Biological Activity of <italic>Pityrosporum</italic>. II. Antitumor and Immune Stimulating Effect of <italic>Pityrosporum</italic> in Mice

Abstract

The antitumor activity of Pityrosporum (P. orbiculare, P. ovale, P. pachydermatis, and Pityrosporum sp.) on Ehrlich ascites carcinomas (EACs) implanted into outbred ICR mice was studied. Pityrosporum significantly prolonged the survival of mice, regardless of the administration mode. In the case of P. orbiculare, the maximum survival time was 32.3 days on the mean and was obtained by injection ip of 1 mg (dry weight) P. orbiculare for 7 consecutive days following inoculation of the tumor cells. In contrast, the mean survival time of the nontreated mice was 14.9 days. For the investigation of the mechanisms of this antitumor activity, an examination was done on the ability of intracellular killing of Salmonella typhimurium and oxygen intermediate release by Pityrosporum, as elicited by mouse peritoneal exudate cells (PEC) or mouse peritoneal macrophages (PM). With about 40-minute incubation, 60-80% of S. typhimurium phagocytized by Pityrosporum elicited PEC or PM or were killed. The amounts of superoxide released from Pityrosporum-elicited cells were 1.5 times higher than those of P. acnes-elicited ones. Furthermore, three serum proteins (LA, LB, and LC), which closely related to the anti-tumor activity of immunomodulators, increased in the mice given Pityrosporum. These results indicated that the better survival rate seen in the case of Pityrosporum administration to mice with an implanted EAC may relate to the potent activation of phagocytes and to the increase in serum proteins LA, LB, and LC.