Diuretic and Antidiuretic Activities of Ethanol Extract and Fractions of Lagopsis supina in Normal Rats

Lagopsis supina is a well-known traditional Chinese medicine and used as an agent for diuresis in China for centuries. This is the first time to evaluate the diuretic activity of the ethanol extract of L. supina (LS) and its four fractions (LSA, LSB, LSC, and LSD) in normal rats. After the administration of LS-H, LS-M, LSB-H, and LSC-L, the urine output of the rats was significantly increased, while the urine excretion was significantly reduced after treatment with LSB-L. The urine Na(+) excretion was remarkably increased with LS-H, LS-M, LSA-H, LSA-L, LSB-H, LSC-L, and LSD-L, and the urine K(+) excretion was significantly increased after administration of LS-H and LSB-H. Moreover, the urine Na(+) and K(+) excretion was significantly reduced after treatment with LSC-H and LSD-H. However, the urine pH values and urine and serum Na(+)-K(+)-ATPase levels did not show remarkable change after administration of LS or its four fractions in comparison with the control group. On the contrary, LS and its four fractions can suppress the renin-angiotensin-aldosterone system (RAAS), including ADH arrest by LSB-H, LSB-L, LSC-L, LSD-L, and LSD-H and ALD arrest by LSD-L, as well as promote ANP release by LS-M, LSB-H, LSC-H, and LSD-H, while furosemide can suppress only arrest of ADH within 24 h compared with the control group. In addition, LS and its four fractions did not change the urine and serum TNF-α and IL-6 levels in normal rats within 24 h. This study will provide a quantitative basis for explaining the natural medicinal use of LS as a diuretic agent for edema and promoting the diuretic process.