Evaluation of hepatoprotective and antioxidant activity of astaxanthin and astaxanthin esters from microalga-Haematococcus pluvialis.

Effect of isolated astaxanthin (ASX) and astaxanthin
esters (ASXEs) from green microalga-Haematococcus
pluvialis on hepatotoxicity and antioxidant activity against carbon
tetrachloride (CCl4) induced toxicity in rats was compared
with synthetic astaxanthin (SASX). ASX, ASXEs, and SASX,
all dissolved in olive oil, fed to rats with 100 and 250 μg/kg b.w
for 14 days. They were evaluated for their hepatoprotective and
antioxidant activity by measuring appropriate enzymes.
Among the treated groups, the SGPT, SGOT and ALP levels
were decreased by 2, 2.4, and 1.5 fold in ASXEs treated group
at 250 μg/Kg b.w. when compared to toxin group. Further,
antioxidant enzymes catalase, glutathione, superoxide dismutase
and lipid peroxidase levelswere estimated in treated groups,
their levels were reduced by 30–50 % in the toxin group, however
these levels restored by 136.95 and 238.48 % in ASXEs
treated group at 250 μg/kg. The lipid peroxidation was restored
by 5.2 and 2.8 fold in ASXEs and ASX treated groups at
250 μg/kg. The total protein, albumin and bilirubin contents
were decreased in toxin group, whereas normalized in ASXEs
treated group. These results indicates that ASX and ASXEs
have better hepatoprotection and antioxidant activity,
therefore can be used in pharmaceutical and nutraceutical applications
and also extended to use as food colorant.