Peptides from Chia Present Antibacterial Activity and Inhibit Cholesterol Synthesis

Michele Silveira Coelho, Rosana Aparecida Manólio Soares-Freitas, José Alfredo Gomes Arêas, Eliezer Avila Gandra, Myriam de las Mercedes Salas-Mellado

In previous studies, it has not been reported that protein isolated from chia interferes favorably with antibacterial activity, and reduces cholesterol synthesis. The objective of this study was to determine whether commonly used commercial microbial proteases can be utilized to generate chia protein-based antibacterial and hypocholesterolemic hydrolysates/peptides, considering the effects of protein extraction method. Alcalase, Flavourzyme and sequential Alcalase-Flavourzyme were used to produce hydrolysates from chia protein (CF), protein-rich fraction (PRF) and chia protein concentrates (CPC1 and CPC2). These hydrolysates were evaluated for their antimicrobial activity against Gram-positive (G+) and Gram-negative (G-) microorganisms. The protein hydrolysates were purified by ultrafiltration through a membrane with 3 kDa nominal molecular weight, for evaluation of hypocholesterolemic activity. An inhibition zone was observed when the hydrolysate was tested against S. aureus, and minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) values were obtained. Peptides from chia protein with molecular mass lower than 3 kDa reduced up to 80.7% of 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMG-CoA reductase) enzymatic reaction velocity. It was also observed that, independent of the method used to obtain chia proteins, the fractions showed relevant bioactivity. Moreover, the intensity of the bioactivity varied with the method for obtaining the protein and with the enzyme used in the hydrolysis process. This is the first report to demonstrate that chia peptides are able to inhibit cholesterol homeostasis.