[In vitro study of the litholytic effects of herbal extracts on cystine urinary calculi].

BACKGROUND

cystine stones represent 1% of urinary calculi in adults and 10% in children and are especially recurrent and resistant to ESWL. Medical therapy is often efficient but often poorly tolerated. In Morocco, various plants, Herniaria hirsuta, Opuntia ficus-indica, Zea mays and Ammi visnaga are proposed against nephrolithiasis. We assessed the effect of plant extracts on the disolution of cystine stones in vitro.

METHODS

an extract of each plant was prepared by infusion of two grams of powdered plants during 30 minutes in 100ml of a boiled NaCl 9 g/L aqueous solution. Each extract was then filtered and thereafter set in a flask containing a cystine stone. The medium was maintained under stirring during 8 weeks. NaCl 9 g/L solution and sodium citrate 3 mmol/L solution were used as controls. At the end of each two weeks period, the stone was removed from the experimental medium and weighted after a 16h drying period at 40°C.

RESULTS

after 8 weeks of experiment, stone dissolution was complete for all herbal extracts, and was earlier in the presence of Zea mays (4 weeks) or of Ammi visnaga (6 weeks) by comparison to only 18 ± 8 and 20 ± 1.5 % for citrate and NaCl solutions, respectively.

CONCLUSIONS

the studied herbal extracts were efficient for dissolving cystine stones, probably resulting from the formation of complexes between cystine and polyhydroxylated molecules present in the extracts. These results, to be confirmed in vivo, underline the potential interest of the plant extracts to treat cystine stones.