Immunopharmacological effect of a Japanese herbal medicine (Hochu-ekki-to) on the elderly

Hochu‐ekki‐to (HOT) has long been used for treatment of the elderly complaining of severe weakness. In this study, we examined its immunopharmacological effect on 16 elderly patients, aged 76.5 years on average and complaining of general fatigue. They were administered orally 7.5 g of HOT every day for at least 120 days (4 months), which provided them with a noticeable improvement of their physical condition. From the immunological point of view, during the observation period, the total number of circulating leukocytes remained unchanged, as well as the ratios between CD3+T‐ and CD20+B‐cells and between CD4+T‐ and CD8+T‐cells. However, as verified on day 30 as well as on day 120 after the administration of HOT, the activity of NK against K562 target cells was significantly enhanced. Also, on days 30 and 120, there was a significant increase in serum IFN‐γ level which is thought to be associated with NK activity. From these results, it may be concluded that the oral administration of HOT to the elderly may help them ameliorate, at least partially, their immunological capacity as well as their physical condition.