Natural Products in Preventing Tumor Drug Resistance and Related Signaling Pathways

The Antitumoral Effect In Ovo of a New Inclusion Complex from Dimethoxycurcumin with Magnesium and Beta-Cyclodextrin

Breast cancer is one of the leading causes of death in the female population because of the resistance of cancer cells to many anticancer drugs used. Curcumin has cytotoxic activities against breast cancer cells, although it has limited use due to its poor bioavailability and rapid metabolic elimination. The synthesis of metal complexes of curcumin and curcuminoids is a relevant topic in the search for more active and selective derivatives of these molecular scaffolds. However, solubility and bioavailability are concomitant disadvantages of these types of molecules. To overcome such drawbacks, the preparation of inclusion complexes offers a chemical and pharmacologically safe option for improving the aqueous solubility of organic molecules. Herein, we describe the preparation of the inclusion complex of dimethoxycurcumin magnesium complex (DiMeOC-Mg, (4)) with beta-cyclodextrin (DiMeOC-Mg-BCD, (5)) in the stoichiometric relationship 1:1. This new inclusion complex's solubility in aqueous media phosphate buffer saline (PBS) was improved by a factor of 6x over the free metal complex (4). Furthermore, 5 affects cell metabolic rate, cell morphology, cell migration, induced apoptosis, and downregulation of the matrix metalloproteinase-2 (MMP-2) and matrix metalloproteinase-9 (MMP-9), interleukin-6 (IL-6), and signal transducer and activator of transcription-3 (STAT3) expression levels on MD Anderson metastasis breast-231 cancer (MDA-MB-231) cell lines. Results of an antitumor assay in an in ovo model showed up to 30% inhibition of tumor growth for breast cancer (MDA-MB-231) when using (5) (0.650 mg/kg dose) and 17.29% inhibition with the free homoleptic metal complex (1.5 mg/kg dose, (4)). While the formulation of inclusion complexes from metal complexes of curcuminoids demonstrates its usefulness in improving the solubility and bioavailability of these metallodrugs, the new compound (5) exhibits excellent potential for use as a therapeutic agent in the battle against breast cancer.

Antitumor Activity and Mechanism of Terpenoids in Seaweeds Based on Literature Review and Network Pharmacology

Seaweeds are a treasure trove of natural secondary metabolites. Terpenoids extracted from seaweeds are shown to possess a variety of antitumor cellular activities. However, due to the complex and diverse structures of terpenoids, their therapeutic targets and complex mechanisms of action have not been clarified. The present study summarises the research on terpenoids from seaweeds in oncological diseases over the last 20 years. Terpenoids show different degrees of inhibitory effects on different types of tumor cells, suggesting that terpenoids in seaweeds may have potential antitumor disease potential. Terpenoids with potential antitumor activity and their mechanism of action are investigated using network pharmacology. A total of 125 terpenoids and 286 targets are obtained. Proto-oncogene tyrosine-protein kinase Src(SRC), Signal transducer and activator of transcription 3 (STAT3), Mitogen-activated protein kinase (MAPK3, MAPK1), Heat shock protein HSP 90-alpha (HSP90AA1), Phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA), and RAC-alpha serine/threonine-protein kinase (AKT1) are defined as core targets. According to GO function and Kyoto encyclopedia of genes and genomes(KEGG) enrichment analysis, terpenoids may affect the Phoshatidylinositol 3'-kinase (PI3K)-Akt signaling pathway, Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor resistance, Prostate cancer, MAPK signaling pathway, and Proteoglycans in cancer. In addition, the molecular docking results show that the selected terpenoids are all able to bind strongly to the active protein. Terpenoids may slow down the progression of cancer by controlling apoptosis, proliferation, and protein and enzyme binding.

Natural medicinal compounds target signal transduction pathways to overcome ABC drug efflux transporter-mediated multidrug resistance in cancer

ATP-binding cassette (ABC) transporters such as ABCB1, ABCG2, and ABCC1 are the major players in drug efflux-mediated multidrug resistance (MDR), which severely affects the efficacy of chemotherapy. Several synthetic compounds block the drug transport by ABC transporters; however, they exhibit a narrow therapeutic window, and produce side effects in non-target normal tissues. Conversely, the downregulation of the expression of ABC drug transporters seems to be a promising strategy to reverse MDR in cancer cells. Several signaling pathways, such as NF-κB, STAT3, Gli, NICD, YAP/TAZ, and Nrf2 upregulate the expression of ABC drug transporters in drug-resistant cancers. Recently, natural medicinal compounds have gained importance to overcome the ABC drug-efflux pump-mediated MDR in cancer. These compounds target transcription factors and the associated signal transduction pathways, thereby downregulating the expression of ABC transporters in drug-resistant cancer cells. Several potent natural compounds have been identified as lead candidates to synergistically enhance chemotherapeutic efficacy, and a few of them are already in clinical trials. Therefore, modulation of signal transduction pathways using natural medicinal compounds for the reversal of ABC drug transporter-mediated MDR in cancer is a novel approach for improving the efficiency of the existing chemotherapeutics. In this review, we discuss the modulatory role of natural medicinal compounds on cellular signaling pathways that regulate the expression of ABC transporters in drug-resistant cancer cells.

