β-Lactoglobulin-exopolysaccharide complex: Structural characterization, antioxidant activity in LPS-induced oxidative damage cell model

Cuicui Duan; Hongru Wang; Yi Zhang; Hui Liu; Siyang Sui; Mengchun Qin; Xiaolei Li; Fumin Ma; Dan Li

doi:10.1016/j.ijbiomac.2025.145653

β-Lactoglobulin-exopolysaccharide complex: Structural characterization, antioxidant activity in LPS-induced oxidative damage cell model

Int J Biol Macromol. 2025 Jun 29;319(Pt 4):145653. doi: 10.1016/j.ijbiomac.2025.145653. Online ahead of print.

Authors

Cuicui Duan¹, Hongru Wang¹, Yi Zhang¹, Hui Liu¹, Siyang Sui¹, Mengchun Qin¹, Xiaolei Li¹, Fumin Ma¹, Dan Li²

Affiliations

¹ Key Laboratory of Agro-products Processing Technology, Jilin Provincial Department of Education, Changchun University, 6543 Weixing Road, Changchun 130022, Jilin Province, People's Republic of China.
² Key Laboratory of Agro-products Processing Technology, Jilin Provincial Department of Education, Changchun University, 6543 Weixing Road, Changchun 130022, Jilin Province, People's Republic of China. Electronic address: drlidan@yahoo.com.

PMID: 40592431
DOI: 10.1016/j.ijbiomac.2025.145653

Abstract

Lactobacillus exopolysaccharides (EPS) have been widely used in fermented food and health care products due to their good biological activities. In this study, EPS derived from Lactobacillus plantarum A106 and β-lactoglobulin (β-Lg) were used to prepare β-Lg-EPS complex, and the structure and antioxidant activity of the complex were studied. The results indicated that the incorporation of EPS with β-Lg could quench the inherent fluorescence of β-Lg and change the conformation and secondary structure, finally improving the thermal stability. Moreover, addition of EPS changed the spherical structure of β-Lg, and the structure of β-Lg-EPS complexes appeared blocky and dendritic. Both ζ potential and particle size of β-Lg-EPS complex were decreased regardless of proportions between β-Lg and EPS. The dispersion system was the most uniform and stable when the ratio of β-Lg to EPS was 10:1. Moreover, β-Lg-EPS complex presented a higher free radical scavenging rate than that of native β-Lg, 64.47 ± 2.77 % for DPPH, 90.09 ± 0.42 % for ABTS⁺ and 26.74 ± 0.56 % for ·OH, respectively. Moreover, β-Lg-EPS complex could alleviate oxidative damage and exert its antioxidant activity by improving cell viability and SOD activity, reducing ROS level, restoring mitochondrial membrane potential and improving apoptosis of LPS-induced RAW264.7 cells.

Keywords: Apoptosis; Lactobacillus exopolysaccharide; Mitochondrial membrane potential; Structural characterization; β-Lactoglobulin.