title: Commercial Honeybush (Cyclopia spp.) Tea Extract Inhibits Osteoclast Formation and Bone Resorption in RAW264.7 Murine Macrophages-An in vitro Study.
abstract: Honeybush tea, a sweet tasting caffeine-free tea that is indigenous to South Africa, is rich in bioactive compounds that may have beneficial health effects. Bone remodeling is a physiological process that involves the synthesis of bone matrix by osteoblasts and resorption of bone by osteoclasts. When resorption exceeds formation, bone remodeling can be disrupted resulting in bone diseases such as osteoporosis. Osteoclasts are multinucleated cells derived from hematopoietic precursors of monocytic lineage. These precursors fuse and differentiate into mature osteoclasts in the presence of receptor activator of NF-kB ligand (RANKL), produced by osteoblasts. In this study, the in vitro effects of an aqueous extract of fermented honeybush tea were examined on osteoclast formation and bone resorption in RAW264.7 murine macrophages. We found that commercial honeybush tea extract inhibited osteoclast formation and TRAP activity which was accompanied by reduced bone resorption and disruption of characteristic cytoskeletal elements of mature osteoclasts without cytotoxicity. Furthermore, honeybush tea extract decreased expression of key osteoclast specific genes, matrix metalloproteinase-9 (MMP-9), tartrate resistant acid phosphatase (TRAP) and cathepsin K. This study demonstrates for the first time that honeybush tea may have potential anti-osteoclastogenic effects and therefore should be further explored for its beneficial effects on bone.
authors.affiliation: Department of Physiology, Faculty of Health Sciences, University of Pretoria, Pretoria 0001, South Africa. amcois.visagie@gmail.com.
authors.forename: Amcois
authors.initials: A
authors.lastname: Visagie
authors.affiliation: Department of Physiology, Faculty of Health Sciences, University of Pretoria, Pretoria 0001, South Africa. abe.kasonga@up.ac.za.
authors.forename: Abe
authors.initials: A
authors.lastname: Kasonga
authors.affiliation: Department of Physiology, Faculty of Health Sciences, University of Pretoria, Pretoria 0001, South Africa. viishwadeepak@gmail.com.
authors.forename: Vishwa
authors.initials: V
authors.lastname: Deepak
authors.affiliation: Department of Physiology, Faculty of Health Sciences, University of Pretoria, Pretoria 0001, South Africa. shaakirah.moosa@up.ac.za.
authors.forename: Shaakirah
authors.initials: S
authors.lastname: Moosa
authors.affiliation: Department of Physiology, Faculty of Health Sciences, University of Pretoria, Pretoria 0001, South Africa. shaakirah.moosa@up.ac.za.
authors.forename: Sumari
authors.initials: S
authors.lastname: Marais
authors.affiliation: School of Food and Nutrition, Massey Institute for Food Science and Technology, Massey University, Palmerston North 4442, New Zealand. m.c.kruger@massey.ac.nz.|Department of Human Nutrition, Faculty of Health Sciences, University of Pretoria, Pretoria 0001, South Africa. m.c.kruger@massey.ac.nz.|Institute for Food, Nutrition and Well-being, University of Pretoria, Pretoria 0001, South Africa. m.c.kruger@massey.ac.nz.
authors.forename: Marlena C
authors.initials: MC
authors.lastname: Kruger
authors.affiliation: Department of Physiology, Faculty of Health Sciences, University of Pretoria, Pretoria 0001, South Africa. magdalena.coetzee@up.ac.za.|Institute for Food, Nutrition and Well-being, University of Pretoria, Pretoria 0001, South Africa. magdalena.coetzee@up.ac.za.
authors.forename: Magdalena
authors.initials: M
authors.lastname: Coetzee
mesh_terms: D000135:Acid Phosphatase / Q000378:metabolism; D000199:Actins / Q000378:metabolism; D000818:Animals; D001862:Bone Resorption / Q000517:prevention & control; D056657:Cathepsin K / Q000378:metabolism; D002454:Cell Differentiation / Q000187:drug effects*; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D002851:Chromatography, High Pressure Liquid; D004353:Drug Evaluation, Preclinical; D016142:Holoprosencephaly; D007527:Isoenzymes / Q000378:metabolism; D008264:Macrophages / Q000166:cytology / Q000187:drug effects*; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism; D051379:Mice; D010010:Osteoclasts / Q000187:drug effects*; D008517:Phytotherapy; D010936:Plant Extracts / Q000494:pharmacology* / Q000627:therapeutic use; D053245:RANK Ligand; D000067996:RAW 264.7 Cells; D013019:South Africa; D000071681:Tartrate-Resistant Acid Phosphatase; D013662:Tea
chemical_list: D000199:Actins; D007527:Isoenzymes; D010936:Plant Extracts; D053245:RANK Ligand; D013662:Tea; D000135:Acid Phosphatase; C000605511:Acp5 protein, mouse; D000071681:Tartrate-Resistant Acid Phosphatase; D056657:Cathepsin K; D020780:Matrix Metalloproteinase 9
keywords: RANKL; RAW264.7  murine macrophages; bone resorption; honeybush tea; osteoclast