title: Antiviral activity of SA-2 against influenza A virus in vitro/vivo and its inhibition of RNA polymerase.
abstract: A target-free and cell-based approach was applied to evaluate the anti-influenza properties of six newly synthesized benzoic acid derivatives. SA-2, the ethyl 4-(2-hydroxymethyl-5-oxopyrrolidin-1-yl)-3-[3-(3-methylbenzoyl)-thioureido] benzoate (compound 2) was screened as a potential drug candidate. In a cytopathic effect assay, SA-2 dose dependently inhibited H1N1, H3N2 and the oseltamivir-resistant mutant H1N1-H275Y influenza viruses in both virus-infected MDCK and A549 cells, with 50% effective concentrations (EC50) in MDCK cells of 9.6, 19.2 and 19.8 μM respectively, and 50% cytotoxic concentration (CC50) of 444.5 μM, showing competitive antiviral activity with oseltamivir in vitro. Orally administered SA-2 effectively protected mice infected with lethal doses of H1N1 or oseltamivir-resistant strain H1N1-H275Y, conferring 70% or 50% survival at a dosage of 100 mg/kg/d, reducing body weight loss, alleviating the influenza-induced acute lung injury, and reducing lung virus titer. Mechanistic studies showed that SA-2 efficiently inhibited the activity of RNA polymerase and suppressed NP and M1 levels during viral biosynthesis by interfering with gene transcription without having an obvious influence on virus entry and release. Based on these favourable findings, SA-2, a novel anti-influenza agent, with its potent anti-influenza activity in vitro and in vivo, could be a promising antiviral for the treatment of infection of influenza A viruses, including oseltamivir-resistant mutants.
authors.affiliation: State Key Laboratory of Natural Medicines, School of Life Science and Technology, China Pharmaceutical University, Nanjing, Jiangsu 210009, PR China.
authors.forename: Jie
authors.initials: J
authors.lastname: Yu
authors.affiliation: Department of Organic Chemistry, School of Science, China Pharmaceutical University, Nanjing, Jiangsu 210009, PR China.
authors.forename: Dechuan
authors.initials: D
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Natural Medicines, School of Life Science and Technology, China Pharmaceutical University, Nanjing, Jiangsu 210009, PR China.
authors.forename: Jing
authors.initials: J
authors.lastname: Jin
authors.affiliation: State Key Laboratory of Natural Medicines, School of Life Science and Technology, China Pharmaceutical University, Nanjing, Jiangsu 210009, PR China.
authors.forename: Jun
authors.initials: J
authors.lastname: Xu
authors.affiliation: State Key Laboratory of Natural Medicines, School of Life Science and Technology, China Pharmaceutical University, Nanjing, Jiangsu 210009, PR China.
authors.forename: Mengwei
authors.initials: M
authors.lastname: Li
authors.affiliation: State Key Laboratory of Natural Medicines, School of Life Science and Technology, China Pharmaceutical University, Nanjing, Jiangsu 210009, PR China.
authors.forename: Hui
authors.initials: H
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Natural Medicines, School of Life Science and Technology, China Pharmaceutical University, Nanjing, Jiangsu 210009, PR China.
authors.forename: Jie
authors.initials: J
authors.lastname: Dou
authors.affiliation: State Key Laboratory of Natural Medicines, School of Life Science and Technology, China Pharmaceutical University, Nanjing, Jiangsu 210009, PR China. Electronic address: cl_zhou@cpu.edu.cn.
authors.forename: Changlin
authors.initials: C
authors.lastname: Zhou
mesh_terms: D000072283:A549 Cells; D055371:Acute Lung Injury / Q000188:drug therapy / Q000821:virology; D000818:Animals; D000998:Antiviral Agents / Q000494:pharmacology*; D001565:Benzoates / Q000737:chemistry / Q000494:pharmacology*; D012321:DNA-Directed RNA Polymerases / Q000037:antagonists & inhibitors* / Q000096:biosynthesis; D004285:Dogs; D004353:Drug Evaluation, Preclinical; D024882:Drug Resistance, Viral / Q000187:drug effects; D057809:HEK293 Cells; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype / Q000187:drug effects*; D053122:Influenza A Virus, H3N2 Subtype / Q000187:drug effects*; D007251:Influenza, Human / Q000188:drug therapy / Q000821:virology; D061985:Madin Darby Canine Kidney Cells; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D009976:Orthomyxoviridae Infections / Q000188:drug therapy / Q000821:virology; D053139:Oseltamivir / Q000031:analogs & derivatives / Q000494:pharmacology; D012254:Ribavirin / Q000494:pharmacology; D014779:Virus Replication / Q000187:drug effects
chemical_list: D000998:Antiviral Agents; D001565:Benzoates; D053139:Oseltamivir; D012254:Ribavirin; D012321:DNA-Directed RNA Polymerases; C535162:oseltamivir carboxylate
keywords: Antiviral activity; Benzoic acid derivatives; Influenza A virus; Oseltamivir-resistant; RNA polymerase inhibition