Antitumor effect of bacterial lipopolysaccharide (LPS) alone and in combination with lentinan on MH-134 tumors in C3H/He mice.

Using C3H/He mice, the antitumor effect of lipopolysaccharide (LPS) alone and in combination with Lentinan extracted from Lentinus edodes was studied. The influence of LPS on cellular immunity and the antitumor effect of the tumor necrosis factor (TNF) were also examined. LPS, which was administered into mice with tumor, induced hemorrhagic necrosis of the tumor within 48 h, demonstrating a high antitumor effect. When LPS was used in combination with Lentinan, the tumor growth was significantly inhibited as compared to that in the control mice. The combination of LPS and Lentinan prevented a decrease in the delayed type hypersensitivity in tumor bearing mice. Application of rabbit serum containing TNF resulted in hemorrhagic necrosis of the tumor within 48 h, as with LPS.