Felipe Hernández-Luis1, Susana Abdala2, Sandra Dévora3, Dora Benjumea4, Domingo Martín-Herrera3. 1. Departamento de Química Física, Universidad de La Laguna, 38207 La Laguna, Tenerife, Spain. 2. Unidad de Farmacología y Farmacognosia, Facultad de Farmacia, Universidad de La Laguna, 38207 La Laguna, Tenerife, Spain. Electronic address: sabdala@ull.es. 3. Unidad de Farmacología y Farmacognosia, Facultad de Farmacia, Universidad de La Laguna, 38207 La Laguna, Tenerife, Spain. 4. Departamento de Farmacia, Universidad de Antioquia, Medellín, Colombia.
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE: Diuretic plants are widely used in traditional medicine in many countries. However, many of these species have not been subjected to experimental studies to confirm that property. In this paper, a simple new method is proposed to evaluate the diuretic activity of plants. We define a new index that takes into account only the volume of urinary excretion and total ion concentration excreted obtained by specific electrical conductivity measurements. MATERIALS AND METHODS: Urine was collected in a graduate cylinder during the 8h after Artemisia thuscula (AT), Withania aristata (WA), Smilax canariensis (SC) and HCTZ oral administration to laboratory mice. To obtain the new index Diuretic Power (DP), we measured the specific electrical conductivity (κ) of the fresh urine samples. We calculated the concentration of a NaCl (or KCl) aqueous solution that has the same specific electrical conductivity as the urine sample. We multiplied this concentration by the corresponding urinary excretion volume, thus obtaining the total mEq. of electrolyte excreted "as if all were NaCl (or KCl)". Finally, we divided these mEq. by those corresponding to the control to obtain the DP value. RESULTS: HCTZ showed a 40% increase in DP, with respect to the control group, independently of the doses used, and the studied plants produced an increase between 7 and 28%. DP values were compared with other common indexes, DI and SIi, showing that the variation sequence of the three indexes was the same for HCTZ, WA and SC. CONCLUSIONS: A new and easy index, that we called diuretic power (DP), for estimating the diuretic activity of drugs or plants is proposed. It allows us to highlight diuretic effect with respect to a control value of a large amount of drugs or plants that had not been previously experimentally studied.
ETHNOPHARMACOLOGICAL RELEVANCE: Diuretic plants are widely used in traditional medicine in many countries. However, many of these species have not been subjected to experimental studies to confirm that property. In this paper, a simple new method is proposed to evaluate the diuretic activity of plants. We define a new index that takes into account only the volume of urinary excretion and total ion concentration excreted obtained by specific electrical conductivity measurements. MATERIALS AND METHODS: Urine was collected in a graduate cylinder during the 8h after Artemisia thuscula (AT), Withania aristata (WA), Smilax canariensis (SC) and HCTZ oral administration to laboratory mice. To obtain the new index Diuretic Power (DP), we measured the specific electrical conductivity (κ) of the fresh urine samples. We calculated the concentration of a NaCl (or KCl) aqueous solution that has the same specific electrical conductivity as the urine sample. We multiplied this concentration by the corresponding urinary excretion volume, thus obtaining the total mEq. of electrolyte excreted "as if all were NaCl (or KCl)". Finally, we divided these mEq. by those corresponding to the control to obtain the DP value. RESULTS:HCTZ showed a 40% increase in DP, with respect to the control group, independently of the doses used, and the studied plants produced an increase between 7 and 28%. DP values were compared with other common indexes, DI and SIi, showing that the variation sequence of the three indexes was the same for HCTZ, WA and SC. CONCLUSIONS: A new and easy index, that we called diuretic power (DP), for estimating the diuretic activity of drugs or plants is proposed. It allows us to highlight diuretic effect with respect to a control value of a large amount of drugs or plants that had not been previously experimentally studied.