RESUMO
Berberine (BBR) and silymarin (SM) are natural compounds extracted from plants known for their antioxidant and chemoprotective effects on the liver. The present study aimed to investigate the beneficial properties of BBR and SM and the association of BBR with SM on liver function using fish as "in vivo" models. Moreover, the study investigated their hepatoprotective role after acetaminophen (APAP) exposure. For this purpose, the fish (N = 360; 118.4 ± 11.09 g) were fed with control or experimental diets for 9 weeks. In the experimental diets, the feed was supplemented with either SM (1 g/kg feed), BBR (100 and 200 mg/kg feed), or a combination of BBR with SM (SM 1 g/kg feed + BBR 100 mg/kg feed and, respectively, SM 1 g/kg feed + BBR 200 mg/kg feed). After the feeding trial, seven fish from each tank were randomly selected and exposed to a single APAP dose. The selected serum biochemical markers, oxidative stress markers, and lysozyme activity were used to evaluate the efficiency of the supplements on carp's health profile, particularly regarding the hepatopancreas function. Our results showed that the inclusion of SM and BBR (either as a single or in combination) reduced the serum contents of total cholesterol, triglyceride, and alanine transaminase. An increase in the high-density cholesterol was observed after the administration of BBR or BBR in association with SM. Both supplements showed hepatoprotective activity against APAP-induced hepatotoxicity, especially BBR. The ameliorative effects of SM (1 g) in association with BBR (100 mg) were highlighted by the modulation of the nonspecific immune system and oxidative stress alleviation after APAP exposure.
RESUMO
The study aimed to compare the growth performance and physiological responses of bester (B) and backcrossed bester â × beluga â (BB) in response to crowding stress under different stocking densities, as well as to establish a threshold stocking density for rearing BB in a recirculating aquaculture system (RAS) without welfare impairment. For this purpose, in the first trial (T1), B (181.15 ± 21.21 g) and BB fingerlings (181.98 ± 28.65 g) were reared in two stocking densities of 2 kg/m2 and 4 kg/m2 in fiberglass tanks (1 m3) for 6 weeks. In a parallel trial (T2), the BB hybrids (335.24 ± 39.30 g) were kept in four initial stocking densities, ranging from 5 kg/m2 to 12 kg/m2. The results of T1 revealed better growth indices (i.e., final mean weight, weight gain, specific growth rate) at lower stocking densities for both hybrids; however, in terms of growth performance, the BB hybrid showed better results when compared with the B hybrid. BB hybrids registered significantly (p < 0.05) lower serum cortisol and MDA and higher lysozyme than B hybrids, showing higher tolerance to crowding stress. Nevertheless, at higher densities, selected serum parameters (i.e., hematological indices, cortisol, glucose, protein, malondialdehyde, lysozyme) and growth performance indices used to evaluate the hybrids indicate that high stocking density could affect the growth and welfare of BB hybrids, and that the selected serum parameters could be used as good indicators for chronic stress caused by overcrowding conditions.
RESUMO
Acipenser stellatus is a critically endangered species due to the anthropic influence. It has been intensively captured for decades because of its high economic value, its roe being used in the caviar industry. Therefore, Acipenser stellatus is intensively raised in fish farms for both conservation and economical purposes. Aquaculture aims to optimize the feeding regime of juveniles in order to improve its profitability. The purpose of this study was to investigate if Acipenser stellatus can adapt to a starvation/refeeding regime by assessing the effects of this regime on oxidative stress biomarkers and antioxidant defense mechanisms in juveniles raised under aquaculture conditions. The juveniles were subjected to two regimes: a 7-day starvation period followed by 21 days of refeeding, respectively a 14-day starvation period followed by 21 days of refeeding. The results showed that both starvation/refeeding regimes induced an enhancement of antioxidant enzymes activities in the intestine of the juveniles. The oxidative damage was counteracted at the protein level. However, lipid peroxidation was significantly induced in the intestine of the juveniles subjected to 14/21-day starvation/refeeding regime. The 7/21-day starvation/refeeding regime proved to be more suitable for Acipenser stellatus and therefore, it could be useful to optimize the feeding practice in aquaculture production.
RESUMO
Acipenser stellatus represents a species of great economical interest due to its roe used for caviar production. Therefore, it has been intensively captured for decades and nowadays, this species is on the verge of extinction. As a consequence, Acipenser stellatus is intensively raised in fish farms. Aquaculture is focused on optimizing the feeding regime of juveniles. The aim of this study was to investigate if Acipenser stellatus can adapt to a starvation/refeeding regime by assessing the effects of this regime on growth performance, oxidative stress biomarkers and heat shock protein (hsp) gene expression in juveniles raised under aquaculture conditions. The juveniles were subjected to two starvation/refeeding regimes: a 7-day starvation period followed by 21 days of refeeding, and a14-day starvation period followed by 21 days of refeeding. The results had shown that the juveniles subjected to 7/21-day starvation/refeeding regime presented a complete compensatory growth, they were able to counteract the oxidative stress by enhancing activities of the antioxidant enzymes and they presented no significant changes in hsp gene expression. In contrast, 14/21-day starvation/refeeding regime negatively influenced growth performance, it induced a high level of oxidative stress that was impossible to counteract and it determined major changes in the hsp gene expression level in the liver of Acipenser stellatus. Thus, Acipenser stellatus seems to be able to adapt only to the 7/21-day starvation/refeeding regime that does not threaten the growth performance and the welfare of juveniles. Therefore, it could be useful to optimize the feeding practice in aquaculture production.