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Qin Y, Yang J, Li H, Li J. Recent advances in the therapeutic potential of nobiletin against respiratory diseases. PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2024; 128:155506. [PMID: 38522319 DOI: 10.1016/j.phymed.2024.155506] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Revised: 02/04/2024] [Accepted: 02/28/2024] [Indexed: 03/26/2024]
Abstract
BACKGROUND Nobiletin is a natural polymethoxylated flavonoid widely present in citrus fruit peels. It has been demonstrated to exert the effects of anti-tumor, anti-inflammation, anti-oxidative, anti-apoptotic and improve cardiovascular function. Increasing evidences suggest that nobiletin plays an important role in respiratory diseases (RDs) treatment. OBJECTIVE This review aimed to investigate the therapeutic potential of nobiletin against RDs, such as lung cancer, COPD, pulmonary fibrosis, asthma, pulmonary infection, acute lung injury, coronavirus disease 2019, and pulmonary arterial hypertension. METHODS We retrieved extensive literature of relevant literatures in English until June 26, 2023 from the database of PubMed, Web of Science, and Scopus databases. The keywords of "nobiletin and lung", "nobiletin and respiratory disease", "nobiletin and chronic respiratory diseases", "nobiletin and metabolites", "nobiletin and pharmacokinetics", "nobiletin and toxicity" were searched in pairs. A total of 298 literatures were retrieved from the above database. After excluding the duplicates and reviews, 53 were included in the current review. RESULTS We found that the therapeutic mechanisms are based on different signaling pathways. Firstly, nobiletin inhibited the proliferation and suppressed the invasion and migration of cancer cells by regulating the related pathway or key target, like Bcl-2, PD-L1, PARP, and Akt/GSK3β/β-catenin in lung cancer treatment. Secondly, nobiletin treats COPD and ALI by targeting classical signaling pathway mediating inflammation. Besides, the available findings show that nobiletin exerts the effect of PF treatment via regulating mTOR pathway. CONCLUSIONS With the wide range of pharmacological activities, high efficiency and low toxicity, nobiletin can be used as a potential agent for preventing and treating RDs. These findings will contribute to further research on the molecular mechanisms of nobiletin and facilitate in-depth studies on nobiletin at both preclinical and clinical levels for the treatment of RDs.
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Affiliation(s)
- Yanqin Qin
- Co-construction Collaborative Innovation Center for Chinese Medicine and Respiratory Diseases by Henan and Education Ministry of P.R. China, Henan Key Laboratory of Chinese Medicine for Respiratory Disease, Henan University of Chinese Medicine, Zhengzhou, 450046, Henan province, China; Academy of Chinese Medical Sciences, Henan University of Chinese Medicine, Zhengzhou, 450046, Henan Province, China
| | - Jingfan Yang
- Co-construction Collaborative Innovation Center for Chinese Medicine and Respiratory Diseases by Henan and Education Ministry of P.R. China, Henan Key Laboratory of Chinese Medicine for Respiratory Disease, Henan University of Chinese Medicine, Zhengzhou, 450046, Henan province, China
| | - Haibo Li
- Co-construction Collaborative Innovation Center for Chinese Medicine and Respiratory Diseases by Henan and Education Ministry of P.R. China, Henan Key Laboratory of Chinese Medicine for Respiratory Disease, Henan University of Chinese Medicine, Zhengzhou, 450046, Henan province, China
| | - Jiansheng Li
- Co-construction Collaborative Innovation Center for Chinese Medicine and Respiratory Diseases by Henan and Education Ministry of P.R. China, Henan Key Laboratory of Chinese Medicine for Respiratory Disease, Henan University of Chinese Medicine, Zhengzhou, 450046, Henan province, China; Department of Respiratory Disease, The first Affiliated Hospital of Henan University of Chinese Medicine, Zhengzhou, 450046, Henan province, China.
