Abstract:In the present study, the effect of Antarctic krill oil on the bioavailability of the natural astaxanthin extract from green alga (Haematococcus pluvialis) was evaluated using male Wistar rats as model animals, which were randomly divided into the control group, astaxanthin group, krill oil + astaxanthin group and fish oil + astaxanthin group. The experimental group rats were intragastrically administered with the corresponding fat emulsion while the control group rats were given the bile salts solution. The gavage doses were converted according to the daily intake of 2 g krill oil or 2 g fish oil per day and 12 mg astaxanthin per day for adults. The astaxanthin levels in intestinal contents, intestinal villus and serum of rats at different time points after gavage were detected and the bioavailability was evaluated using the serum AUC0-t value. The results showed that the astaxanthin levels in intestinal contents, intestinal villus and serum of rats from krill oil + astaxanthin group and fish oil + astaxanthin group were significantly higher when compared with the astaxanthin group(P<0.05). The peak value of the astaxanthin level in the serum of rats from krill oil + astaxanthin group was (15.8±2.09) μg/L, which was 4.02 times (P<0.05) of that in the fish oil + astaxanthin group [(3.94±0.27) μg/L], and 8.37 times (P<0.05) of that in the astaxanthin group [(1.89±0.26) μg/L]. More importantly, the AUC0-t value of rats from krill oil + astaxanthin group was (108.4±2.34) μg·h/L, which was 4.63 times (P<0.05) of that in the fish oil + astaxanthin group [(23.4±0.46) μg·h/L], and 7.55 times (P<0.05) of that in the astaxanthin group [(14.4±0.21) μgo·/L]. Antarctic krill oil could significantly ameliorate the bioavailability of the natural astaxanthin in rats and the effect is better than that of fish oil. This study would provide scientific guidance and theoretical support for the development of new Antarctic krill oil derivatives.