Objective: To investigate the effects of pharmacologic ascorbate (vitamin C) against Influenza A/CA/7/09 (H1N12009).
Methods: BALB/c mice inoculated intranasally with influenza virus were treated with ascorbate (3 mg/g) twice daily by intraperitoneal (i.p.) injection for up to 14 d. Control groups received an equivalent volume of normal saline. Body weights were measured daily. To quantify the level of viral replication in the respiratory tract, the mice were euthanized and lungs removed and prepared as whole lung homogenates.Viral titers were determined by TCID50 assay in MDCK cells. Cytokine titers were determined by ELISA following the manufacturer's protocol (IL-1β, IL-6, TNF-α, IFN-α). For lung histopathologic evaluation, lungs were fixed with 10% neutral-buffered formalin at time of isolation, and then coded, processed into paraffin blocks, sectioned onto glass slides and stained (hematoxylin and eosin).Slides were examined and scored by a pathologist.
Results: Mice infected with influenza virus and treated with pharmacologic ascorbate had higher survival and less weight loss, and had lung viral titers reduced by as much as 10 to 100-fold compared to the controls. Pathologic study of the lungs showed that the treated animals had little inflammation (bronchiolitis, perivasculitis, alveolitis, and vasculitis) compared to the controls.IL-1, IL-6, and IFN-alpha lung levels were lower in the treated animals compared to the controls.
Conclusion: Pharmacologic ascorbate is a pro-oxidant that eliminates influenza virus in the lung, and therefore reduces lung inflammation and lowers death rate in this mouse model.