The efficacy of zymosan in pro-inflammatory cytokine production by peritoneal macrophages of melanoma-bearing mice

Zymosan, a polysaccharide derived from yeast cell wall, has been widely applied as a macrophage-activating factor. Application of immunomodulatory compounds as cancer therapeutics has emerged in recent years. The goal of this study was to assess the effect of zymosan in the modulation of pro-inflammatory cytokines in melanoma-bearing mice. C57BL/6 mice were divided into four groups of seven mice including zymosan (Z group), melanoma (M group), zymosan treated melanoma-bearing mice (ZM group), and control (C group). Mice were treated with zymosan (10 μg) for four continuous days. At the end of the last day (25 days after tumor induction), blood samples and peritoneal macrophages were collected and mice were euthanized. The levels of IL-1β and IL-6 were measured in sera by enzyme-linked immunosorbent assay (ELISA). The expression of messenger RNA (mRNA) levels was analyzed by real-time polymerase chain reaction (RT-PCR). The results showed that zymosan significantly increases both serum release and mRNA levels of IL-1β and IL-6 in mice-bearing melanoma. Phagocytic activity of macrophages increased significantly by zymosan. Thus, our data may suggest that zymosan has a potential activity in cancer regulation and might be used as an adjuvant role in conventional cancer treatment.