Immunomodulatory and anti-SARS activities of Houttuynia cordata

• Published in: Journal of ethnopharmacology Vol. 118; no. 1; pp. 79 - 85
• Main Authors: Lau, Kit-Man, Lee, Kin-Ming, Koon, Chi-Man, Cheung, Crystal Sao-Fong, Lau, Ching-Po, Ho, Hei-Ming, Lee, Mavis Yuk-Ha, Au, Shannon Wing-Ngor, Cheng, Christopher Hon-Ki, Lau, Clara Bik-San, Tsui, Stephen Kwok-Wing, Wan, David Chi-Cheong, Waye, Mary Miu-Yee, Wong, Kam-Bo, Wong, Chun-Kwok, Lam, Christopher Wai-Kei, Leung, Ping-Chung, Fung, Kwok-Pui
• Format: Journal Article
• Language: English
• Published: Shannon Elsevier Ireland Ltd 19.06.2008; Amsterdam; New York: Elsevier; Elsevier
• Subjects: 3C-like protease; acute toxicity; Administration, Oral; animal models; Animals; Anti-viral; Antiviral Agents - administration & dosage; Antiviral Agents - isolation & purification; Antiviral Agents - toxicity; antiviral properties; Biological and medical sciences; CD4-Positive T-Lymphocytes - drug effects; CD4-Positive T-Lymphocytes - metabolism; CD8-Positive T-Lymphocytes - drug effects; CD8-Positive T-Lymphocytes - metabolism; Cell Proliferation - drug effects; China; Coronavirus; disease prevention; dosage; dose response; Dose-Response Relationship, Drug; Drugs, Chinese Herbal - administration & dosage; Drugs, Chinese Herbal - toxicity; Female; Flow Cytometry; General pharmacology; herbal medicines; Houttuynia cordata; Immunomodulation; interleukin-10; interleukin-2; laboratory animals; lymphocytes; Medical sciences; medicinal plants; Mice; Mice, Inbred BALB C; oral administration; Oriental traditional medicine; Pharmacognosy. Homeopathy. Health food; Pharmacology. Drug treatments; plant extracts; pneumonia; proteinases; respiratory tract diseases; RNA-dependent RNA polymerase; SARS; SARS coronavirus; SARS Virus - drug effects; Saururaceae; Severe Acute Respiratory Syndrome - drug therapy; spleen; Spleen - cytology; T-lymphocytes; Toxicity Tests, Acute; China; Anti-viral; 3C-like protease; SARS; Houttuynia cordata; Immunomodulation; RNA-dependent RNA polymerase; Enzyme; Pharmacognosy; Transferases; DNA-directed RNA polymerase; Medicinal plant; Virus; Immunomodulator; Houttuynia cordata;Immunomodulation;SARS;Anti-viral;3C-like protease;RNA-dependent RNA polymerase; Nucleotidyltransferases; Coronavirus; Severe acute respiratory syndrome virus; Plant origin; Coronaviridae; Nidovirales
• ISSN: 0378-8741; 1872-7573
• DOI: 10.1016/j.jep.2008.03.018

Severe acute respiratory syndrome (SARS) is a life-threatening form of pneumonia caused by SARS coronavirus (SARS-CoV). From late 2002 to mid 2003, it infected more than 8000 people worldwide, of which a majority of cases were found in China. Owing to the absence of definitive therapeutic Western medicines, Houttuynia cordata Thunb. (Saururaceae) (HC) was shortlisted by Chinese scientists to tackle SARS problem as it is conventionally used to treat pneumonia. The present study aimed to explore the SARS-preventing mechanisms of HC in the immunological and anti-viral aspects. Results showed that HC water extract could stimulate the proliferation of mouse splenic lymphocytes significantly and dose-dependently. By flow cytometry, it was revealed that HC increased the proportion of CD4 + and CD8 + T cells. Moreover, it caused a significant increase in the secretion of IL-2 and IL-10 by mouse splenic lymphocytes. In the anti-viral aspect, HC exhibited significant inhibitory effects on SARS-CoV 3C-like protease (3CL pro) and RNA-dependent RNA polymerase (RdRp). On the other hand, oral acute toxicity test demonstrated that HC was non-toxic to laboratory animals following oral administration at 16 g/kg. The results of this study provided scientific data to support the efficient and safe use of HC to combat SARS.