Effect of dietary administration of astaxanthin and bile salt on oxidative stress enzymes and blood biochemical parameters of parrot (Cichlasoma synspilum ♀ × Cichlasoma citrinellum ♂) during starvation period

This study was aimed to improve Parrot fish fitness, respecting antioxidant defense system and plasma biochemical parameters affected by starvation. 198 parrot fish (average weight 25.5±6.2 g and length 6.34± 0.43 cm) were randomly distributed in three different treatments, including control (basic diet), astaxanthin (diet enriched with 4g/kg astaxanthin) and astaxanthin-bile salt treatment (diet enriched with 4g/kg astaxanthin and 1200 mg/kg bile salt). The fish were fed for 90 days and then subjected to starvation for 7 days. Bleeding was done at the end of feeding period (before starvation stress) and after starvation phase and some plasma oxidative stress enzymes and blood biochemical parameters were analyzed. Results showed that feeding fish with astaxanthin alone, can reduce the levels of oxidative stress enzymes in fish in comparison to the control at the end of the feeding period while reduced levels of liver enzymes such as asparat aminotransferase and alanine aminotransferase were only observed in fish fed on diet enriched with astaxanthin-bile salt (P<0.05). Starvation caused significant elevation of plasma oxidative stress enzymes in the control group (P<0.05), while such changes were not observed in fish fed on astaxanthin and/or astaxanthin-bile salt treatments (P>0.05). In general, it can be concluded that starvation can cause plasma oxidative stress enzymes elevation, plasma total protein and liver enzymes reduction in parrot fish; nevertheless, by dietary astaxanthin supplementation alone or in combination with bile salt, the negative effects of starvation on parrot fish, at least for some physiological parameters, can minimized.