Identification of Anti-Inflammatory Compounds from Hawaiian Noni (Morinda citrifolia L.) Fruit Juice
Da Young Lee, Jae Sik Yu, Peng Huang, Mallique Qader, Arulmani Manavalan, Xiaohua Wu, Jin‐Chul Kim, Changhyun Pang, Shugeng Cao, Ki Sung Kang, Ki Hyun Kim
Abstract
Noni (Morinda citrifolia L.) fruit juice has been used in Polynesia as a traditional folk medicine and is very popular worldwide as a functional food supplement. In this study, compounds present in Hawaiian Noni fruit juice, with anti-inflammatory activity in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells were identified. Five compounds were isolated using a bioassay-driven technique and phytochemical analysis of noni fruit juice: asperulosidic acid (1), rutin (2), nonioside A (3), (2E,4E,7Z)-deca-2,4,7-trienoate-2-O-β-d-glucopyranosyl-β-d-glucopyranoside (4), and tricetin (5). The structures of these five compounds were determined via NMR spectroscopy and LC/MS. In an anti-inflammatory assay, compounds 1–5 inhibited the production of nitric oxide (NO), which is a proinflammatory mediator, in LPS-stimulated macrophages. Moreover, the mechanisms underlying the anti-inflammatory effects of compounds 1–5 were investigated. Parallel to the inhibition of NO production, treatment with compounds 1–5 downregulated the expression of IKKα/β, I-κBα, and NF-κB p65 in LPS-stimulated macrophages. Furthermore, treatment with compounds 1–5 downregulated the expression of nitric oxide synthase and cyclooxygenase-2. Thus, these data demonstrated that compounds 1–5 present in noni fruit juice, exhibited potential anti-inflammatory activity; these active compounds may contribute preventively and therapeutically against inflammatory diseases.