Increase in anti-inflammatory activities of radical-degraded porphyrans isolated from discolored nori (Pyropia yezoensis)

• Published in: International journal of biological macromolecules Vol. 117; pp. 78 - 86
• Main Authors: Yanagido, Ayana, Ueno, Mikinori, Jiang, Zedong, Cho, Kichul, Yamaguchi, Kenichi, Kim, Daekyung, Oda, Tatsuya
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.10.2018
• Subjects: Animals; Anti-inflammatory activity; Anti-Inflammatory Agents - chemistry; Anti-Inflammatory Agents - pharmacology; Cell Survival - drug effects; Chromatography, Gel; Macrophages - drug effects; Macrophages - metabolism; Mice; Nitric Oxide - metabolism; Osteoclastogenesis; Phytochemicals - chemistry; Phytochemicals - pharmacology; Plant Extracts - chemistry; Plant Extracts - pharmacokinetics; Porphyra - chemistry; Porphyran; Pyropia yezoensis; Radical-degradation; RANK Ligand - metabolism; RAW 264.7 Cells; Sepharose - analogs & derivatives; Sepharose - chemistry; Sepharose - pharmacology; Osteoclastogenesis; Anti-inflammatory activity; Radical-degradation; Pyropia yezoensis; Porphyran
• ISSN: 0141-8130; 1879-0003
• DOI: 10.1016/j.ijbiomac.2018.05.146

The anti-inflammatory properties of porphyrans (D1–D4) obtained from four discolored nori (Pyropia yezoensis) with different growth backgrounds were studied to examine possible variations in their bioactivities. Elution profiles of the porphyrans on Sepharose 4B indicated that D2-porphyran had relatively lower-molecular-size porphyrans than the other porphyrans. Inhibitory activities of the four porphyrans against nitric oxide (NO) and tumor necrosis factor-α (TNF-α) secretion by lipopolysaccharide (LPS)-stimulated RAW264.7 cells were different, whereas no significant differences were observed in the sulfate and anhydrogalactose levels. D2-porphyran showed the highest inhibitory activity against NO and TNF-α secretion by LPS-stimulated RAW264.7 cells, whereas D3- and D4-porphyrans had almost no activity. All porphyrans were efficiently degraded by free radical generated with ascorbate and hydrogen peroxide. The free-radical degradation resulted in a significant increase in the inhibitory activities of the four porphyrans against NO and TNF-α secretion, with varying rates depending on the porphyrans. The ability of D2-porphyran to suppress the receptor activator of nuclear factor κB ligand (RANKL)-induced osteoclastogenesis in RAW264.7 cells was also significantly enhanced after degradation. Our results suggest that molecular size is an important factor affecting the anti-inflammatory activity of porphyrans, and radical degradation might be a promising procedure to obtain active low-molecular-size porphyrans. •Molecular size distribution of porphyrans from discolored nori differ depending on the nori with different growth background.•Anti-inflammatroy activity of the porphyrans are significantly different.•Porphyran with lower molecular size tends to show higher anti-inflammatroy activity.•All porphyrans are efficiently degraded by free radical generated with ascorbate and hydrogen peroxide.•Radical degradation is promising procedure to obtain active low-molecular-size porphyrans, even from inactive porphyrans