Li K, Hao Z, Zhao X, et al. SARS-CoV-2 infection-induced immune responses: Friends or foes? [J]. Scand J Immunol, 2020: e12895.
 Goldstein JL. The Spanish 1918 Flu and the COVID-19 Disease: The Art of Remembering and Foreshadowing Pandemics [J]. Cell, 2020, 183(2): 285-289.
 Ling LJ, Lu Y, Zhang YY, et al. Flavonoids from Houttuynia cordata attenuate H1N1-induced acute lung injury in mice via inhibition of influenza virus and Toll-like receptor signalling [J]. Phytomedicine, 2020, 67: 153150.
 Zhi H, Jin X, Zhu H, et al. Exploring the effective materials of flavonoids-enriched extract from Scutellaria baicalensis roots based on the metabolic activation in influenza A virus induced acute lung injury [J]. J Pharm Biomed Anal, 2020, 177: 112876.
 Lo CY, Tang YS and Shaw PC. Structure and Function of Influenza Virus Ribonucleoprotein [J]. Subcell Biochem, 2018, 88: 95-128.
 Pizzorno A, Padey B, Terrier O, et al. Drug Repurposing Approaches for the Treatment of Influenza Viral Infection: Reviving Old Drugs to Fight Against a Long-Lived Enemy [J]. Front Immunol, 2019, 10: 531.
 Fu YJ, Yan YQ, Qin HQ, et al. Effects of different principles of Traditional Chinese Medicine treatment on TLR7/NF-kappaB signaling pathway in influenza virus infected mice [J]. Chin Med, 2018, 13: 42.
 Zhi HJ, Zhu HY, Zhang YY, et al. In vivo effect of quantified flavonoids-enriched extract of Scutellaria baicalensis root on acute lung injury induced by influenza A virus [J]. Phytomedicine, 2019, 57: 105-116.
 Short KR, Kasper J, van der Aa S, et al. Influenza virus damages the alveolar barrier by disrupting epithelial cell tight junctions [J]. Eur Respir J, 2016, 47(3): 954-966.
 Ma Q, Huang W, Zhao J, et al. Liu Shen Wan inhibits influenza a virus and excessive virus-induced inflammatory response via suppression of TLR4/NF-kappaB signaling pathway in vitro and in vivo [J]. J Ethnopharmacol, 2020, 252: 112584.
 Senthilkumar D, Rajukumar K, Kumar M, et al. Porcine reproductive and respiratory syndrome virus induces concurrent elevation of High Mobility Group Box-1 protein and pro-inflammatory cytokines in experimentally infected piglets [J]. Cytokine, 2019, 113: 21-30.
 He J, Yuan R, Cui X, et al. Anemoside B4 protects against Klebsiella pneumoniae- and influenza virus FM1-induced pneumonia via the TLR4/Myd88 signaling pathway in mice [J]. Chin Med, 2020, 15: 68.
 Doganyigit Z, Okan A, Kaymak E, et al. Investigation of protective effects of apilarnil against lipopolysaccharide induced liver injury in rats via TLR 4/ HMGB-1/ NF-kappaB pathway [J]. Biomed Pharmacother, 2020, 125: 109967.
 Sun Y, Su J, Liu Z, et al. Aflatoxin B1 Promotes Influenza Replication and Increases Virus Related Lung Damage via Activation of TLR4 Signaling [J]. Front Immunol, 2018, 9: 2297.
 Garg S, Garg M, Prabhakar N, et al. Unraveling the mystery of Covid-19 cytokine storm: From skin to organ systems [J]. Dermatol Ther, 2020: e13859.
 Ren JL, Zhang AH and Wang XJ. Traditional Chinese medicine for COVID-19 treatment [J]. Pharmacol Res, 2020, 155: 104743.
 Commission CP. Chinese pharmacopoeia [J]. China Medical Science Press, Beijing, 2010, 228.
 Hsieh W-L, Lin Y-K, Tsai C-N, et al. Indirubin, an acting component of indigo naturalis, inhibits EGFR activation and EGF-induced CDC25B gene expression in epidermal keratinocytes [J]. Journal of dermatological science, 2012, 67(2): 140-146.
 Lin Y-K, Leu Y-L, Yang S-H, et al. Anti-psoriatic effects of indigo naturalis on the proliferation and differentiation of keratinocytes with indirubin as the active component [J]. Journal of dermatological science, 2009, 54(3): 168-174.
 lǚ J. Shijinmo variorum of clinic practices with double-herb prescriptions [M]. People's Medical Publishing House, 2002.
