RESUMO
Osteoarthritis (OA) is a degenerative chronic disease that affects various tissues surrounding the joints, such as the subchondral bone and articular cartilage. The purpose of the study was to investigate the impact of collagen type III (CIII; 10 mg/kg; p.o.) on OA evidenced by restoration of articular cartilage structural changes as well as inflammatory responses using an established rat model of OA. OA was induced in rats by a single intra-articular injection of monosodium iodoacetate (MIA) through the right knee of the rats. Oral administration of CIII was undergone for 14 consecutive days. Changes in joint volume were measured throughout the experiment period with one-week intervals. At the end of the experiment, the rats were placed in the activity cage, and their activities were counted. Oxidative stress and nitrosative biomarkers were assessed by measuring the serum levels of malondialdehyde (MDA), reduced glutathione (GSH) and nitric oxide (NOx). Moreover, inflammatory markers viz. interleukin-6 (IL-6), interleukin-1ß (IL-1ß) and tumor necrosis nuclear factor-alpha (TNF-α) were measured. In addition, radiographic analysis and histopathological examination of the rat's knee were performed. The results of the current study revealed that oral treatment of MIA-induced osteoarthritic rats with CIII (10 mg/kg) for two weeks showed a marked decrease in the joint volume which led eventually to a prominent increase in the motor activity. Furthermore, treatment with CIII restored the serum levels of MDA, GSH, NOx, IL-6, IL-1ß and the TNF-α. Furthermore, CIII succeeded to ameliorate the detrimental effect of MIA on radiographic images and histopathological alterations of the joint. From these findings, it can be concluded that CIII has regenerative and anti-inflammatory properties, thus has the ability to counteract MIA-induced OA in rat. Finally, CIII is said to be a potential anti-osteoarthritic candidate.
RESUMO
BACKGROUND AND PURPOSE: Diabetes mellitus is a disorder accompanied by oxidative and inflammatory responses, that might exacerbate vascular complications. The purpose of this study was to investigate the potential antioxidant and anti-inflammatory effects of melatonin (MLN) on streptozotocin (STZ)-induced diabetic rats subjected to middle cerebral artery occlusion followed by reperfusion (MCAO/Re). EXPERIMENTAL APPROACH: Diabetes was induced in rats by a single injection of STZ (55 mg/kg; i.p.). The cerebral injury was then induced by MCAO/Re after six weeks. After 24 h of MCAO/Re the MLN (10 mg/kg) was administered orally for 14 days. Serum and tissue samples were extracted to determine malondialdehyde (MDA), reduced glutathione (GSH), nitric oxide (NO), interleukin-1ß (IL-1ß), and the tumor necrosis factor- α (TNF-α). Part of the brain tissue was kept in formalin for pathological and immunohistochemical studies to determine nuclear factor kappa B (NF-kB) and cyclooxygenase-2 (COX-2) immune reactivity. FINDINGS/RESULTS: MCAO/Re in STZ-induced hyperglycaemic rats caused a decrease in brain GSH, an increase in brain MDA, and NO was increased in both serum and brain tissue. Rats showed a prominent increase in the serum and brain inflammatory markers viz. IL-1ß and TNF-α. Oral treatment with MLN (10 mg/kg) for two weeks reduced the brain levels of MDA, NO, IL-1ß, and TNF-α. Impressive amelioration in pathological findings, as well as a significant decrease in NF-kB and COX2 immune stained cells of the cerebral cortex, hippocampus, and cerebellum, occurred after treatment with MLN. It also succeeded to suppress the exacerbation of damage in the brain of hyperglycaemic rats. CONCLUSION AND IMPLICATIONS: Daily intake of MLN attenuates the exacerbation of cerebral ischemic injury in a diabetic state.
