Diuretic activity of aqueous ethanolic extract of leaves of Costus speciosusin normal Wistar albino rats

Costus speciosus is a medicinal herb with various proven pharmacological actions. Traditionally it has been reported to possess diuretic activities which have not yet been scientifically explored. This study attempts to explore the diuretic activity of aqueous-ethanolic extract of the leaves of Costus speciosusin healthy Wistar albino rats. The study was conducted in saline primed Wistar albino rats (n=6) using frusemide (20 mg/kg per oral) as the reference diuretic drug with two oral doses of aqueous-ethanolic extract of Costus speciosus200mg/kg and 400mg/kg respectively. Urine volume and electrolytes (Sodium, Potassium and Chloride) excretion was estimated at the end of 24 hours. Data was analyzed by one-way ANOVA followed by Tukey's test. P < 0.05 was considered as statistically significant. Costus speciosusextract significantly increased the volume of urine (10 ± 3ml/100g/24hr and 14 ±2.5ml/100gm/24hr), increasing the diuretic index to 1.25 and 1.75 for 200mgkg and 400mg/kg dose ranges respectively (P< 0.05). The test drug, when compared to the control group, showed a significant increase in the excretion of sodium, potassium and chloride excretion. However, the electrolyte secretions were less when compared to frusemide indicating a weaker saluretic action. These findings support the use of Costus speciosus as a diuretic agent with an action similar to that of the loop diuretic, frusemide. Further studies with larger doses and longer duration exploring the exact mechanism of action are warranted.