Correction of Aberrant NADPH Oxidase Activity in Blood-Derived Mononuclear Cells from Type II Diabetes Mellitus Patients by a Naturally Fermented Papaya Preparation

Abstract Supplementation of standardized fermented papaya preparation (FPP) to adult diabetic mice improves dermal wound healing outcomes. Peripheral blood mononuclear cells (PBMC) from type II diabetes mellitus (T2DM) patients elicit a compromised respiratory burst activity resulting in increased risk of infections for the diabetic patients. Aims: The objectives of the current study were to determine the effect of FPP supplementation on human diabetic PBMC respiratory burst activity and to understand underlying mechanisms of such action of FPP. Results: When stimulated with phorbol 12-myristate 13-acetate, the production of reactive oxygen species by T2DM PBMC was markedly compromised compared to that of the PBMC from non-DM donors. FPP treated ex vivo improved respiratory burst outcomes in T2DM PBMC. FPP treatment significantly increased phosphorylation of the p47phox subunit of NADPH oxidase. In addition, the protein and mRNA expression of Rac2 was potently upregulated after FPP supplemention. The prox...