Macroporous resin extraction of PHNQs from Evechinus chloroticus sea urchin and their in vitro antioxidant, anti-bacterial and in silico anti-inflammatory activities

This study investigated the polyhydroxyl-1,4-naphthoquinone (PHNQ) composition and bioactivities of Evechinus chloroticus sea urchin shell and spine waste extracted using the macroporous resins NKA-9, D4020, D4006, and D101. The mineral and protein contents in the shell and spine were found to be 85.21% and 84.14%, 3.85% and 8.96%, respectively. Spine PHNQs extracted using the D4006 resin had the highest total phenolic content (TPC) while the D101 and D4020 resin extracts had a lower TPC (p < 0.05). The best extraction was obtained with the D4006 resin and spine extracts had higher antioxidant activity (DPPH, ABTS, ORAC and FRAP) than shell extracts (p < 0.05). The Minimum Inhibitory Concentration of PHNQ extracts against Escherichia coli and Staphylococcus aureus ranged from 2.5 to 10 mg/mL, with the D4006 resin extract having the best activity. An in silico docking study of spinochrome A and B that is present in the PHNQ extracts, suggested a potent anti-inflammatory activity. The results suggest that macroporous resin extraction of PHNQs from E. chloroticus shell and spine is an effective way to obtain natural bioactives.