Safety of astaxanthin-rich fraction of Haematococcus pluvialis microalgae

Abstract

Astaxanthin, is a valuable component of a natural origin, is promising as a food supplement worldwide. The principle commercial productive source of astaxanthin is the green microalgae Haematococcus pluvialis (H. pluvialis). The present study was aimed to investigate the acute and chronic dietary supplementation of an astaxanthin-Rich Fraction (ARF) of H. pluvialis .The extraction of H. pluvialis fine powder with dichloromethane: methanol (3:1, V/V) revealed 6.1% containing all-trans-astaxanthin (10.85 mg/g, crud extract) as quantified by HPLC‎. While, the ARF fractionated by column chromatography contains all-trans-astaxanthin (‎16.21 mg/g of astaxanthin). The LD50 of the biomass was greater than 5000mg/kg body weight for 24 h. In chronic toxicity study, rats and mice (15/sex/group) were supplemented daily for three continuous months with 500 mg /kg /bodyweight /day with ARF. The ARF supplementation was associated with yellow color staining of fur and feces. Various blood and chemical parameters were included in this study as profile of blood picture (CBC), hepatic enzymes, total bilirubin (TB), renal tests, albumin, and glucose levels. Examination of liver, kidney and heart architectures was also performed. The exposing of the two sexes of mice and rats to 50 mg /kg/day of ARF did not exhibit any toxicity symptoms and no mortality, no effect on the levels of blood chemistry and biomarkers as well as pathological examination. So, it could be concluded that, ARF is safe at the dose 50mg/kg in chronic toxicity, suggesting its promising benefits as food additives beside its usefulness as a therapeutic candidate against different prospective illness.