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 2008 John Wiley & Sons, Ltd.