Rhus chinensis Mill.: A medicinal plant with promising inhibition of calcium oxalate crystallization, an in-vitro study.

The fruit of Rhus chinensis Mill. is traditionally used for the treatment of kidney diseases and
urinary stones. The present work investigated the effectiveness of the extract obtained from
the R. chinensis fruit pulp (RCFP) (water extract) on the inhibition of calcium oxalate (CaOx)
crystallization in-vitro, at different concentrations (1-10 mg/ml). The rates of nucleation and
aggregation were evaluated by comparing the slope of turbidity in the presence of the fruit
extract with that obtained in the control. The results of the samples were compared with a
parallel study conducted with standards like Citric acid (CA) and Malic acid (MA), Cystonea
marketed polyherbal combination (CYS), under identical concentrations. The densities of
the formed crystals were observed under a light microscope. RCFP (water extract)
significantly inhibited the slope of nucleation and aggregation of CaOx crystallization, and
decreased the crystal density. The standards- CA, MA and CYS also exhibited similar effects.
The study reveals that the organic acid in RCFP (water extract) was found effective in the
prevention of the experimentally induced urinary stones and thus substantiating the
traditional claim. Hence, the fruit of R. chinensis has a beneficial inhibitory effect on in-vitro
crystallization of CaOx crystals.