 Naganuma M. Treatment with indigo naturalis for inflammatory bowel disease and other immune diseases [J]. Immunol Med, 2019, 42(1): 16-21.
 Gu S, Xue Y, Gao Y, et al. Mechanisms of indigo naturalis on treating ulcerative colitis explored by GEO gene chips combined with network pharmacology and molecular docking [J]. Sci Rep, 2020, 10(1): 15204.
 Lin SC, Kappes MA, Chen MC, et al. Distinct susceptibility and applicability of MDCK derivatives for influenza virus research [J]. PLoS One, 2017, 12(2): e0172299.
 Konevtsova OV, Roshal DS, Losdorfer BoZic A, et al. Hidden symmetry of the anomalous bluetongue virus capsid and its role in the infection process [J]. Soft Matter, 2019, 15(38): 7663-7671.
 Huang D, Peng WJ, Ye Q, et al. Serum-Free Suspension Culture of MDCK Cells for Production of Influenza H1N1 Vaccines [J]. PLoS One, 2015, 10(11): e0141686.
 Larson KC, Lipko M, Dabrowski M, et al. Gng12 is a novel negative regulator of LPS-induced inflammation in the microglial cell line BV-2 [J]. Inflamm Res, 2010, 59(1): 15-22.
 Zhu H, Lu X, Ling L, et al. Houttuynia cordata polysaccharides ameliorate pneumonia severity and intestinal injury in mice with influenza virus infection [J]. J Ethnopharmacol, 2018, 218: 90-99.
 Xu YY, Zhang YY, Ou YY, et al. Houttuyniacordata Thunb. polysaccharides ameliorates lipopolysaccharide-induced acute lung injury in mice [J]. J Ethnopharmacol, 2015, 173: 81-90.
 Hodgins B, Pillet S, Landry N, et al. Prime-pull vaccination with a plant-derived virus-like particle influenza vaccine elicits a broad immune response and protects aged mice from death and frailty after challenge [J]. Immun Ageing, 2019, 16: 27.
 Thornton HV, Turner KME, Harrison S, et al. Assessing the potential of upper respiratory tract point-of-care testing: a systematic review of the prognostic significance of upper respiratory tract microbes [J]. Clin Microbiol Infect, 2019, 25(11): 1339-1346.
 Zhang S, Hu B, Xu J, et al. Influenza A virus infection induces liver injury in mice [J]. Microb Pathog, 2019, 137: 103736.
 Tong T, Wu YQ, Ni WJ, et al. The potential insights of Traditional Chinese Medicine on treatment of COVID-19 [J]. Chin Med, 2020, 15: 51.
 Lau K-M, Lee K-M, Koon C-M, et al. Immunomodulatory and anti-SARS activities of Houttuynia cordata [J]. Journal of ethnopharmacology, 2008, 118(1): 79-85.
 Lau T, Leung P, Wong E, et al. Using herbal medicine as a means of prevention experience during the SARS crisis [J]. The American journal of Chinese medicine, 2005, 33(03): 345-356.
 Peng J, Fan G and Wu Y. Isolation and purification of clemastanin B and indigoticoside A from Radix Isatidis by high-speed counter-current chromatography [J]. Journal of Chromatography A, 2005, 1091(1): 89-93.
 Wang J and Qi F. Traditional Chinese medicine to treat COVID-19: the importance of evidence-based research [J]. Drug Discov Ther, 2020, 14(3): 149-150.
 Li K, Chen X, Zhong J, et al. The effects of the Xijiao Dihuang decoction combined with Yinqiao powder on miRNA-mRNA profiles in mice infected with influenza a virus [J]. BMC Complement Med Ther, 2020, 20(1): 286.
 Lin YK, See LC, Huang YH, et al. Efficacy and safety of Indigo naturalis extract in oil (Lindioil) in treating nail psoriasis: a randomized, observer-blind, vehicle-controlled trial [J]. Phytomedicine, 2014, 21(7): 1015-1020.
 Lin YK, Chen HW, Yang SH, et al. Protective effect of indigo naturalis extract against oxidative stress in cultured human keratinocytes [J]. J Ethnopharmacol, 2012, 139(3): 893-896.
 Liu Z, Yang ZQ and Xiao H. Antiviral activity of the effective monomers from Folium Isatidis against influenza virus in vivo [J]. Virol Sin, 2010, 25(6): 445-451.
 Lee CL, Wang CM, Hu HC, et al. Indole alkaloids indigodoles A-C from aerial parts of Strobilanthes cusia in the traditional Chinese medicine Qing Dai have anti-IL-17 properties [J]. Phytochemistry, 2019, 162: 39-46.
