Citrus limonoid nomilin inhibits osteoclastogenesis in vitro by suppression of NFATc1 and MAPK signaling pathways.

Abstract

BACKGROUND:

Animal experiment studies have revealed a positive association between intake of citrus fruits and bone health. Nomilin, a limonoid present in citrus fruits, is reported to have many biological activities in mammalian systems, but the mechanism of nomilin on bone metabolism regulation is currently unclear.

PURPOSE:

To reveal the mechanism of nomilin on osteoclastic differentiation of mouse primary bone marrow-derived macrophages (BMMs) and the mouse RAW 264.7 macrophage cell line into osteoclasts.

STUDY DESIGN:

Controlled laboratory study. Effects of nomilin on osteoclastic differentiation were studied in in vitro cell cultures.

METHODS:

Cell viability of RAW 264.7 cells and BMMs was measured with the Cell Counting Kit. TRAP-positive multinucleated cells were counted as osteoclast cell numbers. The number and area of resorption pits were measured as bone-resorbing activity. Osteoclast-specific genes expression was evaluated by quantitative real-time PCR; and proteins expression was evaluated by western blot.

RESULTS:

Nomilin significantly decreased TRAP-positive multinucleated cell numbers compared with the control, and exhibited no cytotoxicity. Nomilin decreased bone resorption activity. Nomilin downregulated osteoclast-specific genes, NFATc1 and TRAP mRNA levels. Furthermore, nomilin suppressed MAPK signaling pathways.

CONCLUSION:

This study demonstrates clearly that nomilin has inhibitory effects on osteoclastic differentiation in vitro. These findings indicate that nomilin-containing herbal preparations have potential utility for the prevention of bone metabolic diseases.

• Authors: Yoshifumi Kimira, Yuri Taniuchi, Sachie Nakatani, Yuusuke Sekiguchi, Hyoun Ju Kim, Jun Shimizu, Midori Ebata, Masahiro Wada, Akiyo Matsumoto, Hiroshi Mano
• Journal: Phytomedicine : international journal of phytotherapy and phytopharmacology (Phytomedicine) Vol. 22 Issue 12 Pg. 1120-4 (Nov 15 2015) ISSN: 1618-095X [Electronic] Germany
• PMID: 26547535 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2015 Elsevier GmbH. All rights reserved.

Chemical References

• Benzoxepins
• Isoenzymes
• Limonins
• NFATC Transcription Factors
• Nfatc1 protein, mouse
• nomilin
• Acid Phosphatase
• Acp5 protein, mouse
• Tartrate-Resistant Acid Phosphatase

Topics

• Acid Phosphatase (metabolism)
• Animals
• Benzoxepins (pharmacology)
• Bone Resorption
• Cell Differentiation (drug effects)
• Citrus (chemistry)
• Isoenzymes (metabolism)
• Limonins (pharmacology)
• MAP Kinase Signaling System (drug effects)
• Macrophages (drug effects)
• Male
• Mice
• NFATC Transcription Factors (metabolism)
• Osteoclasts (drug effects)
• RAW 264.7 Cells (drug effects)
• Tartrate-Resistant Acid Phosphatase