Edible red seaweed Campylaephora hypnaeoides J. Agardh alleviates obesity and related metabolic disorders in mice by suppressing oxidative stress and inflammatory response

In-depth analysis of microplastics reported from animal and algae seafood species: Implications for consumers and environmental health

Macroalgae are able to retain environmental microplastics (MPs). The potential ingestion of MP through Atlantic agar Gelidium corneum and different animal species (hake, glass eels, mussels, topshells, anemones, sea cucumbers) that are seafood resources in Spain, was estimated from published MPs data calculating daily dose and annual ingestion rate. The study region was Asturias (SW Bay of Biscay). Lower MP ingestion rate from algae than from any animal analysed revealed a reduced risk of MP intake, probably because the alga is harvested from quite clean subtidal zones. However, MP bioconcentration in Atlantic agar was higher than in sea cucumbers, mussels or glass eels. Compared with other algae, G. corneum ranked the highest for MP retention rate, perhaps for its intricate branching and gelatinous surface, suggesting a possible use in MP bioremediation. More experimental studies in MP uptake by macroalgae are recommended to understand their implication in the accumulation of this pollutant.

Edible Red Seaweed Hypnea asiatica Ameliorates High-Fat Diet-Induced Metabolic Diseases in Mice

Metabolic diseases, including obesity, diabetes, and fatty liver disease, are dramatically increasing around the world. Seaweed is low in calories and rich in many active ingredients that are necessary for maintaining good health, and is expected to be effective for preventing metabolic diseases. The purpose of this study was to examine the effects of a traditional Japanese edible seaweed Hypnea asiatica (H. asiatica) on obesity, using a mouse model. H. asiatica was dried and powdered, mixed with a high-fat diet, and fed to male C57BL/6J mice for 13 weeks. On the last day of the experiment, blood samples were collected under anesthesia and biochemical parameters such as lipids and adipokines were measured. Liver and adipose tissue were excised, weighed, and oxidant/antioxidant parameters were measured. Some mice were perfused with a fixative solution containing formalin, and tissue specimens were prepared. A glucose tolerance test was used to assess insulin resistance. The inhibition of lipase activity was evaluated in vitro. Thirteen-week supplementation with H. asiatica suppressed body weight gain, body fat accumulation, and blood glucose levels. H. asiatica also improved fatty liver and hypercholesterolemia, and reduced the oxidant and inflammatory parameters of serum and liver. H. asiatica increased fecal triglyceride excretion and polyphenol-rich ethanol extract of H. asiatica inhibited lipase activity in vitro. These results suggest that polysaccharides and polyphenols in H. asiatica may ameliorate obesity and diabetes by inhibiting intestinal fat absorption and reducing oxidative stress and inflammation. H. asiatica may be useful in preventing metabolic diseases such as obesity, diabetes, and fatty liver.

The anti-obesity and anti-diabetic effects of the edible seaweed Gloiopeltis furcata (Postels et Ruprecht) J. Agardh in mice fed a high-fat diet

Obesity and diabetes are serious, chronic medical conditions associated with a wide range of life-threatening conditions. The aim of this study was to investigate the effects of the edible red seaweed Gloiopeltis furcata (Postels et Ruprecht) J. Agardh (G. furcata) on the development of obesity, diabetes and related metabolic diseases in mice. Male C57BL/6J mice were fed a high-fat (HF) diet (60% energy as fat), or an HF diet containing 2% (w/w) or 6% powdered G. furcata for 13 weeks. Polysaccharides of G. furcata were isolated and their anti-inflammatory effects were evaluated in lipopolysaccharide-stimulated RAW264.7 cells. The HF diet group showed greater weight gain, lipid accumulation in the body and liver, and increased serum levels of glucose and cholesterol in comparison to the normal group fed a normal diet (10% energy as fat). The treatment of HF diet mice with G. furcata reduced these changes and stimulated the fecal excretion of fat. In addition, G. furcata suppressed the HF diet-induced elevation of inflammation and oxidative stress markers in the serum and liver. The isolated sulfated polysaccharide from G. furcata inhibited pancreatic lipase activity and decreased the production of nitric oxide and TNF-α in the murine macrophage cell line RAW264.7. These results show that G. furcata treatment can attenuate obesity, diabetes, hepatic steatosis, and dyslipidemia in mice fed an HF diet, which is associated with inhibited intestinal fat absorption and reduced inflammation and oxidative stress by a sulfated polysaccharide.