We studied here the effect of 3 kinds of kampo-hozais (Shofu-san, Ji-zuso-i
ppo and Unsei-in) on the induction of oral tolerance to ovalbumin (OVA) in
C3H/HeN mice by measuring serum levels of OVA-specific antibodies. Oral tol
erance was induced by a single administration of OVA (2 or 20 mg, p.o.) 7 d
before the immunization. Among those kampo-hozais, mice administered Ji-zu
so-ippo for 7 d before feeding of 2 mg OVA had significantly lower levels o
f anti-OVA IgG and IgG1, and further, Ji-zuso-ippo tended to reduce anti-OV
A Igs in 20 mg OVA-fed mice, whereas Ji-zuso-ippo did not alter anti-OVA Ig
s in non-OVA-fed mice. Unsei-in also slightly augmented the suppression of
anti-OVA IgG and IgG1; however, this lowering action of Unsi-in should be d
ue to its immunosuppressive effect. Shofu-san did not alter these anti-OVA
Ig levels in serum. These results suggested that Ji-zuso-ippo could augment
the induction of oral tolerance.