Prathak Tabthipwon

The Use of Natural Carotenoids and Growth Performance, Skin Pigmentation, and Immune Response in Fancy Carp (Cyprinus carpio)

Fancy carp were fed seven dietary treatments with natural pigment sources (tea, mulberry, cassava) at a specific rate to achieve a total carotenoid (TC) concentration in the diet of 25 mg/kg. Growth performance among treatments was not significantly different (p ≥ 0.05). TC and skin redness (a*) of fish fed tea leaves was higher than the other treatments (p ≤ 0.05). Fish fed with tea extract and cassava leaves had higher serum astaxanthin concentrations than the other groups (p ≤ 0.05). This group also retained serum astaxanthin and red color better than other groups two weeks post treatment (p ≤ 0.05). Phagocytic activity was significantly greater in fish fed carotenoid supplements compared with the control group (P ≤ 0.05). Therefore, dietary supplementation with 25 mg/kg tea leaves is sufficient to obtain good coloration in fancy carp as well as enhance immunity.

Comparative pharmacokinetics after feeding fancy carp (Cyprinus carpio) with diets containing carotenoids from natural sources [tea (Camellia sinensis) , mulberry (Morus alba) , and cassava (Manihot esculenta) leaf]

The carotenoid composition of tea, mulberry, and cassava leaf has been determined by TLC on silica gel 60 with 75:15:10 (v/v) petroleum ether-diethyl ether-acetone as mobile phase. Spectrodensitometric detection was performed at 450 nm. The results showed lutein and β-carotene were the main carotenoids in all the leaves. Tannin was found in tea leaves at a level of 4.60 ± 0.07 g kg−1. The amount of cyanide in cassava leaf was equivalent to 918.31 ± 11.37 mg hydrocyanic acid kg−1. A pharmacokinetic study of total carotenoids was designed with three experimental fancy carp diets based on tea, mulberry, and cassava leaves as raw materials. The results showed that the maximum concentrations of serum total carotenoids in fish fed with tea, mulberry, and cassava leaves were 0.0022, 0.0016, and 0.0018 µg mL−1 48, 72, and 48 h after feeding, respectively (Tmax). The volumes of distribution were 23.40, 22.28, and 23.39 mL kg−1, total body clearance was 0.24, 0.30, and 0.41 mL h−1 kg−1, and the area under the concentration-time curve was 108.23, 79.74, and 60.58 µg h mL−1, respectively. It is concluded that when fish were fed a tea leaf diet carotenoids were absorbed more readily than from other diets. Similar serum astaxanthin levels were observed for fancy carp on all diets 48 h after feeding, and astaxanthin concentration in blood serum continued to increase with time. These studies indicated that irrespective of the lutein and β-carotene content of the three plant leaves in the diet, the fancy carp can convert them to astaxanthin in serum.