Diuretic and saluretic effects of Baccharis dracunculifolia DC. (Asteraceae)

Baccharis dracunculifolia DC. (Asteraceae) is an aromatic and medicinal species that is native to Brazil and other South American countries. It is popularly known as "alecrim-do-campo", "alecrim-de-vassoura", and "vassourinha", being used as infusions for various ailments. Moreover, in Brazil, this species is commonly utilized for treating cardiovascular disorders. Despite its common use , there is no evidence in the literature demonstrating the effects of B. dracunculifolia leaves on the cardiovascular system.

We aimed to investigate the cardiorenal properties of the aqueous extract (ESBD) and essential oil (EOBD) of B. dracunculifolia aerial parts on Wistar rats.

First, the plant material was collected and identified, its essential oil (EOBD) was extracted by hydro-distillation, while an ethanolic fraction was prepared after the obtention of the aqueous extract by infusion (ESBD). The chemical compositions of EOBD and ESBD were determined by GC-MS and LC-DAD-HRMS, respectively. The acute toxicity test was performed on female Wistar rats to determine the toxic effects after a single administration. Finally, the potential diuretic and hypotensive effects of ESBD and EOBD (doses at 30, 100, and 300 mg/kg) were evaluated on normotensive male Wistar rats.

Thirty-eight compounds were annotated in EOBD by GC-MS (thirty-one identified), which was mainly composed by monoterpene hydrocarbons (81.9 %), highlighting α-pinene (14.2 %), β-pinene (39.8 %), and limonene (21.3 %). LC-DAD-HRMS analysis from ESBD revealed twenty-three compounds, including flavonoids (C-glycosylated flavones, O-glycosylated flavonols, and an aglycone flavanonol), and phenolic acid derivatives such as caffeoylquinic (chlorogenic), coumaroylquinic, and feruloylquinic acids. No signs of toxicity were observed after acute treatment with ESBD and EOBD, and it was suggested that the oral median lethal dose (LD₅₀) of the extracts is above 2000 mg/kg. In addition, a 7-day oral treatment with ESBD at a dose of 300 mg/kg was able to significantly increase urinary volume (thus, acting as diuretics) and renal excretion of sodium and chloride (saluretic action).

The findings of this study showed that a fraction derived from of the ethanol-soluble fraction of the aqueous extract (ESBD) and essential oil (EOBD) of B. dracunculifolia leaves is safe for acute administration on female Wistar rats. Additionally, oral treatment with ESBD (dose at 300 mg/kg) showed potential diuretic and saluretic effects in normotensive male Wistar rats.