Chronic administration of Norwegian Ascophyllum nodosum phytocomplex inhibits high-fat-diet-induced obesity in male rats

Several biologically active compounds are present in seaweeds that show a wide range of biological properties, such as antibiotic, anti-inflammatory, antioxidant, cytotoxic, antitumour and anti-obesity activities. The aim was to evaluate the anti-obesity effects of chronic treatment with Norwegian Ascophyllum nodosum phytocomplex in rats. We also investigated the effects of this phytocomplex on blood glucose and serum lipid levels, and α-amylase, lipase, alanine aminotransferase and aspartate aminotransferase activities. Five groups of male Sprague-Dawley rats were fed for 8 weeks with standard diet, highfat diet (HFD) or HFD plus three different doses of Norwegian A. nodosum phytocomplex (HFD Low, HFD Medium, HFD High). Feeding with HFD resulted in increased body weight and deposition of visceral and abdominal white adipose tissue. These effects were significantly reduced by supplementation with high doses of A. nodosum phytocomplex in the feed, which suggests a potent anti-obesity activity of this phytocomplex. Increased serum levels of triglycerides and α-amylase activity were observed in rats fed with HFD at sacrifice. These were inhibited in a dose-dependent manner by feeding with the added A. nodosum phytocomplex in HFD Medium and HFD High. Increased liver and kidney weights were also inhibited in a dose-dependent manner by added A. nodosum phytocomplex, with significant effects at the highest phytocomplex dose. Rats fed with HFD showed a changed, irregular, liver morphology, increased infiltration of inflammatory cells and increased intravascular spaces compared to controls. These effects were partially corrected by HFD High, which suggests potent anti-inflammatory activity of the A. nodosum phytocomplex.