title: Effective inhibition of skin cancer, tyrosinase, and antioxidative properties by astaxanthin and astaxanthin esters from the green alga Haematococcus pluvialis.
abstract: Astaxanthin mono- (AXME) and diesters (AXDE) were characterized and examined for anticancer potency with total carotenoids (TC) and astaxanthin (AX) against UV-7,12-dimethylbenz(a)anthracene (DMBA)-induced skin cancer model in rat. At 200 μg/kg bw, AXDE and AXME reduced UV-DMBA-induced tumor incidences up to 96 and 88%, respectively, when compared to AX (66%) and TC (85%). UV-DMBA has been known to generate high levels of free radicals and tyrosinase enzyme, leading to characteristic symptoms of skin pigmentation and tumor initiation. Intriguingly, ~7-fold increase in tyrosinase and 10-fold decrease in antioxidant levels were normalized by AXDE and AXME as opposed to only ~1.4-2.2-fold by AX and TC, respectively. This result together with the appearance of 72 and 58 ng/mL of retinol in the serum of respective AXE-treated (AXDE + AXME) and AX-treated animals suggested that better anticancer potency of AXEs could be due to increased bioavailability.
authors.affiliation: Plant Cell Biotechnology Department, ‡Biochemistry & Nutrition Department, and #Food Engineering Department, Central Food Technological Research Institute, CSIR , Mysore 570 020, Karnataka, India.
authors.forename: Ambati Ranga
authors.initials: AR
authors.lastname: Rao
authors.forename: H N
authors.initials: HN
authors.lastname: Sindhuja
authors.forename: Shylaja M
authors.initials: SM
authors.lastname: Dharmesh
authors.forename: Kadimi Udaya
authors.initials: KU
authors.lastname: Sankar
authors.forename: Ravi
authors.initials: R
authors.lastname: Sarada
authors.forename: Gokare Aswathanarayana
authors.initials: GA
authors.lastname: Ravishankar
mesh_terms: D015127:9,10-Dimethyl-1,2-benzanthracene; D000818:Animals; D000975:Antioxidants / Q000032:analysis / Q000494:pharmacology*; D001682:Biological Availability; D002273:Carcinogens; D000460:Chlorophyta / Q000737:chemistry*; D004952:Esters / Q000494:pharmacology*; D014442:Monophenol Monooxygenase / Q000037:antagonists & inhibitors*; D051381:Rats; D017208:Rats, Wistar; D012878:Skin Neoplasms / Q000139:chemically induced / Q000473:pathology / Q000517:prevention & control*; D014801:Vitamin A / Q000097:blood; D024341:Xanthophylls / Q000097:blood / Q000493:pharmacokinetics / Q000494:pharmacology
chemical_list: D000975:Antioxidants; D002273:Carcinogens; D004952:Esters; D024341:Xanthophylls; D014801:Vitamin A; D015127:9,10-Dimethyl-1,2-benzanthracene; C005948:astaxanthine; D014442:Monophenol Monooxygenase