Hibiscus Sabdariffa L. Flowers and Olea Europea L. Leaves Extract-Based Formulation for Hypertension Care: In Vitro Efficacy and Toxicological Profile

Abstract

Olea europaea L. leaves extract (Oe) and Hybiscus sabdariffa L. flowers extract (Hs) have calcium antagonistic properties. Aim of this work was to study the cardiovascular effects of Pres Phytum(®), a nutraceutical formulation containing a mixture of the two extracts and the excipients, and investigate its possible off-target effects, using in vitro biological assays on guinea pig isolated organs. Cardiovascular effects were assessed using guinea pig atria and aorta. The effects of Pres Phytum on spontaneous gastrointestinal, urinary, and respiratory tracts smooth muscle contractility were evaluated. Pres Phytum exerted a vasorelaxant effect (IC50 = 2.38 mg/mL) and a negative chronotropic effect (IC50 = 1.04 mg/mL) at concentrations lower than those producing smooth muscle spontaneous contractility alterations in the other organs. Compared to Pres Phytum, the mixture did not exert negative inotropic activity, while it maintained a negative chronotropic efficacy (IC50 = 1.04 mg/mL). These experimental data suggest a possible nutraceutical use of this food supplement for the management of preclinical hypertension.

Olive Leaves and Hibiscus Flowers Extracts-Based Preparation Protect Brain from Oxidative Stress-Induced Injury

“…To better understand the mechanism underlying PRES neuroprotection, it is crucial to refer to its main components. PRES composition, characterized by HPLC coupled to a UV-Vis and QqQ-Ms detector, has already been reported [8,9] and the main components, fully detailed in Materials and Methods, consist in elenolic acid glucoside (23.65 ± 0.79 mg/g), oleuropein (215.1 ± 1.64 mg/g), oleuropein isomer (51.09 ± 0.35 mg/g) for Olea europaea L. leaves, and hibiscus acid (139.2 ± 0.47 mg/g) for Hibiscus sabdariffa L. calyces. These compounds possess antioxidant properties [29][30][31] and this could be at the basis of the ability of PRES to revert ROS formation and thus to elicit neuroprotection.…”

“…Pres Phytum ® was made up by the 13:2 (w/w) mixture of the extracts from Olea europaea L. leaves (OEE) and Hibiscus sabdariffa L. calyces (HSE). Detailed information about the preparation of both extracts, the preparation of the mixture and its composition, assessed by HPLC coupled to a UV-Vis and QqQ-Ms detector, has already been reported [8,9]. Briefly, the main components were (mg/g): in OEE, hydroxyoleuropein (8.96 ± 0.42), elenolic acid glucoside (23.65 ± 0.79), oleuropein (215.1 ± 1.64), oleuropein isomer (51.09 ± 0.35), ligstroside (11.03 ± 0.04), verbascoside (4.67 ± 0.44), rutin (0.69 ± 0.06), luteolin-7-O-rutinoside (0.74 ± 0.04), luteolin-7-O-glucoside (5.83 ± 0.24), luteolini-4-O-glucoside (4.20 ± 0.12); in HSE, hibiscus acid (139.2 ± 0.47 mg/g).…”

“…Human SH-SY5Y neuroblastoma cells (ECACC Cat# 94030304, passages [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20], grown in standard conditions, as already reported [14] were sub-cultured at 70-80% confluent, medium changed twice/week and experiments were performed by using cells in the exponential phase of growth.…”

Thymus vulgaris L. Essential Oil Solid Formulation: Chemical Profile and Spasmolytic and Antimicrobial Effects

“…The organs studied were stomach, ileum, proximal colon and gallbladder. Briefly, the organs were set up rapidly under a suitable resting tension in 15 mL organ bath, containing appropriate physiological salt solution (PSS) consistently warmed and buffered to pH 7.4 by saturation with 95% O 2 —5% CO 2 gas and used as previously described [ 13 ].…”

Flavonoids and Their Metabolites: Prevention in Cardiovascular Diseases and Diabetes

“…Several natural extracts, e.g., from leaves of Olea europea L., or calyces of Hibiscus sabdariffa L. [ 12 ], exert multiple effects that result in an inhibition of atherosclerosis and hypertension. The effects include vasorelaxant, antioxidant and antinflammatory activities.…”