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de Almeida Marques DP, Andrade LAF, Reis EVS, Clarindo FA, Moraes TDFS, Lourenço KL, De Barros WA, Costa NEM, Andrade LMD, Lopes-Ribeiro Á, Coêlho Maciel MS, Corrêa-Dias LC, de Almeida IN, Arantes TS, Litwinski VCV, de Oliveira LC, Serafim MSM, Maltarollo VG, Guatimosim SC, Silva MM, Tsuji M, Ferreira RS, Barreto LV, Barbosa-Stancioli EF, da Fonseca FG, De Fátima Â, Coelho-Dos-Reis JGA. New anti-SARS-CoV-2 aminoadamantane compounds as antiviral candidates for the treatment of COVID-19. Virus Res 2024; 340:199291. [PMID: 38065303 PMCID: PMC10733093 DOI: 10.1016/j.virusres.2023.199291] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2023] [Revised: 11/29/2023] [Accepted: 11/30/2023] [Indexed: 12/17/2023]
Abstract
Here, the antiviral activity of aminoadamantane derivatives were evaluated against SARS-CoV-2. The compounds exhibited low cytotoxicity to Vero, HEK293 and CALU-3 cells up to a concentration of 1,000 µM. The inhibitory concentration (IC50) of aminoadamantane was 39.71 µM in Vero CCL-81 cells and the derivatives showed significantly lower IC50 values, especially for compounds 3F4 (0.32 µM), 3F5 (0.44 µM) and 3E10 (1.28 µM). Additionally, derivatives 3F5 and 3E10 statistically reduced the fluorescence intensity of SARS-CoV-2 protein S from Vero cells at 10 µM. Transmission microscopy confirmed the antiviral activity of the compounds, which reduced cytopathic effects induced by the virus, such as vacuolization, cytoplasmic projections, and the presence of myelin figures derived from cellular activation in the face of infection. Additionally, it was possible to observe a reduction of viral particles adhered to the cell membrane and inside several viral factories, especially after treatment with 3F4. Moreover, although docking analysis showed favorable interactions in the catalytic site of Cathepsin L, the enzymatic activity of this enzyme was not inhibited significantly in vitro. The new derivatives displayed lower predicted toxicities than aminoadamantane, which was observed for either rat or mouse models. Lastly, in vivo antiviral assays of aminoadamantane derivatives in BALB/cJ mice after challenge with the mouse-adapted strain of SARS-CoV-2, corroborated the robust antiviral activity of 3F4 derivative, which was higher than aminoadamantane and its other derivatives. Therefore, aminoadamantane derivatives show potential broad-spectrum antiviral activity, which may contribute to COVID-19 treatment in the face of emerging and re-emerging SARS-CoV-2 variants of concern.
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Affiliation(s)
- Daisymara Priscila de Almeida Marques
- Laboratório de Virologia Básica e Aplicada (LVBA), Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Luis Adan Flores Andrade
- Laboratório de Virologia Básica e Aplicada (LVBA), Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil; Centro Tecnológico de Vacinas (CT Vacinas), Belo Horizonte, MG, Brazil
| | - Erik Vinicius Sousa Reis
- Laboratório de Virologia Básica e Aplicada (LVBA), Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Felipe Alves Clarindo
- Laboratório de Virologia Básica e Aplicada (LVBA), Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Thaís de Fátima Silva Moraes
- Laboratório de Virologia Básica e Aplicada (LVBA), Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Karine Lima Lourenço
- Laboratório de Virologia Básica e Aplicada (LVBA), Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil; Centro Tecnológico de Vacinas (CT Vacinas), Belo Horizonte, MG, Brazil
| | - Wellington Alves De Barros
- Departamento de Química, Instituto de Ciências Exatas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Nathália Evelyn Morais Costa
- Departamento de Química, Instituto de Ciências Exatas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Lídia Maria de Andrade
- Departamento de Física, Instituto de Ciências Exatas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Ágata Lopes-Ribeiro
- Laboratório de Virologia Básica e Aplicada (LVBA), Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Mariella Sousa Coêlho Maciel
- Laboratório de Virologia Básica e Aplicada (LVBA), Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Laura Cardoso Corrêa-Dias
- Laboratório de Virologia Básica e Aplicada (LVBA), Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Isabela Neves de Almeida
- Departamento de Análises Clínicas, Escola de Farmácia, Universidade Federal de Ouro Preto, Ouro Preto, MG, Brazil; Laboratório de Micobacterioses, Faculdade de Medicina, Universidade Federal de, Minas Gerais, Belo Horizonte, MG, Brazil
| | - Thalita Souza Arantes
- Centro de Microscopia, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Vivian Costa Vasconcelos Litwinski
- Departamento de Morfologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Avenida Antônio Carlos, Belo Horizonte, MG, Brazil
| | - Leonardo Camilo de Oliveira
- Departamento de Morfologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Avenida Antônio Carlos, Belo Horizonte, MG, Brazil
| | - Mateus Sá Magalhães Serafim
- Laboratório de Virus, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Avenida Antônio Carlos, Belo Horizonte, MG, Brazil
| | - Vinicius Gonçalves Maltarollo
- Departamento de Produtos Farmacêuticos da Faculdade de Farmácia, Universidade Federal de Minas Gerais, Avenida Antônio Carlos, Belo Horizonte, MG, Brazil
| | - Silvia Carolina Guatimosim
- Departamento de Fisiologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Avenida Antônio Carlos, Belo Horizonte, MG, Brazil
| | - Mário Morais Silva
- Departamento de Fisiologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Avenida Antônio Carlos, Belo Horizonte, MG, Brazil
| | - Moriya Tsuji
- Aaron Diamond AIDS Research Center, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Rafaela Salgado Ferreira
- Laboratório de Modelagem Molecular e Planejamento de Fármacos, Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Avenida Antônio Carlos, Belo Horizonte, MG, Brazil
| | - Luiza Valença Barreto
- Laboratório de Modelagem Molecular e Planejamento de Fármacos, Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Avenida Antônio Carlos, Belo Horizonte, MG, Brazil
| | - Edel Figueiredo Barbosa-Stancioli
- Laboratório de Virologia Básica e Aplicada (LVBA), Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Flávio Guimarães da Fonseca
- Laboratório de Virologia Básica e Aplicada (LVBA), Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil; Centro Tecnológico de Vacinas (CT Vacinas), Belo Horizonte, MG, Brazil
| | - Ângelo De Fátima
- Departamento de Química, Instituto de Ciências Exatas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil.
