Luteolin-3'-O-Phosphate Inhibits Lipopolysaccharide-Induced Inflammatory Responses by Regulating NF-κB/MAPK Cascade Signaling in RAW 264.7 Cells.

Jung-Hwan Kim,Min-Seon Kim,Won-Jae Chi,Seung-Young Kim,Tae-Jin Park,Jin-Soo Park

doi:10.3390/molecules26237393

Abstract

Luteolin (LT), present in most plants, has potent anti-inflammatory properties both in vitro and in vivo. Furthermore, some of its derivatives, such as luteolin-7-O-glucoside, also exhibit anti-inflammatory activity. However, the molecular mechanisms underlying luteolin-3′-O-phosphate (LTP)-mediated immune regulation are not fully understood. In this paper, we compared the anti-inflammatory properties of LT and LTP and analyzed their molecular mechanisms of action; we obtained LTP via the biorenovation of LT. We investigated the anti-inflammatory activities of LT and LTP in macrophage RAW 264.7 cells. We confirmed from previously reported literature that LT inhibits the production of nitric oxide and prostaglandin E2, as well as the expression of inducible NO synthetase and cyclooxygenase-2. In addition, expressions of inflammatory genes and mediators, such as tumor necrosis factor-α, interleukin-6, and interleukin-1β, were suppressed. LTP showed anti-inflammatory activity similar to LT, but better anti-inflammatory activity in all the experiments, while also inhibiting mitogen-activated protein kinase and nuclear factor-kappa B more effectively than LT. At a concentration of 10 μM, LTP showed differences of 2.1 to 44.5% in the activity compared to LT; it also showed higher anti-inflammatory activity. Our findings suggest that LTP has stronger anti-inflammatory activity than LT.

Highlights

Inflammation is a unique limiting process for the identification and destruction of invading pathogens; it is achieved through biological reactions that occur in the human body, and it restores normal tissue structure and function [1,2,3,4]
The LT biorenovation product separated through the ethyl acetate (EA) fraction was divided into an EA layer and a water layer, and HPLC analysis was performed
We purified only luteolin -O-phosphate (LTP) from the water layer, and the analysis of the LTP using electrospray ionization mass spectrometry (ESIMS) revealed a peak at m/z 286 (Figure 1b). These results suggested that LTP is the molecular formula C15H11O9P as determined using high-resolution ESI/MS (HRESI/MS) and that this compound is in the form of phosphoric acid bound to LT

Summary

Introduction

Inflammation is a unique limiting process for the identification and destruction of invading pathogens; it is achieved through biological reactions that occur in the human body, and it restores normal tissue structure and function [1,2,3,4]. Active research and development are currently being carried out to increase the bioactivity of existing natural products and organic compounds using biorenovation technology [18,19] Among these studies, attempts are being made to improve the biological activities of organic compounds using biorenovation, in which organic compounds are structurally transformed by inducing the enzyme-catalyzed reactions by microorganisms [20,21]. Biorenovation methods have been used to study natural products that exhibit better anti-inflammatory activity than conventional substances, such as increasing cell viability or inhibiting NO production [27,28]. We compared the differences in the anti-inflammatory activities of LT and LTP using RAW 264.7 cells and investigated the underlying molecular mechanisms of LTP activity

Analysis and Identification of LT Biorenovation Conversion Products

Discussion

Biorenovation of LT

HPLC Analysis of the LT Biorenovation Product

Western Blot Analyses

Statistical Analysis