Recently, there has been great interest in plant-derived compounds known as phytochemicals. The pentacyclic oleanane-, ursane-, and lupane-type triterpenes are phytochemicals that exert significant activity against diseases like cancer. Lung cancer is the leading cause of cancer-related death worldwide. Although chemotherapy is the treatment of choice for lung cancer, its effectiveness is hampered by the dose-limiting toxic effects and chemoresistance. Herein, we investigated six pentacyclic triterpenes, oleanolic acid, ursolic acid, asiatic acid, betulinic acid, betulin, and lupeol, on NSCLC A549 cells. These triterpenes have several structural variations that can influence the activation/inactivation of key cellular pathways. From our results, we determined that most of these triterpenes induced apoptosis, S-phase and G2/M-phase cycle arrest, the downregulation of ribonucleotide reductase (RR), reactive oxygen species, and caspase 3 activation. For chemoresistance markers, we found that most triterpenes downregulated the expression of MAPK/PI3K, STAT3, and PDL1. In contrast, UrA and AsA also induced DNA damage and autophagy. Then, we theoretically determined other possible molecular targets of these triterpenes using the online database ChEMBL. The results showed that even slight structural changes in these triterpenes can influence the cellular response. This study opens up promising perspectives for further research on the pharmaceutical role of phytochemical triterpenoids.

Nanosized drug delivery systems (DDS) have been studied as a novel strategy against cancer due to their potential to simultaneously decrease drug inactivation and systemic toxicity and increase passive and/or active drug accumulation within the tumor(s). Triterpenes are plant-derived compounds with interesting therapeutic properties. Betulinic acid (BeA) is a pentacyclic triterpene that has great cytotoxic activity against different cancer types. Herein, we developed a nanosized protein-based DDS of bovine serum albumin (BSA) as the drug carrier combining two compounds, doxorubicin (Dox) and the triterpene BeA, using an oil-water-like micro-emulsion method. We used spectrophotometric assays to determine protein and drug concentrations in the DDS. The biophysical properties of these DDS were characterized using dynamic light scattering (DLS) and circular dichroism (CD) spectroscopy, confirming nanoparticle (NP) formation and drug loading into the protein structure, respectively. The encapsulation efficiency was 77% for Dox and 18% for BeA. More than 50% of both drugs were released within 24 h at pH 6.8, while less drug was released at pH 7.4 in this period. Co-incubation viability assays of Dox and BeA alone for 24 h demonstrated synergistic cytotoxic activity in the low μM range against non-small-cell lung carcinoma (NSCLC) A549 cells. Viability assays of the BSA-(Dox+BeA) DDS demonstrated a higher synergistic cytotoxic activity than the two drugs with no carrier. Moreover, confocal microscopy analysis confirmed the cellular internalization of the DDS and the accumulation of the Dox in the nucleus. We determined the mechanism of action of the BSA-(Dox+BeA) DDS, confirming S-phase cell cycle arrest, DNA damage, caspase cascade activation, and downregulation of epidermal growth factor receptor (EGFR) expression. This DDS has the potential to synergistically maximize the therapeutic effect of Dox and diminish chemoresistance induced by EGFR expression using a natural triterpene against NSCLC.

Clinically approved iron chelators, originally designed to address iron overload disorders, have emerged as potential anticancer agents. Deferasirox (Def), a tridentate iron chelator, has demonstrated antiproliferative effects in cancer. Background/Objectives: This study aims to elucidate the mechanism of action of Def and its impact on non-small cell lung carcinoma (NSCLC). Methods: NSCLC A549 cells were treated with Def to assess cytotoxicity, the effect on nuclear and mitochondrial pathways, and iron-containing proteins and genes to evaluate anti-metastasis and chemoresistance. A lung carcinoma mouse model was used for in vivo studies. Results: Our findings revealed that Def induced cytotoxicity, effectively chelated intracellular iron, and triggered apoptosis through the increase in phosphatidylserine externalization and caspase 3 activity. Additionally, Def caused G0/G1 cell cycle arrest by downregulating the ribonucleotide reductase catalytic subunit. Furthermore, Def perturbed mitochondrial function by promoting the production of reactive oxygen species and the inhibition of glutathione as a measurement of ferroptosis activation. Def demonstrated inhibitory effects on cell migration in scratch assays, which was supported by the upregulation of n-myc downstream-regulated gene 1 and downregulation of the epidermal growth factor receptor protein. Also, Def downregulated one of the main markers of chemoresistance, the ABCB1 gene. In vivo experiments using a lung carcinoma mouse model showed that Def treatment did not affect the animal’s body weight and showed a significant decrease in tumor growth. Conclusions: This investigation lays the groundwork for unraveling Def action’s molecular targets and mechanisms in lung carcinoma, particularly within iron-related pathways, pointing out its anti-metastasis and anti-chemoresistance effect.

