San-Huang-Xie-Xin-Tang Protects against Activated Microglia- and 6-OHDA-Induced Toxicity in Neuronal SH-SY5Y Cells

Yu-Tzu Shih,Ing-Jun Chen,Yi-Ching Lo,Yang-Chang Wu

doi:10.1093/ecam/nep025

Abstract

San-Huang-Xie-Xin-Tang (SHXT), composed of Coptidis rhizoma, Scutellariae radix and Rhei rhizoma, is a traditional Chinese herbal medicine used to treat gastritis, gastric bleeding and peptic ulcers. This study investigated the neuroprotective effects of SHXT on microglia-mediated neurotoxicity using co-cultured lipopolysaccharide (LPS)-activated microglia-like BV-2 cells with neuroblastoma SH-SY5Y cells. Effects of SHXT on 6-hydroxydopamine (6-OHDA)-induced neurotoxicity were also examined in SH-SY5Y cells. Results indicated SHXT inhibited LPS-induced inflammation of BV-2 cells by downregulation of iNOS, NO, COX-2, PGE2, gp91phox, iROS, TNF-α, IL-1β, inhibition of IκBα degradation and upregulation of HO-1. In addition, SHXT increased cell viability and down regulated nNOS, COX-2 and gp91phox of SH-SY5Y cells co-cultured with LPS activated BV-2 cells. SHXT treatment increased cell viability and mitochondria membrane potential (MMP), decreased expression of nNOS, COX-2, gp91phox and iROS, and inhibited IκBα degradation in 6-OHDA-treated SH-SY5Y cells. SHXT also attenuated LPS activated BV-2 cells- and 6-OHDA-induced cell death in differentiated SH-SY5Y cells with db-cAMP. Furthermore, SHXT-inhibited nuclear translocation of p65 subunit of NF-κB in LPS treated BV-2 cells and 6-OHDA treated SH-SY5Y cells. In conclusion, SHXT showed protection from activated microglia- and 6-OHDA-induced neurotoxicity by attenuating inflammation and oxidative stress.

Highlights

Inflammation appears to be a complicating factor in many age-related neurodegenerative diseases, such as Parkinson’s disease (PD) [1], Alzheimer’s disease (AD) [2] and multiple sclerosis [3]
The present study demonstrated that SHXT could inhibit LPS-activated microglia- and neurotoxin 6-OHDA-induced neurotoxicity
In 6-OHDA-induced neurotoxicity, the protective effects of SHXT are mediated by downregulating nNOS, COX-2 and gp91phox, decreased iROS level, IκBα degradation and NF-κBp65 translocation and increased mitochondria membrane potential of SHSY5Y cells (Figure 7)

Summary

Introduction

Inflammation appears to be a complicating factor in many age-related neurodegenerative diseases, such as Parkinson’s disease (PD) [1], Alzheimer’s disease (AD) [2] and multiple sclerosis [3]. Activated microglia enhances pro-inflammatory and neurotoxic responses and neuronal injury [5, 6]. Microgliamediated neurotoxicity was induced through release of proinflammatory cytokines such as tumor-necrosis factor alpha (TNF)-α, interleukin 1β (IL-1β), nitric oxide (NO) and prostaglandin E2 (PGE2), this yields enhanced reactive oxygen species (ROS) [7] and reactive nitric oxide species (RNS) [8, 9]. The deleterious consequences of excessive oxidation and pathophysiological role of ROS have been intensively studied in Alzheimer’s disease. Studies indicated that antiinflammatory or anti-oxidative stress drugs exert neuroprotective effects [10,11,12,13]. Anti-inflammatory agents and antioxidants are considered a promising approach to slowing the progression and limiting the extent of neuronal cell loss in these disorders

Methods

Results

Conclusion