Therapeutic Potential of Andrographolide Isolated from the Leaves of Andrographis paniculata Nees for Treating Lung Adenocarcinomas

Andrographolide sensitizes KRAS-mutant colorectal cancer cells to cetuximab by inhibiting the EGFR/AKT and PDGFRβ/AKT signaling pathways

BACKGROUND

Cetuximab, an inhibitor targeting EGFR, is widely applied in clinical management of colorectal cancer (CRC). Nevertheless, drug resistance induced by KRAS-mutations limits cetuximab's anti-cancer effectiveness. Furthermore, the persistent activation of EGFR-independent AKT is another significant factor in cetuximab resistance. Nevertheless, the mechanism that EGFR-independent AKT drives cetuximab resistance remains unclear. Thus, highlighting the need to optimize therapies to overcome cetuximab resistance and also to explore the underlying mechanism.

PURPOSE

This work aimed to investigate whether and how andrographolide enhance the therapeutic efficacy of cetuximab in KRAS-mutant CRC cells by modulating AKT.

METHODS

The viabilities of CRC cell lines were analyzed by CCK-8. The intracellular proteins phosphorylation levels were investigated by Human Phospho-kinase Antibody Array analysis. Knockdown and transfection of PDGFRβ were used to evaluate the role of andrographolide on PDGFRβ. The western blotting was used to investigate Wnt/β-catenin pathways, PI3K/AKT, and EMT in KRAS-mutant CRC cells. The animal models including subcutaneous tumor and lung metastasis were performed to assess tumor response to therapy in vivo.

RESULTS

Andrographolide was demonstrated to decrease the expression of PI3K and AKT through targeting PDGFRβ and EGFR, and it enhanced cetuximab effect on KRAS-mutant CRC cells by this mechanism. Meanwhile, andrographolide helped cetuximab to inhibit Wnt/β-catenin, CRC cell migration and reduced Vimentin expression, while increasing that of E-cadherin. Lastly, co-treatment with cetuximab and andrographolide reduced the growth of KRAS-mutant tumors and pulmonary metastases in vivo.

CONCLUSIONS

Our findings suggest that andrographolide can overcome the KRAS-mutant CRC cells' resistance to cetuximab through inhibiting the EGFR/PI3K/AKT and PDGFRβ /AKT signaling pathways. This research provided a possible theory that andrographolide sensitizes KRAS-mutant tumor to EGFR TKI.

Phytochemicals Showing Antiangiogenic Effect in Pre-clinical Models and their Potential as an Alternative to Existing Therapeutics

Angiogenesis, the formation of new blood vessels from a pre-existing vascular network, is an important hallmark of several pathological conditions, such as tumor growth and metastasis, proliferative retinopathies, including proliferative diabetic retinopathy and retinopathy of prematurity, age-related macular degeneration, rheumatoid arthritis, psoriasis, and endometriosis. Putting a halt to pathology-driven angiogenesis is considered an important therapeutic strategy to slow down or reduce the severity of pathological disorders. Considering the attrition rate of synthetic antiangiogenic compounds from the lab to reaching the market due to severe side effects, several compounds of natural origin are being explored for their antiangiogenic properties. Employing pre-clinical models for the evaluation of novel antiangiogenic compounds is a promising strategy for rapid screening of antiangiogenic compounds. These studies use a spectrum of angiogenic model systems that include HUVEC two-dimensional culture, nude mice, chick chorioallantoic membrane, transgenic zebrafish, and dorsal aorta from rats and chicks, depending upon available resources. The present article emphasizes the antiangiogenic activity of the phytochemicals shown to exhibit antiangiogenic behavior in these well-defined existing angiogenic models and highlights key molecular targets. Different models help to get a quick understanding of the efficacy and therapeutics mechanism of emerging lead molecules. The inherent variability in assays and corresponding different phytochemicals tested in each study prevent their immediate utilization in clinical studies. This review will discuss phytochemicals discovered using suitable preclinical antiangiogenic models, along with a special mention of leads that have entered clinical evaluation.

Mechanism of andrographis paniculata on lung cancer by network pharmacology and molecular docking

BACKGROUND

Traditional Chinese medicine (TCM) has been widely recognized and accepted worldwide to provide favorable therapeutic effects for cancer patients. As Andrographis paniculata has an anti-tumor effect, it might inhibit lung cancer.

OBJECTIVE

The drug targets and related pathways involved in the action of Andrographis paniculata against lung cancer were predicted using network pharmacology, and its mechanism was further explored at the molecular level.

