Combs W, Sonis ST, Fitzgerald J, Tracy C, Wilson R. In vivo and in vitro effects of beta-carotene and algae extracts in murine tumor models.
Nutr Cancer 1989;
12:371-80. [PMID:
2608541 DOI:
10.1080/01635588909514038]
[Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
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.
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