Effects of graded levels of dietarymyo-inositol on non-specific immune and specific immune parameters in juvenile Jian carp (Cyprinus carpiovar. Jian)

Abstract

The aim of this study was to evaluate the e¡ects of myo-inositol (MI) on non-speci¢c immune and speci-¢c immune defence in ¢sh. A total of 1050 Jian carp (Cyprinus carpio var. Jian) (22.28 AE 0.07 g) were randomly distributed into seven groups, of three replicates each, of feeding diets containing graded levels of MI (163.5, 232.7, 384.2, 535.8, 687.3, 838.8 and 990.3 mg MI kg À 1 diet). After a 60-day growth trial, an infectious trial was conducted by injection of Aeromonas hydrophila for 17 days. Results showed that the red blood cell (RBC) and the white blood cell count were signi¢cantly increased with increasing MI levels up to 535.8 mg kg À 1 diet (Po0.05). The spleen index showed a tendency similar to RBC, whereas the head kidney index showed the inverse pattern (Po0.05). The phagocytic activity of leucocytes, haemagglutination titre, lysozyme activity, anti-A. hydrophila antibody titre and immunoglobulin M, after being injected with A. hydrophila, were all improved with an increase in the MI levels up to 232.7^687.3 mg kg À 1 diet respectively (Po0.05). Myo-inositol did not in£uence serum acid phosphatase activity and total iron-binding capacity (P40.05). These results suggested that MI could enhance non-speci¢c immune and speci¢c immune responses in ¢sh.

Dietary myo-inositol modulates immunity through antioxidant activity and the Nrf2 and E2F4/cyclin signalling factors in the head kidney and spleen following infection of juvenile fish with Aeromonas hydrophila

“…Immunity in fish is largely dependent on the growth of the immune organs [9]. Our previous study demonstrated that MI could enhance the growth of the head kidney and spleen in juvenile Jian carp [14]. These findings indicated that MI might influence immunity in the head kidney and spleen of fish, which required further investigation.…”

“…This study used the same animal trial described in our previous study [14]. The experimental diets and the preparation and storage of diets were the same as described in our previous study [14].…”

“…These immune cells can secrete humoural components such as lysozyme, acid phosphatase (ACP) and complement that play crucial roles in innate immune response [12]. Our previous studies observed that vitamin nutrition (i.e., vitamin B6 [13], MI [14], and choline [15]) could increase the serum lysozyme activity in juvenile Jian carp. However, whether vitamins such as MI can influence these humoural components to enhance the immunity in immune organs has not been studied in animals.…”

“…Therefore, determining the MI requirements of juvenile Jian carp based on the immune indicators is valuable. This study is an extension of a series of studies on the physiological functions of MI and its roles in maintaining the health of animals [5,14]. Aeromonas hydrophila is a common pathogenic bacterium in fish that causes massive mortalities and large economic losses in the natural environment and fish farms worldwide [37].…”

The impaired intestinal mucosal immune system by valine deficiency for young grass carp (Ctenopharyngodon idella) is associated with decreasing immune status and regulating tight junction proteins transcript abundance in the intestine

“…The requirement of dietary valine has been determined in juvenile grass carp [24] but may vary with the growth stage of the fish [25,26]. In addition, the requirements of nutrients may vary with the sensitive indicators [27,28]. Therefore, it is valuable to determine the valine requirements of grass carp based on the immune and growth indicators.…”