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Zhang J, Hom K, Zhang C, Nasr M, Gerzanich V, Zhang Y, Tang Q, Xue F, Simard JM, Zhao RY. SARS-CoV-2 ORF3a Protein as a Therapeutic Target against COVID-19 and Long-Term Post-Infection Effects. Pathogens 2024; 13:75. [PMID: 38251382 PMCID: PMC10819734 DOI: 10.3390/pathogens13010075] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Revised: 01/08/2024] [Accepted: 01/11/2024] [Indexed: 01/23/2024] Open
Abstract
The COVID-19 pandemic caused by SARS-CoV-2 has posed unparalleled challenges due to its rapid transmission, ability to mutate, high mortality and morbidity, and enduring health complications. Vaccines have exhibited effectiveness, but their efficacy diminishes over time while new variants continue to emerge. Antiviral medications offer a viable alternative, but their success has been inconsistent. Therefore, there remains an ongoing need to identify innovative antiviral drugs for treating COVID-19 and its post-infection complications. The ORF3a (open reading frame 3a) protein found in SARS-CoV-2, represents a promising target for antiviral treatment due to its multifaceted role in viral pathogenesis, cytokine storms, disease severity, and mortality. ORF3a contributes significantly to viral pathogenesis by facilitating viral assembly and release, essential processes in the viral life cycle, while also suppressing the body's antiviral responses, thus aiding viral replication. ORF3a also has been implicated in triggering excessive inflammation, characterized by NF-κB-mediated cytokine production, ultimately leading to apoptotic cell death and tissue damage in the lungs, kidneys, and the central nervous system. Additionally, ORF3a triggers the activation of the NLRP3 inflammasome, inciting a cytokine storm, which is a major contributor to the severity of the disease and subsequent mortality. As with the spike protein, ORF3a also undergoes mutations, and certain mutant variants correlate with heightened disease severity in COVID-19. These mutations may influence viral replication and host cellular inflammatory responses. While establishing a direct link between ORF3a and mortality is difficult, its involvement in promoting inflammation and exacerbating disease severity likely contributes to higher mortality rates in severe COVID-19 cases. This review offers a comprehensive and detailed exploration of ORF3a's potential as an innovative antiviral drug target. Additionally, we outline potential strategies for discovering and developing ORF3a inhibitor drugs to counteract its harmful effects, alleviate tissue damage, and reduce the severity of COVID-19 and its lingering complications.
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Affiliation(s)
- Jiantao Zhang
- Department of Pathology, University of Maryland School of Medicine, Baltimore, MD 21201, USA; (J.Z.); (C.Z.)
| | - Kellie Hom
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, MD 21201, USA; (K.H.); (F.X.)
| | - Chenyu Zhang
- Department of Pathology, University of Maryland School of Medicine, Baltimore, MD 21201, USA; (J.Z.); (C.Z.)
| | - Mohamed Nasr
- Drug Development and Clinical Sciences Branch, Division of AIDS, NIAID, National Institutes of Health, Bethesda, MD 20892, USA;
| | - Volodymyr Gerzanich
- Department of Neurosurgery, University of Maryland School of Medicine, Baltimore, MD 21201, USA; (V.G.); (J.M.S.)
| | - Yanjin Zhang
- Department of Veterinary Medicine, University of Maryland, College Park, MD 20742, USA;
| | - Qiyi Tang
- Department of Microbiology, Howard University College of Medicine, Washington, DC 20059, USA;
| | - Fengtian Xue
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, MD 21201, USA; (K.H.); (F.X.)
| | - J. Marc Simard
- Department of Neurosurgery, University of Maryland School of Medicine, Baltimore, MD 21201, USA; (V.G.); (J.M.S.)