 Zhang M, Ding X, Kang J, et al. Marine Natural Product for Pesticide Candidate: Pulmonarin Alkaloids as Novel Antiviral and Anti-Phytopathogenic-Fungus Agents [J]. J Agric Food Chem, 2020, 68(41): 11350-11357.
 Gao P, Wang L, Zhao L, et al. Anti-inflammatory quinoline alkaloids from the root bark of Dictamnus dasycarpus [J]. Phytochemistry, 2020, 172: 112260.
 Kim M, Park KH and Kim YB. Identifying Active Compounds and Targets of Fritillariae thunbergii against Influenza-Associated Inflammation by Network Pharmacology Analysis and Molecular Docking [J]. Molecules, 2020, 25(17).
 Yamashiro R, Misawa T and Sakudo A. Key role of singlet oxygen and peroxynitrite in viral RNA damage during virucidal effect of plasma torch on feline calicivirus [J]. Sci Rep, 2018, 8(1): 17947.
 Abdul-Cader MS, Ahmed-Hassan H, Amarasinghe A, et al. Toll-like receptor (TLR)21 signalling-mediated antiviral response against avian influenza virus infection correlates with macrophage recruitment and nitric oxide production [J]. J Gen Virol, 2017, 98(6): 1209-1223.
 El Sahly HM, Makedonas G, Corry D, et al. An evaluation of cytokine and cellular immune responses to heterologous prime-boost vaccination with influenza A/H7N7-A/H7N9 inactivated vaccine [J]. Hum Vaccin Immunother, 2020: 1-8.
 Yagmurdur H, Binnetoglu K, Astarci HM, et al. Propofol attenuates cytokine-mediated upregulation of expression of inducible nitric oxide synthase and apoptosis during regeneration post-partial hepatectomy [J]. Acta Cir Bras, 2017, 32(5): 396-406.
 Adams C, Sawh F, Green-Johnson JM, et al. Characterization of casein-derived peptide bioactivity: Differential effects on angiotensin-converting enzyme inhibition and cytokine and nitric oxide production [J]. J Dairy Sci, 2020, 103(7): 5805-5815.
 Wu J. Tackle the free radicals damage in COVID-19 [J]. Nitric Oxide, 2020, 102: 39-41.
 Ciaglia E, Malfitano AM, Laezza C, et al. Immuno-Modulatory and Anti-Inflammatory Effects of Dihydrogracilin A, a Terpene Derived from the Marine Sponge Dendrilla membranosa [J]. Int J Mol Sci, 2017, 18(8).
 Talaat KR, Halsey NA, Cox AB, et al. Rapid changes in serum cytokines and chemokines in response to inactivated influenza vaccination [J]. Influenza Other Respir Viruses, 2018, 12(2): 202-210.
 Barnes BJ, Adrover JM, Baxter-Stoltzfus A, et al. Targeting potential drivers of COVID-19: Neutrophil extracellular traps [J]. J Exp Med, 2020, 217(6).
 Vardhana SA and Wolchok JD. The many faces of the anti-COVID immune response [J]. J Exp Med, 2020, 217(6).
 Sumikoshi M, Hashimoto K, Kawasaki Y, et al. Human influenza virus infection and apoptosis induction in human vascular endothelial cells [J]. Journal of medical virology, 2008, 80(6): 1072-1078.
 Teijaro John R, Walsh Kevin B, Cahalan S, et al. Endothelial Cells Are Central Orchestrators of Cytokine Amplification during Influenza Virus Infection [J]. Cell, 2011, 146(6): 980-991.
 VanPatten S and Al-Abed Y. High Mobility Group Box-1 (HMGb1): Current Wisdom and Advancement as a Potential Drug Target [J]. J Med Chem, 2018, 61(12): 5093-5107.
 Vijayakumar EC, Bhatt LK and Prabhavalkar KS. High Mobility Group Box-1 (HMGB1): A Potential Target in Therapeutics [J]. Curr Drug Targets, 2019, 20(14): 1474-1485.
 Zheng J and Perlman S. Immune responses in influenza A virus and human coronavirus infections: an ongoing battle between the virus and host [J]. Curr Opin Virol, 2018, 28: 43-52.
 Tao X, Sun X, Yin L, et al. Dioscin ameliorates cerebral ischemia/reperfusion injury through the downregulation of TLR4 signaling via HMGB-1 inhibition [J]. Free Radical Biology and Medicine, 2015, 84: 103-115.
 Sohn KM, Lee SG, Kim HJ, et al. COVID-19 Patients Upregulate Toll-like Receptor 4-mediated Inflammatory Signaling That Mimics Bacterial Sepsis [J]. J Korean Med Sci, 2020, 35(38): e343.
