piperine-consuming group, protein concentration and the activities of antioxidative enzymes, such as superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT) and glutathione S-transferase (GST), were higher than in the control group. The activities of aspartate aminotransferase (AST), alanine aminotransferase (ALT) and alkaline phosphatase (ALP) were also higher in the piperine-treated group. Neutral and acidic proteases inhibitors, as well as neutral protease activities, were higher in the haemolymph of the piperine-treated workers than in untreated bees. Acidic protease activities in the haemolymph were higher in untreated workers only on days 18 and 32. Alkaline protease activities in the control bees were higher from day 10. From 10 days old, the total antioxidant capacity level was significantly higher in the haemolymph of piperine-treated workers. Piperine decreased DNA methylation levels significantly in the older bees. The compound could have the potential to be a natural diet supplement increasing apian resistance to stress factors.

To evaluate the action mode of Berberis vulgaris root extract in the alleviation of oxidative stress, female Japanese quails (n 180, aged 5 weeks) were reared, either at 22°C for 24 h/d (thermoneutral, TN) or 34°C for 8 h/d (heat stress, HS), and fed one of three diets: diets containing 0, 100 or 200 mg of B. vulgaris root extract per kg for 12 weeks. Exposure to HS depressed feed intake by 8·5 % and egg production by 12·1 %, increased hepatic malondialdehyde (MDA) level by 98·0 % and decreased hepatic superoxide dismutase, catalase and glutathione peroxidase activities by 23·5, 35·4 and 55·7 %, respectively (P< 0·001 for all). There were also aggravations in expressions of hepatic NF-κB and heat-shock protein 70 (HSP70) by 42 and 43 %, respectively and suppressions in expressions of nuclear factor (erythroid-derived 2)-like 2 (Nrf2) and haeme-oxygenase 1 (HO-1) by 57 and 61 %, respectively, in heat-stressed quails (P< 0·001 for all). As supplemental B. vulgaris extract increased, there were linear increases in performance parameters, activities of antioxidant enzymes and hepatic Nrf2 and HO-1 expressions (P< 0·001 for all) and linear decreases in hepatic MDA level and NF-κB and HSP70 expressions at a greater extent in quails reared under TN condition and those reared under HS condition. In conclusion, dietary supplementation of B. vulgaris root extract to quails reduces the detrimental effects of oxidative stress and lipid peroxidation resulting from HS via activating the host defence system at the cellular level.

Aiming to further characterize the haemocyte subsets in Biomphalaria snails, we have performed a detailed flow cytometric analysis of whole haemolymph cellular components using a multiparametric dual colour labelling procedure. Ethidium bromide/acridine orange fluorescence features were used to first select viable haemocytes followed by flow cytometric morphometric analysis based on the laser scatter properties (forward scatter-FSC and side scatter-SSC). Our findings demonstrated that B. glabrata (BG-BH, highly susceptible to S. mansoni) and 2 strains of B. tenagophila (BT-CF, moderately susceptible and BT-Taim, resistant to S. mansoni) have 3 major circulating haemocyte subsets, referred to as small, medium and large haemocytes. The frequency of small haemocytes was higher in BG-BH, while medium haemocytes were the most abundant cell-type in both B. tenagophila strains. Schistosoma mansoni infection resulted in early reduction of large and medium circulating haemocytes followed by an increase of small haemocytes. Although parasite infection induced haemocyte alterations in all Biomphalaria strains, the response was particularly intense in BT-Taim, the parasite-resistant snail. Interestingly, the trematode infection induces changes in haemocytes with less granular rather than in those with more granular profile. The results indicated that, in B. tenagophila of Taim strain, circulating haemocytes, especially the medium and high subset with less granular profile, are very reactive cells upon S. mansoni infection, suggesting that this cell subset would participate in the early parasite destruction observed in this snail strain.