Chia (Salvia hispanica L.) Seeds Contain a Highly Stable Trypsin Inhibitor with Potential for Bacterial Management Alone or in Drug Combination Therapy with Oxacillin

Abstract

The emergence of antibiotic resistance poses a serious and challenging threat to healthcare systems, making it imperative to discover novel therapeutic options. This work reports the isolation and characterization of a thermostable trypsin inhibitor from chia (Salvia hispanica L.) seeds, with antibacterial activity against Staphylococcus aureus sensitive and resistant to methicillin. The trypsin inhibitor ShTI was puri ed from chia seeds through crude extract heat treatment, followed by a nity and reversed-phase chromatography. Tricine-SDS-PAGE revealed a single glycoprotein band of ~11 kDa under nonreducing conditions, con rmed by mass spectrometry analysis (11.558 kDa). ShTI was remarkably stable under high temperatures (100 °C; 120 min.) and a broad pH range (2 -10; 30 min.).Upon exposure to DTT (0.1 M; 120 min.), ShTI antitrypsin activity was partially lost (~ 38%), indicating the participation of disul de bridges in its structure. ShTI is a competitive inhibitor (Ki = 1.79 x 10-8 M; IC50 = 1.74 x 10-8 M) that forms a 1:1 stoichiometry ratio for the ShTI: trypsin complex. ShTI displayed antibacterial activity alone (MICs range from 15.83 to 19.03 µM) and in drug combination with oxacillin (FICI range from 0.20 to 0.33) against strains of S. aureus, including methicillin-resistant strains.Overproduction of reactive oxygen species and plasma membrane pore formation are involved in the antibacterial action mode of ShTI. Overall, ShTI represents a novel candidate for use as a therapeutic agent for the bacterial management of S. aureus infections.

A comparative study of the digestion behavior and functionality of protein from chia (Salvia hispanica L.) ingredients and protein fractions

“…Recently, the existence of ShTl (trypsin inhibitor) in chia seeds has been confirmed, presenting a MW of ∼11 kDa under non-reducing conditions. ShTl exhibited resistance to high temperature (100 °C) and acid-alkaline (pH 2–10) conditions ( de Souza et al, 2022 ). Thus, enabling its protein extraction during sample preparation steps used in this study.…”

Plant Protease Inhibitors as Emerging Antimicrobial Peptide Agents: A Comprehensive Review

“…More recently, a trypsin inhibitor named ShTI was isolated and characterized from mucilage and fat-free chia seeds (S. hispanica L.). This inhibitor demonstrated exceptional thermostability and wide pH tolerance, likely due to its disulfide bridge structure [99]. ShTI exhibited antibacterial activity against S. aureus, including strains resistant to methicillin.…”

Nutritional and Functional New Perspectives and Potential Health Benefits of Quinoa and Chia Seeds

“…It can replace the use of animal fat, and mucilage applied as a versatile function food additive, or food ingredient replacer [148][149][150]. Chia seed contains trypsin inhibitors that can be potentially employed as antimicrobial agents against methicillin-resistant Staphylococcus aureus [151]. Antioxidant properties of yoghurts are highly facilitated by chia seeds and after soaked in apple juice [152].…”