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

## TL;DR

This study shows that a Lactobacillus paracasei L-30 extract boosts immune responses in macrophages by activating specific signaling pathways.

## Contribution

The novel Lactobacillus paracasei L-30 extract is shown to enhance immune activity through NF-κB and MAPK pathways in macrophages.

## Key findings

- L-30 extract increases phagocytosis and production of NO and ROS in RAW264.7 macrophages.
- The extract activates NF-κB and MAPK pathways, leading to increased cytokine and chemokine levels.
- MAPK pathway inhibitors reduce the production of iNOS, COX-2, and NO induced by the extract.

## 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.