Anti-inflammatory effects of Perilla frutescens in activated human neutrophils through two independent pathways: Src family kinases and Calcium

Chun-Yu Chen,Pei-Jen Chung,Liang-Mou Kuo,Yann-Lii Leu,Yu-Ting Kuo,Wei-Che Sung,Hsuan-Wu Yang,Yu Fang,Tsong-Long Hwang,Chwan-Fwu Lin,Yung-Fong Tsai,Ming-Chung Lee

doi:10.1038/srep18204

Abstract

The leaves of Perilla frutescens (L.) Britt. have been traditionally used as an herbal medicine in East Asian countries to treat a variety diseases. In this present study, we investigated the inhibitory effects of P. frutescens extract (PFE) on N-formyl-Met-Leu-Phe (fMLF)-stimulated human neutrophils and the underlying mechanisms. PFE (1, 3, and 10 μg/ml) inhibited superoxide anion production, elastase release, reactive oxygen species formation, CD11b expression, and cell migration in fMLF-activated human neutrophils in dose-dependent manners. PFE inhibited fMLF-induced phosphorylation of the Src family kinases (SFKs), Src (Tyr416) and Lyn (Tyr396), and reduced their enzymatic activities. Both PFE and PP2 (a selective inhibitor of SFKs) reduced the phosphorylation of Burton’s tyrosine kinases (Tyr223) and Vav (Tyr174) in fMLF-activated human neutrophils. Additionally, PFE decreased intracellular Ca2+ levels ([Ca2+]i), whereas PP2 prolonged the time required for [Ca2+]i to return to its basal level. Our findings indicated that PFE effectively regulated the inflammatory activities of fMLF-activated human neutrophils. The anti-inflammatory effects of PFE on activated human neutrophils were mediated through two independent signaling pathways involving SFKs (Src and Lyn) and mobilization of intracellular Ca2+.

Highlights

Perilla frutescens (L.) belongs to the Lamiaceae family and is widely used as a common vegetable crop, condiment, and traditional herbal medicine in East Asian countries[1,2]
We found that a non-toxic level of P. frutescens var. crispa extract (PFE) reduced superoxide anion (O2 ̇–) production, elastase release, reactive oxygen species (ROS) formation, CD11b expression, and chemotactic migration in N-formyl-Met-Leu-Phe-induced human neutrophils
In order to evaluate whether PFE affected neutrophil function and inflammatory responses, we first investigated the effects of PFE on O2 ̇− production, elastase release, and ROS formation in fMLF-activated human neutrophils

Summary

Introduction

Perilla frutescens (L.) belongs to the Lamiaceae family and is widely used as a common vegetable crop, condiment, and traditional herbal medicine in East Asian countries[1,2]. Neutrophils are the most plentiful leukocyte in human blood, accounting for about 50-75% of circulating leukocytes During inflammation, they are the first immune cells to arrive and execute their pathogen-eliminating function via multiple intra- and extracellular mechanisms[16,17,18]. In order to ameliorate these conditions, many studies have investigated the pharmacological modulation of activated human neutrophils by natural products and their mechanisms of action. This present study investigated the modulatory effects of a P. frutescens var. We found that a non-toxic level of PFE reduced superoxide anion (O2 ̇–) production, elastase release, ROS formation, CD11b expression, and chemotactic migration in N-formyl-Met-Leu-Phe (fMLF)-induced human neutrophils. Many of the observations made in this study demonstrated that the anti-inflammatory effects of PFE were mediated through two pathways: blockade of Src family kinases (SFKs) and reducing intracellular Ca2+ mobilization

Methods

Results

Conclusion