The Effects of the Combination of Rhein and Platelet-Rich Plasma on Human Articular Chondrocytes

Background: The presence of side effects and low bioavailability of rhein has limited its use in the treatment of osteoarthritis. We aimed to evaluate the in vitro response of human articular chondrocytes to the presence of the combination of platelet-rich plasma (PRP) and rhein. Methods: Solutions of rhein were prepared to assess solubility and select a working concentration. A stimulus with interleukin-1β (IL-β, 10 ng/mL) was induced for 24 h on human chondrocytes. Five treatment groups were established: control, IL-β control, PRP, rhein, and PRP + rhein. Cell viability, cell migration, nitric oxide (NO) production, tumor necrosis factor-α (TNF-α), and gene expression analyses were carried out. Results: A concentration of 50 mg/L was selected after a dose–response curve assay. Both NO and tumor TNF-α production significantly decreased after PRP and PRP + rhein treatments at 24 and 48 h. The wound healing assay revealed a significant stimulation of migration after 72 h with the PRP and PRP + rhein treatments. Expression of IL-1β, IL-6, MMP-13, and ADAMTS-5 was significantly downregulated, particularly after treatment with the combination of PRP + rhein. Conclusions: Much of the determinations denoted a better performance of the combination of PRP and rhein in decreasing the levels of the different targets evaluated; however, this was not great enough to detect a significant difference in comparison with the PRP treatment alone.