title: Protective effects of the Tougu Xiaotong capsule on morphology and osteoprotegerin/nuclear factor-κB ligand expression in rabbits with knee osteoarthritis.
abstract: The imbalance of subchondral bone remodeling is a common pathological feature in the progression of osteoarthritis. In the current study, using a rabbit model of knee osteoarthritis, the effects of the Tougu Xiaotong capsule (TGXTC) on the cartilage and subchondral bone were investigated. In addition, osteoprotegerin (OPG), an inducer of bone formation, and receptor activator of nuclear factor‑κB ligand (RANKL), a regulator of bone resorption in the subchondral bone, were assessed, in order to further explore the protective role of TGXTC in subchondral bone remodeling. The rabbit model of knee osteoarthritis, which was induced by a modified version of Hulth's method, was treated with TGXTC or glucosamine hydrochloride for 4 or 8 weeks. Subsequently, the tibia and femur were harvested for observation of cartilage histology, and the subchondral bone was observed by scanning electron microscopy. The expression levels of OPG and RANKL at the gene and protein levels were determined by reverse transcription‑quantitative polymerase chain reaction and western blotting. TGXTC and glucosamine hydrochloride were identified to mitigate cartilage injury, reduce trabecular number and thickness and accelerate trabecular separation. It was additionally observed that the level of OPG mRNA and protein expression was reduced, and the RANKL mRNA and protein expression level was increased, in addition to the observation of a lower OPG/RANKL ratio in the TGXTC and hydrochloride groups. Taken together, these results suggest that TGXTC may mitigate cartilage injury and subchondral sclerosis, thus delaying the pathological development of osteoarthritis. This is suggested to be mediated partly through the reduction of OPG expression and increase of RANKL expression, which reduces the OPG/RANKL ratio, suppressing excessive bone formation.
authors.affiliation: Fujian Academy of Integrative Medicine, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350122, P.R. China.
authors.forename: Sainan
authors.initials: S
authors.lastname: Chen
authors.affiliation: Fujian Academy of Integrative Medicine, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350122, P.R. China.
authors.forename: Yunmei
authors.initials: Y
authors.lastname: Huang
authors.affiliation: Fujian Academy of Integrative Medicine, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350122, P.R. China.
authors.forename: Wenlie
authors.initials: W
authors.lastname: Chen
authors.affiliation: Fujian Academy of Integrative Medicine, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350122, P.R. China.
authors.forename: Guangwen
authors.initials: G
authors.lastname: Wu
authors.affiliation: National Laboratory of Traditional Chinese Medicine Pharmacology (Cell Structure and Function), Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350122, P.R. China.
authors.forename: Naishun
authors.initials: N
authors.lastname: Liao
authors.affiliation: National Laboratory of Traditional Chinese Medicine Pharmacology (Cell Structure and Function), Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350122, P.R. China.
authors.forename: Xihai
authors.initials: X
authors.lastname: Li
authors.affiliation: National Laboratory of Traditional Chinese Medicine Pharmacology (Cell Structure and Function), Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350122, P.R. China.
authors.forename: Meiya
authors.initials: M
authors.lastname: Huang
authors.affiliation: Fujian Academy of Integrative Medicine, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350122, P.R. China.
authors.forename: Ruhui
authors.initials: R
authors.lastname: Lin
authors.affiliation: National Laboratory of Traditional Chinese Medicine Pharmacology (Cell Structure and Function), Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350122, P.R. China.
authors.forename: Chao
authors.initials: C
authors.lastname: Yu
authors.affiliation: National Laboratory of Traditional Chinese Medicine Pharmacology (Cell Structure and Function), Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350122, P.R. China.
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Li
authors.affiliation: Fujian Academy of Integrative Medicine, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350122, P.R. China.
authors.forename: Xianxiang
authors.initials: X
authors.lastname: Liu
mesh_terms: D000818:Animals; D002214:Capsules; D002356:Cartilage / Q000187:drug effects / Q000473:pathology; D004365:Drugs, Chinese Herbal / Q000494:pharmacology / Q000627:therapeutic use*; D005260:Female; D005269:Femur / Q000187:drug effects / Q000473:pathology / Q000648:ultrastructure; D020370:Osteoarthritis, Knee / Q000188:drug therapy* / Q000235:genetics / Q000473:pathology*; D053244:Osteoprotegerin / Q000235:genetics / Q000378:metabolism*; D020011:Protective Agents / Q000494:pharmacology / Q000627:therapeutic use*; D053245:RANK Ligand / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D011817:Rabbits
chemical_list: D002214:Capsules; D004365:Drugs, Chinese Herbal; D053244:Osteoprotegerin; D020011:Protective Agents; D053245:RANK Ligand; D012333:RNA, Messenger; C528129:tougu xiaotong