In vitro Growth and Inhibition Studies of Monosodium Urate Monohydrate Crystals by Different Herbal Extracts

Problem statement: A large number of people in the world have been suffering from gout for centuries. Gout is the term given to a metabolic condition in which the signs and symptoms results from the deposition of crystals of Monosodium Urate Monohydrate (MSUM) in various connective tissues. Approach: It was quite difficult to grow good quality large MSUM crystals because uric acid was having very low solubility in any known solvents. Results: Attempts were made in the present investigation to grow MSUM crystals in vitro by single diffusion gel growth technique, which is quite suitable to mimic the growth of MSUM crystals in vivo up to a certain extent. Good quality needle type crystals were grown in the gel, which were characterized by FT-IR, Powder X-ray diffraction and Thermo-gravimetry. The characterization study confirmed the formation of MSUM crystals in the experiments. Herbal extract solutions of Boswellia serrata Linn., Aerva lanata juss ex. Schult, Routula aquatica Lour. and Boerhavia diffusa Linn., were used for the growth inhibition study of MSUM crystals. Aqueous herbal extract solutions were poured as supernatant solutions along with the control solution on the set gels during the crystal growth experiment. The growth observations and the measurements of crystal dimensions using optical microscope suggested that Routula aquatica Lour. and Aerva lanata juss ex. Schult extracts exhibited good crystal growth inhibition results. Conclusion: Routula aquatica Lour. extract dissolved MSUM crystals after 15 days of pouring the supernatant solution on the gel. This in vitro study may be helpful for in vivo studies, which may further lead to develop a preclinical formulation for gout treatment.