薬理と治療

Abstract

Objectives　This study aimed to investigate the effects of shark liver oil（SLO）and lactic acid bacteria（LAB）on natural killer（NK）activity and cytokine production in mice infected with the influenza A virus. Methods　Female BALB/cCrSlc mice were allocated to the control, SLO and LAB groups, and treated orally with water for injection at 0.2 mL/mouse, SLO at 0.2 mL/mouse, and LAB at 2.5 mg/0.2 mL/ mouse, respectively, twice a day for 17 days. On the day 15, influenza A virus PR╱8╱34（H1N1）was nasally infected to the mice. Observation of general signs （once a day）and body weight measurement（twice a week）were conducted until the day 18. On the day 18, spleen was extracted from mice and dispersed. NK activity against YAC-1 cells（mouse leukemia cell line）and cytokines（IL-4, IFN-γ）in culture supernatant of the splenocytes were measured. Results　After infection, slight piloerection and hyperpnea were observed in the control and LAB groups. In the SLO group, slight piloerection was observed during administration period. Body weight of the mice in the LSO group significantly increased on the day 18 compared with the control group. As for NK activity, the cytotoxicity of the SLO group was slightly higher than the control group whereas the effect was not statistically significant. The cytotoxicity of the LAB group was comparable to that of the control group. There was no significant difference between the groups as to the IL-4 concentration. The IFN-γ concentration in the LSO group but not of the LAB group was significantly higher than that of the control group. Conclusions　It was suggested that the SLO might alleviate the symptoms of influenza virus infection via the facilitation of cytokine production.