International Journal of Medicinal Plants Research

ISSN 2169-303X

International Journal of Medicinal Plants Research ISSN 2169-303X Vol. 9 (8), pp. 001-008, August, 2020. © International Scholars Journals

Full Length Research Paper

Anti-inflammatory activity of brown alga Dictyota dichotoma in murine macrophage RAW 264.7 cells

Weon-Jong Yoon1, Young Min Ham1, Kil-Nam Kim1, Soo-Yeung Park1, Nam Ho Lee2, Chang-Gu Hyun1*, and Wook Jae Lee1*

1Research Group for Cosmetic Materials, Jeju Biodiversity Research Institute (JBRI) and Jeju Hi-Tech Industry Development Institute (HiDI), Jeju 697-943, Korea.

2Department of Chemistry, Cheju National University, Jeju 690-756, Korea

Accepted 16 April, 2020

Abstract

COX-2 (Cyclooxygenase-2) and iNOS (inducible nitric oxide synthase) are involved in various pathophysiological processes such as inflammation. In a search for inhibitors of COX-2 and iNOS, we found that extracts of Dictyota dichotoma inhibit Nitric oxide (NO) and PGE2 generation in LPS-stimulated RAW 264.7 macrophage cells, as well as levels of iNOS and COX-2 mRNA and protein. D. dichotoma were extracted with 80% EtOH. The extract was then partitioned with hexane, CH2Cl2, EtOAc, BuOH, and water, successively. The results indicate that the CH2Cl2 fraction of D. dichotoma extract is an effective inhibitor of LPS- induced NO and PGE2 production in RAW 264.7 cells. These inhibitory effects of the CH2Cl2 fraction of D. dichotoma were accompanied by decreases in the expression of iNOS and COX-2 proteins and iNOS and COX-2 mRNA in dose-dependent pattern. To test the inhibition effects of D. dichotoma fractions on other cytokines, we also performed RT-PCR on TNF- , IL-1 , and IL-6 in LPS-stimulated RAW 264.7 macrophage cells. In these assays, the CH2Cl2 fraction of D. dichotoma also showed decreases in the expression of TNF- , IL-1 , and IL-6 mRNA. Based on these results, we suggest that D. dichotoma extracts may be considered possible anti-inflammatory candidates for human health.

Key words: COX-2, Cytokine, Dictyota dichotoma, inflammation, iNOS (inducible nitric oxide synthase), PGE2.