Małgorzata Zielińska-Przyjemska

In vitro effects of beetroot juice and chips on oxidative metabolism and apoptosis in neutrophils from obese individuals

Oxidative stress and inflammation are involved in the development of obesity. Beetroot (Beta vulgaris var. rubra) is a food ingredient containing betalain pigments that show antioxidant activity. The in vitro effect of beetroot juice and chips on oxidative metabolism and apoptosis in neutrophils from obese individuals has been investigated. Fifteen obese women (aged 45 ± 9 years, BMI >30 kg/m2) and nine healthy controls (women, aged 29 ± 11 years, BMI = 22.2 ± 1.6 kg/m2) were examined. The investigated products were used as concentrates and after transport and digestion in an artificial gastrointestinal tract. Neutrophil oxidant production, in response to phorbol 12‐myristate 13‐acetate, was characterized by luminol‐dependent chemiluminescence and a flow cytometric dichlorofluorescin oxidation assay. Caspase‐3 activity, a marker of apoptosis, was measured by cleavage of the fluorogenic substrate Ac‐DEVD‐AMC. Neutrophils from obese individuals had a significantly higher ROS production compared with the controls (p < 0.05). Beetroot products inhibited neutrophil oxidative metabolism in a concentration‐dependent manner. Also observed were the pro‐apoptotic effects of beetroot at a concentration range of 0.1–10% in 24 h culture of stimulated neutrophils. These natural products (in both the liquid and solid state) have antioxidant and antiinflammatory capacity, and could be an important adjunct in the treatment of obesity. Copyright

Citrus Fruit Flavonoids Influence on Neutrophil Apoptosis and Oxidative Metabolism

Citrus flavonoids are dietary antioxidants that may protect against oxidative stress linked to inflammation and reduce the risk of macromolecule damage caused by free radicals. Three citrus flavonoids – naringin, naringenin and hesperidin – have been examined for their ability to activate caspase‐3, a marker of apoptosis execution, in human polymorphonuclear neutrophils in vitro, stimulated and non‐stimulated with phorbol 12‐myristate 13‐acetate. The flavonoid potency to reduce reactive oxygen species generation was also assessed in measurements of superoxide radical and luminol dependent chemiluminescence. The caspase‐3 activity depended on the time of flavonoid treatment and was increased markedly in phorbol‐treated cells incubated with flavonoids for 24 h. Hesperidin at a concentration of 100 µm exerted the strongest stimulating effect on the enzyme (137% of control). Flavonoids inhibited the neutrophil ability to generate superoxide radical and 10–100 µm hesperidin appeared the most active phytochemical. The antioxidant capacity of the examined flavonoids was most prominently expressed in the chemiluminescent measurements. The obtained results suggest that reactive oxygen species may inhibit apoptosis via caspase‐3 inhibition and the antioxidant action of citrus flavonoids may reverse this process. Copyright

The Beetroot Component Betanin Modulates ROS Production, DNA Damage and Apoptosis in Human Polymorphonuclear Neutrophils

The aim of this study was to evaluate the effect of betanin, one of the beetroot major components, on ROS production, DNA damage and apoptosis in human resting and stimulated with phorbol 12‐myristate13‐acetate polymorphonuclear neutrophils, one of the key elements of the inflammatory response.