Carotenoids in cancer, mastalgia, and AIDS: prevention and treatment--an overview.

In 1980, two carotenoids, beta-carotene (BC) and canthaxanthine (CX) with and without pro-vitamin A activity, respectively, were orally administered to female Swiss albino mice and were found to substantially prevent skin carcinogenesis induced by benzo(a)pyrene (BP). This preventive effect was observed in darkness by means of photocarcinogenic enhancement (PCE) following UV (300 to 400 nm) irradiation. In 1984, the same experiment produced antitumorigenic activity when applied to breast carcinogenesis induced in mice by 8-methoxypsoralen (8-MOP) plus UV-A light and, in 1985, when directed toward gastric carcinogenesis induced in rats by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG). These data suggested a rationale for human intervention to prevent, by carotenoid supplementation, a second primary malignancy after the primary malignancy has been radically excised. In the 1980s, a pilot clinical study (15 cases) showed a longer than expected disease-free interval in all surviving patients. It was also subsequently found that, if treated daily with 20 mg of BC and intermittently with retinol 150 to 300,000 IU daily for seven days just prior to menses, women suffering from cyclical mastalgia were relieved from pain, without any toxic side effects. When BC was given in high daily doses (60 mg) to 60 drug addicts suffering from AIDS-related complex (ARC), they recovered from their objective and subjective symptoms (but not from lymphadenopathy) with improvement in their general health and increased performance status. At higher doses, BC (with or without hyperthermia) was effective even in patients in advanced stages of AIDS. A debate has arisen concerning a recent statement by the U.S. Government that "beta-carotene supplements do not protect Americans against cancer or heart disease, and may actually increase the risk of deadly lung tumors in smokers".

beta-Carotene storage in rat organs following carrier mediated supplementation.

One rat group was supplemented with beta-carotene (BC) both in beadlets and the crystalline form in arachidic oil as a carrier added to standard diet; another rat group was given 1 ml crystalline BC-arachidic oil by gavage twice a week. In both rat groups, each rat ingested 350 mg BC/week for 12 weeks. The animals were then sacrificed and BC levels together with retinyl palmitate presence were assessed by HPLC analysis in liver, lung, kidney, small intestine, mesenteric fat, brain, spleen, stomach and blood plasma. In the first group, high BC storage, ranging from 4.2 to 45.2 nmols/g wet tissue, was found in liver, small intestine, spleen; lesser BC levels were found in lung, kidney, stomach, blood serum; retinyl palmitate was found in liver and lung. In the second group BC levels ranging from 0.5 up to 5,763 nmols/g wet tissue were detected in all organs, except for brain and stomach; the highest levels were in the lung; retinyl palmitate was detected in liver. The lung appeared to be a target organ for BC, as confirmed by its presence in the lungs of control rats fed standard diet and given 1 ml of arachidic oil alone by gavage twice a week.(ABSTRACT TRUNCATED AT 250 WORDS)

Beta-carotene supplementation associated with intermittent retinol administration in the treatment of premenopausal mastodynia.

Twenty-five women, 23-41 year old, suffering from premestrual cyclical mastodynia linked or otherwise to benign breast disease (BBD), with moderate or severe pain at least seven days before each menstrual period, were treated with daily beta-carotene (BC) supplementation associated with intermittent administration of retinol (all-trans-retinol 300,000 IU per day). In this therapy retinol was given for 7 days immediately before each menstrual period. After 6 months' treatment, the results revealed marked reduction in breast pain, and sometime recovery, in 23-41 year old women with no toxic side effects. But no such advantages in 5 women with non-cyclical mastodynia treated as above were found. Above this age range, the advantages appear to be absent. All the women developed a healthy look because of a slight tanning of the skin due to beta-carotene supplementation. These data demonstrated a therapeutic synergism between BC and retinol.