Evaluation of the Immunomodulatory Potential of Rhodium(III) Complexes with Cyclodextrins

Rhodium(III) (RhIII) is a metal with potential immunomodulatory and anti-inflammatory activity. In an attempt to improve their biological activities, RhIII complexes are being produced. Therefore, this study aimed to evaluate the immunomodulatory potential of RhIII and its coordination complexes (CCs) with beta cyclodextrin (βCD) and hydroxypropyl-beta-cyclodextrin (HPβCD). The physicochemical characterization of the complexes has been performed. Immunomodulatory activities were evaluated in vitro and in vivo in a carrageenan-induced mouse paw edema model. The results confirm the formation of CCs, being endothermic for the βCD system and exothermic for the HPβCD system. Moreover, the CCs self-assemble into supramolecular structures, as shown by dynamic light scattering (DLS) and zeta potential measurements. RhIII and CCs reduced the nitric oxide production and the expression of nuclear factor kappa B (NF-κB) and reduced the thickness of the paws. The results obtained in the present study demonstrate the immunomodulatory activity and anti-inflammatory potential of RhIII and its CCs.