(E)-9-Octadecenoic Acid Ethyl Ester Derived from Lotus Seedpod Ameliorates Inflammatory Responses by Regulating MAPKs and NF-κB Signalling Pathways in LPS-Induced RAW264.7 Macrophages.

Chuanqi Xie,Mingyuan Cao,Lei Wu,Wei Xiong,Shufen Wang,Talha Bin Emran

doi:10.1155/2022/6731360

Abstract

Inflammation is generally considered a key risk factor in the progress of several chronic diseases, such as arthritis, gastritis, and hepatitis. Natural products with anti-inflammatory ability have played a great role in the process of overcoming these inflammatory diseases. In this study, we evaluated the anti-inflammatory activities of ten natural compounds derived from lotus seedpod and discovered (E)-9-octadecenoic acid ethyl ester (E9OAEE) inhibited the production of nitric oxide (NO) optimally in lipopolysaccharide (LPS)-induced RAW264.7 macrophages. Furthermore, we explored the effects of E9OAEE on inflammatory responses and the underlying mechanisms in LPS-induced RAW264.7 macrophages. The results indicated that E9OAEE significantly suppressed the production of NO, prostaglandin E2 (PGE2), and tumour necrosis factor-α (TNFα) in a dose-dependent manner. The protein expression and mRNA levels of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX2) were inhibited by pretreatment of E9OAEE. Furthermore, E9OAEE restrained the phosphorylation of mitogen-activated protein kinase (MAPKs) family members, ERK, P38, and JNK stimulated by LPS-treated for 30 min and prevented the nuclear translocation of nuclear factor-kappa B (NF-κB) prompted by LPS-treated for 6 h in RAW264.7 macrophages. Taken together, we discovered an anti-inflammatory component from lotus seedpod and identified E9OAEE attenuated the inflammatory response in LPS-induced RAW264.7 macrophages probably by regulating the activation of MAPKs and NF-κB signalling pathways, which would provide some base for the development of new anti-inflammatory drugs.

Highlights

Inflammation is a series of physiological reactions to exogenous stimuli and conditions, and is considered a key risk factor in the progress of several chronic diseases, including autoimmune diseases, arthritis, obesity, diabetes, and cancer [1, 2]
Macrophages are important immune cells closely related to inflammation by regulating the expression of inflammatory proteins and genes such as inducible nitric oxide synthase (iNOS) and COX2 and the production of proinflammatory cytokines including nitric oxide (NO), prostaglandin E2 (PGE2), tumour necrosis factor-α (TNFα), and interleukin (IL)-6 and IL-1β, which can be continuously activated in response to LPS. e uncontrolled inflammatory responses are closely associated with the development of inflammatory diseases
To investigate the anti-inflammatory potential of E9OAEE, we initially evaluated its effect on the viability of RAW264.7 macrophages using the MTT assay. e results showed that E9OAEE had Primer name iNOS-F iNOS-R COX2-F COX2-R glyceraldehyde 3-phosphate dehydrogenase (GAPDH)-F GAPDH-R

Summary

Introduction

Inflammation is a series of physiological reactions to exogenous stimuli and conditions, and is considered a key risk factor in the progress of several chronic diseases, including autoimmune diseases, arthritis, obesity, diabetes, and cancer [1, 2]. Macrophages are important immune cells closely related to inflammation by regulating the expression of inflammatory proteins and genes such as iNOS and COX2 and the production of proinflammatory cytokines including NO, PGE2, TNFα, and interleukin (IL)-6 and IL-1β, which can be continuously activated in response to LPS. MAPKs is a kinase family, which contains several members, such as ERK, p38, and JNK, which mediates numerous cellular activities, including proinflammatory cytokine production, cell proliferation, differentiation, survival, and apoptosis As such, these signalling molecules may be the therapeutic targets of antiinflammatory agents [29]. E9OAEE regulated the activation of MAPKS signalling pathways, including ERK, P38, and JNK, and the nuclear translocation of nuclear factor-kappa B Taken together, these results will provide guidance and theoretical basis for the high value-added utilization of lotus seedpod

Materials and Methods

Results

Discussion

Conclusion