Psychotria Serpens Linn Improves Ankle Traumatic Arthritis by Repressing NF-κB/p38-MAPK Pathway

Abstract

Background: This study aimed to evaluate the efficacy of the water extract of Psychotria serpens Linn (PSL) based on a rat model of post-traumatic ankle arthritis (PTAA) and tumor necrosis factor alpha (TNF-α)-induced apoptosis in chondrocytes, and to explore the related therapeutic mechanism based on nuclear factor-kappaB (NF-κB)/p38 mitogen-activated protein kinase (p38-MAPK) pathway. Methods: After the PTAA rat model was successfully established, the rats were randomly divided into 4 groups (n = 4 per group): model group, ibuprofen group, PSL 5 g/kg group and PSL 20 g/kg group. X-ray imaging, hematoxylin and eosin (H&E) staining of ankle joints and modified safranin O-fast green staining and scoring of cartilage were carried out after the operation. Next, C28/I2 chondrocytes were cultured and divided into 5 groups: normal group, TNF-α group, TNF-α+4-Phenylbutyric acid (4-PBA) group (positive control), TNF-α+PSL group (300 μg/mL, 400 μg/mL, 500 μg/mL). The endoplasmic reticulum stress-related apoptosis of C28/I2 chondrocytes was induced by TNF-α. After the treatment of the chondrocytes with water extract of PSL, cell viability was measured by Cell Counting Kit-8 (CCK-8), apoptosis was detected by flow cytometry, and expression of NF-κB/p38-MAPK pathway was detected by Quantitative Real-Time Polymerase Chain Reaction (qRT-PCR) and western blotting. Results: In the in vivo experiments, compared with the model group, H&E staining of the rats ankle joint, and modified safranin O-fast green staining and cartilage scoring (p < 0.05) all showed that PSL improved the PTAA healing in rats. In the in vitro experiments, compared with the TNF-α group, PSL significantly increased cell viability (p < 0.05) and proliferation (p < 0.05) and repressed apoptosis (p < 0.05) in TNF-α-treated chondrocytes and downregulated the expression of the NF-κB/p38-MAPK pathway (p < 0.05). Conclusions: PSL has a significant beneficial effect on traumatic ankle arthritis, the mechanism of which may be related to the repression of the NF-κB/p38-MAPK pathway.