Effects of Long-Term Administration of Gardeniae Fructus on Intra-Abdominal Organs of Rats

Many recent reports have suggested a possible association between Japanese traditional (Kampo) medicines containing Gardeniae Fructus (GF, the fruit of Gardenia jasminoides J. Ellis) and the mesenteric phlebosclerosis (MP). MP is a chronic orphan disease characterized by venous calcification extending from the colonic wall to the mesentery, usually developing in the proximal colon. In the present study, we administered GF to Wistar/ST female rats as 1% and 2% feed in the diet for 11 months to evaluate any calcification and/or fibrosis of veins in the colonic wall and mesentery. The reversibility of GF's effects was examined by feeding a normal diet for an additional 3 months. A significant decrease in body weight gain and food consumption occurred in the 2% GF group. Pigmentation of the liver, kidney, and spleen in macroscopic or histopathological examination was observed after 11-month administration, which disappeared after the 3-month recovery period. Histopathological findings such as fibrous thickening and calcification of vein walls, characteristic of human MP, were not observed. Fibrosis in the colonic lamina propria was observed in the 2% GF group but not in the 1% GF group during the treatment period, but the incidence as well as grade of this type of fibrosis decreased in the recovery period, suggesting that the effects of GF were reversible. In the present study, chronic GF administration did not result in any venous pathological changes but induced pigmentation in the liver, kidneys, and spleen and moderate fibrosis in the colonic lamina propria, all of which being reversible. Further studies are required to determine the association between GF and MP.