α-Carotene

α-Carotene, a precursor of vitamin A, is used as an anti-metastatic agent or as an adjuvant for anti-cancer agents. α-Carotene is isolated from yellow-orange and dark-green vegetables^[1][2]. In Vitro: α-Carotene (0.5-2.5 μM; 24 hours) significantly increases protein expression of TIMP-1 and TIMP-2 in a concentration-dependent manner in LLC cells. AC (0.5-2.5 μM) significantly increases PAI-1 protein expression. α-Carotene (2.5 μM) also significantly inhibits integrin β1-mediated phosphorylation of focal adhesion kinase (FAK) which then decreased the phosphorylation of MAPK family^[2].
α-Carotene (0.5, 1, 2.5 μM; 48 hours) significantly and concentration-dependently inhibits invasion of LLC during 48 h of incubation^[2].
α-Carotene (0.5, 1, 2.5 μM; 24 hours) significantly decreases activities of MMP-9, -2 and uPA in concentration-dependent manner in LLC cells^[2].
α-Carotene (2, 5, 10 μM; 7 days) inhibits the proliferation of the human neuroblastoma cell line GOTO in a dose- and time-dependent manner. α-Carotene (5 μM; 48 hours) halts the cell cycle at the G0/G1 phase concomitantly with a reduction in the mRNA expression of the protooncogene N-Myc^[3].
In Vivo: α-Carotene (5 mg/kg; oral; twice a week; for additional 3 weeks) alone significantly decreases lung metastasis without affecting primary tumor growth^[2].