[Pharmacological treatment of osteoarthritis-related pain]

Phytochemical Evaluation and Anti-Inflammatory Potential of Miconia albicans (Sw.) Triana Extracts

The plant Miconia albicans (Sw.) Triana has been popularly used in Brazil to treat chronic inflammatory disturbances, such as osteoarthritis. This disease affects 250 million people worldwide, and is associated with intense pain and loss of articular function. There is a lack of information about the phytochemistry and bioactivity of M. albicans. Therefore, this study determined the chemical composition of some extracts and evaluated their cytotoxicity, along with their antioxidant and anti-inflammatory, activities using in vitro models. Aqueous and ethanolic extracts were prepared. Afterwards, a liquid–liquid partition was developed using chloroform, ethyl acetate, and n-butanol. The extracts were characterized by LC–MS, and their biological activities were evaluated on epithelial cells (Vero), tumoral hepatic cells (Hep-G2), and THP-1 macrophages. LC–MS analyses identified several flavonoids in all fractions, such as quercetin, myricetin, and their glycosides. The crude extracts and n-butanol fractions did not present cytotoxicity to the cells. The non-toxic fractions presented significant antioxidant activity when evaluated in terms of DPPH scavenging activity, lipid peroxidation, and ROS inhibition. THP-1 macrophages treated with the n-butanol fraction (250 µg/mL) released fewer pro-inflammatory cytokines, even in the presence of LPS. In the future, it will be necessary to identify the phytochemicals that are responsible for anti-inflammatory effects for the discovery of new drugs. In vivo studies on M. albicans extracts are still required to confirm their possible mechanisms of action.

Production and Secretion of Gelsolin by Both Human Macrophage- and Fibroblast-like Synoviocytes and GSN Modulation in the Synovial Fluid of Patients with Various Forms of Arthritis

Gelsolin (GSN) is an actin-binding protein involved in cell formation, metabolism and wound closure processes. Since this protein is known to play a role in arthritis, here we investigate how the synovial membrane with its specific synoviocytes contributes to the expression of GSN and how the amount of GSN expressed is modulated by different types of arthritis. Synovial membranes from adult healthy subjects and patients with rheumatoid arthritis (RA) and osteoarthritis (OA) are analyzed by immunofluorescence, Western blot and ELISA. Macrophage-like synoviocytes (MLS) and fibroblast-like synoviocytes (FLS) were isolated, cultured and analyzed for their potential to produce and secrete GSN. In addition, the GSN concentrations in the synovial fluid of various forms of arthritis are determined by ELISA. GSN is produced by the healthy and arthritic synovial membranes. Both forms of synoviocytes (MLS and FLS) release GSN. The results show that there is a significant reduction in GSN in the synovial fluid in adult patients with OA. This reduction is also detectable in adult patients with RA but is not as evident. In juvenile arthritis, there is a slight increase in GSN concentration in the synovial fluid. This study shows that primary MLS and FLS express GSN and that these cells, in addition to articular chondrocytes, contribute to GSN levels in synovial fluid. Furthermore, GSN concentrations are modulated in different types of arthritis. Further studies are needed to fully understand how GSN is involved in joint homeostasis.

LIM mineralization protein-1 inhibits IL-1β-induced human chondrocytes injury by altering the NF-κB and MAPK/JNK pathways

