https://www.ibric.org/myboard/read.php?Board=hbs_treatise&id=47569&idauthorid=25532&stype=2&skin=agriff_treatise&BackLink=L2FncmlmZi90cmVhdGlzZV9pbmRleC5waHA/c3R5cGU9MiZzb3J0PSZTZWFyY2hZZWFyPSZTZWFyY2hNb249JnN0YXJ0eT0yMDIwJnN0YXJ0bT0wNCZQYWdlPTEz
Pinocembrin attenuates lipopolysaccharide-induced inflammatory responses in Labeo rohita macrophages via the suppression of the NF-¥êB signalling pathway
Sib Sankar Giria, c, 1, Shib Sankar Senb, 1, Venkatachalam Sukumaranc, Se Chang Parka
a Laboratory of Aquatic Biomedicine, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, Seoul, South Korea
b School of Life Sciences, Jawaharlal Nehru University, New Delhi, India
c Dept. of Zoology, Kundavai Nachiyar Government Arts College for Women (Autonomous), Thanjavur, Tamil Nadu, India
1 These authors contributed equally to this work.
Corresponding author : Venkatachalam Sukumaran, Se Chang Park
Abstract
Pinocembrin is a flavonoid that has been reported to exhibit various pharmacological and biological activities including antimicrobial, antioxidant, and anti-inflammatory. To explore the anti-inflammatory activity of pinocembrin in a fish cell line, we investigated its ability to regulate the inflammatory mediators elevated by lipopolysaccharide (LPS) in Labeo rohita head-kidney (HK) macrophages. HK macrophages of L. rohita were treated with LPS (1 ¥ìg mL-1) in the presence or absence of pinocembrin. We examined the inhibitory effect of pinocembrin on LPS-induced nitric oxide (NO) and prostaglandin E2 (PGE2) production. The inhibitory effect of pinocembrin on nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) was investigated by RT-PCR and western blot. The effect of pinocembrin on pro-inflammatory cytokines (tumour necrosis factor alpha (TNF-¥á) and interleukin-1¥â (IL-1¥â)) and anti-inflammatory cytokine IL-10 was investigated by ELISA and RT-PCR. The phosphorylation of three mitogen activated protein kinases (MAPKs) ERK, JNK, and p38 was analysed by western blot. Pinocembrin inhibited LPS-induced productions of NO and PGE2, and also markedly inhibited TNF-¥á, IL-1¥â, iNOS, and COX-2 production in a concentration-dependent manner. In addition, TNF-¥á and IL-1¥â mRNA ____expression____ levels decreased significantly, while IL-10 mRNA ____expression____ increased (P < 0.05) with pinocembrin pre-treatment. RT-PCR and western blot analysis showed that pinocembrin decreased both the mRNA and protein ____expression____ levels of LPS-induced iNOS and COX-2 in HK macrophages. Pinocembrin suppressed the phosphorylation of MAPK in LPS-stimulated HK macrophages. Further, pinocembrin significantly inhibited LPS-induced NF-¥êB transcriptional activity via the attenuation of I¥êB¥á degradation. Taken together, pinocembrin reduced the levels of pro-inflammatory mediators, such as iNOS, COX-2, TNF-¥á, and IL-1¥â, by inhibiting NF-¥êB activation via the suppression of ERK and p38 phosphorylation, and by attenuating the degradation of I¥êB¥á. These results suggest that pinocembrin is a potential novel candidate for the treatment of inflammatory conditions in L. rohita macrophages.
Keywords : Labeo rohita; macrophages; Lipopolysaccharide; Pinocembrin; NF-¥êB signalling pathway