CONTEXT: Oysters [Crassostrea plicatula Gmelin (Ostreidae)] are widely used for food in coastal areas. It is reported to have several qualities such as improving sexual and immune function. They has been approved by Chinese Ministry of Health as a functional food. OBJECTIVE: The effects of five types of oyster components (oyster meat, oyster glycogen, oyster protein, cooked liquid components, and water-insoluble components) on the swimming endurance of mice were investigated. MATERIALS AND METHODS: First, the amino acid composition and sugar content of the five oyster components were analyzed by a physicochemical test. In the in vivo test, the control group was administered distilled water, and the five intervention groups were treated with various samples for 15 consecutive days [0.8 mg protein/(g BW·d) or 0.2 mg glycogen/(g BW·d)]. The swimming time was recorded through the exhaustive swimming test. The levels of serum lactic acid, blood urea nitrogen (BUN), liver glycogen, and gastrocnemius muscle glycogen were determined. RESULTS: Oyster protein had a minimum F-value (the mole ratio of branched-chain amino acids to aromatic amino acids) (2.68), contained 1.85 mmol/mL taurine and no sugar. The components (except for oyster protein) significantly improved endurance capacity of mice and increased the liver and muscle glycogen contents (p<0.05), and reduced the lactic acid and BUN levels (p<0.05). Oyster protein had little effect. DISCUSSION AND CONCLUSION: The effects of oyster components on the swimming endurance of mice may be attributed to the high ratio of the branched-chain amino acid composition, bioactivity of taurine, and glycogen.
CONTEXT: Oysters [Crassostrea plicatula Gmelin (Ostreidae)] are widely used for food in coastal areas. It is reported to have several qualities such as improving sexual and immune function. They has been approved by Chinese Ministry of Health as a functional food. OBJECTIVE: The effects of five types of oyster components (oyster meat, oyster glycogen, oyster protein, cooked liquid components, and water-insoluble components) on the swimming endurance of mice were investigated. MATERIALS AND METHODS: First, the amino acid composition and sugar content of the five oyster components were analyzed by a physicochemical test. In the in vivo test, the control group was administered distilled water, and the five intervention groups were treated with various samples for 15 consecutive days [0.8 mg protein/(g BW·d) or 0.2 mg glycogen/(g BW·d)]. The swimming time was recorded through the exhaustive swimming test. The levels of serum lactic acid, blood ureanitrogen (BUN), liver glycogen, and gastrocnemius muscle glycogen were determined. RESULTS: Oyster protein had a minimum F-value (the mole ratio of branched-chain amino acids to aromatic amino acids) (2.68), contained 1.85 mmol/mL taurine and no sugar. The components (except for oyster protein) significantly improved endurance capacity of mice and increased the liver and muscle glycogen contents (p<0.05), and reduced the lactic acid and BUN levels (p<0.05). Oyster protein had little effect. DISCUSSION AND CONCLUSION: The effects of oyster components on the swimming endurance of mice may be attributed to the high ratio of the branched-chain amino acid composition, bioactivity of taurine, and glycogen.