Cancer Protective Action of Polysaccharide, Derived from Red Microalga Porphyridium Cruentum—A Biological Background

ABSTRACT

The cell wall sulfated polysaccharide of the red microalga Porphyridium cruentum (Rhodophyta) (PcrPSH) exhibited strong antitumor activity against Graffi myeloid tumor in hamsters both in vitro and in vivo. When tested in vivo, depending on the concentration and the way of application, this polysaccharide decreased transplantability in all experimental groups till 20 days of observation and mortality rate. The tumor growth was retarded and the mean survival time was prolonged with 10 - 16 days. Applied in in vitro experiments the PcrPSH increased both—spreading and phagocytic ability of peritoneal macrophages from healthy and Graffi tumor bearing hamsters in a dose—dependent manner. Primary Graffi tumor cell culture, cultivated in the presence of PcrPSH showed significant decrease of cell viability, determined by MTT test, while in cells derived from bone marrow it was increased at the same conditions of cultivation and concentration of polysaccharide. Primary Graffi tumor cell culture, treated with PcrPSH showed the appearance of a characteristic DNA ladder on agarose gel electrophoresis, which is a biochemical hallmark of apoptosis. The manifested anticancer activity of PcrPSH could be associated with its immunostimulating action as well as with direct cytotoxic properties. Based on these results, we could suggest that the tested algal PcrPSH is a promising candidate as an antitumor agent. Further studies will be done to clarify the mechanisms of a biological action of PcrPSH.

Keywords:

• apoptosis
• Graffi myeloid tumor
• macrophages
• Porphyridium cruentum
• red microalga