Pharmacokinetic study and phytochemical analysis of beetroot powder as an initial stage of the development of an NO-boosting formulation as a food supplement with cardioprotective properties and potential donor of nitric oxide

Background — Production of nitric oxide (NO) can be modulated endogenously by enzymatic synthesis of NO from L-arginine within the body or exogenously via diet. Bioactive NO levels can be influenced by adding various foods rich in nitrite and nitrate (NOx). Objective — The aim of the present study was to investigate pharmacokinetics and perform phytochemical analysis of NOx as an active component in finely dispersed powder of a dried beetroot formulation to assess the shelf life that corresponds to minimal losses in the NOx contents while preserving optimal pharmacokinetic characteristics. Results — The beetroot powder was manufactured by infrared dehydration of beetroot. The NOx content per dry weight of the beetroot powder was 25.2 g/kg (25,200 mg/kg), which was 10-fold higher than NOx content per kg of untreated beetroot. The data indicated that powdered beetroot can be stored at room temperature for at least a year without detectable loss in nitrate content. Tmax for NOx was 30 min after loading, and Cmax for NOx was 209 μM or 52% of the loading dose of 400 mg contained in 11 g of dry beetroot powder. The half-life of NOx delivered to the blood plasma (T1/2) was 10 h. Conclusion — The recommended daily dose of the beetroot powder is 16 g, which is equivalent to 400 mg of NOx. Considering pharmacokinetic characteristics, the data indicated that the beetroot formulation is able to boost NO levels after being added to the diet and may be used to normalize the level of NOx in the blood and tissues to compensate for pathological changes in synthesis or bioavailability of endogenous NO.