- Research & Development Service, VA Maryland Health Care System, Baltimore, MD 21201, USA
| | - Richard Y. Zhao
- Department of Pathology, University of Maryland School of Medicine, Baltimore, MD 21201, USA; (J.Z.); (C.Z.)
- Research & Development Service, VA Maryland Health Care System, Baltimore, MD 21201, USA
- Department of Microbiology-Immunology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
- Institute of Human Virology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
- Institute of Global Health, University of Maryland School of Medicine, Baltimore, MD 21201, USA
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Jiang NN, Ye YS, Liu X, Wang YL, Xu G. Rearranged Homoadamantane-Type Polycyclic Polyprenylated Acylphloroglucinols from Hypericum pseudohenryi. Org Lett 2023; 25:8965-8969. [PMID: 38064279 DOI: 10.1021/acs.orglett.3c03143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2023]
Abstract
Hypseudohenones A-C (1-3), the first rearranged homoadamantane-type polycyclic polyprenylated acylphloroglucinols, were isolated from Hypericum pseudohenryi. Their structures with an unprecedented tricyclo[4.3.1.13,8]undecane-2,4,10-trione core were determined by spectroscopic analysis, quantum-chemical calculations, and X-ray crystallography. A method for determining the relative configuration at C-3 was established by the peak shape of H-28 or J-value of H-3/H-28. Moreover, 2-3 exhibited significant AChE inhibitory activity, and the interactions of 2-3 with AChE were evaluated by molecular docking.
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Affiliation(s)
- Na-Na Jiang
- State Key Laboratory of Phytochemistry and Plant Resources in West China and Yunnan Key Laboratory of Natural Medicinal Chemistry, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, People's Republic of China
- University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
| | - Yan-Song Ye
- State Key Laboratory of Phytochemistry and Plant Resources in West China and Yunnan Key Laboratory of Natural Medicinal Chemistry, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, People's Republic of China
| | - Xia Liu
- Chongqing Hospital of Traditional Chinese Medicine, Chongqing 400021, People's Republic of China
| | - Yong-Ling Wang
- Department of Pharmacy, Affiliated Hospital of Zunyi Medical University, Zunyi 563003, People's Republic of China
| | - Gang Xu
- State Key Laboratory of Phytochemistry and Plant Resources in West China and Yunnan Key Laboratory of Natural Medicinal Chemistry, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, People's Republic of China
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Wang Z, Song XQ, Xu W, Lei S, Zhang H, Yang L. Stand Up to Stand Out: Natural Dietary Polyphenols Curcumin, Resveratrol, and Gossypol as Potential Therapeutic Candidates against Severe Acute Respiratory Syndrome Coronavirus 2 Infection. Nutrients 2023; 15:3885. [PMID: 37764669 PMCID: PMC10535599 DOI: 10.3390/nu15183885] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Revised: 08/31/2023] [Accepted: 09/05/2023] [Indexed: 09/29/2023] Open
Abstract
The COVID-19 pandemic has stimulated collaborative drug discovery efforts in academia and the industry with the aim of developing therapies and vaccines that target SARS-CoV-2. Several novel therapies have been approved and deployed in the last three years. However, their clinical application has revealed limitations due to the rapid emergence of viral variants. Therefore, the development of next-generation SARS-CoV-2 therapeutic agents with a high potency and safety profile remains a high priority for global health. Increasing awareness of the "back to nature" approach for improving human health has prompted renewed interest in natural products, especially dietary polyphenols, as an additional therapeutic strategy to treat SARS-CoV-2 patients, owing to its good safety profile, exceptional nutritional value, health-promoting benefits (including potential antiviral properties), affordability, and availability. Herein, we describe the biological properties and pleiotropic molecular mechanisms of dietary polyphenols curcumin, resveratrol, and gossypol as inhibitors against SARS-CoV-2 and its variants as observed in in vitro and in vivo studies. Based on the advantages and disadvantages of dietary polyphenols and to obtain maximal benefits, several strategies such as nanotechnology (e.g., curcumin-incorporated nanofibrous membranes with antibacterial-antiviral ability), lead optimization (e.g., a methylated analog of curcumin), combination therapies (e.g., a specific combination of plant extracts and micronutrients), and broad-spectrum activities (e.g., gossypol broadly inhibits coronaviruses) have also been emphasized as positive factors in the facilitation of anti-SARS-CoV-2 drug development to support effective long-term pandemic management and control.
