Olive leaf extract green-formulated manganese nanoparticles: Characterization and antioxidant, cytotoxicity and anti-breast carcinoma properties

Abstract

Olives are rich in many plant compounds; Antioxidants in olives protect against the occurrence of many cardiovascular diseases, blood pressure, diabetes, various types of cancers and tissue damage caused by free radicals. These antioxidant compounds include oluropine, hydroxytyrosol, tyrosol, oleanolic acid, and quercetin. Recent studies have focused on the therapeutic efficacies of manganese nanoparticles mediated by medicinal plants. The study investigated the characteristics of green manganese nanoparticles formulated using olive leaf extract on breast carcinoma cells. The nanoparticles were analyzed using FE-SEM, XRD, FT-IR, and UV–Vis techniques. The formation of manganese nanoparticles was confirmed by observing bands at 219 and 290 nm. The Mn-O vibration can be identified by the peaks observed at 516 and 610 cm−1. The peaks at 72.69, 60, 53.26, 44.97, 40.25, 34.83, and 28.48 corresponding to manganese nanoparticles (444), (440), (510), (420), (400), (222), and (220) diffraction planes, indicate the manganese nanoparticles formation. The MTT assay was employed to evaluate the anti-breast carcinoma effects (on CAMA-1 and MCF-7 cells) as well as the cytotoxicity effects (on HUVEC cell line) of manganese NPs. Results from the DPPH test showed that MnNPs and BHT at doses of 231 and 84 μg/ml were able to eliminate 50 % of radicals. The findings from the MTT experiment indicate that over 3 days, the cancer cells percentage that survived decreased proportionally to the increase in nanoparticle concentration. Furthermore, the data demonstrate that the cancer cells survival rate decreased with the rise in nanoparticle concentration, ultimately reaching a point where no viable cells were observed at a concentration of 1000 μg/ml. The most effective cytotoxicity was observed at a concentration of 1000 μg/ml. The MTT findings indicate that the IC50 values are 173 and 256 µg/ml, representing the concentration of nanoparticles at which half of the CAMA-1 and MCF-7 breast carcinoma cells in the culture medium are eradicated. Analysis of the gene expression levels of PIK3, AKT, and mTOR, linked to the mTOR pathway, in addition to Bax, Bcl2, and Caspase-3, demonstrates that copper nanoparticles efficiently control PC14 cell apoptosis and proliferation by regulating the PI3K-Akt-mTOR signaling pathway. The mTOR pathway could potentially be related to the suppression of the cell cycle and the initiation of apoptosis due to nanoparticles.