Korean Red Ginseng enhances pneumococcal Δ vaccine efficacy by inhibiting reactive oxygen species production.

BACKGROUND

, more than 90 serotypes of which exist, is recognized as an etiologic agent of pneumonia, meningitis, and sepsis associated with significant morbidity and mortality worldwide. Immunization with a pneumococcal mutant (Δ) has been shown to confer comprehensive, long-term protection against even nontypeable strains. However, Δ is effective as a vaccine only after at least three rounds of immunization. Therefore, treatments capable of enhancing the efficiency of Δ immunization should be identified without delay. Mayer has already been shown to have pharmacological and antioxidant effects. Here, the ability of Korean Red Ginseng (KRG) to enhance the efficacy of Δ immunization was investigated.

METHODS

Mice were treated with KRG and immunized with Δ before infection with the pathogenic strain D39. Total reactive oxygen species production was measured using lung homogenates, and inducible nitric oxide (NO) synthase and antiapoptotic protein expression was determined by immunoblotting. The phagocytic activity of peritoneal macrophages was also tested after KRG treatment.

RESULTS

Compared with the other treatments, KRG significantly increased survival rate after lethal challenge and resulted in faster bacterial clearance via increased phagocytosis. Moreover, KRG enhanced Δ vaccine efficacy by inhibiting reactive oxygen species production, reducing extracellular signal-regulated kinase apoptosis signaling and inflammation.

CONCLUSION

Taken together, our results suggest that KRG reduces the time required for immunization with the Δ vaccine by enhancing its efficacy.