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Affiliation(s)
- Zhonglei Wang
- Key Laboratory of Green Natural Products and Pharmaceutical Intermediates in Colleges and Universities of Shandong Province, School of Chemistry and Chemical Engineering, Qufu Normal University, Qufu 273165, China; (W.X.); (S.L.); (H.Z.)
- School of Pharmaceutical Sciences, Key Laboratory of Bioorganic Phosphorus, Chemistry & Chemical Biology (Ministry of Education), Tsinghua University, Beijing 100084, China
| | - Xian-qing Song
- General Surgery Department, Baoan Central Hospital, Affiliated Baoan Central Hospital of Guangdong Medical University, Shenzhen 518000, China
| | - Wenjing Xu
- Key Laboratory of Green Natural Products and Pharmaceutical Intermediates in Colleges and Universities of Shandong Province, School of Chemistry and Chemical Engineering, Qufu Normal University, Qufu 273165, China; (W.X.); (S.L.); (H.Z.)
| | - Shizeng Lei
- Key Laboratory of Green Natural Products and Pharmaceutical Intermediates in Colleges and Universities of Shandong Province, School of Chemistry and Chemical Engineering, Qufu Normal University, Qufu 273165, China; (W.X.); (S.L.); (H.Z.)
| | - Hao Zhang
- Key Laboratory of Green Natural Products and Pharmaceutical Intermediates in Colleges and Universities of Shandong Province, School of Chemistry and Chemical Engineering, Qufu Normal University, Qufu 273165, China; (W.X.); (S.L.); (H.Z.)
| | - Liyan Yang
- School of Physics and Physical Engineering, Qufu Normal University, Qufu 273165, China
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Breitinger U, Sedky CA, Sticht H, Breitinger HG. Patch-clamp studies and cell viability assays suggest a distinct site for viroporin inhibitors on the E protein of SARS-CoV-2. Virol J 2023; 20:142. [PMID: 37422646 PMCID: PMC10329798 DOI: 10.1186/s12985-023-02095-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2022] [Accepted: 06/08/2023] [Indexed: 07/10/2023] Open
Abstract
BACKGROUND SARS-CoV-2 has caused a worldwide pandemic since December 2019 and the search for pharmaceutical targets against COVID-19 remains an important challenge. Here, we studied the envelope protein E of SARS-CoV and SARS-CoV-2, a highly conserved 75-76 amino acid viroporin that is crucial for virus assembly and release. E protein channels were recombinantly expressed in HEK293 cells, a membrane-directing signal peptide ensured transfer to the plasma membrane. METHODS Viroporin channel activity of both E proteins was investigated using patch-clamp electrophysiology in combination with a cell viability assay. We verified inhibition by classical viroporin inhibitors amantadine, rimantadine and 5-(N,N-hexamethylene)-amiloride, and tested four ivermectin derivatives. RESULTS Classical inhibitors showed potent activity in patch-clamp recordings and viability assays. In contrast, ivermectin and milbemycin inhibited the E channel in patch-clamp recordings but displayed only moderate activity on the E protein in the cell viability assay, which is also sensitive to general cytotoxic activity of the tested compounds. Nemadectin and ivermectin aglycon were inactive. All ivermectin derivatives were cytotoxic at concentrations > 5 µM, i.e. below the level required for E protein inhibition. CONCLUSIONS This study demonstrates direct inhibition of the SARS-CoV-2 E protein by classical viroporin inhibitors. Ivermectin and milbemycin inhibit the E protein channel but their cytotoxicity argues against clinical application.
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Affiliation(s)
- Ulrike Breitinger
- Department of Biochemistry, German University in Cairo, Main Entrance of Al Tagamoa Al Khames, New Cairo, 11835, Egypt.
| | - Christine Adel Sedky
- Department of Biochemistry, German University in Cairo, Main Entrance of Al Tagamoa Al Khames, New Cairo, 11835, Egypt
| | - Heinrich Sticht
- Division of Bioinformatics, Institute for Biochemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Hans-Georg Breitinger
- Department of Biochemistry, German University in Cairo, Main Entrance of Al Tagamoa Al Khames, New Cairo, 11835, Egypt
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