OBJECTIVETo study the influence of canthaxanthin on D-galactose induced osseous changes of rat.

METHODSForty-five six-week-old Wistar male rats were randomly divided into model group, canthaxanthin group and young control group. In addition, 15 sixteen-month-old Wistar male rats were used as old control group. Model group and canthaxanthin group were given injections of D-galactose for 5 months (20 mg/kg/once per-day) to cause aging of rat. Then routine osseous parameters were tested and compared among the 4 groups.

RESULTSCompared with young control group, the BMD, parameters of structural mechanics and biomechanics, bone calcium, manganese, magnesium and the content of hydroxyproline in the model group decreased significantly (P < 0.01), however, the content of bone phosphorus, the activity of bone and serum ALP increased significantly (P < 0.01). Those changes of the model group were the same as the old control group,but the changes in the canthaxanthin group significantly differed with the model group (P < 0.01).

CONCLUSIONThe high does of D-galactose intake can cause aging and osteoporosis at the same time in rat, but canthaxanthin can prevent and inhibit D-galactose induced osseous changes.

Alkaline Phosphatase ; blood ; Animals ; Biomechanical Phenomena ; Bone Density ; drug effects ; Bone and Bones ; chemistry ; drug effects ; Calcium ; analysis ; Canthaxanthin ; pharmacology ; Galactose ; toxicity ; Male ; Malondialdehyde ; blood ; Rats ; Rats, Wistar ; Superoxide Dismutase ; blood

OBJECTIVETo investigate the effects of various carotenoids on the proliferation, cell cycle, apoptosis and expression of bcl-2 gene in breast cancer cell MCF-7.

METHODSTime and dose effects of individual carotenoids were detected using the MTT assay. The effects of individual carotenoids on cell cycle and the apoptosis were observed by flow cytometry. The expression of bcl-2 mRNA gene was detected using the RT-PCR method.

RESULTSAll 4 carotenoids tested inhibited the proliferation of MCF-7 cell line, but with different potencies. beta-carotene and lycopene were the most active inhibitors (inhibition rate 88.2% and 87.8%, respectively) followed by zeaxanthin and astaxanthin. All 4 carotenoids did not induce cell apoptosis. Cell cycle progression was blocked at G(2)/M phase with 60 micromol/L lycopene and at G(0)/G(1) phase with 60 micromol/L zeaxanthin dipalmitate. Carotenoids down regulated bcl-2 gene expression.

CONCLUSIONCarotenoids could inhibit the proliferation of human beast cancer MCF-7 cell line in vitro and the action of carotenoids may be worked through different pathways.

Breast Neoplasms ; drug therapy ; genetics ; pathology ; Canthaxanthin ; pharmacology ; Carotenoids ; pharmacology ; Cell Cycle ; drug effects ; Cell Division ; drug effects ; Gene Expression Regulation, Neoplastic ; drug effects ; Humans ; Proto-Oncogene Proteins c-bcl-2 ; genetics ; RNA, Messenger ; drug effects ; genetics ; metabolism ; Reverse Transcriptase Polymerase Chain Reaction ; Tumor Cells, Cultured ; Xanthophylls ; Zeaxanthins ; beta Carotene ; analogs & derivatives ; pharmacology