In recent times, a great interest has been motivated in plant-derived compounds known as phytochemicals. The pentacyclic oleanane-, ursane-, lupane-type triterpenes are phytochemicals that exert significant activities against diseases like cancer. Lung cancer is the leading cause of cancer-related death worldwide. Although chemotherapy is the treatment of choice for lung cancer, its effectiveness is hampered by the dose‐limiting toxic effects and chemoresistance. Herein, we investigated the structure-activity relationship of six pentacyclic triterpenes: oleanolic acid (OleA), ursolic acid (UrA), asiatic acid (AsA), betulinic acid (BeA), betulin (Betu), lupeol (Lupe), on NSCLC A549 cells. From our studies, we confirmed that all these triterpenes showed cytotoxicity in the mid µM range, where BeA showed the strongest effect. Then, we determined that most of these triterpenes induced S-phase and G2/M phase cycle arrest, reactive oxygen species, mitochondrial depolarization, and caspase 3 activation. For chemoresistance markers, we elucidated that most triterpenes downregulated STAT3 and PDL1 genes. In contrast, ursane-type UrA and AsA also induced DNA damage, reactive nitrogen species and autophagy. These results showed that even slight structural changes in these triterpenes can influence the cellular response and mechanistic pathways. This study opens promising perspectives for further research on the pharmaceutical role of phytochemical triterpenoids.

Nanosized drug delivery systems (DDS) have been studied as a novel strategy against cancer due to their potential to simultaneously decrease drug inactivation and systemic toxicity and increase passive and/or active drug accumulation within the tumor(s). Triterpenes are plant-derived compounds with interesting therapeutic properties. Betulinic acid (BeA) is a pentacyclic triterpene which has great cytotoxic activity against different cancer types. Herein, we developed a nanosized protein-based DDS of bovine serum albumin (BSA) as the drug carrier combining two compounds: doxorubicin (Dox) and the triterpene BeA using an oil-water-like micro-emulsion method. Spectrophotometric assays were performed to determine protein and drug concentrations in the DDS. The biophysical properties of these DDS were characterized using dynamic light scattering (DLS) and circular dichroism (CD) spectroscopy confirming nanoparticle (NP) formation and drug loading into the protein structure, respectively. The encapsulation efficiency was 77% for Dox and 18% for BeA. More than 50% of both drugs were released within 24 h, at pH 6.8, while less drug was released at pH 7.4 in this time period. Co-incubation viability assays of Dox and BeA alone for 24 h demonstrated synergistic cytotoxic activity in the low μM range against the non-small cell lung carcinoma (NSCLC) A549 cells. Viability assays of the BSA(Dox+BeA) DDS demonstrated a higher synergistic cytotoxic activity than the two drugs with no carrier. Moreover, confocal microscopy analysis confirmed cellular internalization of the DDS and nucleus accumulation of the Dox. We determined the mechanism of action of the BSA(Dox+BeA) DDS, confirming S-phase cell cycle arrest, DNA damage, caspase cascade activation, and downregulation of the epidermal growth factor receptor (EGFR) expression. This DDS has the potential to synergistically maximize the therapeutic effect of Dox and diminish chemoresistance induced by EGFR expression using a natural triterpene against NSCLC.