Studies (Glutathione and Flu)
1. Inhibition of influenza infection by glutathione Jiyang Cai *, Yan Chen*, Shaguna Seth†, Satoru Furukawa‡, Richard W. Compans† and Dean P. Jones*
* Department of Biochemistry, Emory University School of Medicine, Atlanta, GA, USA
† Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, GA, USA
‡ Nutri-Quest, Inc., Chesterfield, MO, USA
Received 27 August 2002; revised 23 December 2002; accepted 9 January 2003. ; Available online 6 March 2003.
Infection by RNA virus induces oxidative stress in host cells. Accumulating evidence suggests that cellular redox status plays an important role in regulating viral replication and infectivity. In this study, experiments were performed to determine whether the thiol antioxidant glutathione (GSH) blocked influenza viral infection in cultures of Madin-Darby canine kidney cells or human small airway epithelial cells. Protection against production of active virus particles was observed at a low (0.05–0.1) multiplicity of infection (MOI). GSH inhibited expression of viral matrix protein and inhibited virally induced caspase activation and Fas upregulation. In BALB/c mice, inclusion of GSH in the drinking water decreased viral titer in both lung and trachea homogenates 4 d after intranasal inoculation with a mouse-adapted influenza strain A/X-31. Together, the data suggest that the thiol antioxidant GSH has an anti-influenza activity in vitro and in vivo. Oxidative stress or other conditions that deplete GSH in the epithelium of the oral, nasal, and upper airway may, therefore, enhance susceptibility to influenza infection.
Address correspondence to: Dr. Jiyang Cai, Emory University School of Medicine, Department of Biochemistry, Atlanta, GA 30322, USA, USA; Tel: (404) 727-5865; Fax: (404) 727-3231
Free Radical Biology and Medicine Volume 34, Issue 7 , 1 April 2003, Pages 928-936
2. Attenuation of influenza-like symptomatology and improvement of cell-mediated immunity with long-term N-acetylcysteine treatment.
De Flora S, Grassi C, Carati L.
Institute of Hygiene and Preventive Medicine, University of Genoa, Italy.
N-acetylcysteine (NAC), an analogue and precursor of reduced glutathione, has been in clinical use for more than 30 yrs as a mucolytic drug. It has also been proposed for and/or used in the therapy and/or prevention of several respiratory diseases and of diseases involving an oxidative stress, in general. The objective of the present study was to evaluate the effect of long-term treatment with NAC on influenza and influenza-like episodes. A total of 262 subjects of both sexes (78% > or = 65 yrs, and 62% suffering from nonrespiratory chronic degenerative diseases) were enrolled in a randomized, double-blind trial involving 20 Italian Centres. They were randomized to receive either placebo or NAC tablets (600 mg) twice daily for 6 months. Patients suffering from chronic respiratory diseases were not eligible, to avoid possible confounding by an effect of NAC on respiratory symptoms. NAC treatment was well tolerated and resulted in a significant decrease in the frequency of influenza-like episodes, severity, and length of time confined to bed. Both local and systemic symptoms were sharply and significantly reduced in the NAC group. Frequency of seroconversion towards A/H1N1 Singapore 6/86 influenza virus was similar in the two groups, but only 25% of virus-infected subjects under NAC treatment developed a symptomatic form, versus 79% in the placebo group. Evaluation of cell-mediated immunity showed a progressive, significant shift from anergy to normoergy following NAC treatment. Administration of N-acetylcysteine during the winter, thus, appears to provide a significant attenuation of influenza and influenza-like episodes, especially in elderly high-risk individuals. N-acetylcysteine did not prevent A/H1N1 virus influenza infection but significantly reduced the incidence of clinically apparent disease.
PMID: 9230243 [PubMed - indexed for MEDLINE]