title: Paeoniflorin inhibits nucleus pulposus cell apoptosis by regulating the expression of Bcl-2 family proteins and caspase-9 in a rabbit model of intervertebral disc degeneration.
abstract: Apoptosis plays a key role in the pathogenesis of internal disc disruption (IDD); therefore, the inhibition of apoptosis may offer a novel approach for treating IDD diseases. The aim of the present study was to investigate the effects and the underlying mechanisms of paeoniflorin through the detection of relevant indicators in a rabbit model of IDD. In total, 144 rabbits were used in the study and divided into four groups (n=36 per group). Rabbits successfully modeled with IDD received an intragastric injection of 120 mg/kg·day paeoniflorin (high-dose group), 30 mg/kg·day paeoniflorin (low-dose group) or saline (model saline group), while rabbits without IDD were used as a normal control group. The apoptosis rate of disc nucleus pulposus cells was detected using flow cytometry. In addition, the expression levels of Bcl-2, Bax and caspase-9 in the disc tissues were detected using immunohistochemistry and western blot analysis prior to and following the treatment. The results indicated that the expression levels of Bax in the low- and high-dose paeoniflorin groups were significantly reduced, while the Bcl-2 expression levels were significantly increased when compared with the model saline group (P<0.01). In addition, the expression levels of cleaved caspase-3 and cleaved caspase-9 were reduced in the low- and high-dose paeoniflorin groups, as compared with the model saline group (P<0.05). Furthermore, the average apoptotic index of the high- and low-dose paeoniflorin groups was decreased when compared with the model saline group (P<0.05). In conclusion, paeoniflorin was demonstrated to inhibit the apoptosis of nucleus pulposus cells and the activation of caspase-3 and caspase-9 through the regulation of Bcl-2 family protein expression. These results provide an experimental basis for the future treatment of IDD with paeoniflorin.
authors.affiliation: Department of Pharmacy, The First Affiliated Hospital of Wengzhou Medical University, Wenzhou, Zhejiang 325000, P.R. China.
authors.forename: Lijun
authors.initials: L
authors.lastname: Shi
authors.affiliation: Department of Orthopedics, The First Affiliated Hospital of Wengzhou Medical University, Wenzhou, Zhejiang 325000, P.R. China.
authors.forename: Honglin
authors.initials: H
authors.lastname: Teng
authors.affiliation: Department of Orthopedics, The First Affiliated Hospital of Wengzhou Medical University, Wenzhou, Zhejiang 325000, P.R. China.
authors.forename: Minyu
authors.initials: M
authors.lastname: Zhu
authors.affiliation: Department of Orthopedics, The First Affiliated Hospital of Wengzhou Medical University, Wenzhou, Zhejiang 325000, P.R. China.
authors.forename: Chi
authors.initials: C
authors.lastname: Li
authors.affiliation: Department of Orthopedics, The First Affiliated Hospital of Wengzhou Medical University, Wenzhou, Zhejiang 325000, P.R. China.
authors.forename: Kelun
authors.initials: K
authors.lastname: Huang
authors.affiliation: Department of Orthopedics, The First Affiliated Hospital of Wengzhou Medical University, Wenzhou, Zhejiang 325000, P.R. China.
authors.forename: B I
authors.initials: BI
authors.lastname: Chen
authors.affiliation: Department of Orthopedics, The First Affiliated Hospital of Wengzhou Medical University, Wenzhou, Zhejiang 325000, P.R. China.
authors.forename: Yusen
authors.initials: Y
authors.lastname: Dai
authors.affiliation: Department of Orthopedics, The First Affiliated Hospital of Wengzhou Medical University, Wenzhou, Zhejiang 325000, P.R. China.
authors.forename: Jing
authors.initials: J
authors.lastname: Wang
keywords: Bax; Bcl-2; cell apoptosis; intervertebral disc degeneration; paeoniflorin