Elucidation of the Molecular-Mechanisms and In Vivo Evaluation of the Anti-inflammatory Effect of Alginate-Derived Seleno-polymannuronate

Abstract

Alginate-derived polymannuronate (PM) is a type of polysaccharide found in edible brown seaweeds. Seleno-polymannuronate (Se-PM) was prepared from PM via synthesis using sulfation- and selenation-replacement reactions. The anti-inflammatory activity of Se-PM and its corresponding molecular mechanisms were investigated. In lipopolysaccharide (LPS)-activated murine macrophage RAW264.7 cells, Se-PM significantly attenuated the production of nitric oxide (NO), prostaglandin E (PGE), and reactive oxygen species (ROS); the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2); and the secretion of proinflammatory cytokines. Moreover, Se-PM remarkably suppressed the LPS-induced activation of the nuclear-factor (NF)-κB and mitogen-activated-protein-kinase (MAPK) signaling pathways in RAW264.7 cells. Furthermore, Se-PM also decreased the production of proinflammatory mediators in LPS-triggered primary murine macrophages. Additionally, Se-PM inhibited the inflammatory response in the air-pouch inflammation model. These results might contribute to the overall understanding of the potential health benefits of Se-PM for food and drug applications.

Elucidation of The Anti‐Inflammatory Effect of Vanillin In Lps‐Activated THP‐1 Cells

“…Of note, the primary role of ROS during inflammation has also been found (Bi et al., ). The overproduction of ROS not only leads to oxidative stress but also exacerbates the inflammation (Nam, Son, Yang, Lee, & Lee, ).…”

“…Indeed, we also found the products of NO and PGE2 increased with the overexpression of iNOS and COX‐2. Previous study has reported that NO and PGE2 are critical inflammatory mediators and release during the inflammatory response (Bi et al., ). Therefore, it's crucial to suppress the products of iNOS and COX‐2.…”

“…In this study, we observed a rise in the expression of iNOS and COX‐2 in THP‐1 cells treated with LPS alone, which was in accordance with the findings of previous study (Guo et al., ). Reportedly, iNOS and COX‐2 are vital regulators of NO and PGE2 products, respectively (Bi et al., ; Pham et al., ; Yang et al., ; Yashaswini, Kurrey, & Singh, ). Indeed, we also found the products of NO and PGE2 increased with the overexpression of iNOS and COX‐2.…”

“…Although accumulating evidence has identified that inflammation is a double‐edged sword. Although inflammatory response is precisely regulated in the body, chronic and excessive inflammation seems to be inevitable due to the increasing incidences of the diseases associated with chronic inflammation such as cardiovascular diseases, type 2 diabetes, arthritis, cancer, Alzheimer's disease, and so on (Bi et al., ; Niu et al., ; Walker et al., ). Therefore, seeking proper component with anti‐inflammatory property from natural beverages and foods is of great value.…”

“…However, choosing human cells as the cell model to explore the inhibitory effect of VA on human inflammation is more suitable and valuable. In view of monocytes (major components of the innate immune system of the human body) playing crucial roles in host defenses against infection through inflammation (Bi et al., ; Pham et al., ), THP‐1 human monocytic cell was chosen as the cell model to uncover the anti‐inflammatory effect of VA in the present study. Moreover, to explore the mechanism underlying the anti‐inflammatory effect, the effect of VA on the expression of upstream signaling pathway needs to be conducted.…”