Nano-encapsulation using macrocyclic carbohydrate polymers (β-cyclodextrins) of Periploca angustifolia extract: Physical stability and protective effect against cadmium-induced alterations in HepG2 cells.

The nano-encapsulation of Periploca angustifolia phenolic extract using the macrocyclic carbohydrate polymers (β‑cyclodextrins) is a most approach compared with other encapsulation methods. In this work, the β‑Cyclodextrins-PAE complex stability has been evaluated by advanced analytical methods and techniques including HPLC, FTIR and XRD. The results showed that CdCl₂ treatment caused a significant decrease in cell viability. The CdCl₂-induced damage in the HepG2 cells were significantly ameliorated (p < 0.001) by treatment of the PAE and β‑Cyclodextrins-PAE complex. Thus, pretreatment with 100 μg mL^-1 of β‑Cyclodextrins-PAE complex significantly protect HepG2 cells against cytotoxicity induced by cadmium exposure more effectively than PAE only. However, Cd-intoxication significantly (p < 0.001) increased these enzymes activity. Additionally, reactive oxygen species generation was significantly decreased when cells were treated with nano-encapsulation PAE. The levels of supernatant antioxidant parameters including superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and GSH were significantly (p < 0.001) decreased in Cd-treated cells with concomitant enhancement of lipid peroxidation. In addition, β‑Cyclodextrins-PAE pretreatment significantly (p < 0.01) inhibited Cd-exposure activated the apoptotic pathway caspace-3 and caspace-9. This effect may be due to the ability of β‑Cyclodextrins molecules to enhance stability and permeability properties.