The edible seaweed Laminaria japonica contains cholesterol analogues that inhibit lipid peroxidation and cyclooxygenase enzymes

Xingyu Lu; Amila A Dissanayake; Chuqiao Xiao; Jie Gao; Mouming Zhao; Muraleedharan G Nair

doi:10.1371/journal.pone.0258980

The edible seaweed Laminaria japonica contains cholesterol analogues that inhibit lipid peroxidation and cyclooxygenase enzymes

PLoS One. 2022 Jan 27;17(1):e0258980. doi: 10.1371/journal.pone.0258980. eCollection 2022.

Authors

Xingyu Lu¹, Amila A Dissanayake², Chuqiao Xiao^{3

4}, Jie Gao^{1

2}, Mouming Zhao³, Muraleedharan G Nair²

Affiliations

¹ School of Light Industry and Food Engineering, Guangxi University, Nanning, China.
² Department of Horticulture, Bioactive Natural Products and Phytoceuticals Laboratory, Michigan State University, East Lansing, Michigan, United States of America.
³ School of Food Science and Engineering, South China University of Technology, Guangzhou, China.
⁴ Chaozhou Branch of Chemistry and Chemical Engineering Guangdong Laboratory, Chaozhou, China.

Abstract

In this study, 5 sterols were isolated and purified from Laminaria japonica, commonly known as edible brown seaweed, and their structures were identified based on detailed chemical methods and spectroscopic analyses. Spectroscopic analyses characterized 5 sterols as 29-Hydroperoxy-stigmasta-5,24(28)-dien-3β-ol, saringosterol (24-vinyl-cholest-5-ene-3β,24-diol), 24-methylenecholesterol, fucosterol (stigmasta-5,24-diene-3β-ol), and 24-Hydroperoxy-24-vinyl-cholesterol. The bioactivities of these sterols were tested using lipid peroxidation (LPO) and cyclooxygenase (COX-1 and -2) enzyme inhibitory assays. Fucosterol exhibited the highest COX-1 and -2 enzyme inhibitory activities at 59 and 47%, respectively. Saringosterol, 24-methylenecholesterol and fucosterol showed higher LPO inhibitory activity at >50% than the other compounds. In addition, the results of molecular docking revealed that the 5 sterols were located in different pocket of COX-1 and -2 and fucosterol with tetracyclic skeletons and olefin methine achieved the highest binding energy (-7.85 and -9.02 kcal/mol) through hydrophobic interactions and hydrogen bond. Our results confirm the presence of 5 sterols in L. japonica and its significant anti-inflammatory and antioxidant activity.

MeSH terms

Cholesterol / analogs & derivatives*
Cholesterol / chemistry
Cholesterol / pharmacology
Cyclooxygenase 1 / chemistry
Cyclooxygenase 1 / metabolism
Cyclooxygenase 2 / chemistry
Cyclooxygenase 2 / metabolism
Cyclooxygenase Inhibitors / chemistry
Cyclooxygenase Inhibitors / pharmacology*
Humans
Laminaria / chemistry*
Lipid Peroxidation / drug effects*
Molecular Docking Simulation
Molecular Structure
Protein Conformation
Sterols / chemistry
Sterols / pharmacology*
Stigmasterol / analogs & derivatives
Stigmasterol / chemistry
Stigmasterol / pharmacology

Substances

Cyclooxygenase Inhibitors
Sterols
saringosterol
fucosterol
Cholesterol
Stigmasterol
Cyclooxygenase 1
Cyclooxygenase 2
PTGS1 protein, human
24-methylenecholesterol

Grants and funding

YES - Jie Gao gratefully acknowledge the financial support from China Scholarship Council (CSC) and National Natural Science Foundation of China (Project No. 32001696). This research is also a contribution from Michigan State University AgBioResearch (MICL01680). The nuclear magnetic resonance data were obtained on instrumentation that was purchased, in part, with the funds from NIH grant no. 1-S10-RR04750, NSF grant no. CHE-88-00770, and NSF grant no. CHE-92-13241. HRMS data were obtained at the Michigan State University Mass Spectrometry Facility, which is supported, in part, by a grant (DRR-00480) from the Biotechnology Research Technology Program, National Centre for Research Resources, National Institutes of Health.