Bio-inspired deposition of gold nanoparticles onto the surface of kaolin for in vitro management of human ovarian cancer and modulation of the inflammatory response in adenomyosis-induced mice in vivo via the MAPK signaling pathway

A mild and eco-friendly protocol has been developed for the preparation of kaolin-decorated Au nanoparticles mediated by Ephedra root extract as a green reducing and stabilizing agents without any toxic substrates. Structural features of the prepared Au NPs/Kaolin were assessed through FE-SEM, TEM, and XRD techniques. TEM images show the good deposition of Au NPs over the surface of extract-modified kaolin without aggregation. Towards the medicinal application, its antioxidant efficacy was assessed by the DPPH method, and the corresponding IC₅₀ value was obtained as 104 μg/mL. Cytotoxicity of the nanoformulated bio-composite was ascertained through MTT analysis against human ovarian carcinoma cells, i.e., PA-1 and SK-OV-3. The IC₅₀ in those studies was 250 and 119 μg/mL against PA-1and SK-OV-3 cells, respectively. In the in vivo design, tamoxifen was used to induce the experimental adenomyosis model in mice. After treatment, the thymus, spleen, uterine, and body weights of all animals were measured. Then, inflammatory factor expression and myometrial infiltration were determined by qRT-PCR, ELISA, and histology examination in the uterus. Western blotting, qRT-PCR, and immune histochemical (IHC) staining were applied to analyze the MAPK/ERK signaling pathway protein expression. Au NPs/Kaolin bio-nanocomposite ameliorated the adenomyosis symptoms by raising the thymus and spleen index and decreasing the myometrial infiltration. The raised levels of TNF-α, IL-6, and IL-1β in adenomyosis model mice uterus and serum were also reduced after Au NPs/Kaolin bio-nanocomposite treatment. The adenomyosis amelioration of Au NPs/Kaolin bio-nanocomposite was gained by preventing the MAPK/ERK signaling pathway, including decreasing the expressions of protein and mRNA of p-p38/p38, p-JNK/JNK, and p-ERK/ERK.