In vivo and in vitro effects of beta-carotene and algae extracts in murine tumor models.
Phycotene, an algae extract with known antineoplastic activity, was demonstrated to prolong, but not sustain, an increased survival rate in a murine fibrosarcoma model when it was combined with immunotherapy. It was further shown that splenocytes from phycotene and beta-carotene-treated survivors could not confer protection to a fresh tumor cell challenge in virgin mice after adoptive transfer. In a series of cytotoxicity assays, phycotene combined with immunization was demonstrated to enhance cell-mediated and complement-dependent cytotoxicity in the first 14-21 days. However, after 21 days, the phycotene and immunization groups exhibited a decreased ability to mediate immune cytotoxicity compared with immunization-only controls. This may serve to explain the in vivo findings that while survival was increased early on in active immunization and phycotene-treated mice, it eventually dropped to the level of the active immunization controls.
Combs
W
W
Department of Surgery, Brigham and Women's Hospital, Boston, MA.
Sonis
S T
ST
Fitzgerald
J
J
Tracy
C
C
Wilson
R
R
D000818:Animals; D002338:Carotenoids / Q000627:therapeutic use*; D004195:Disease Models, Animal; D005354:Fibrosarcoma / Q000188:drug therapy / Q000628:therapy*; D007167:Immunotherapy; D066298:In Vitro Techniques; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D010936:Plant Extracts / Q000627:therapeutic use*; D019207:beta Carotene
D010936:Plant Extracts; C052392:phycotene; D019207:beta Carotene; D002338:Carotenoids