The effects of dietary medicinal herbs on growth and some non-specific immunity were investigated in juvenile red sea bream Pagrus major. The fish (mean body weight 24.0 Ϯ 0.2 g) were fed fishmeal diets supplemented with either Massa medicata (Mm), Crataegi fructus (Cf), Artemisia capillaries (Ac), Cnidium officinale (Co), or a mixture of all the herbs (HM), and a control diet without medicinal herbs, for 12 weeks. Survival, specific growth rate, feed efficiency, condition factor and hemoglobin levels were higher in fish given herbal diets than fish given the control diet without herbs. Significantly higher serum high density lipoprotein-cholesterol level and lysozyme activity were detected in HM and Co diet groups, and alternative complement pathway activity was detected in the HM diet group. However, significantly lower serum alanine aminotransferase and aspartate aminotransferase activities were obtained in all herbal diet groups compared with the control diet group. Pathogen challenge test by intraperitoneal injection of Vibrio anguillarum indicated that highest survival was obtained in the HM diet group followed by Ac, Co, Cf, and Mm diet groups. The lowest survival was obtained in the control group. These results reveal that medicinal herbs in diets enhance growth and some non-specific immunity of red sea bream.KEY WORDS: growth performance, medicinal herbs, non-specific immunity, red sea bream.

Though diketopiperazines (DKP) are formed in most experiments concerning the prebiotic peptide formation, the molecules have not been paid attention in the studies of chemical evolution. We have found that triglycine, tetraglycine or pentaglycine are formed in aqueous solution of glycine anhydride (DKP) and glycine, diglycine or triglycine, respectively. A reaction of alanine with DKP resulted in the formation of glycylglycylalanine under the same conditions. These results indicate that the formation of the peptide bonds proceeds through the nucleophilic attack of an amino group of the amino acids or the oligoglycines on the DKP accompanied by the ring-opening. The formation of glycine anhydride, di-, tri- and tetraglycine was also observed in a mixed aqueous solution of urea and glycine in an open system to allow the evaporation of ammonia. A probable pathway is proposed for prebiotic peptide formation through diketopiperazine on the primitive Earth.

The effect of dietary medicinal herbs on lipid metabolism and stress recovery was investigated in red sea bream Pagrus major. Fish (mean body weight 24.0 ± 0.2 g) were fed on test fish meal diets supplemented with either Massa Medicata (Mm), Crataegi Fructus (Cf), Artemisia capillaries (Ac), or Cnidium officinale (Co), or with a mixture of the four herbs (HM) for 12 weeks. A control group was fed a diet without herbs in the same manner. A high survival rate was observed in the herbal diet groups. The final mean body weight, feed efficiency, protein efficiency ratio, and apparent protein and lipid retention in the Ac, Co, and HM groups were higher than those in the control and Mm groups. Final carcass, hepatic lipid and triglyceride contents, and plasma triglyceride and nonesterified fatty acid levels were lower in the Ac, Co, and HM groups compared to those of control and Mm groups. However, final hepatic phospholipid, plasma phospholipid, and high density lipoprotein cholesterol levels were higher in the Ac, Co, and HM diets groups than in the control and Mm groups. The Cf, Co, Ac, and HM groups showed faster recovery time in the 2-phenoxyethanol anesthesia test and a higher recovery rate in the 10-min air exposure test than those of the control and Mm groups. Moreover, the Cf, Ac, Co, and HM diet groups had a significantly lower plasma cortisol level than the control and Mm diet group, but the glucose level in the herbal diet groups was higher than that in the control group after a 1-h air exposure. These results indicate that the addition of medicinal herbs to the fish diet improved lipid utilization and stress recovery in red sea bream.

By heating an aqueous solution of aspartic acid and urea, carbamylaspartic acid is first formed and then the molecule is cyclized to dihydroorotic acid (DHO) with loss of water. Irradiation of an aqueous solution of DHO with a tungsten lamp yields orotic acid by photo-dehydrogenation of the molecule. This pathway of orotic acid formation is quite similar to that of biosynthesis of the molecule.

The e¡ects of the dietary medicinal herbs Massa medicata, Crataegi fructus (Cf), Artemisia capillaries, Cnidium o⁄cinale and their mixture (HM), on growth and resistance againstVibrio anguillarum were examined using larval red sea bream, Pagrus major. The methanol extracts of Cf and HM inhibited the proliferation of seven infectious bacterial strains including the genera Aeromonas, Edwasiella, Photobavterium, Pseudomonas and Vibrio. Rotifers enriched with emulsi¢ed bonito oil containing extracts of Cf and HM lowered the bacterial counts in their body on TCBS medium for the genus Vibrio in comparison with rotifers enriched by emulsi¢ed bonito oil alone. Although statistically not signi¢cant, larvae fed rotifer forti¢ed with Cf from 3 to 20 days after hatching showed the best growth and ¢nal body weight followed by those given rotifer with HM and control enrichment. However, ¢nal body length of larvae fed rotifer with Cf was signi¢cantly larger than larvae fed on rotifers enriched with other herb extracts. After a challenge test withV. anguillarum, survival of larvae fed rotifer with Cf and HM was signi¢cantly higher than for the control treatment. These results revealed that Cf and HM in rotifer is useful to promote growth and resistance against V. anguillarum in red sea bream larvae, providing a new technology for mass production of disease-resistant fry and ¢ngerlings.