A combination of flaxseed oil (FO) and the carotenoid astaxanthin (ASX) might offer potential to help treat non-alcoholic fatty liver disease (NAFLD), according to the authors of a study published in the journal Nutrients.
“FO plus ASX can reduce hepatic steatosis, triacylglycerol, cholesterol and oxidative stress, suggesting that this may reduce NAFLD induced by a high-fat diet,” concluded the team of Chinese researchers behind the study. “Thus, flaxseed oil + astaxanthin may be promising for hepatoprotection but more work is required in additional NAFLD models to confirm this hypothesis.”
Lower fat accumulation
The Chinese team fed 40 rats one of four different high-fat (20% fat) diets: 100% lard as a control; 75% lard and 25% FO and ASX (L-FO+ASX); 50% lard and 50% FO and ASX (M-FO+ASX); and 100% FO and ASX (H-FO+ASX).
The flax oil and astaxanthin mixture contained one gram of ASX per 1 kilogram of FO, the authors added.
After 10 weeks on the diets,rats were killed and their livers analysed. All rats fed FO+ASX mixtures were found to have lower levels of fatty liver issues, with M-FO+ASX and H-FO+ASX showing significant effects on triacylglycerol and cholesterol levels in the liver.
Steatosis in the livers of the all-lard control group reached over 30%, while livers from rats in the H-FO+ASX group was less than half this level.
Similarly, hepatic trigyceride levels in the H-FO+ASX group were around a third of those in the control group.
“Reducing hepatic lipid accumulation is key (an important mechanism) for the combination of FO and ASX to reversing initial NAFLD,” the researchers wrote in their study.
The researchers highlighted α-linolenic acid (ALA) as a key ingredient in flaxseed oil in terms of helping to combat fatty liver. They noted ALA can suppress a number of lipogenic enzymes, and can help boost the activity of fatty acid metabolism receptors.
“Thus, the combination of FO and ASX may decrease hepatic triacylglycerol and cholesterol by suppressing hepatic lipogenesis and cholesterol synthesis as well as by promoting lipid oxidation,” wrote the researchers.
Higher antioxidant levels in FO+ASX rats
They also found animals on the H-FO+ASX diet had significantly higher levels of antioxidants including superoxide dismutase, glutathione, glutathione peroxidase and catalase.
“More antioxidant activity and reduced lipid peroxidation suggested alleviation of hepatic oxidative stress,” they wrote.
“Although FO may reduce hepatic [glutathione] depletion by lowering cholesterol and triacylglycerol, the potent antioxidant properties of ASX should be mainly responsible for the dramatic hepatic oxidative stress improvement effect after FO + [lard] consumption,” the researchers added.
Published online ahead of print, doi: 10.3390/nu9030271
“A Combination of Flaxseed Oil and Astaxanthin Improves Hepatic Lipid Accumulation and Reduces Oxidative Stress in High Fat-Diet Fed Rats”
Authors: Xu, J.; Rong, S.; Gao, H.; Chen, C.; Yang, W.; Deng, Q.; Huang, Q.; Xiao, L.; Huang, F.