The Anti-Muscle Atrophy Effects of Ishige sinicola in LPS-Induced C2C12 Myotubes through Its Antioxidant and Anti-Inflammatory Actions

Abstract

Inflammation and oxidative stress are known to be major factors in muscle atrophy. The objective of this study was to evaluate whether the antioxidant activity of Ishige sinicola ethanol extract (ISE) and fractions from ISE could prevent lipopolysaccharide (LPS)-induced muscle atrophy in C2C12 myotubes. IS was extracted with ethanol and fractionated with five organic solvents. Then, ISE and five fractions from ISE were used to evaluate the total antioxidant activity and the protective effect of LPS-induced muscle atrophy in C2C12 myotubes. The ISE and butanol (BuOH) fraction showed higher total antioxidant activity and higher total phenol content than other fractions of ISE. The ISE and BuOH fraction significantly attenuated the LPS-induced diameter of C2C12 myotubes as well as the mRNA and protein expression levels of the muscle-specific E3 ubiquitin ligases. The mRNA expression of forkhead box O type 3α was stimulated by LPS, which was suppressed by the BuOH fraction but not ISE. Furthermore, ISE and the BuOH fraction significantly reduced LPS-stimulated gene expression of pro-inflammatory cytokines and inflammation-inducible enzymes, which was mediated by through the inhibition of the p38/extracellular signal-regulated kinase signaling pathway. Thus, ISE exerts a protective effect against muscle atrophy in LPS-induced C2C12 myotubes through the antioxidant activity and anti-inflammatory effects of ISE.

Systemic LPS Administration Stimulates the Activation of Non-Neuronal Cells in an Experimental Model of Spinal Muscular Atrophy

“…LPS-mediated modifications of alternative splicing and gene transcription have previously been shown to lead to a decrease in SMN protein levels in the CNS and peripheral tissues [42,[46][47][48][49][50]. A different mechanism linked to LPS-induced protein damage may be the abnormal homeostasis of the ubiquitin-proteasome system [51][52][53]. In particular, exposure to LPS amplifies the activation of the ubiquitin-proteasome system, which in turn causes subsequent muscle damage and protein degradation in the skeletal muscles [54,55].…”

Suppression of Pro-Inflammatory M1 Polarization of LPS-Stimulated RAW 264.7 Macrophage Cells by Fucoxanthin-Rich Sargassum hemiphyllum

“…TPC and total antioxidant activities, including ABTS, DPPH, and FRAP assay of SHE and its five fractions, were evaluated as previously described in our methods [40][41][42]. TPC was quantified and expressed as mg GAE/g dry weight for both SHE and its respective fractions through comparison with a calibration curve established using standard gallic acid.…”

“…For M1 polarization experiments, RAW 264.7 macrophages and BMDM were treated with SHE and its Hex fraction at 0, 25, and 50 µg/mL for 6 h and then induced by 100 ng/mL of LPS and 50 ng/mL of INF-γ for 24 h in the presence or absence of SHE and its Hex fraction. Total RNA was extracted from macrophages using homemade Trizol reagent, and cDNA synthesis and qRT-PCR analysis using the SYBR Green Q-PCR Master Mix (Smart Gene, Daejeon, Republic of Korea) and QuantStudio™ 1 Real-Time PCR system (Thermo Fisher Scientific) were conducted as previously described in our methods [41,42]. The primers used in this study are listed in Supplementary Table S1.…”

“…The lysate protein concentrations were measured by using the Pierce™ BCA protein assay kit (Thermo Fisher Scientific). Western blot analysis was performed as previously described in our methods [41,42].…”