The Immune-Enhancing Effects of a Lactobacillus paracasei L-30 Extract Through the NF-κB and MAPK Pathways in RAW264.7.

Abstract

Immune enhancement is an important factor that not only helps prevent infections but also affects overall health. This study aims to evaluate the immunostimulatory effects of a novel Lactobacillus strain, Lactobacillus paracasei L-30, and to elucidate its underlying mechanisms. The extract obtained from Lactobacillus paracasei L-30 significantly increased phagocytosis and the production of NO and ROS in RAW264.7 macrophages. The protein and mRNA expression levels of COX-2 and iNOS which are immune regulators were upregulated by the L-30 extract. The levels of cytokines and chemokines, such as G-CSF, IL-6, MIP-1α, MIP-1γ, RANTES, sTNF RI, and sTNF RII, were increased by the treatment with the L-30 extract. In addition, the L-30 extract degraded IκB-α and induced the phosphorylation of NF-κB. Furthermore, the MAPK signaling pathways ERK, JNK, and p38 were activated by the L-30 extract. The production of iNOS, COX-2, and NO was inhibited by MAPK pathway inhibitors. Therefore, our data suggest that the Lactobacillus paracasei L-30 extract has the potential to be developed as a healthy functional food that can enhance immune responses by activating macrophages.