title: Isobutyrylshikonin inhibits lipopolysaccharide-induced nitric oxide and prostaglandin E2 production in BV2 microglial cells by suppressing the PI3K/Akt-mediated nuclear transcription factor-κB pathway.
abstract: Microglia are important macrophages to defend against pathogens in the central nervous system (CNS); however, persistent or acute inflammation of microglia lead to CNS disorders via neuronal cell death. Therefore, we theorized that a good strategy for the treatment of CNS disorders would be to target inflammatory mediators from microglia in disease. Consequently, we investigated whether isobutyrylshikonin (IBS) attenuates the production of proinflammatory mediators, such as nitric oxide (NO) and prostaglandin E2, in lipopolysaccharide (LPS)-stimulated BV2 microglial cells. Treatment with IBS inhibited the secretion of NO and prostaglandin E2 (as well as the expression of their key regulatory genes), inducible NO synthase (iNOS), and cyclooxygenase-2 (COX-2). Isobutyrylshikonin also suppressed LPS-induced DNA-binding activity of nuclear transcription factor-κB (NF-κB), by inhibiting the nuclear translocation of p50 and p65 in addition to blocking the phosphorylation and degradation of IκBα. Pretreatment with pyrrolidine dithiocarbamate, a specific NF-κB inhibitor, showed the down-regulation of LPS-induced iNOS and COX-2 messenger RNA by suppressing NF-κB activity. This indirectly suggests that IBS-mediated NF-κB inhibition is the main signaling pathway involved in the inhibition of iNOS and COX-2 expression. In addition, IBS attenuated LPS-induced phosphorylation of PI3K and Akt, which are upstream molecules of NF-κB, in LPS-stimulated BV2 microglial cells. The functional aspects of the PI3K/Akt signaling pathway were analyzed with LY294002, which is a specific PI3K/Akt inhibitor that attenuated LPS-induced iNOS and COX-2 expression by suppressing NF-κB activity. These data suggest that an IBS-mediated anti-inflammatory effect may be involved in suppressing the PI3K/Akt-mediated NF-κB signaling pathway.
authors.affiliation: Department of Marine Life Sciences, Jeju National University, Jeju 690-756, Republic of Korea.
authors.forename: Rajapaksha Gedara Prasad Tharanga
authors.initials: RG
authors.lastname: Jayasooriya
authors.affiliation: Division of Wood Chemistry & Microbiology, Department of Forest Products, Korea forest Research Institute, 57 Hoegiro, Dongdaemun-gu, Seoul 130-712, Republic of Korea.
authors.forename: Kyoung-Tae
authors.initials: KT
authors.lastname: Lee
authors.affiliation: Department of Marine Life Sciences, Jeju National University, Jeju 690-756, Republic of Korea.
authors.forename: Chang-Hee
authors.initials: CH
authors.lastname: Kang
authors.affiliation: Department of Marine Life Sciences, Jeju National University, Jeju 690-756, Republic of Korea.
authors.forename: Matharage Gayani
authors.initials: MG
authors.lastname: Dilshara
authors.affiliation: Division of Wood Chemistry & Microbiology, Department of Forest Products, Korea forest Research Institute, 57 Hoegiro, Dongdaemun-gu, Seoul 130-712, Republic of Korea.
authors.forename: Hak-Ju
authors.initials: HJ
authors.lastname: Lee
authors.affiliation: Department of Biochemistry, College of Oriental Medicine, Dong-Eui University, Busan 614-050, Republic of Korea.
authors.forename: Yung Hyun
authors.initials: YH
authors.lastname: Choi
authors.affiliation: Department of Microbiology, College of Medicine, Inje University, Busan 614-735 Republic of Korea. Electronic address: cihima@inje.ac.kr.
authors.forename: Il-Whan
authors.initials: IW
authors.lastname: Choi
authors.affiliation: Department of Marine Life Sciences, Jeju National University, Jeju 690-756, Republic of Korea. Electronic address: immunkim@jejunu.ac.kr.
authors.forename: Gi-Young
authors.initials: GY
authors.lastname: Kim
mesh_terms: D000975:Antioxidants / Q000494:pharmacology; D002460:Cell Line; D002493:Central Nervous System Diseases / Q000188:drug therapy / Q000378:metabolism; D051546:Cyclooxygenase 2 / Q000378:metabolism; D015232:Dinoprostone / Q000096:biosynthesis*; D015536:Down-Regulation; D007249:Inflammation / Q000139:chemically induced / Q000188:drug therapy / Q000378:metabolism*; D018836:Inflammation Mediators / Q000378:metabolism; D008070:Lipopolysaccharides; D029684:Lithospermum / Q000737:chemistry*; D008264:Macrophages / Q000187:drug effects / Q000378:metabolism; D017628:Microglia / Q000187:drug effects* / Q000378:metabolism; D016328:NF-kappa B / Q000378:metabolism*; D009285:Naphthoquinones / Q000302:isolation & purification / Q000494:pharmacology* / Q000627:therapeutic use; D009569:Nitric Oxide / Q000096:biosynthesis*; D052247:Nitric Oxide Synthase Type II / Q000378:metabolism; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D010766:Phosphorylation; D008517:Phytotherapy; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology / Q000627:therapeutic use; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D011759:Pyrrolidines / Q000494:pharmacology; D015398:Signal Transduction; D013859:Thiocarbamates / Q000494:pharmacology
chemical_list: D000975:Antioxidants; D018836:Inflammation Mediators; D008070:Lipopolysaccharides; D016328:NF-kappa B; D009285:Naphthoquinones; D010936:Plant Extracts; D011759:Pyrrolidines; D013859:Thiocarbamates; C000599768:isobutyrylshikonin; C020972:pyrrolidine dithiocarbamic acid; D009569:Nitric Oxide; C496319:NOS2 protein, human; D052247:Nitric Oxide Synthase Type II; D051546:Cyclooxygenase 2; D019869:Phosphatidylinositol 3-Kinases; D051057:Proto-Oncogene Proteins c-akt; D015232:Dinoprostone
keywords: Isobutyrylshikonin; Nitric oxide; Nuclear factor-κB; PI3K/Akt; Prostaglandin E(2)