Effects ofmyo‐inositol on growth performance, body composition, antioxidant status, non‐specific immunity and lipid metabolism of juvenile Chinese mitten crab (Eriocheir sinensis)

Abstract

This study evaluated the effects of dietary myo‐inositol (MI) levels on growth, body composition, antioxidant status, non‐specific immunity and lipid metabolism in juvenile Chinese mitten crab (Eriocheir sinensis). A total of 960 crabs was fed with six diets supplemented with graded levels of MI (0, 204, 406, 810, 1,650 and 3,211 mg/kg) for 8 weeks. The crabs fed with diets containing 1,650 mg/kg MI had significantly higher final body weight, weight gain and specific growth rate than those fed 0, 204, 406 and 810 mg/kg MI (p < .05). The lowest moulting frequency was observed in the crabs fed diets without supplemented MI. The crabs fed with diets containing 1,650 and 3,211 mg/kg MI had significantly lower total lipid content in the whole body than those fed diets without supplemented MI (p < .05). The myo‐inositol level in hepatopancreas increased with increasing dietary MI up to 1,650 mg/kg before reaching plateau. The crabs fed 1,650 mg/kg MI had significantly higher total antioxidant capacity and glutathione peroxidase activity in hepatopancreas than those fed diets without supplemented MI (p < .05). However, the crabs fed diets without supplemented MI had the highest level of malondialdehyde in hepatopancreas compared with those fed with MI supplementation. The highest serum alkaline phosphatase activity was also observed in crabs fed 1,650 mg/kg MI. Total protein and haemocyanin contents in serum were significantly increased with increasing dietary MI levels (p < .05). The triglyceride contents in hepatopancreas significantly decreased with increasing dietary MI levels (p < .05). Results of real‐time quantitative PCR revealed that dietary MI reduced hepatic triglyceride accumulation probably through inhibiting lipid synthesis‐related genes and promoting lipid export‐related genes at the transcriptional level. Broken‐line analysis of weight gain, specific growth rate and MI levels in hepatopancreas against dietary MI levels indicates that the optimal MI requirement for juvenile crabs ranged from 1,613 to 1,707 mg/kg. The dietary MI supplementation can improve growth performance, antioxidant capacity and non‐specific immunity and reduce hepatopancreatic triglyceride accumulation in juvenile crab.

Alleviation of the Adverse Effect of Dietary Carbohydrate by Supplementation of Myo-Inositol to the Diet of Nile Tilapia (Oreochromis niloticus)

“…Moreover, the activities of GST/GOT and ALT/GPT were the most sensitive indicators of liver cell damage, which is increased by dietary MI, this indicates that the addition of MI alleviates the damage of liver cells and avoids the formation of fatty liver [ 77 ]. AKP and ACP are essential enzymes for growth metabolism, homeostasis and health [ 17 , 78 , 79 ]. Therefore, the activities of AKP and ACP in the liver tissue also indirectly reflect the health of the liver [ 80 ].…”

“…Weight gain (WG %) = 100 × (final body weight-initial body weight)/initial body weight; Survival rate (SR %) = 100 × (final fish number/initial fish number); Feed conversion ratio (FCR) = total feed intake weight/(final body weight-initial body weight); Condition factor (CF %) = 100 × wet body weight/body length; Hepatosomatic index (HSI %) = 100 × wet hepatopancreas weight/wet body weight; Visceral index (VIS %) = 100 × wet visceral weight/wet body weight [13,17].…”

“…In turbot Scophthalmus maximus , MI plays a vital role in transmembrane signal transfer, protection of the liver, and lipid metabolism [ 16 ]. In other aquatic animals, dietary supplementation with MI can reduce lipid accumulation in tissues and decrease the chance of becoming a fatty liver [ 17 ]. Although MI can reduce lipid accumulation in aquatic animals, the underlying molecular mechanism is still not clear.…”

Myo-inositol improves growth performance and regulates lipid metabolism of juvenile Chinese mitten crab (Eriocheir sinensis) fed different percentage of lipid

“…Previous studies reported that there was a close link between the regulation of AMPK activity and IP3R mediated Ca 2+ signalling pathway (27,28) . So far, many investigations have reported that MI plays a crucial part in the regulation of lipid metabolism in aquatic animals (13,15,29) . However, in contrast, no information has been reported on the specific molecular mechanism of MI regulating lipid metabolism.…”

“…Particularly, lipid metabolism mediated by dietary MI was explored at different lipid levels to understand the role of MI in promotion of lipid utilization in crustacean. were prepared with the process in detail described in our previous study (29) . The experimental diets were stored at -20 ℃ until use.…”