(all-e)-phytoene and Skin-Neoplasms

This paper describes the development of the use of carotenoid pigments in the treatment of light-sensitive skin diseases. It also discusses the animal and human studies involved in determining whether carotenoids have any anti-cancer activity. The possible mechanisms of carotenoid photoprotective and anti-cancer actions are briefly discussed.

Topics: 9,10-Dimethyl-1,2-benzanthracene; Adolescent; Adult; Animals; Bacteria; Bacterial Physiological Phenomena; beta Carotene; Canthaxanthin; Carotenoids; Child; Child, Preschool; Diet; Humans; Infant; Light; Neoplasms; Neoplasms, Experimental; Photochemistry; Photosensitivity Disorders; Porphyrias; Protoporphyrins; Skin Diseases; Skin Neoplasms; Sunburn; Sunlight; Ultraviolet Rays

Epidemiological investigations have shown that cancer risk is inversely related to the consumption of green and yellow vegetables and fruits. Since beta-carotene is present in abundance in these vegetables and fruits, it has been investigated extensively as a possible cancer preventive agent. However, various carotenoids that coexist with beta-carotene in vegetables and fruits also have anticarcinogenic activity. Some of them, such as alpha-carotene, showed higher potency than beta-carotene in suppressing experimental carcinogenesis. Thus, we have carried out more extensive studies on cancer-preventive activities of natural carotenoids, which found that lycopene and lutein had potent anticarcinogenic activity. In the present study, the cancer-preventive activity of phytoene was also confirmed biotechnologically when mammalian cells producing phytoene were resistant to H-ras-induced cell transformation. Further studies on various natural carotenoids besides beta-carotene should be continued to obtain more information about the potential of natural carotenoids in the field of cancer prevention.

Topics: 3T3 Cells; Animals; Anticarcinogenic Agents; Carotenoids; Genes, ras; Liver Neoplasms, Experimental; Mice; Rats; Rats, Sprague-Dawley; Skin Neoplasms

Mice were given either beta-carotene or either of two carotenoids with no vitamin A activity--canthaxanthin or phytoene--or placebo. Skin tumors were induced in each group by each of three methods: (1) UV-B (290--320 nm); (2) dimethylbenz(a)anthracene (DMBA)/croton oil applications; (3) DMBA followed by low-dose UV-B. For tumors induced by UV-B alone, beta-carotene-phytoene- and canthaxanthin-treated mice developed fewer tumors per mouse, with a delay in tumor appearance, than did control mice. For tumors induced by DMBA/croton oil or DMBA/UV-B, mice receiving beta-carotene showed a significant difference in tumor numbers and appearance time from placebo mice; phytoene and canthaxanthin treatment had no effect.

Topics: 9,10-Dimethyl-1,2-benzanthracene; Animals; beta Carotene; Canthaxanthin; Carcinoma, Squamous Cell; Carotenoids; Croton Oil; Female; Mice; Mice, Inbred Strains; Neoplasms, Experimental; Neoplasms, Radiation-Induced; Papilloma; Skin Neoplasms; Ultraviolet Rays