Effect of Haskap (Lonicera caerulea) on streptococcus pneumoniae infected aged-mouse

      Background: Pneumonia is a high fatal disease in the world today. As streptococcus pneumoniae is most popular in bacterial pneumonia, improvement of pneumococcal pneumonia is considered to be one of the important factors in the longevity of the elderly. Haskap (Lonicera caerulea) is a fruit of a plant which has been eaten by the Ainu people (indigenous people in Hokkaido: northern part of Japan) as a fruit of longevity. However, there have been no scientific evidences of the Haskap as longevity so far. In this study, we examined whether Haskap fruit extract (HKP) is effective in aged-mouse infected with S. pneumoniae.
      Methods and materials: 72 weeks old BALB / c female mice were orally administered HKP. On the second day of oral administration, mice were infected with S. pneumoniae ATCC 49619 strain intranasally. After that murine general condition such as survival rate were evaluated until 5 days. Lung tissue was aseptically isolated from mice at the time of death or 5 days after oral administration, and the number of colonies was counted after culturing on a blood agar medium at 37 °C under 5% CO2 for 24 hours.Further, alveolar macrophage were collected from murine lung tissue treated with the HKP for 4 days. As a phagocytic assay, both alveolar macrophage and S. pneumoniae were mixed for 1 hour. Thereafter, the mixed samples were cultured on a blood agar medium, and then the number of colonies was evaluated.
      Results: Although all untreated mice died up to 5 days, all HKP treated mice survived. Moreover, in the lung, the number of bacterial colonies from HKP treated mouse was decreased compared to untreated mouse. In the phagocytic assay, the number of bacteria in the HKP treated group decreased significantly compared to that in the untreated group.
      Conclusion: Our results suggest that Haskap may ameliorate the pneumococcal infectious disease in aged-mouse because of uptakes of the phagocytic ability.