Induction of multiple pro-inflammatory cytokines by respiratory viruses and reversal by standardized Echinacea, a potent antiviral herbal extract

Potential of the Phytomedicine Echinacea in the Treatment of Pulmonary Infections and Bronchitis

“…In rhinovirus infected human bronchial and lung epithelial cell lines, the virus stimulated the secretion of numerous cytokines, including the proinflammatory IL-1, IL-6, IL-8 and TNF, which are known to be collectively involved in many of the symptoms common to pulmonary infections. Echinaforce was able to completely or partly reverse this stimulation (Sharma et al, 2008b;2009a). It was also shown that EF could be added before or after virus infection, with similar success, and furthermore the results were not affected by virus dose or time of exposure to EF (Sharma et al, 2008b A similar result was obtained with other viruses and cell types.…”

“…It was also shown that EF could be added before or after virus infection, with similar success, and furthermore the results were not affected by virus dose or time of exposure to EF (Sharma et al, 2008b A similar result was obtained with other viruses and cell types. Thus HSV-1, influenza A virus, adenovirus type 3 and 11, and respiratory syncytial virus, all stimulated the secretion of proinflammatory cytokines, although the pattern and relative amounts of stimulation differed; but in each case the stimulation was reversed by EF (Sharma et al, 2009a; Table 3). However, only live infectious viruses were able to do this, for infection by equivalent doses of ultraviolet-inactivated viruses failed to elicit the responses.…”

“…This suggests that the virus has to enter the cells and undergo some degree of gene expression in order to stimulate the cytokine expression and secretion. It is also interesting that adenoviruses, which are not vulnerable to direct attack by Echinacea, could nevertheless stimulate cytokine secretion, and were susceptible to cytokine inhibition (Sharma et al, 2009a).…”

“…However, recent virological studies have shown that direct cytopathic damage by the pathogen is not a prerequisite for the induction of inflammatory mediators. For example, rhinoviruses and respiratory syncytial virus generally show limited replication and cause little or no cellular damage, yet they can induce large amounts of inflammatory cytokines (Mosser et al, 2005;Sharma et al, 2009a). Thus, the epithelium has a two-fold function in response to potential pathogens; it has a barrier function and also serves as a sensor that signals an efficient antimicrobial response.…”

“…Recent detailed studies with the standardized preparation Echinaforce  (EF, comprising ethanol extracts of E. purpurea, 95% aerial parts plus 5% roots) revealed that this preparation was very active as a virucidal agent against several viruses with membranes, as indicated in Table 1. In addition to HSV-1 and respiratory syncytial virus, all tested human and avian strains of influenza A virus, as well as influenza B virus, were susceptible (Sharma et al, 2009a;Pleschka et al, 2009). In addition, rhinoviruses were also equally susceptible at the relatively high concentrations of EF recommended for oral consumption (Table 1).…”