Antitumor activity of sediment fractions from Fusobacterium nucleatum culture supernatant.

The present study was carried out to examine antitumor activity of extracts from Fusobacterium nucleatum culture supernatant. The extracts were prepared as sediment fractions by ethanol precipitation, isoelectric point precipitation and proteolytic enzyme-treatment. An ethanol fraction obtained by addition of 60% ethanol to the culture supernatant showed effective antitumor activity to ascites and solid type tumor of Ehrlich carcinoma and also to solid type tumor of Sarcoma 180 in ICR mice. A sediment fraction extracted by adjusting an ethanol fraction to pH 4.0 was also found to give distinctive antitumor activity to Ehrlich ascites carcinoma. This fraction was further treated with pronase to eliminate free nucleotides, and then ultrafiltrated. The pronase-treated fraction gave better antitumor activity to both ascites and solid type tumor of Ehrlich carcinoma or Sarcoma 180. The ratios (%) indicating antitumor activity ranged from 131 to 188% even at 4-8 weeks after the tumor cell inoculation.