Dietary glycerol monolaurate improves bone growth through the regulation of IGF-1 in the fish model

Abstract

Glycerol monolaurate (GML) has the potential of antibacterial and growth-promoting in food. Recent research reported that GML could significantly increase the body index of fish, but whether GML can exert growth-promoting ability via regulating bone metabolism remains unknown. This study explored the effects of GML on the bone growth of fish models and its mechanisms by analyzing the expression of insulin-like growth factor 1(IGF-1). The micro-CT scanning results showed that the dietary supplementation of 750 mg/kg GML significantly increased the body length and bone mineral density, and improved the bone microarchitecture parameters of the caudal vertebrae of zebrafish (Danio rerio). The centrum part of the vertebra was easier to respond to the regulatory effect of GML than the neural arch and the haemal arch. Mechanistically, the content of serum IGF-1, the expression of osteogenic differentiation-related genes, and genes involved in IGF-1/PI3K/Akt signaling pathway were significantly increased. The liver proteomic analysis showed the consistent results that GML supplementation could up-regulate the expression of hepatic IGF-1, and that energy metabolism and growth and development-related metabolic pathways were implicated in the GML bone growth boosting effects. These findings highlight that GML could be used as a functional food additive to improve bone growth and health.