Effect of Passiflora setacea juice and its phenolic metabolites on insulin resistance markers in overweight individuals and on microglial cell activity

Abstract

Passiflora setacea (PS) is a species of wild Brazilian passion fruit, rich in bioactive compounds. Scientific evidence suggests that food rich in polyphenols can modulate inflammation, thereby playing an important role in preventing chronic non-communicable diseases, such as type 2 diabetes (DT2) and cardiovascular diseases (CVD). This study aimed to investigate the effect of PS consumption on metabolic and inflammatory biomarkers in overweight male volunteers and to identify the underlying mechanism of action using an in vitro study using phenolic metabolites isolated from the plasma of volunteers at physiologically relevant concentrations. Volunteers participated in a double-blind, placebo-controlled (PB) study with two phases: phase I (acute study) and phase II (chronic study). In phase I, 15 volunteers ingested a single dose of 50 g, 150 g of PS pulp and PB in three different interventions. In phase II, nine volunteers ingested 50 g of PS or PB for 14 days. Blood samples were collected before (T0 h) and 3 h (T3 h) (phase I) or 15 days after (phase II) ingestion of PS or PB. Blood biochemical markers, HOMA IR, and inflammatory markers were analyzed and data on BMI, waist circumference, and consumption of polyphenol-rich foods were collected. Phenolic metabolites were extracted from plasma by solid-phase separation and were used to treat BV-2 cells stimulated by LPS or anacardic acid to assess p50, p65 and PPAR-γ activation. It was observed that the consumption of a single dose of PS juice significantly reduced basal insulin levels and HOMA IR. After prolonged consumption for two weeks, PS contributed to the reduction of circulating levels of IL-6. BV-2 cells treated with PS phenolic metabolites showed increased PPAR-γ activity, which resulted in an anti-inflammatory and anti-diabetic effect of PS metabolites. In conclusion, PS juice consumption exerts beneficial effects on inflammatory markers in overweight individuals, being a possible and important tool in the prevention of T2D and CVD in risk groups.