Evaluation of diuretic activity of Vanillin in healthy Wistar Albino rats

Vanilla (Vanilla planifolia), a monocotyledonous orchid, native of Central America, grown for the attractive aroma produced by its fruit is reported to have been used by the Aztec people in Mexico to promote diuresis and purify blood. However a search of literature revealed no scientific data to prove this claim and hence we decided to evaluate its diuretic potential in a murine model.

The study was conducted in saline primed Wistar albino rats (n=6) using hydrochlorothiazide (10 mg/kg) as the reference diuretic drug with two oral doses of vanillin, 250mg/kg and 500mg/kg respectively. Urine volume and electrolytes (Sodium, Potassium and Chloride) excretions were estimated at the end of 24 hours and data was analyzed by Kruskall Wallis and Mann Whitney tests. P < 0.05 was considered as statistically significant.

Vanillin statistically increased the volume of urine in a dose dependent manner increasing the diuretic index to 2.35 and 2.85 for 250mgkg and 500mg/kg dose ranges respectively when compared to hydrochlorothiazide (2.74) (P< 0.01). The test drug, when compared to the control group, showed a significant increase in the excretion of sodium, and chloride excretion in a dose dependent manner. The increase in potassium excretion was significant only at a higher dose (500mg/kg), the saluretic index being 3.48 and 2.48 at 250mg/kg and 500mg/kg dose respectively compared to Hydrochlorothiazide which showed a saluretic index of 1.81. Conclusion: These findings indicate that vanillin has significant diuretic activity with a potassium sparing effect at lower doses and further studies with larger doses and longer duration are warranted.