Hochuekkito, a Japanese Herbal Medicine, Restores Metabolic Homeostasis between Mitochondrial and Glycolytic Pathways Impaired by Influenza A Virus Infection

Background: Hochuekkito (HKT), a traditional Japanese herbal medicine (Kampo), has been used to treat symptoms of several diseases. In a recent clinical study, HKT was shown to be protective against the influenza virus infection. However, the underlying mechanism of the prophylactic effect is not clear. Mitochondrial and glycolytic pathways play important roles in cellular energy metabolism to maintain biological functions. These metabolic pathways are affected by the influenza virus infection. In this study, we examined the relationship between the preventive effects of HKT against the influenza virus infection and cellular energy metabolism in mitochondria and glycolysis using Madin-Darby canine kidney cells and influenza A/PR/8/34 (H1N1) virus (IAV). Methods: Mitochondrial and glycolytic metabolic pathways were evaluated on the basis of the oxygen consumption rate (OCR) and extracellular acidification rate (ECAR), respectively, using the XF24 Extracellular Analyzer. Results: The OCR/ECAR ratio in IAV-infected cells was lower than that in control cells. Cells that were treated with HKT before IAV infection showed a metabolic pattern similar to that in the control cells (increase in both OCR and ECAR). Conclusions: Our results suggest that HKT not only activates both mitochondrial and glycolytic energy metabolism in IAV-infected cells but also helps maintain metabolic homeostasis similar to that in noninfected cells.