title: Protective effect of gedunin on TLR-mediated inflammation by modulation of inflammasome activation and cytokine production: Evidence of a multitarget compound.
abstract: Activation of toll-like receptors (TLRs) by pathogen-associated molecular patterns (PAMPs) triggers an innate immune response, via cytokine production and inflammasome activation. Herein, we have investigated the modulatory effect of the natural limonoid gedunin on TLR activation in vitro and in vivo. Intraperitoneal (i.p.) pre- and post-treatments of C57BL/6 mouse with gedunin impaired the influx of mononuclear cells, eosinophils and neutrophils, as well as the production of tumor necrosis factor (TNF)-α, interleukin (IL)-6 and nitric oxide (NO), triggered by lipopolysaccharide (LPS) in mouse pleura. Accordingly, in vitro post-treatment of immortalized murine macrophages with gedunin also impaired LPS-induced production of such mediators. Gedunin diminished LPS-induced expression of the nucleotide-binding domain and leucine-rich repeat protein-3 (NLRP3) on pleural leukocytes in vivo and in immortalized macrophages in vitro. In line with this, gedunin inhibited LPS-induced caspase-1 activation and the production of IL-1β in vivo and in vitro. In addition, gedunin treatment triggered the generation of the anti-inflammatory factors IL-10 and heme oxigenase-1 (HO-1) at resting conditions or upon stimulation. We also demonstrate that gedunin effect is not restricted to TLR4-mediated response, since this compound diminished TNF-α, IL-6, NO, NLRP3 and IL-1β, as well as enhanced IL-10 and HO-1, by macrophages stimulated with the TLR2 and TLR3 agonists, palmitoyl-3-Cys-Ser-(Lys)4 (PAM3) and polyriboinosinic:polyribocytidylic acid (POLY I:C), in vitro. In silico modeling studies revealed that gedunin efficiently docked into caspase-1, TLR2, TLR3 and to the myeloid differentiation protein-2 (MD-2) component of TLR4. Overall, our data demonstrate that gedunin modulates TLR4, TLR3 and TLR2-mediated responses and reveal new molecular targets for this compound.
authors.affiliation: Laboratório de Farmacologia Aplicada, Farmanguinhos, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil.
authors.forename: Perla Villani
authors.initials: PV
authors.lastname: Borges
authors.affiliation: Laboratório de Farmacologia Aplicada, Farmanguinhos, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil.
authors.forename: Katelim Hottz
authors.initials: KH
authors.lastname: Moret
authors.affiliation: Department of Pharmaceutical Chemistry, Gokaraju Rangaraju College of Pharmacy, Osmania University, Hyderabad, India; Centro de Desenvolvimento Tecnológico em Saúde, CDTS/INCT-IDN, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil.
authors.forename: Nulgumnalli Manjunathaiah
authors.initials: NM
authors.lastname: Raghavendra
authors.affiliation: Laboratório de Farmacologia Aplicada, Farmanguinhos, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil; Centro de Desenvolvimento Tecnológico em Saúde, CDTS/INCT-IDN, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil.
authors.forename: Thadeu Estevam
authors.initials: TE
authors.lastname: Maramaldo Costa
authors.affiliation: Laboratório de Imunofarmacologia, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil.
authors.forename: Ana Paula
authors.initials: AP
authors.lastname: Monteiro
authors.affiliation: Laboratório de Imunofarmacologia, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil.
authors.forename: Alan Brito
authors.initials: AB
authors.lastname: Carneiro
authors.affiliation: Laboratório de Farmacologia Aplicada, Farmanguinhos, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil.
authors.forename: Patrícia
authors.initials: P
authors.lastname: Pacheco
authors.affiliation: Laboratório de Pesquisas sobre o Timo, Instituto Oswaldo Cruz, Departamento de Imunologia, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil.
authors.forename: Jairo Ramos
authors.initials: JR
authors.lastname: Temerozo
authors.affiliation: Laboratório de Pesquisas sobre o Timo, Instituto Oswaldo Cruz, Departamento de Imunologia, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil.
authors.forename: Dumith Chequer
authors.initials: DC
authors.lastname: Bou-Habib
authors.affiliation: Laboratório de Farmacologia Aplicada, Farmanguinhos, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil; Centro de Desenvolvimento Tecnológico em Saúde, CDTS/INCT-IDN, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil.
authors.forename: Maria
authors.initials: M
authors.lastname: das Graças Henriques
authors.affiliation: Laboratório de Farmacologia Aplicada, Farmanguinhos, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil; Centro de Desenvolvimento Tecnológico em Saúde, CDTS/INCT-IDN, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil. Electronic address: cpenido@cdts.fiocruz.br.
authors.forename: Carmen
authors.initials: C
authors.lastname: Penido
mesh_terms: D000818:Animals; D016207:Cytokines; D058847:Inflammasomes / Q000187:drug effects* / Q000378:metabolism; D007249:Inflammation / Q000188:drug therapy* / Q000378:metabolism; D018836:Inflammation Mediators / Q000494:pharmacology*; D036701:Limonins / Q000494:pharmacology*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D000071199:NLR Family, Pyrin Domain-Containing 3 Protein / Q000378:metabolism; D020011:Protective Agents / Q000494:pharmacology*; D015398:Signal Transduction / Q000187:drug effects; D051193:Toll-Like Receptors / Q000378:metabolism*; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: D016207:Cytokines; D058847:Inflammasomes; D018836:Inflammation Mediators; D036701:Limonins; D000071199:NLR Family, Pyrin Domain-Containing 3 Protein; D020011:Protective Agents; D051193:Toll-Like Receptors; D014409:Tumor Necrosis Factor-alpha; C106014:gedunin
keywords: Cytokines; Gedunin; Inflammasome; LPS; Macrophage; Toll-like receptor