The inhibitory effect of kampou extracts on in vitro calcium oxalate crystallization and in vivo stone formation in an animal model.

Kampou medicine is a traditional Japanese therapeutic system which originated in China and was used to treat various diseases for hundreds of years until it was superseded by Western medicine. In recent years, there has been a resurgence of interest in Kampou medicine among many physicians. Unfortunately, however, little evaluation has been performed using objective scientific methods until now, and the pharmacodynamics of Kampou medicine are still unclear. Generally speaking, Kampou medicine has been shown to have fewer side-effects than Western medicine based on the experience gained from its long usage. We first selected 16 Kampou extracts for screening as possible calcium oxalate stone prophylactic agents in vitro. This resulted in the selection of two kinds of Kampou extracts, Takusya and Kagosou, as potential Kampou extracts for stone prophylaxis. Next, these two Kampou extracts were tested in vivo for their effects on stone formation in an animal model. Takusya showed significant stone prophylaxis, while Kagosou did not. Lastly, Chorei-to, which contains Takusya and has been approved for prescription as a Kampou medicine for urolithiasis patients in Japan, was examined in vivo at two different concentrations. As a result, a low dose of Chorei-to which corresponded to the human daily dose per unit of body weight exhibited apparent stone prophylaxis, despite the disadvantage of decreasing citrate excretion. In contrast, high doses of Chorei-to did not exhibit stone prophylaxis in vivo.(ABSTRACT TRUNCATED AT 250 WORDS)