Integrated biomarker parameters response to the toxic effects of high stocking density, CuSO4, and trichlorfon on fish and protective role mediated by Angelica sinensis extract.

The present study explored the protective role of dietary the extract of Angelica sinensis (EAs) on high density, CuSO4, or trichlorfon-treated Crucian carp (Carassius auratus auratus). Firstly, the study showed that the optimum density for growth and growth inhibition was 0.49 and 0.98 fish L-1 water, respectively. Dietary EAs relieved the high density-induced growth inhibition in Crucian carp. The appropriate concentration of EAs for recovery of growth was estimated to be 4.30 g kg-1 diet in high-density fish. Moreover, high density decreased both digestive and absorptive enzyme activities and increased lipid oxidation in digestive organs, suggesting the ability of high density to induce oxidative damage. However, dietary EAs inhibited the oxidative damage through elevating ROS scavenging ability and enzymatic antioxidant activity in digestive organs. Secondly, our data demonstrated that the appropriate concentration of CuSO4 to induce the decrease in feed intake (FI) was 0.8 mg Cu L-1 water. Dietary EAs returned to FI of Crucian carp treated with CuSO4. The appropriate concentration of EAs for recovery of FI was estimated to be 4.25 g kg-1 diet. Moreover, dietary EAs suppressed the CuSO4-induced decrease in digestion and absorption capacity and increase in protein metabolism in digestive organs of Crucian carp. Finally, the present results suggested that dietary EAs inhibited the trichlorfon-induced rollover (loss of equilibrium) in Crucian carp. The appropriate concentration of EAs for inhibition of rollover was estimated to be 4.18 g kg-1 diet. Moreover, trichlorfon stimulated not only the decrease in energy metabolism but also lipid and protein oxidation, suggesting that trichlorfon caused loss of function and oxidative damage in muscles of fish. However, dietary EAs improved muscular function and inhibited oxidative damage via quenching ROS and elevating non-enzymatic and enzymatic antioxidant activity in muscles of trichlorfon-induced fish. So, EAs could be used as an inhibitor of high density, CuSO4, and trichlorfon stress in fish.

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.