Sour cherry seed kernel extract increases heme oxygenase-1 expression and decreases representation of CD3+ TNF-α+ and CD3+IL-8+ subpopulations in peripheral blood leukocyte cultures from type 2 diabetes patients.

The present study evaluates a hypothesis that sour cherry (Prunus cerasus) seed extracts (SCE) modulate CD3+ T lymphocyte activity in ways predictive of potential for uses of SCE in management of inflammatory diseases. Peripheral blood mononuclear cells (PBMC) from 12 type 2 diabetes (T2DM) patients and eight healthy control subjects were cultured 24 h with 100 ng/ml lipopolysaccharide (LPS) to increase inflammatory signaling and co-incubated with 0.5-100 µg/ml SCE. Cultures were evaluated by two-color flow cytometry for percent representation of CD3+ IL8+ and CD3+TNF-α cells which express interleukin-8 (IL-8), and tumor necrosis factor-α, (TNF-α+) respectively, and by enzyme-linked immunoassay for lymphocyte-associated heme oxygenase-1 (HO-1, known to be induced by SCE). SCE dosage ranges of 0.5-100 µg/ml in cell cultures significantly suppressed LPS-increased CD3+TNF-α+ and CD3+IL8+ representation from all participants (p < 0.05), with greater pharmacological effect noted in suppression of CD3+TNF-α+ noted in cells from T2DM patients versus healthy control subjects. These effects correlated with increased HO-1 expression in SCE-treated PBMC from all subjects (p < 0.05). Since TNF-α and IL-8 are diagnostic/prognostic biomarkers for many inflammatory syndromes, the capacity of SCE to down-regulate representation of cells that express them suggests potential for therapeutic use of SCE in T2DM and other diseases.