ABSTRACT
<p><b>OBJECTIVE</b>To study the effect of different extracts of Alisma orientalis on urinary calcium oxalate stone formation in rats and to identify the effective constituents.</p><p><b>METHOD</b>Different extracts were administered through a stomach tube to rats of different groups with renal calcium oxalate stones induced by ethylene glycol (EG) and ammonium chloride (AC).</p><p><b>RESULT</b>In the rats administered with ethyl acetate elution of ethyl acetate extract, blood Cr, BUN, renal tissue calcium content, urinary calcium excretion and crystals deposition in renal tissue were significantly lower than those of the stone formation group.</p><p><b>CONCLUSION</b>The ethyl acetate elution of ethyl acetate fraction extract of Alisma orientalis can significantly inhibit urinary calcium oxalate stone formation in rats and be the most effective constituent of Alisma orientalis.</p>