RESUMO
OBJECTIVE: Calcium oxalate monohydrate (COM) crystals are frequently found in urinary calculi (stones). MATERIAL AND METHODS: COM crystals were grown by the single diffusion gel growth technique and the inhibitory effects of aqueous extracts of leaves, stems and rhizome of Costus igneus on the growth of COM crystals were studied. RESULTS: With an increase in the concentration of aqueous extract of C. igneus, the weight of the formed crystals was gradually reduced from 2.15 to 0.07 g(leaves), 0.06 g (rhizome) and 0.03 g (stem). The crystals harvested from the COM were characterized by Fourier transform infrared spectroscopy to confirm the functional groups and powder X-ray diffraction analyses to confirm the crystalline phases of COM crystals. A scanning electron microscopy study confirmed that the morphology of the crystals changed from hexagonal (COM) to bipyramids of calcium oxalate dihydrate (COD). CONCLUSIONS: This study confirms that using aqueous extracts of stem and rhizome of C. igneus can promote the formation of COD crystals and reduce the nucleation rate of COM crystals, a major component of calcium urinary stones.