الفهرس 
Chemical composition of BAOnly 14 pages are availabe for public view
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Abstract
Brown algae (BA) belongs to the group Heterokontophyta, a large group of eukaryotic organisms distinguished most prominently by having chloroplasts surrounded by four membranes. In Egypt, BA is naturally spread over large areas of marine beaches. The present study aims to determine the chemical composition and bioactive compounds in BA samples collected from the shores of the Egyptian Seas and to investigate the effect of brown algae (Sargassum subrepandum) ethanolic extract (BAE) on obesity complications induced by a high-fat diet in rats. Results indicated that carbohydrates were the largest compound (60.59%) followed by Dietary fiber (48.78 %), ash (19.45%), crude fiber (7.14%), total protein (4.02%), and crude fat (0.82%). Also, polysaccharides were the largest compound followed by phenolics, tannins, carotenoids, and flavonoids. β-carotene assay (BCA) indicated that ethanol extract (EtE) recorded the highest antioxidant activity followed by methanol extract (MeE) and water extract (AqE). The values of EtE extract are coming well i.e. closing to the line of 50 mg α-tocopherol followed by MeE and AqE, respectively. Also, AqE possessed the highest free radical scavenging activity (FRSA). For Half-maximal Inhibitory Concentration )IC50(, the AqE, EtE, and MeE recorded 19.92, 10.41, and 12.52 μg/mL, respectively. The IC50 of BHT (standard) was 7.78 μg/mL. The BCA and FRSA of different tested extracts and standards were in the following order: standards (BHT/ α-tocopherol) >EtE >MeE >AqE. the effect of brown algae (Sargassum subrepandum) ethanolic extract (BAE) on obesity complications induced by high-fat diet in rats, Thirty six rats were divided into two main groups, the first group (group 1, 6 rats) still fed on basal diet and the other main group (30 rats) was with high-fat diet (HFD) for 8 weeks which classified into five subgroups as follow: group (2), fed on HFD as a positive control; group (3), fed on HFD containing 0.25 % BAE; group (4), fed on HFD containing 0.50 % BAE; group (5), fed on HFD containing 0.75 % BAE and group (6), fed on HFD containing 1.0 % BAE. The results showed rats of the normal group increased in their amount by 90.11% when compared to the baseline. Rats of the obese group increased by the rate of 147.02% when compared to the control (- v) group. Also, the addition of 0.25, 0.50, 0.75 to 1.00% of BAE induced a significant (p≤0.05) decrease in the bodyweight of the obese rats when compared to the control (+ v) group. Also, BAE was effective in protecting against obese complications including inhibiting hepatotoxicity through liver serum enzymes-lowering activity, improvement of the serum immunological parameters, and decreasing rate on the formation of MDA in serum, in evidence of lipid peroxidation and oxidative stress. In conclusion, Brown algae extracts (BAE) contain several classes of phytochemicals with other compounds that are responsible for different biological activities including antioxidant and radical scavenging activities. Therefore, we recommended brown algae powder and/or extracts (BAE) by concentrations ranging 0.25-1.0 % amount to be included in daily diets, drinks, food supplementation, and pharmacological formulae.