METHODS

This work selected the effective components and targets of Andrographis paniculata against the Traditional Chinese Medicine System Pharmacology (TCMSP) database. Targets related to lung cancer were searched for in the GEO database (accession number GSE136043). The volcanic and thermal maps of differential expression genes were produced using the software R. Then, the target genes were analyzed by GO and KEGG analysis using the software R. This also utilized the AutoDock tool to study the molecular docking of the active component structures downloaded from the PubChem database and the key target structures downloaded from the PDB database, and the docking results were visualized using the software PyMol.

RESULTS

The results of molecular docking show that wogonin, Mono-O-methylwightin, Deoxycamptothecine, andrographidine F_qt, Quercetin tetramethyl (3',4',5,7) ether, 14-deoxyandrographolide, andrographolide-19-β-D-glucoside_qt and 14-deoxy-11-oxo-andrographolide were potential active components, while AKT1, MAPK14, RELA and NCOA1 were key targets.

CONCLUSION

This study showed the main candidate components, targets, and pathways involved in the action of Andrographis paniculata against lung cancer.

Acute and Subacute Toxicity Assessment of Andrographolide-2-hydroxypropyl-β-cyclodextrin Complex via Oral and Inhalation Route of Administration in Sprague-Dawley Rats

Objective

Acute and subacute toxicity analysis of AND-2-HyP-β-CYD complex was conducted in Sprague-Dawley (SD) rats following oral and inhalation routes of administration.

Methods and Results

Single dose acute toxicity was carried out at 2000 mg/kg of AND-2-HyP-β-CYD complex, while the doses of 200, 400, and 666 mg/kg were administered, over a period of 28 days under repeated dose oral toxicity study. Hence, LD50 (lethal dose) was found to be >2000 mg/kg in addition to NOAEL (no observed adverse effect level) of 666 mg/kg. Correspondingly, single dose acute inhalation toxicity of AND-2-HyP-β-CYD complex was carried out at 5 mg/L/4 h/day and subacute inhalation toxicity at 0.5, 1, and 1.66 mg/L/4 h/day over a period of 28 days. The NOAEL and LOAEL (lowest observed adverse effect level) were estimated to be 0.5 mg/L/4 h/day and 1 mg/L/4 h/day, respectively.

Conclusion

The findings of the present study would further be useful in assessing and utilizing the medicinal and therapeutic benefits of AND-2-HyP-β-CYD complex.

Andrographolide inhibits prostate cancer by targeting cell cycle regulators, CXCR3 and CXCR7 chemokine receptors

Despite state of the art cancer diagnostics and therapies offered in clinic, prostate cancer (PCa) remains the second leading cause of cancer-related deaths. Hence, more robust therapeutic/preventive regimes are required to combat this lethal disease. In the current study, we have tested the efficacy of Andrographolide (AG), a bioactive diterpenoid isolated from Andrographis paniculata, against PCa. This natural agent selectively affects PCa cell viability in a dose and time-dependent manner, without affecting primary prostate epithelial cells. Furthermore, AG showed differential effect on cell cycle phases in LNCaP, C4-2b and PC3 cells compared to retinoblastoma protein (RB(-/-)) and CDKN2A lacking DU-145 cells. G2/M transition was blocked in LNCaP, C4-2b and PC3 after AG treatment whereas DU-145 cells failed to transit G1/S phase. This difference was primarily due to differential activation of cell cycle regulators in these cell lines. Levels of cyclin A2 after AG treatment increased in all PCa cells line. Cyclin B1 levels increased in LNCaP and PC3, decreased in C4-2b and showed no difference in DU-145 cells after AG treatment. AG decreased cyclin E2 levels only in PC3 and DU-145 cells. It also altered Rb, H3, Wee1 and CDC2 phosphorylation in PCa cells. Intriguingly, AG reduced cell viability and the ability of PCa cells to migrate via modulating CXCL11 and CXCR3 and CXCR7 expression. The significant impact of AG on cellular and molecular processes involved in PCa progression suggests its potential use as a therapeutic and/or preventive agent for PCa.

