Effect of fermented oyster extract on growth promotion in Sprague–Dawley rats

Background: Oysters (Crassostrea gigas) are a popular marine product worldwide and have the advantage of nutritional benefits. This study aimed to investigate the effect of fermented oyster extract (FO) on growth promotion, including analysis of body size, bone microarchitecture, hematology and biochemistry in vivo. Methods: The amount of nutrients and gamma aminobutyric acid (GABA) were determined. Sprague–Dawley rats were randomly divided into four groups: the control group, FO 50 group (FO 50 mg/kg), and FO 100 group (FO 100 mg/kg) were administered orally once daily and the recombinant human growth hormone (rhGH) group (200 μg/kg) was intraperitoneally injected once daily for 14 days. Results: Oral administration of FO 100 significantly increased body length and had no effect on organ damage or hematological profiles. However, administration of rhGH significantly induced hypertrophy of the liver, kidney and spleen along with a marked increase in body length. Tibia length and the growth plate were increased, and bone morphometric parameters were slightly improved by FO and rhGH administration. Serum analysis showed that the levels of GH and insulin like growth factor-1 (IGF-1) were slightly upregulated by FO administration. Nevertheless, the protein expression of hepatic IGF-1 was markedly increased by FO 100 and rhGH administration. Conclusions: FO have high content of GABA, and induced positive effects on body length, tibial length, growth-plate length and hepatic IGF-1 synthesis in SD rats with no toxicity or alterations of hematological profile. Therefore, these results suggest that GABA-enriched FO could be considered a potential alternative treatment for growth stimulation.