Efficacy of Eisenia bicyclis phlorotannins in the treatment of diabetes and reducing inflammation

Crude phlorotannins from Eisenia bicyclis (CPEb), a common perennial brown seaweed were screened for pharmacological activities such as anti-inflammatory, antioxidant, and antidiabetic effects. Crude Phlorotannins (CPEb) studied by FT-IR, LC-MS, UHPLC, and UV chromatography showed the occurrence of dieckol, 8, 8'-bieckol, fucofuroeckol, and the carotenoid, zeaxanthin (0.5 mg/kg). LPS, an inflammatory mediator, enhanced the production of cytokines such IL-1 (interleukin-1), IL-6 (interleukin-6), IL-8 (interleukin-8), IL-10 (interleukin-10), TNF-α (tumour necrosis factor-α), chemokine CXCL10, and NF-κB (nuclear factor kappa-light-chain-enhancer of activated B cells) in differentiated THP1 macrophage cells. On differentiated human monocytic cell line LPS-induced THP1 cells, CPEb was found to have anti-inflammatory effects by reducing the expression of IL-1, IL-6, IL-8 (1.2 fold), CXCL10, NF-κB, and TNF-α. CPEb promoted 2-NBDG absorption in differentiated C2C12 myotubes under both basal (16.08%) and insulin-stimulated (51.09%) conditions. CPEb increased IRS/AKT-dependent glucose absorption and also activates the AMPK pathway. Anti-α-glucosidase, anti-inflammatory and antioxidant activity of CPEb indicate their role in treating hyperglycemia by scavenging ROS and inflammatory responses. [Display omitted] •Crude Phlorotannin extracts of Eisenia bicyclis (CPEb) reduces hyperglycemia and inflammation.•Presence of dieckol, 8, 8'-bieckol, fucofuroeckol, zeaxanthin in CPEb extracts.•CPEb regulated inflammatory gene expression in differentiated LPS-induced THP1 cells.•CPEb promoted 2-NBDG uptake in C2C12 myotubes under basal and insulin-stimulation.•CPEb activates both IRS/AKT-dependent ad AMPK mediated glucose absorption.