Animal models of osteoarthritis: characterization of a model induced by Mono-Iodo-Acetate injected in rabbits

Knee Osteoarthritis is a considerable public health concern, both in terms of life quality and treatment financial impacts. To investigate this disease, animal models are deemed a promising alternative. In fact, although a perfect model is generally farfetched, the creation of models that simulate human disease as accurately as possible remains an important research stake. This study aims to highlight the usefulness of the model induced by injected Mono-Iodo-Acetate and to standardize it for the rabbit species. Osteoarthritis was induced by an infra-patellar injection of 0.2 ml of an MIA solution in the left knee of 24 female New Zealand rabbits. The right knee served as a control by receiving an injection of physiological serum. The rabbits were divided into 4 groups of 6 individuals each according to the dose of MIA received per knee. All rabbits were euthanized 30 days after the injection. After sacrifice, the knees were carefully dissected and macroscopic and microscopic scores of cartilage, meniscal and synovial lesions were attributed to each group. Our study followed the laboratory animal care and management guideline published in 2017 by the Canadian Council of Animal Care. The control knees of all rabbits showed no macroscopic or microscopic lesions. The macroscopic lesions: osteophytes, meniscal lesions, fibrillation and erosion of the cartilage and microscopic lesions: disorganization of the chondrocytes, decrease in proteoglycans and synovial inflammation clinically diagnosed in human pathology were all detected and were similarly reproducible among the knees of the same group. Through this work, we highlighted the merits of the arthritis model induced by MIA, namely its simulation of several aspects of human pathology. Further advantages are low cost, speed, reproducibility. This model notably avoids delicate and risky surgical operations.

Understanding the Molecular Mechanisms Underlying the Pathogenesis of Arthritis Pain Using Animal Models

Arthritis, including osteoarthritis (OA) and rheumatoid arthritis (RA), is the leading cause of years lived with disability (YLD) worldwide. Although pain is the cardinal symptom of arthritis, which is directly related to function and quality of life, the elucidation of the mechanism underlying the pathogenesis of pain in arthritis has lagged behind other areas, such as inflammation control and regulation of autoimmunity. The lack of therapeutics for optimal pain management is partially responsible for the current epidemic of opioid and narcotic abuse. Recent advances in animal experimentation and molecular biology have led to significant progress in our understanding of arthritis pain. Despite the inherent problems in the extrapolation of data gained from animal pain studies to arthritis in human patients, the critical assessment of molecular mediators and translational studies would help to define the relevance of novel therapeutic targets for the treatment of arthritis pain. This review discusses biological and molecular mechanisms underlying the pathogenesis of arthritis pain determined in animal models of OA and RA, along with the methodologies used.

Therapeutic Effects of Olive and Its Derivatives on Osteoarthritis: From Bench to Bedside

Osteoarthritis is a major cause of morbidity among the elderly worldwide. It is a disease characterized by localized inflammation of the joint and destruction of cartilage, leading to loss of function. Impaired chondrocyte repair mechanisms, due to inflammation, oxidative stress and autophagy, play important roles in the pathogenesis of osteoarthritis. Olive and its derivatives, which possess anti-inflammatory, antioxidant and autophagy-enhancing activities, are suitable candidates for therapeutic interventions for osteoarthritis. This review aimed to summarize the current evidence on the effects of olive and its derivatives, on osteoarthritis and chondrocytes. The literature on animal and human studies has demonstrated a beneficial effect of olive and its derivatives on the progression of osteoarthritis. In vitro studies have suggested that the augmentation of autophagy (though sirtuin-1) and suppression of inflammation by olive polyphenols could contribute to the chondroprotective effects of olive polyphenols. More research and well-planned clinical trials are required to justify the use of olive-based treatment in osteoarthritis.

Suppressive Effect of the n-Hexane Extract of Litsea japonica Fruit Flesh on Monosodium-Iodoacetate-Induced Osteoarthritis in Rats

We examined the antiosteoarthritic effect of the n-hexane extract of Litsea japonica fruit flesh (LJF-HE) in a rat model of monosodium-iodoacetate- (MIA-) induced osteoarthritis. LJF-HE significantly reduced the difference in weight-bearing capabilities of the hind paws between healthy and MIA-treated rats. Histological examination of the knee joints indicated that LJF-HE suppressed cartilage and bone destruction. Additionally, there were decreases in the expression of matrix metalloproteinase-2 and metalloproteinase-9 and cyclooxygenase-2 in the joints. The serum levels of deoxypyridinoline (DPD) and osteocalcin, which are markers of bone metabolism, also decreased. Furthermore, LJF-HE significantly suppressed infiltration of inflammatory cells into the synovium and inhibited the expression of proinflammatory cytokines such as tumor necrosis factor- (TNF-) α, interleukin- (IL-) 1, and IL-6 in the joints and serum. The serum levels of leukotriene B4 and lipoxygenase were also significantly lowered by LJF-HE. Finally, LJF-HE inhibited the production of nitric oxide, prostaglandin E2, IL-6, and TNF-α in lipopolysaccharide-activated macrophages, which might be associated with inhibited phosphorylation of p38 mitogen-activated protein kinase and c-Jun N-terminal kinase. Our data suggest that LJF-HE has an anti-inflammatory effect and may have potential as an antiosteoarthritic agent.