Traditional Korean Doenjang Restores Splenic and NK Cell Function in Cyclophosphamide-Induced Immunosuppressed Rats

Area of Science:

• Immunology
• Food Science
• Nutritional Biochemistry

Background:

• Fermented soybean foods, like Korean doenjang, possess bioactive compounds linked to health benefits.
• Doenjang consumption is associated with protection against various health issues, including immunosuppression.
• Understanding the immunomodulatory effects of regional doenjang varieties is crucial for its functional application.

Purpose of the Study:

• To investigate the immunoenhancing effects of doenjang from four Korean regions.
• To evaluate doenjang's efficacy in mitigating cyclophosphamide (CP)-induced immunosuppression in a rat model.

Main Methods:

• Rats were immunosuppressed using cyclophosphamide (CP) and administered doenjang for four weeks.
• Immune status was assessed through spleen weight, hematological parameters, natural killer cell activity, splenocyte proliferation, and cytokine levels (IL-2, IL-12, IFN-γ).
• Mitogen-activated protein kinase/nuclear factor kappa B signaling pathways and splenic histology were analyzed.

Main Results:

• Doenjang administration restored spleen weight and normalized white blood cell, lymphocyte, neutrophil, and monocyte counts.
• Enhanced immune responses were observed, including increased natural killer cell activity and splenocyte proliferation.
• Elevated levels of IL-2, IL-12, interferon-γ, and immunoglobulin G were detected, alongside the recovery of suppressed signaling pathways and improved splenic structure.

Conclusions:

• Regional varieties of doenjang effectively counteract CP-induced immune dysfunction in rats.
• Doenjang demonstrates significant potential as a functional dietary intervention for immune support.