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

Abstract

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.

Graphical Abstract

Keywords:

• Magallana bilineata
• sulphated glycosaminoglycan
• anti-inflammatory
• lipopolysaccharide-induced macrophages
• cytokines

Acknowledgments

The authors are grateful to the Director, Central Marine Fisheries Research Institute for supporting the research. Thanks are due to the Chairperson, Department of Biosciences, Mangalore University (Karnataka, India) for the necessary support. The authors are thankful to SAIF, IIT Madras, for providing the spectroscopic data.

Authors’ contributions

SK conducted experiments and analysed spectral and biological data. KC acquired funds, conceived, designed, and supervised the research. SD has drafted the manuscript. All authors read and approved the manuscript.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Ethical approval

The research did not include any human subjects or animal experiments.

Data availability statement

The supplementary material comprises experimental procedures, chromatographic and spectral data, photographs, as well as cell line information.

Additional information

Funding

The work was funded by the National Agricultural Science Fund, Indian Council of Agricultural Research, Government of India, under the project titled ‘Development of Small Molecular Weight Bioactives and Polysaccharides from Marine and Coastal Bivalves to develop Prospective Nutraceutical Products’ grant number NASF/BGAM-9018/2022-23.