Objective
The study examines the effect of the hydro-alcoholic extract of Cinnamomum zeylanicum Blume bark on crystallization of calcium oxalate.
Methods
The antilithiatic effect of various concentrations of the hydro-alcoholic extract of C. zeylanicum was investigated at various stages of stone formation, using Cystone as a standard reference drug. The effect on calcium oxalate crystallization was evaluated by measuring the change in turbidity over time, during crystal nucleation, growth and aggregation, in the metastable solution of calcium chloride and sodium oxalate. The slope from the change in turbidity over time was measured using a spectrophotometer at 620 and 214?nm in respective tests. The inhibition rate was estimated by comparing turbidity in the presence and absence of extract. Crystals formed under experimental conditions were observed under a light microscope, and number and shape of the crystals were assessed in a randomly selected field. Phytochemical analysis and high-performance thin-layer chromatography of the extract was also carried out.
Results
C. zeylanicum significantly reduced crystal nucleation at concentrations of 4, 8 and 10?mg/mL (P? Conclusion
We found that C. zeylanicum hydro-alcoholic extract has notable inhibitory effects on various stages of crystallization, in terms of turbidity of solution, as well as the crystal size, number and morphology.

Key words: Antilithiatic activity, Calcium oxalate, Inorganic inhibitors, In vitro, Unani medicine