Notch1-MAPK Signaling Axis Regulates CD133+ Cancer Stem Cell-Mediated Melanoma Growth and Angiogenesis

Functional characterization and understanding of the intricate signaling mechanisms in stem-like cells is crucial for the development of effective therapies in melanoma. We have studied whether melanoma cells are phenotypically distinct and hierarchically organized according to their tumorigenic nature. We report that melanoma-specific CD133⁺ cancer stem cells exhibit increased tumor-initiating potential, tumor-endothelial cell interaction, and lung metastasis. These cells are able to transdifferentiate into an endothelial-like phenotype when cultured under endothelial differentiation-promoting conditions. Mechanistically, Notch1 upregulates mitogen-activated protein kinase activation through CD133, which ultimately controls vascular endothelial growth factor and matrix metalloproteinase expression in CD133⁺ stem cells leading to melanoma growth, angiogenesis, and lung metastasis. Blockade or genetic ablation of Notch1 and mitogen-activated protein kinase pathways abolishes melanoma cell migration and angiogenesis. Chromatin immunoprecipitation and reporter assays revealed that Notch1 intracellular domain regulates CD133 expression at the transcriptional level. Andrographolide inhibits Notch1 intracellular domain expression, Notch1 intracellular domain-dependent CD133-mediated mitogen-activated protein kinase and activator protein-1 activation, and epithelial to mesenchymal-specific gene expression, ultimately attenuating melanoma growth and lung metastasis. Human malignant melanoma specimen analyses revealed a strong correlation between Notch1 intracellular domain, CD133, and p-p38 mitogen-activated protein kinase expression and malignant melanoma progression. Thus, targeting Notch1 and its regulated signaling network may have potential therapeutic implications for the management of cancer stem cell-mediated melanoma progression.

Identification of the Novel TMEM16A Inhibitor Dehydroandrographolide and Its Anticancer Activity on SW620 Cells

TMEM16A, a calcium-activated chloride channel (CaCC), is highly amplified and expressed in human cancers and is involved in the growth and metastasis of some malignancies. Inhibition of TMEM16A represents a novel pharmaceutical approach for the treatment of cancers and metastases. The purpose of this study is to identify a new TMEM16A inhibitor, investigate the effects of this inhibitor on the proliferation and metastasis of TMEM16A-amplified SW620 cells, and to elucidate the underlying molecular mechanism in vitro. We identified a novel small-molecule TMEM16A inhibitor dehydroandrographolide (DP). By using patch clamp electrophysiology, we showed that DP inhibited TMEM16A chloride currents in Fisher rat thyroid (FRT) cells that were transfected stably with human TMEM16A and in TMEM16A-overexpressed SW620 cells but did not alter cystic fibrosis transmembrane conductance regulator (CFTR) chloride currents. Further functional studies showed that DP suppressed the proliferation of SW620 cells in a dose- and time-dependent manner using MTT assays. Moreover, DP significantly inhibited migration and invasion of SW620 cells as detected by wound-healing and transwell assays. Further mechanistic study demonstrated that knockdown of human TMEM16A decreased the inhibitory effect of DP on the proliferation of SW620 cells and that TMEM16A-dependent cells (SW620 and HCT116) were more sensitive to DP than TMEM16A-independent cells (SW480 and HCT8). In addition, we found that treatment of SW620 cells with DP led to a decrease in TMEM16A protein levels but had no effect on TMEM16A mRNA levels. The current work reveals that DP, a novel TMEM16A inhibitor, exerts its anticancer activity on SW620 cells partly through a TMEM16A-dependent mechanism, which may introduce a new targeting approach for an antitumour therapy in TMEM16A-amplified cancers.

Lactoferrin protects against chemical-induced rat liver fibrosis by inhibiting stellate cell activation

Liver diseases, which can be caused by alcohol abuse, chemical intoxication, viral hepatitis infection, and autoimmune disorders, are a significant health issue because they can develop into liver fibrosis and cirrhosis. Lactoferrin (LF), a siderophilic protein with 2 iron-binding sites, has been demonstrated to possess a multitude of biological functions, including antiinflammation, anticancer, and antimicrobial effects, as well as immunomodulatory-enhancing functions. In the current study, we induced hepatotoxicity in rats with dimethylnitrosamine (DMN) to establish a situation that would enable us to evaluate the hepatoprotective effects of LF against hepatic injury. Our results showed that DMN-induced hepatic pathological damage significantly decreased the body weight and liver index, increased the mRNA and protein levels of collagen α-1(I) (ColIα-1) and α-smooth muscle actin, and increased the hydroxyproline content. However, treatment with LF significantly increased body weight and liver index, decreased the mRNA and protein levels of ColIα-1 and α-smooth muscle actin, and suppressed the hydroxyproline content when compared with the DMN-treated group. Liver histopathology also showed that low-dose LF (100mg/kg of body weight) or high-dose LF (300 mg/kg of body weight) could significantly reduce the incidences of liver lesions induced by DMN. These results suggest that the LF exhibits potent hepatoprotection against DMN-induced liver damage in rats and that the hepatoprotective effects of LF may be due to the inhibition of collagen production and to stellate cell activation.