 Wang QW, Su Y, Sheng JT, et al. Anti-influenza A virus activity of rhein through regulating oxidative stress, TLR4, Akt, MAPK, and NF-kappaB signal pathways [J]. PLoS One, 2018, 13(1): e0191793.
 Dai JP, Wang QW, Su Y, et al. Emodin Inhibition of Influenza A Virus Replication and Influenza Viral Pneumonia via the Nrf2, TLR4, p38/JNK and NF-kappaB Pathways [J]. Molecules, 2017, 22(10).
 Ren Z, Li J, Song X, et al. The regulation of inflammation and oxidative status against lung injury of residue polysaccharides by Lentinula edodes [J]. Int J Biol Macromol, 2018, 106: 185-192.
 Kosai K, Seki M, Yanagihara K, et al. Elevated levels of high mobility group box chromosomal protein-1 (HMGB-1) in sera from patients with severe bacterial pneumonia coinfected with influenza virus [J]. Scand J Infect Dis, 2008, 40(4): 338-342.
 Deng Y, Yang Z, Gao Y, et al. Toll-like receptor 4 mediates acute lung injury induced by high mobility group box-1 [J]. PLoS One, 2013, 8(5): e64375.
 Fagone P, Shedlock DJ, Bao H, et al. Molecular adjuvant HMGB1 enhances anti-influenza immunity during DNA vaccination [J]. Gene Ther, 2011, 18(11): 1070-1077.
 Middleton EA, He XY, Denorme F, et al. Neutrophil extracellular traps contribute to immunothrombosis in COVID-19 acute respiratory distress syndrome [J]. Blood, 2020, 136(10): 1169-1179.
 Diao JX, Ou JY, Dai H, et al. Antioxidant and Antiapoptotic Polyphenols from Green Tea Extract Ameliorate CCl4-Induced Acute Liver Injury in Mice [J]. Chin J Integr Med, 2020, 26(10): 736-744.
 Koivisto AE, Olsen T, Paur I, et al. Effects of antioxidant-rich foods on altitude-induced oxidative stress and inflammation in elite endurance athletes: A randomized controlled trial [J]. PLoS One, 2019, 14(6): e0217895.
 Chen J, Jin Y, Yang Y, et al. Epithelial Dysfunction in Lung Diseases: Effects of Amino Acids and Potential Mechanisms [J]. Adv Exp Med Biol, 2020, 1265: 57-70.
 Tan L, Tu Y, Wang K, et al. Exploring protective effect of Glycine tabacina aqueous extract against nephrotic syndrome by network pharmacology and experimental verification [J]. Chin Med, 2020, 15: 79.
 Khazdair MR and Boskabady MH. A double-blind, randomized, placebo-controlled clinical trial on the effect of carvacrol on serum cytokine levels and pulmonary function tests in sulfur mustard induced lung injury [J]. Cytokine, 2019, 113: 311-318.
 Nakayama T, Kumagai T, Kashiwagi Y, et al. Cytokine production in whole-blood cultures following immunization with an influenza vaccine [J]. Hum Vaccin Immunother, 2018, 14(12): 2990-2998.
 Rudd JM, Pulavendran S, Ashar HK, et al. Neutrophils Induce a Novel Chemokine Receptors Repertoire During Influenza Pneumonia [J]. Front Cell Infect Microbiol, 2019, 9: 108.
 Wang W, Yang P, Zhong Y, et al. Monoclonal antibody against CXCL-10/IP-10 ameliorates influenza A (H1N1) virus induced acute lung injury [J]. Cell Res, 2013, 23(4): 577-580.
 Chen S, Liu G, Chen J, et al. Ponatinib Protects Mice From Lethal Influenza Infection by Suppressing Cytokine Storm [J]. Front Immunol, 2019, 10: 1393.
 Yu H, Li TN, Ran Q, et al. Strobilanthes cusia (Nees) Kuntze, a multifunctional traditional Chinese medicinal plant, and its herbal medicines: A comprehensive review [J]. J Ethnopharmacol, 2021, 265: 113325.
 Plitzko I, Mohn T, Sedlacek N, et al. Composition of Indigo naturalis [J]. Planta Med, 2009, 75(8): 860-863.
 Xu ZL and Huang XJ. Therapeutic Approaches for Acute Promyelocytic Leukaemia: Moving Towards an Orally Chemotherapy-Free Era [J]. Front Oncol, 2020, 10: 586004.
 Sekhon S and Koo J. Indirubin: a novel topical agent in the treatment of psoriasis [J]. Br J Dermatol, 2018, 178(1): 21.