Phytochemical-based nanotherapeutics for cancer cells: Synthesis, efficacy, and PBPK modeling

The use of plant derived phytochemicals has captured great attention owing to their potential antitumor, anti-inflammatory, antimicrobial and antioxidant effects to be used as pharmacological agents. The integration of nanoparticles (NPs) into drug delivery systems has been shown to enhance the pharmacokinetic profiles of therapeutic agents. Combining NPs with phytochemicals or drug molecules holds promise as systems that could provide effective therapeutic outcomes. In the present study, nanocarrier-phytochemical conjugates (C60-ATQ) were synthesized and characterized via DLS, ELS, NMR, FTIR, XRD, UV-Vis spectroscopy, TGA and DSC analyses. In vitro cytotoxicity analyses were carried out on human pancreatic and human leukemic cell lines to investigate the effects of various phytochemicals, NPs (AuNPs and Carbon-based NPs), drugs, their combinations, and conjugated forms. In vitro, Betulin and Thymoquinone showed the most cytotoxic effect as single agents, Temsirolimus + Betulin or Curcumin and AuNP + Temsirolimus combinations exhibited enhanced cytotoxic responses as combinative treatments. Betulin and Curcumin induced sustained oxidative stress and a progressive, time-dependent decline in MMP, suggesting their cytotoxic and pro-apoptotic effects in Molt-4 cells. RNA-sequencing of Betulin-treated Molt-4 cells revealed 478 differentially expressed genes related to stress, apoptosis, and metal ion imbalance, highlighting strong metallothionein upregulation and hemoglobin gene downregulation. PBPK modeling was used to predict the distribution of these compounds in humans through interspecies scaling from rats, providing insights into their potential tissue distribution and in vivo behavior. The model evaluation depicted that lipophilicity, fraction unbound value in plasma and the plasma protein scale factor were the most significant parameters that affect the AUC and the Cmax. This thesis study, which includes the integration of phytochemicals and nanotechnology for enhanced drug delivery, provides valuable insights into tissue targeting and bioavailability, crucial for optimizing their use in clinical settings.