PHOTOPROTECTIVE EFFECTS OF DIETARY CANTHAXANTHIN IN ARTEMESIA LONGINARIS

MARCOVAL, M.A,; FENUCCI, J.L.; ESPINO, M.L.; DIAZ, A.C.; ARZOZ, N.S.; VELURTAS, S.M.

BIOCELL

INST HISTOL EMBRIOL-CONICET

Año: 2019 vol. 43 p. 26 - 26

0327-9545

Artemesia longinaris is a species of commercial interest distributed along the South American coast (23-50°S). During the last decades, it has shown an increase in ultraviolet radiation (UVR) above Earth´s surface. While penaeoid shrimps are coastal species that inhabit generally at depths greater than 10m, under cutivation conditions are kept in ponds at 2 m deep, so they are exposed to extreme environmental conditions. Carotenoids are considered bioaccumulative photoprotective compounds in integument of crustaceans, which must be incorporated with diet. Although astaxanthin (Ax) is the main carotenoid, decapods are able to synthesize it from other carotenoids, e.g. canthaxanthin. The aim of this study was to determine the bioaccumulation of carotenoids from a diet added with canthaxanthin on juveniles A. longinaris and its possible protective effects under conditions of stress by UVR. Previous to the experiment with radiation, prawns (1.5±0.3g) were placed during 5 weeks in individual aquaria under controlled conditions of temperature, pH, salinity and photosynthetically active radiation (PAR) under three feeding treatments. One group fed with basal diet (B) (45% protein, 8% lipid, 7% water and 7% ash) and others with 100 (C100) and 300 (C300) mg canthaxanthin Kg-1 diet. After 4 weeks animals were subjected to two radiation treatments, by triplicate: B+PAR (400-700nm), C100 or C300+PAR (400-700nm), and C100 or C300+UVR (280-700nm). Survival varied between 83-100% for PAR treatment, under stress by UVR the C300 treatment showd the same survival than PAR treatment (83%). Concentration of β-carotene and both, free and esterified Ax forms, were significantly higher in prawns fed with C100 and C300+PAR (β-carotene: 5.51±1.01 and 5,63±0,57; free Ax: 2.73±0.51 and 2.78±0.88; esterified Ax: 1.88±0.49 and 1.22±0.49μg g-1, respectively) than B+PAR (β-carotene: 2.86±0.92; free Ax: 1.25043; esterified Ax: 1.04±0.26μg g-1). There were no significant differences between C100 and C300+UVR (values varied between β-carotene: 1.44-1.07; free Ax: 0.78-0.77μg g-1), but these values were significantly lower than those recorded for C100 and C300+PAR, except for esterified Ax (0.58-0.67μg g-1). It can be concluded that canthaxanthin acts as a protector of UVR stress in A. longinaris, through biotransformation and bioaccumulation of carotenoids.