The purpose of our study is to investigate the comparative effects of materials based on silver and gold nanoparticles functionalized with polyphenols from Cornus Mas extract (AgNPs-CM and AuNPs-CM) in vivo on experimental inflammation. The nanoparticles were obtained at room temperature under UV irradiation and were characterized by different methods: ultraviolet-visible spectroscopy, transmission electron microscopy, X ray diffraction, Fourier transform infrared spectroscopy and dynamic light scattering. The modulatory effects of AgNPs-CM and AuNPs-CM on inflammation were quantified by oxidative stress parameters, pro and anti-inflammatory cytokines levels and apoptosis assessment at 2 h, 24 and 48 h after induction of inflammation with carrageenan in the paw tissue of Wistar rats. Our results showed that silver and gold nanoparticles only partial and for a short period have mobilized the antioxidant defense mechanisms. In addition, they diminished inflammation and apoptosis in the early stage while later, at 48 h, exerted an immunomodulatory effect, activated ERK ½ and induced apoptosis. The photoreduced silver and gold nanoparticles, functionalized with natural compounds, modulated the inflammation in a similar manner in the soft tissue injected with carrageenan. In order to decipher the mechanisms involved in interactions of metallic nanoparticles with biological systems and for a complete assessment of the risks and benefits of these products in clinical practice long term studies are necessary.
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