Improved Joint Health Following Oral Administration of Glycosaminoglycans with Native Type II Collagen in a Rabbit Model of Osteoarthritis

Protective Effects of a Mixed Medicinal Herb Extract (NUC1) on Collagenase-Induced Osteoarthritis in Rabbits

NUC1 (Nutraceutical compound 1) is an ethanol extract composed of a formulation based on medicinal herbs traditionally used for the treatment of arthritis in Korea and China. This study investigated the therapeutic effects of NUC1 on osteoarthritis (OA). The protective effect of NUC1 on OA was tested in a rabbit model of collagenase-induced arthritis (CIA) for 4 weeks. Results were compared among four groups (n = 9 per group): the normal group (untreated), the CIA group (vehicle control), the NUC1 group (CIA rabbits treated with 200 mg/kg NUC1), and the JOINS group (positive control, CIA rabbits treated with 200 mg/kg JOINS tablet). NUC1 significantly inhibited NO production (p < 0.05 at 125 μg/ml, p < 0.01 at 250 μg/ml, and p < 0.001 at 500 μg/ml) and iNOS expression in macrophages, in a concentration-dependent manner. NUC1 also inhibited the release and protein expression of MMP-1, 3, and 13, in TNF-α-induced chondrosarcoma cells in a concentration-dependent manner. In vivo, the MMP-1 and MMP-3 levels in synovial fluids were significantly (p < 0.05) lower in NUC1 group (77.50 ± 20.56 and 22.50 ± 7.39 pg/ml, respectively) than in the CIA group (148.33 ± 68.58 and 77.50 ± 20.46 pg/ml, respectively). Also, in histopathological, NUC1 ameliorated articular cartilage damage in OA by increasing the abundance of chondrocytes and proteoglycan in the articular cartilage. Thus, NUC1 showed promise as a potential therapeutic agent, and it can be generalized to a broader study population in different OA animal models.

Hyaluronic Acid-Extraction Methods, Sources and Applications

In this review, a compilation of articles in databases on the extraction methods and applications of hyaluronic acid (HA) was carried out. HA is a highly hydrated component of different tissues, including connective, epithelial, and neural. It is an anionic, linear glycosaminoglycan (GAG) primarily found in the native extracellular matrix (ECM) of soft connective tissues. Included in the review were studies on the extraction methods (chemical, enzymatical, combined) of HA, describing advantages and disadvantages as well as news methods of extraction. The applications of HA in food are addressed, including oral supplementation, biomaterials, medical research, and pharmaceutical and cosmetic industry applications. Subsequently, we included a section related to the structure and penetration routes of the skin, with emphasis on the benefits of systems for transdermal drug delivery nanocarriers as promoters of percutaneous absorption. Finally, the future trends on the applications of HA were included. This final section contains the effects before, during, and after the application of HA-based products.

Natural product, bilobalide, improves joint health in rabbits with osteoarthritis by anti-matrix degradation and antioxidant activities

Osteoarthritis (OA) is a common chronic musculoskeletal disease reported in veterinary clinics that severely reduces the quality of life of animals. The natural product, bilobalide, has positive effects on chondroprotection but its exact mechanism of action is unclear. This study aimed to investigate the antioxidant and anti-matrix degradation activities of bilobalide in a rabbit model of OA and its protective effects on joints. We also investigated the possible mechanisms underlying these effects. The rabbit OA model was established by intra-articular injection of 4% papain. Thirty healthy male New Zealand rabbits were randomly divided into control, untreated OA, Cel (100 mg/kg celecoxib intervention as a positive control), BB-L and BB-H (40 mg /kg and 80 mg /kg bilobalide gavage treatment, respectively) groups. Two weeks after surgical induction, bilobalide or celecoxib was administered by gavage daily for 8 weeks. After 8 weeks of bilobalide intervention, cartilage macroscopic observation and histopathological images showed alleviation of cartilage damage after bilobalide treatment, and the Osteoarthritis Research Society International (OARSI) score was significantly lower than that in the OA group. Bilobalide reduced the expression of metalloproteinase 3 (MMP-3) and MMP-13 in cartilage tissue of OA rabbits and reversed the levels of serum C-telopeptides of type II collagen (CTX-II), cartilage oligomeric matrix protein (COMP), interleukin 1(IL-1), and tumor necrosis factor (TNF-α). Bilobalide (80 mg/kg) could improve the biomechanical properties and microstructural changes in subchondral bone in the early stage of OA in rabbits, thereby delaying subchondral bone damage. Mechanistically, bilobalide exerted antioxidant and anti-matrix degradation effects by upregulating the oxidative stress signaling Nrf2/HO-1 pathway and inhibiting cartilage degeneration in rabbit OA. We thus speculate that bilobalide supplements recovery from OA damage.