Bioactivities of Sargassum elegans, Bryopsis myosuroides, Callophyllis variegata seaweeds on diabetes and obesity-related biochemical parameters: A comparative in vitro study

Diabesity’ is the occurrence of diabetes in the presence of obesity. Numerous reports have shown that seaweeds possess beneficial biological activities. This study assessed the effects of three seaweeds Bryopsis myosuroides (green), Callophyllis variegata (red), and Sargassum elegans (brown), on diabetes and obesity-related parameters in vitro. The antioxidant potential, carbohydrate and lipid digestive enzyme inhibitory activity, and glucose uptake activities of ethanolic and sulphated polysaccharides (SPs) rich extracts were evaluated. The SP-rich or ethanolic extracts of S. elegans showed the greater inhibition of 2,2-diphenyl-1-picrylhydrazyl (DPPH) (IC₅₀ 46.6 ± 1.00 g/mL), hydroxyl radical (OH) (IC₅₀ 353.70 ± 2.01 μg/mL), and nitric oxide (NO) (IC₅₀ 407.5 ± 0.95 μg/mL) compared to other seaweeds. Moreover, the SP-rich extract of S. elegans exhibited higher inhibition of α- glucosidase (IC₅₀ 123.8 ± 1.69 μg/mL), whereas B. myosuroides SP-rich extract had better α-amylase (IC₅₀ 55.7 ± 0.98 μg/mL) and pancreatic lipase inhibitory activities (IC₅₀ 481.1 ± 0.9 μg/mL) compared to other seaweeds. Liquid Chromatography Mass Spectroscopy (LC-MS) was used to identify the compounds present in the seaweed extracts. These include Taxifolin, Amentoflavone-7,4′,4″‘-Trimethyl Ether, Chrysophenol, and Glucotropaeolin, which have been previously reported to possess biological activities beneficial to human health. Although all three seaweeds evaluated in this study demonstrated antioxidant, digesting enzyme inhibitory and glucose uptake activity to different extents, S. elegans (brown) depicted the highest activity in most assays compared to the other seaweeds. However, further research is required to assess the effects of these seaweed extracts on diabetes and obesity via ex vivo and in vivo experimental animal models.