ORIGINAL ARTICLE Gallic acid, a phenolic compound isolated from Mimosa bimucronata (DC.) Kuntze leaves, induces diuresis and saluresis in rats Fabile Schlickmann 1 & Thaise Boeing 1 & Luisa Nathália Bolda Mariano 1 & Rita de Cássia Melo Vilhena de Andrade Fonseca da Silva 1 & Luisa Mota da Silva 1 & Sérgio Faloni de Andrade 1 & Priscila de Souza 1 & Valdir Cechinel-Filho 1 Received: 14 February 2018 /Accepted: 6 April 2018 # Springer-Verlag GmbH Germany, part of Springer Nature 2018 Abstract Although present in the leaves of Mimosa bimucronata (DC.) and many other medicinal plants commonly used to augment urinary volume excretion, the effects of gallic acid as a diuretic agent remain to be studied. Wistar rats were orally treated with vehicle, hydrochlorothiazide, or gallic acid. The effects of gallic acid in the presence of hydrochlorothiazide, furosemide, amiloride, L-NAME, atropine, and indomethacin were also investigated. Diuretic index, pH, conductivity, and electrolyte excretion were evaluated at the end of the experiment (after 8 or 24 h). Gallic acid induced diuretic and saluretic (Na + and Cl - ) effects, without interfering with K + excretion, when orally given to female and male rats at a dose of 3 mg/kg. These effects were associated with increased creatinine and conductivity values while pH was unaffected by any of the treatments. Plasma Na + , K + , and Cl - levels were not affected by any of the acute treatments. The combination with hydrochlorothiazide or furosemide was unable to intensify the effects of gallic acid when compared with the response obtained with each drug alone. On the other hand, the treatment with amiloride plus gallic acid amplified both diuresis and saluresis, besides to a marked potassium-sparing effect. Its diuretic action was significantly prevented in the presence of indomethacin, a cyclooxygenase inhibitor, but not with the pretreatments with L-NAME or atropine. Although several biological activities have already been described for gallic acid, this is the first study demonstrating its potential as a diuretic agent. Keywords Flavonoid . Diuretic . Natriuretic . Saluretic . Cyclooxygenase Introduction Gallic acid, also known as 3,4,5-trihydroxybenzoic acid, is a naturally phenolic acid found widely distributed in fruits and plants, either in its regular form or as derivatives, including in wine and green tea (Blanco et al. 1998; Ow and Stupans 2003). Gallic acid and its derivatives are known to display a variety of biological functions, in addition to their primary antioxidant activity (Govea-Salas et al. 2016; Omobowale et al. 2017; Phonsatta et al. 2017), like antiproliferative (Subramanian et al. 2016), hypoglycemic (Huang et al. 2016), and anti-inflammatory (Lin et al. 2015) effects. A previous study has demonstrated that the phenolic com- pounds are the majorities of the specie M. bimucronata, in- cluding methyl gallate and gallic acid, and the extracts and methyl gallate present diuretic, natriuretic, and kaliuretic prop- erties when orally given to rats (Schlickmann et al. 2017). Although gallic acid was identified as one of the main com- ponents of M. bimucronata and in many others plants with diuretic activity indication, no study has been conducted so far evaluating its effects on experimental trials. Moreover, gallic acid already revealed several biological properties in the car- diovascular and renal system, demonstrating its therapeutic potential for conditions that affect these systems, which stands out a cardioprotective action against advanced glycation end product-induced cell proliferation (Umadevi et al. 2012) and cardiac remodeling (Umadevi et al. 2014), a vasorelaxant (de Oliveira et al. 2016) and antihypertensive (Jin et al. 2017; * Priscila de Souza priscilasouza_rc@yahoo.com.br 1 Programa de Pós-Graduação em Ciências Farmacêuticas, Universidade do Vale do Itajaí (UNIVALI), Rua Uruguai, 458, Itajaí, SC 88302-901, Brazil Naunyn-Schmiedeberg's Archives of Pharmacology https://doi.org/10.1007/s00210-018-1502-8