Gold nanoparticles phytoreduced with Cornus mas extract mitigate some of gliadin effects on Caco-2 cells

Celiac disease (CD) is an autoimmune condition that occurs in genetically predisposed people where the ingestion of gluten produces damage in the small intestine. The treatment accepted until now is a strict gluten free diet. This implies the need for novel or adjuvant treatments, in addition to the standard of care. The present study aimed to assess the effect of gold nanoparticles phytosynthesized with Cornus mas extract (AuCM) compared to Cornus mas extract (CM) and luteolin (LT) on Caco-2 cells, exposed or not to gliadin. Ultraviolet-visible spectroscopy and transmission electron microscopy were used for the characterization of AuCM. Measured cellular outcomes included oxidative stress markers (malondialdehyde level, catalase and superoxide dismutase activities), inflammatory response and cellular signaling and transcription factors involved in apoptosis (NFκB, pNFκB, NOS2, TNF-α, TRAIL, Bax, Bcl-2, p53). The internalization of gold nanoparticles in cells was evidenced by transmission electron microscopy (TEM). The gliadin administration induced oxidative stress, improved the activity of antioxidants enzymes, increased NOS2 and NFκB expressions and reduced pNFκB/NFκB ratio. In addition, gliadin enhanced TRAIL and Bcl-2 levels and reduced p53 expression in Caco-2 cells. The pretreatment with AuCM, CM extract and LT diminished oxidative stress and reduced NOS2 activity. AuCM and CM treatment amplified the expression of p53 and pNFκB/NFκB ratio and diminished Bcl-2, NFκB and pNFκB, especially AuCM. The results obtained confirmed that AuCM mitigate some of gliadin effects on Caco-2 cells through modulation of oxidative stress and inflammation.