[Inhibitory effect of oral administration of Takusya on calcium oxalate crystallization in human whole urine]

We previously reported that Takusya had the inhibitory effect on in vitro calcium oxalate crystallization and in vivo stone formation in an animal model and it could be a prophylactic agent against calcium oxalate stone formation. We studied the effect of Takusya on calcium oxalate crystallization in human urine. Takusya (500 mg/day and 1,000 mg/day) was administered to 16 healthy men for 3 days and then 24-hour urine samples were collected to measure the urinary excretion of calcium, phosphate, magnesium, uric acid, creatinine, citric acid and oxalic acid. The urine samples before the administration of Takusya was used as a control. The size and distribution of crystals, which were formed in the urine samples by adding calcium chloride and sodium oxalate, were measured using the Coulter counter technique. Urinary magnesium excretion was significantly reduced by 1,000 mg/day of Takusya compared with the control (p < 0.05). The growth of crystals was significantly inhibited by 500 mg/day of Takusya in the large crystal formers whose urine created crystals more than 3.5 microns before the administration of Takusya (p < 0.05). These findings suggested that Takusya inhibited the growth of crystals formed in human urine.