Effect of Ethanol Root Extract of <i>Equisetum arvense</i> (L) on Urinary Bladder Activity in Rats and Analysis of Principal Plant Constituents

Abstract

Purpose : To investigate the mechanism of action by which ethanol root extract of Equisetum arvense influences urinary bladder activity in rats, and to characterize the major compounds of the extract. Methods: Ethanol (95 %) was used for hot extraction for 3 h in a Soxhlet extraction apparatus. A total of 36 female rats were divided into Equisetum arvense root extract-treated group (EA) and control group. Rats in EA group were treated with a standard diet containing 0.2 % of the extract, while rats in the control group were fed with the diet only. After 3 weeks, 12 rats underwent cystometry with 0.2 % acetic acid solution and bladder activity was recorded. In another 12 rats, blood pressure, body weight and adenosine triphosphate were measured. In the remaining 12 rats, 0.2 % acetic acid solution was infused into the bladder and urinary adenosine triphosphate determined before and after the stimulation. Results: The results showed that during cystometry with acetic acid, the time interval between urinary bladder contractions was shorter and maximum bladder contraction pressure was much greater in rats in the control group, but in the Equisetum arvense group, the changes were much lower. Also in the Equisetum arvense group, plasma adrenaline and noradrenaline levels were lower than for the control group. Furthermore, increase in the levels of urinary adenosine triphosphate was smaller in Equisetum arvense group than in control group. Conclusion: This study suggests that Equisetum arvense ethanol root extract influences urinary bladder activity by decreasing adenosine triphosphate release, and is therefore a potential therapeutic agent against bladder disorder. However, there is need for further investigation of its exact mechanism of action.