The potential of nutraceutical based compounds in targeting senescent cells in vitro

As a consequence of our cells preventing malignancy, cells become arrested in their cell cycle yet remain metabolically active, accumulating and causing tissue dysfunction contributing to poorer health quality in later life. This is known as cellular senescence. Certain nutraceuticals possess anti-inflammatory properties to combat the effects of cellular senescence. An in vitro senescence model through the artificial induction of senescence via DNA damage using irradiation in a mouse cell line was established. Thorough validation of the model for key markers of senescence was conducted of which include; lysosomal betagalactosidase staining, protein detection for cell cycle inhibitors, proliferation assays, cell cycle analysis and imaging such as light microscopy, immunofluorescence imaging, scanning electron microscopy and transmission electron microscopy. The platform was then used to experimentally test nutraceutical compounds with the potential to prevent senescence (Senostatic) or induce apoptosis (Senolytic) of senescent cells. Nutraceuticals which were tested include Holy Basil, Allicin and Phytol. Apoptosis of senescent cells were measured through Cell counting, TUNEL assay, Annexin V-FITC detection, Bcl-2 detection by western blot. Senostatic properties were investigated through cell proliferation counts, p21 detection by Western blot, Cell cycle analysis by propidium iodide staining and Beta-galactosidase staining. Finally transcriptomic analysis of the platform when treated with the nutraceuticals was also performed using Nanostring. Annexin V-FITC and TUNEL assay analysis showed all three nutraceuticals to have senolytic properties and an increase in cell death was seen in Allicin treated cells as a result of senolytic effect. An increase in cell viability in Allicin and Phytol treated cells showed senostatic activity. Reduced Beta-Galactosidase analysis was seen in all treated cells and an increased percentage of cells in S phase of Holy Basil treated cells indicating senostatic potential. Nanostring analysis further confirmed the senescence model with upregulation of key genes associated with senescence.