Several species of Cuphea are used medicinally and are reported to have cardioprotective, diuretic, and antihypertensive properties. In Brazil, Cuphea species are collectively called "sete-sangrias" due to their similar appearances and are also used interchangeably for the same therapeutic purposes. So the aim of the study was to characterize morphoanatomy of leaves and stems, evaluate the safety, and investigate the diuretic, hypotensive, vasodilatory, and antioxidant properties of ethanol-soluble fraction of Cuphea calophylla var. mesostemon (Koehne) S.A. Graham. Initially, the morphoanatomical characterization of the leaves and stems of C. calophylla var. mesostemon was performed. For the pharmacological evaluation, the ethanol-soluble fraction from Cuphea calophylla (ESCC) was obtained and chemically characterized by high-performance liquid chromatography coupled with a diode array detector and tandem mass spectrometry techniques. Then, acute toxicity, diuretic, hypotensive, antioxidant, and vasodilatory effects were evaluated in Wistar rats. The main chemical compounds identified from ESCC were gallic acid derivatives, ellagitannins, and flavonoids. ESCC showed no acute toxic effect. ESCC showed no acute toxic effect and the estimated median lethal dose (LD50) was above 2000 mg/kg. ESCC treatment (30, 100, and 300 mg/kg) did not present any significant acute diuretic or hypotensive effects. However, an important reduction in the elimination of electrolytes was observed after the acute administration, and a significant increase in renal sodium elimination was observed after 7 days of treatment. In the cardiac tissue, the groups treated with ESCC presented significant increase in superoxide dismutase activity.
Keywords: Lythraceae; antioxidant; diuretic; hypertension; morphoanatomy.