ANGIOTENSIN CONVERTING ENZYME (ACE) INHIBITORY ACTIVITY OF CRUDE AND FRACTIONATED SNAKEHEAD (Channa striata) MEAT EXTRACT

The existence of endogenous bioactive protein or peptide with angiotensin-converting enzyme (ACE) inhibitory activity in snakehead meat is promising to be investigated. The purposes of this research were to extract ACE inhibitory endogenous bioactive protein or peptide from snakehead meat and to fractionate the active compounds using ultrafiltration. The extraction in this research employs two kinds of solvents, e.i aquadest and 50% ethanol. Then, the extract is fractionated with the ultrafiltration using the 10,000; 5,000 and 3,000 MWCO membranes to separate the protein or peptide of with the sizes of >10 kDa, 5 – 10 kDa, 3 – 5 kDa and <3 kDa. The parameters being observed from the crude extracts and its fractions included the protein and peptide content, the ACE inhibitory activity (in vitro), and the protein and peptide profiles determined by using the SDS PAGE.  The result of this research revealed that the snakehead meat contained ACE inhibitory endogenous bioactive protein or peptide. The 50% ethanol was more effective in extracting peptide sized <10 kDa than the aquadest. Yet, the aquadest was better in extracting higher molecular weight protein of >10 kDa than the 50% ethanol was. The bioactivity of 50% ethanol extraction was higher than the aquadest extraction. The highest bioactivity of 95.18% was gained from the fraction 5 – 10 kDa of 50% ethanol extract