Inhibition of cartilage degradation and suppression of PGE2 and MMPs expression by pomegranate fruit extract in a model of posttraumatic osteoarthritis

Abstract

Background Osteoarthritis (OA) is characterized by cartilage degradation in the affected joints. Pomegranate fruit extract (PFE) inhibits cartilage degradation in vitro. Here we determined whether oral consumption of PFE inhibits disease progression in rabbits with surgically-induced OA. Methods OA was surgically induced in the tibiofemoral joints of adult NZW rabbits. In one group animals were fed PFE in water for 8 weeks post-surgery. In the second group, animals were fed PFE for 2 weeks before surgery andfor 8 weeks post-surgery.Histological assessment and scoring of the cartilage was per OARSI guidelines. Gene expression and MMPs activity were determined using qRT-PCR and fluorometric assay, respectively. IL-1β, MMP-13, IL-6, PGE2 and COL2A1 levels in synovial fluid/plasma/culture mediawere quantified using ELISA. Expression of active Caspase-3 and PARP p85 was determined by immunohistochemistry. Effect of PFE and inhibitors of MMP-13, MAPK and NF-κB was studied in IL-1β-stimulated rabbit articular chondrocytes. Results Safranin-O-staining and chondrocyte cluster formation was significantly reduced in the ACLT+PFE fed groups. Expression of MMP-3, MMP-9 and MMP-13 mRNAwas higher in the cartilage of rabbits given water alone but was significantly lower in the animals fed PFE. PFE-fed rabbits had lowerIL-6, MMP-13 and PGE2 levels in the synovial fluid and plasma respectively and showed higher expression of ACAN and COL2A1 mRNA. Significantly higher numbers of chondrocytes were positive for markers of apoptosisin the joints of rabbits with OA given water only compared to rabbits in the PFE-fed groups. PFE pretreatment significantly reduced IL-1β induced IL-6 and MMPs expression in rabbit articular chondrocytes. These effects were also mimicked using MMP-13, MAPK and NF-κB inhibitors in IL-1β-stimulated rabbit chondrocytes. In an in vitro activity assay, PFE blocked the activity of MMP-13.Like MAPK and NF-κB inhibitors, PFE was also effective in inhibiting IL-1β-induced PGE2 production in rabbit chondrocytes. PFE also reversed the inhibitory effect of IL-1β on COL2A1 mRNA and protein expression in IL-1β-stimulated rabbit chondrocytes. Conclusion Our data highlighted the chondroprotective effects of PFE oral consumption in a model of post-traumatic OA and suggests that PFE derived compounds may have potential value in the management of OA.

Protective effects of quercetin against inflammation and oxidative stress in a rabbit model of knee osteoarthritis

“…worsen the degeneration and exfoliation of articular cartilage, leading to the development of OA (Akhtar, Khan, Ashruf, & Haqqi, 2017;Wang et al, 2017). The levels of MMP-1, MMP-3, MMP-9, and MMP-13 in serum, joint synovial fluid, and cartilage in OA joints were higher than those in healthy joints, and the increase amount was consistent with the degree of cartilage destruction (Akhtar et al, 2017;Chijimatsu et al, 2015). TIMP-1 is one of the TIMP family that has been extensively studied so far.…”

“…Degeneration of articular cartilage is related to altered expression of MMPs. MMPs can degrade many cartilage extracellular matrix (Type II collagen fibers, proteoglycans, and other substances) and worsen the degeneration and exfoliation of articular cartilage, leading to the development of OA (Akhtar, Khan, Ashruf, & Haqqi, ; Wang et al, ). The levels of MMP‐1, MMP‐3, MMP‐9, and MMP‐13 in serum, joint synovial fluid, and cartilage in OA joints were higher than those in healthy joints, and the increase amount was consistent with the degree of cartilage destruction (Akhtar et al, ; Chijimatsu et al, ).…”

Derivation of notochordal cells from human embryonic stem cells reveals unique regulatory networks by single cell‐transcriptomics

“…RNA from different experimental conditions (Day 0, 4 and 6) was isolated using TRIzol reagent (Invitrogen) as previously described (Akhtar, Khan, Ashruf, & Haqqi, 2017;Khan, Ahmad, & Haqqi, 2018;Khan, Haseeb, Ansari, Devarapalli et al, 2017). RNA was treated with DNAse I (Invitrogen) and reverse-transcribed to complementary DNA (cDNA) using random hexamers using qScript cDNA synthesis kit (Quantabio) following manufacturer's instructions.…”

Cirsium japonicum var. maackii and apigenin block Hif‐2α‐induced osteoarthritic cartilage destruction

“…Pro-inflammatory cytokines (IL-1β, IL-6, IL-17 and TNF-α) were purchased from GenScript (Piscataway, NJ, USA). Mouse articular chondrocytes were treated with IL-1β (1 ng/mL), IL-6 (100 ng/mL), IL-17 (10 ng/ mL) or TNF-α (50 ng/mL) and co-treated with CJM extract (10,50 or 100 μg/mL), apigenin (10,25 or 50 μmol/L), cirsimarin (10, 25 or 50 μmol/L) or cirsimaritin (10,25 or 50 μmol/L) for 24 h before they were harvested.…”

“…Among the numerous MMP isotypes, MMP3 and MMP13 play major roles in cartilage matrix degradation . MMP3 and MMP13 possess aggrecanase and collagenase activities, respectively, and they degrade aggrecan, type II collagen and other extracellular matrix (ECM) components . Furthermore, ADAMTS4 and ADAMTS5 cleave aggrecan in vivo and are responsible for the up‐regulated aggrecanase activity observed in OA development .…”