Previous research has reported that diets rich in anthocyanins can prevent metabolic diseases. Researchers at the Tianjin University of Science and Technology and Beijing Technology & Business University sought to determine the molecular mechanism behind the anti-obesity effects of blackberry and blueberry anthocyanin intake in mice on a high-fat diet.
They divided 60 mice equally into five groups: the first was fed a low-fat diet, the second a high-fat diet, the third a high-fat diet with Orlistat (a drug designed to treat obesity), the fourth a high-fat diet enriched with blackberry anthocyanins, and the fifth a high-fat diet enriched with blueberry anthocyanins.
After 12 weeks, the researchers observed that the consumption of blackberry and blueberry anthocyanins had inhibited weight gain in the supplemented mice by a respective 40.5% and 55.4%.
The anthocyanins had also significantly lowered serum and hepatic lipid levels, and raised hepatic superoxide dismutase and glutathione peroxidase activities, both of which have important antioxidant actions.
Additionally, blackberry and blueberry anthocyanins had "effectively increased" the supplemented mice's levels of faecal short-chain fatty acids (SCFAs), particularly acetic and butyric acids.
They were also found to attenuate the expression of inflammatory markers such as tumour necrosis factor-alpha (TNF-α), interleukin-6, and nuclear factor-kappa B (NF-κB) genes.
Furthermore, the results suggested that blackberry and blueberry anthocyanins had significantly affected the liver's lipid and glucose metabolic pathways, including the insulin-signalling pathway and glutathione metabolism.
The researchers wrote that blackberry and blueberry anthocyanins "ameliorated diet-induced obesity by alleviating oxidative stress and inflammation, and accelerating energy expenditure".
Anthocyanins, which are essentially the pigments seen in foods such as different types of berries, and vegetables such as eggplant and red cabbage, have been reported by earlier studies To have a cariety of health benefits, including improvements in gut health, systemic inflammation, cognitive performance, and insulin resistance.
Anti-obesity impact of anthocyanins
In the current study, the researchers noted that consuming blackberry and blueberry anthocyanins did not alter the mice's daily food intake but significantly lowered the weight of adipose tissue and retroperitoneal fat.
It also markedly increased their faecal concentrations of acetic, butyric and propionic acids. These SCFAs, especially acetic and butyric acids, presented a balance between fatty acid synthesis, oxidation, and lipolysis.
The researchers concluded: "Our data demonstrate that blackberry and blueberry anthocyanins inhibited body weight gain by 40.5% and 55.4%, respectively.
"Furthermore, blackberry and blueberry anthocyanins significantly reduced serum and hepatic lipids, significantly increased hepatic superoxide dismutase and glutathione peroxidase activities — as well as faecal acetate and butyrate levels — and significantly attenuated the expression of the TNF-α, IL-6, and NF-κB genes.
"Moreover, blackberry and blueberry anthocyanins significantly affected the hepatic lipid and glucose metabolic pathways, including glycerophospholipid metabolism, glutathione metabolism, and the insulin-signalling pathway.
"Therefore, blackberry and blueberry anthocyanins ameliorated diet-induced obesity by alleviating oxidative stress and inflammation, and accelerating energy expenditure."
Source: Oxidative Medicine and Cellular Longevity Volume
"Blackberry and Blueberry Anthocyanin Supplementation Counteract High-Fat-Diet-Induced Obesity by Alleviating Oxidative Stress and Inflammation and Accelerating Energy Expenditure"
Authors: Tao Wu, et al.