Evaluation of cytokines in protective effect of docosahexaenoic acid in experimental achilles tendinopathy rat model induced with type-1 collagenase.

BACKGROUND: We aimed to investigate the effectiveness of docosahexaenoic acid (DHA) as a treatment for Achilles tendinopathy (AT) induced with type-I collagenase in rats and compare it with collagen. METHODS: The AT model was induced with type I collagenase, and animals were randomly assigned to groups. Group 1:AT, Group 2: Collagen (7.2 mg/kg/day), Group 3:DHA (300 mg/kg/day), and Group 4:DHA (100 mg/kg/day). Right tendons of Group1 were used as a healthy control (HC). Oral treatments were applied for eight weeks. Serum tumor necrosis factor-alpha(TNF-α), matrix metalloproteinase-13 (MMP-13), and interleukin-1 beta(IL-1ß) concentrations were determined by ELISA. Tendon samples were taken for histopathological evaluation and examined immunohistochemically with antibodies specific for Col1A1, TNF-α, MMP-13, IL-1ß, and nitric oxide synthase-2(NOS-2). The ultimate tensile force (UTF) yield force(YF) and stiffness were measured by biomechanical assessments. RESULTS: UTF,YF and stiffness values were increased in all treatment groups compared to the AT control, a significant increase was found in Group 2 (p < 0.05). There was severe degeneration of tendon cells in the AT control. The tendon cells in samples from Groups 2-3 were less degraded, and this was statistically significant (p < 0.05). TNF-α, MMP-13, IL-1ß, and NOS-2 expressions were significantly higher in the AT control compared to the HC. In all treatment groups, their concentrations were lower than in the AT control. Serum TNF-α, MMP-13, and IL-1ß levels were lower in all treatment groups (Especially in Group3 (p < 0.001)) compared to Group1. CONCLUSION: The efficacy of high-dose DHA as a treatment for AT was investigated from biochemical, histopathological, and biomechanical perspectives. The results showed that DHA could be an alternative treatment compound to collagen.

The Effect of Parietin Isolated From Rheum ribes L on In Vitro Wound Model Using Human Dermal Fibroblast Cells.

Parietin is one of the well-known anthraquinone compounds that can be extracted from Rheum ribes L. In this study, we aimed to investigate the effects of parietin isolated from Rheum ribes L on an in vitro wound model using human dermal fibroblast cells and compare its effectiveness against zinc. The antioxidant effect of parietin was determined by using the 1,1-diphenyl-2-picrylhydrazine (DPPH) method. Human dermal fibroblast cells were cultured in proculture medium and were kept until 100% confluence was achieved. The wound model was created by using a pipette tip. After that, different concentrations of parietin and zinc (final concentrations in the well to be 5-250 µM and 25-200 µM, respectively) were added into the medium. The proliferation-inducing effect on cell viability was determined by using MTT assay. Images of cells were taken at 0, 12, and 24 hours. According to the DPPH method, parietin exhibited have antioxidant activity. According to the MTT results, parietin exhibited significant proliferation-inducing effect on cell viability in a dose range of 5 to 10 M, and zinc showed significant proliferation-inducing effect on cell viability at dose 50 µM ( P < .05). In addition, the image of cell proliferation was also shown at the same doses at 24 hours. In this study, we claim that parietin induces cell proliferation at low doses in cases of dermal fibroblast loss. In conclusion, parietin as an alternative to zinc in wound healing could be used by clinicians in the future with more extensive studies.