Crassostrea gigas peptic hydrolysate: a source of various biologically active molecules

摘要

Crassostrea gigas from Atlantic coast were digested by pepsin at pH 2 and 40℃ during 3 hours. Using Guinea pig ileum test, presence of opi-oid molecules was assessed. The hydrolysate was only able to decrease partially Guinea pig ileum electrically induced contractions. Only a pseu-do-opioid effect was observed. The anti-hypertensive potential of the hydrolysate was checked using the ability of the hydrolysate to inhibit the Angiotensin converting enzyme (ACE). This enzyme is partially responsible of hypertension. Only 20 minutes of hydrolysis allowed the production of an hydrolysate able to inhibit 90% of ACE activity. The concentration of hydrolysate needed to inhibit 50% of ACE activity (IC_(50)) was 72mg/l. Peptic oysters hydrolysate was analysed on RP-HPLC and 7 fractions were manually collected. ACE test was performed on each fraction. The fraction 6 was the most efficient since it had ah IC_(50) of 5.3mg/l. Molecules contained in fraction 6 should be identified and tested in vitro and in vivo. No anti-oxidant activities were evidenced in oysters hydrolysate fractions obtained by RP-HPLC but two fractions exhibited interesting antiviral effects against herpes virus type 1. Further work will concern mainly anti-hypertensive potential of peptic oysters hydrolysate fractions and search of antiviral molecules. Such oysters hydrolysates produced by a classical gastric enzyme could be of interest for the emerging nutraceutical market.