PAW may regulate chronic rejection-induced vasculopathy in OAT rats. Daily intake of PAW lowered the progression of vasculopathy in OAT-recipient ACI/NKyo rats by inhibiting collagen accumulation, proliferation of smooth muscle cells and fibroblasts, and T lymphocyte infiltration in the vessel wall. Moreover, the results showed reduced T and B lymphocytes, plasma cells, and macrophage activation in the spleens of the OAT-recipient ACI/NKyo rats that were administered PAW. Therefore, this study highlights the therapeutic roles of PAW and provides a more effective drug therapeutic route in vasculopathy.