Effect of aqueous extract of Tournefortia sarmentosa on the regulation of macrophage immune response

• T. sarmentosa extract decreases the production reactive oxygen species of macrophages.
• T. sarmentosa extract increases macrophage phagocytosis and adhesion.
• T. sarmentosa extract activates phosphorylated p38 MAPK in macrophages.
• T. sarmentosa extract increases the LPS-stimulated IL-6, IL-8, and TNF-α production.

Tournefortia sarmentosa, a Chinese herbal medicine, is considered an antioxidant or a detoxicant agent. Recent studies have shown that T. sarmentosa plays an important role in inhibiting low-density-lipoprotein oxidation and attenuating acetaminophen-induced hepatotoxicity. However, information regarding the signaling mechanism of T. sarmentosa-mediated immunoregulation is still limited. Here, we provide evidence that treating macrophages with T. sarmentosa extract leads to a decrease in reactive oxygen species (ROS) production and subsequently suppresses phosphorylated ERK1/2. In contrast, our data revealed that T. sarmentosa extract increases macrophage phagocytosis and adhesion. Also, T. sarmentosa extract activates phosphorylated p38 MAPK in macrophages. We further discovered that T. sarmentosa extract could increase the lipopolysaccharides-stimulated IL-6, IL-8, and TNF-α production of macrophages. This result suggests that T. sarmentosa extract might enhance inflammation. Taken together, our results suggest that T. sarmentosa extract exerts dual functions on the macrophages: suppressing ROS within cells and enhancing inflammatory responses by improving phagocytic ability and proflammatory cytokine release.