Camel and Horse Milk Casein Hydrolysates Exhibit Angiotensin Converting Enzyme Inhibitory and Antioxidative Effects In Vitro and In Silico

Angiotensin converting enzyme (ACE) and reactive oxygen species are crucial targets for nutritional management of hypertension. The aim of this study is to investigate ACE inhibitory and antioxidative effects of camel and horse milk casein hydrolysates. After casein was isolated from raw camel and horse milk, the purity and molecular weights of the isolated casein were verified using SDS-PAGE prior to digestion with pepsin, trypsin and combined enzymes. The results obtained showed that hydrolysates obtained from pepsin and trypsin combined enzymes exhibited higher ACE-inhibitory activity than individual enzymes. In addition, DPPH radical scavenging activity (%) was significantly (p < 0.05) higher for camel milk casein hydrolysate than horse milk casein hydrolysate. Both hydrolysates displayed significant (p < 0.05) inhibition of lipid peroxidation and hydroxyl radical when compared with standard antioxidant (BHA). Moreover, simulation of casein proteolysis in silico generated fragments with potential ACE inhibitory activity using molecular docking analysis. The present findings suggested that camel and horse milk casein hydrolysates contain bioactive peptides responsible for ACE inhibition and antioxidative effects and thus could be exploited for the treatment and management of hypertension.