Sulphated glycosaminoglycan isolated from the edible slipper oyster Magallana bilineata (Röding, 1798) attenuates inflammatory cytokines on lipopolysaccharide-prompted macrophages

The slipper oyster Magallana bilineata (Ostreidae) is considered as culinary delicacy among marine bivalves, and a sulphated glycosaminoglycan, 4,6-O-SO₃-β-(1→3)-GalNAcp (unit A) and β-(1→4)-GlcAp (unit B) as principle structural motif containing laterally branched 4-O-SO₃-β-glucopyranose (unit C) (MBP-3) was isolated from this species. Nuclear magnetic resonance (NMR), Fourier transform infra-red (FTIR), and mass spectroscopy techniques were used to characterise MBP-3. MBP-3 exhibited anti-inflammatory activities against inflammatory 5-lipoxygenase (IC₅₀ 0.11 mg mL^-1) and cyclooxygenase-2 (IC₅₀ 0.12 mg mL^-1) enzymes. MBP-3 (at 100 μg mL^-1) showed effective downregulation against pro-inflammatory cytokines generation, namely interleukins-6, 1β, (IL-6, 1β) (1-1.7 pg mL^-1) and tumour necrosis factor-α (TNF-α) (4 pg mL^-1) along with substantial downregulation of ROS production in lipopolysaccharide (LPS)-inflamed cells. MBP-3 blocked the mRNA of NF-κB, cyclooxygenase-2 (COX-2), and other cytokines, in lipopolysaccharide-induced macrophages. The potential to constrain inflammatory cytokine production revealed its application to develop functional food to attenuate inflammation-associated disorders.