Nigerooligosaccharides Augments Mitogen‐Induced Proliferation and Suppresses Activation‐Induced Apoptosis of Human Peripheral Blood Mononuclear Cells

Abstract

Nigerooligosaccharides (NOS), a mixture of nigerose and nigerosylmaltooligosaccharides, consists of immunopotentiating oligosaccharides found in foodstuffs. We have previously reported that activation of peripheral blood mononuclear cells (PBMC) in response to concanavalin A (Con A) or a streptococcal preparation of OK‐432 is augmented in healthy young adults and elderly subjects after the intake of NOS‐supplemented syrup. A reappraisal of the data suggests that NOS augments proliferation but partly suppresses activation‐induced apoptosis of PBMC in response to these mitogens. To confirm this hypothesis, PBMC from healthy male subjects were stimulated with Con A or OK‐432 in the presence of nigerose at the concentrations at which it was detected in the blood of subjects who had ingested NOS‐supplemented syrup. Cellular activation, specifically metabolic demand, viability and proliferation, was assessed from glucose consumption, by WST‐1 colorimetry and by 5‐bromo‐2′‐deoxy‐uridine incorporation assay, respectively. The Con A‐induced activation of PBMC in each measurement was significantly augmented by nigerose. OK‐432‐induced decreases in the viability of PBMC were significantly inhibited by nigerose. Stimulation of PBMC with Con A or OK‐432 induced apoptosis, but nigerose suppressed such activation‐induced cell death. These results indicated that nigerose activated PBMC in vitro in a manner similar to the process observed in vivo, providing further evidence for the effectiveness of consumption of NOS‐supplemented syrup.

Key Words :

• Nigerooligosaccharides
• Peripheral blood mononuclear cells
• Metabolic demand
• Proliferation
• Apoptosis