We found that a herbal medicine (
Mao-to) relieves the side effects of
interferon (IFN)-beta and the combination
therapy improves the biochemical response rate. However, the exact mechanism by which
Mao-to is effective remains to be established. We conducted a controlled trial to clarify the effects of
Mao-to. The study was carried out in 18 patients with
chronic hepatitis C, and we examined subjective symptoms, body temperature and
cytokines such as
interleukin (IL)-beta, IL-1receptor antagonist (ra),
IL-6 and
TNF-alpha. Each patient received 6 million units of IFN-beta intravenously.
Mao-to was given orally just before, just after, and 1 hour after IFN administration. The control study was carried out 6 months after the combination
therapy of
Mao-to and IFN-beta. The scores for general malaise,
arthralgia and discomfort were significantly lower in the combination group than in control group. Body temperature did not significantly differ between the two groups. Plasma
IL-6 level and
IL-1ra were significantly elevated in the combination group compared to control (P = 0.0057 and 0.0003, respectively).
Mao-to did not affect plasma concentrations of IL-1beta and
TNF-alpha. We considered the increment of
IL-1ra caused by
Mao-to is to be one of the key factors involved in reducing the flu-like symptoms accompanying IFN-beta and improving the biochemical response rate.