Inhibitions of urinary oxidative stress and renal calcium level by an extract of Quercus salicina Blume/Quercus stenophylla Makino in a rat calcium oxalate urolithiasis model

Abstract

To clarify the mechanism of Urocalun, an extract of Quercus salicina Blume/Quercus stenophylla Makino (QS), in the treatment of urolithiasis. Rat calcium oxalate urolithiasis was induced by oral administration of ethylene glycol and the vitamin D3 analog alfa-calcidol for 14 days. QS extract was repeatedly given to rats. After the last administration, biochemistries in urine and plasma, renal calcium, and urinary malondialdehyde (an oxidative stress marker) were measured. Ethylene glycol and alfa-calcidol treatment increased urinary malondialdehyde and renal calcium levels. This increase was significantly suppressed by the administration of QS extract, suggesting that the inhibition of renal calcium accumulation by QS extract is due to its antioxidative activity. These findings suggest that the antioxidative activity of QS extract plays a role in the prevention of stone formation and recurrence in urolithiasis.