Toxicological evaluation of pterospartum tridentatum flower water

Pterospartum tridentatum Willk. (prickled broom) is an autochthonous plant, common in Portuguese territory. The yellow flowers are widely used in traditional medicine, as a potential cure for all body illnesses, mainly for throat irritation treatment or for diabetes, hypertension and hypercholesterolemia therapy. Despite its wide traditional use, no toxicological assessment of this plant has been performed, as far as we know. The major goal of this work was the P. tridentatum water extracts safety assessment. Methodology: Chemical characterization of MS analysis of P. tridentatum flower extract was performed by ESI-MS spectroscopy; phenols and quercetins content were also determined. Antioxidant activity was evaluated through -carotene bleaching test and ABTS radical-scavenging activity. Oxygen consumption of isolated mitochondria was determined polarographically with a Clark oxygen electrode and mitochondrial respiratory rates evaluated accordingly to Chance and Williams (1956) and mitochondrial swelling was evaluated the apparent absorbance changes at 520 nm. Results and discussion: A high antioxidant activity of P. tridentatum flower water extract was assessed in good agreement with its ESI-MS spectrum that revealed the presence of several flavonoids, as luteolin-O-(O-acetyl)-glucuronide, luteolin-Oglucuronide or isorhamnetin-O-hexoside. Mitocondrial respiratory rates (state 4, state 3 and FCCP-stimulated respiration) and respiratory indexes (respiratory control and P/O ratios) showed no consistent decrease of respiratory and phosphorylative efficiencies for the concentrations tested (up to 500 μg.mL-1). In conclusion, for the concentration range commonly used P. tridentatum flowers usage can be regarded as harmless and trustworthy and due to its great antioxidant properties it is useful to counteract diabetes mellitus associated diseases.