Osteoarthritis (OA) is a common degenerative disease that is associated with the degradation of articular cartilage. Accumulating evidence has confirmed that LIM mineralization protein-1 (LMP-1) is an important agent of bone formation and has been shown to be osteoinductive in various types of disease. However, the underlying mechanisms of LMP-1 in the pathogenesis of OA remain unknown. The present study aimed to evaluate the role and potential mechanism of LMP-1 in IL-1β-stimulated OA chondrocytes. CHON-001 cells were transfected with pcDNA3.1-LMP-1, pcDNA3.1, negative control-small interfering (si)RNA or LMP-1 siRNA for 24 h and then induced by IL-1β for 12 h to establish an OA model in vitro. Cell viability, apoptosis and inflammatory cytokine (IL-6, IL-8 and TNF-α) release were assessed using MTT assay, flow cytometry and ELISA, respectively. The expression levels of LMP-1, cleaved-caspase 3, phosphorylated (p)-p65, p65, p-JNK and JNK were analyzed using reverse transcription-quantitative PCR and western blotting. Overexpression of LMP-1 notably alleviated the IL-1β-induced inflammatory response in CHON-001 cells, as shown by increased cell viability, decreased apoptosis, suppressed expression of cleaved-caspase 3 and a decreased cleaved-caspase 3/caspase 3 ratio. Moreover, IL-1β-induced secretion of IL-6, IL-8 and TNF-α in CHON-001 cells; this was reversed by pcDNA3.1-LMP-1. However, knocking down LMP-1 expression exert opposite effects on the IL-1β-induced inflammatory response in CHON-001 cells, as evidenced by the decreased cell viability, increased apoptosis, enhanced expression of cleaved-caspase 3 and cleaved-caspase 3/caspase 3 ratio and enhanced secretion of IL-6, IL-8 and TNF-α observed. The present data demonstrated that LMP-1 siRNA notably inhibited LMP-1 expression, suppressed cell viability, promoted apoptosis and enhanced cleaved-caspase 3 expression and cleaved-caspase 3/caspase 3 ratio. In addition, LMP-1 siRNA promoted the release of inflammatory factors in CHON-001 cells. It was also found that pcDNA3.1-LMP-1 inhibited p-p65 and p-JNK expression, as well as decreasing the p-p65/p65 and p-JNK/JNK ratio. Nevertheless, there was no significant difference in the mRNA expression levels of p65 and JNK between the groups. Taken together, these findings indicated that overexpression of LMP-1 alleviated IL-1β-induced chondrocytes injury by regulating the NF-κB and MAPK/JNK pathways, suggesting that LMP-1 may be a valuable therapeutic agent for OA treatment.

Disease Burden and Costs in Moderate-to-Severe Chronic Osteoarthritis Pain Refractory to Standard of Care: Ancillary Analysis of the OPIOIDS Real-World Study

Introduction

To determine the disease burden and costs in moderate-to-severe chronic osteoarthritis (OA) pain refractory to standard-of-care treatment in the Spanish National Health System (NHS).

Methods

Ancillary analysis of the OPIOIDS real-world, non-interventional, retrospective, 4-year longitudinal study including patients aged at least 18 years with moderate-to-severe chronic OA pain refractory to standard-of-care with sequential NSAIDs plus opioids. Burden assessment included measurement of analgesia, cognitive functioning, basic activities of daily living, severity and frequency of comorbidities, and all-cause mortality. Costs accounted for healthcare resource utilization and related costs (year 2018).

Results

Records of 13,317 patients were analyzed; 68.9 (14.7) years old, 71.3% (70.5–72.1%) women, 58.1% refractory to NSAID plus weak opioid and 41.9% to NSAID plus strong opioid, accounting for 10.7% (10.5–10.8%) of patients with chronic OA pain. Mean number of comorbidities was 2.9 (1.8) and its severity was 1.8 (1.7). Pain decreased by 0.9 points (12.2%) and cognitive declined by 2.3 points (9.1%, with 4.3% more patients with cognitive deficit) and dependency worsened by 0.4 points (0.5%, with 2.3% more patients with severe-to-total dependence) over a mean treatment period of 188.6 (185.4–191.8) days on NSAIDs followed by 400.6 (393.7–407.5) days on opioids. The adjusted mortality rate was higher in patients with OA taking NSAID plus strong opioids; hazard ratio 1.44 (1.26–1.65; p < 0.001). The 4-year healthcare cost was €7350/patient (€7193–7507 or €1838/year) and was higher in those taking strong versus weak opioids; €9886 (€9608–10,164, €2472/year) vs. €5519 (€5349–5689, €1380/year), p < 0.001. Analgesia cost (16.0% of total cost, 70.2% opioids) was higher with strong versus weak opioids, 19.6% vs. 11.3%, p < 0.001.

Conclusions

In routine clinical practice in Spain, patients with moderate-to-severe chronic OA pain refractory to standard analgesic treatment with NSAIDs plus opioids reported modest reductions in pain, while presenting a considerable burden of comorbidities, cognitive impairment, and dependency. Healthcare costs significantly increased for the NHS particularly with NSAIDs plus strong opioids.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40744-020-00271-y.