Jatrophone: a cytotoxic macrocylic diterpene targeting PI3K/AKT/NF-κB pathway, inducing apoptosis and autophagy in resistant breast cancer cells

BACKGROUND

Breast cancer is a prevalent malignant tumor that affects women worldwide. The primary challenge in treating breast cancer is combating drug resistance, which contributes to relapse and metastasis. Jatrophone is a unique macrocyclic jatrophane diterpene found in various Jatropha and Euphorbia species. It possesses diverse biological and pharmacological activities, including anticancer activity. However, it is unclear whether jatrophone can overcome drug resistance in breast cancer.

METHODS

This study includes the investigation of the cytotoxicity of jatrophone on doxorubicin-resistant breast cancer cells (MCF-7ADR) and the underlying molecular mechanisms. The effects of jatrophone on cell viability were determined using the sulforhodamine B (SRB) assay, while flow cytometry was used to evaluate cell cycle progression, apoptosis, and autophagy. A scratch assay was conducted to observe cell migration, and western blotting was used to measure downstream protein levels (PI3K, AKT, and NF-κB). Unpaired Student's t-tests were used for comparison between the two groups and the results were analyzed by one-way ANOVA with Tukey- Kremer post hoc test.

RESULTS

It was shown that jatrophone exhibited potent cytotoxic activity on MCF-7ADR cells in a dose-dependent manner, with an IC50 value of 1.8 µM. It also significantly induced cell cycle S and G/M phase arrest. Interestingly, jatrophone induced both early and late apoptotic cell death, as well as autophagic cell death, with negligible necrosis. Furthermore, jatrophone treatment diminished the migration of MCF-7ADR cells. At the molecular level, jatrophone treatment significantly down-regulated the expression levels of PI3K, AKT, and NF-κB. β.

CONCLUSIONS

The results of the study suggest that jatrophone decreases the proliferation of MCF-7/ADR cells at a low micromolar concentration; induces cell cycle arrest; promotes apoptotic, and autophagic cell death; inhibits migration and EMT; and works on resistance by a mechanism involving the inhibition of the PI3K/Akt/ NF-κB pathway. These findings provide evidence of the potential of jatrophone to be a promising lead compound for targeting doxorubicin-resistant breast cancer cells and could be further investigated for its clinical application as a chemotherapy adjuvant.

Circular RNAs in gynecologic cancers: mechanisms and implications for chemotherapy resistance

Chemotherapy resistance remains a major challenge in the treatment of gynecologic malignancies. Increasing evidence suggests that circular RNAs (circRNAs) play a significant role in conferring chemoresistance in these cancers. In this review, we summarize the current understanding of the mechanisms by which circRNAs regulate chemotherapy sensitivity and resistance in gynecologic malignancies. We also discuss the potential clinical implications of these findings and highlight areas for future research. CircRNAs are a novel class of RNA molecules that are characterized by their unique circular structure, which confers increased stability and resistance to degradation by exonucleases. Recent studies have shown that circRNAs can act as miRNA sponges, sequestering miRNAs and preventing them from binding to their target mRNAs. This can lead to upregulation of genes involved in drug resistance pathways, ultimately resulting in decreased sensitivity to chemotherapy. We discuss several specific examples of circRNAs that have been implicated in chemoresistance in gynecologic cancers, including cervical cancer, ovarian cancer, and endometrial cancer. We also highlight the potential clinical applications of circRNA-based biomarkers for predicting chemotherapy response and guiding treatment decisions. Overall, this review provides a comprehensive overview of the current state of knowledge regarding the role of circRNAs in chemotherapy resistance in gynecologic malignancies. By elucidating the underlying mechanisms by which circRNAs regulate drug sensitivity, this work has important implications for improving patient outcomes and developing more effective therapeutic strategies for these challenging cancers.

Phytochemical Analysis and Profiling of Antioxidants and Anticancer Compounds from Tephrosia purpurea (L.) subsp. apollinea Family Fabaceae

Tephorosia purpurea subsp. apollinea was extracted with methanol and n-hexane to obtain sub-fractions. The chemical compounds identified with GC-MS and HPLC in T. purpurea subsp. apollinea extracts showed antioxidant and anticancer properties. The antioxidant and anticancer activities were investigated using DDPH and ABTS assays, and MTT assay, respectively. Stigmasta-5,24(28)-dien-3-ol, (3 β,24Z)-, 9,12,15-octadecatrienoic acid methyl ester, phytol, chlorogenic acid, and quercetin were the major chemical compounds detected in T. purpurea subsp. apollinea. These compounds possessed antioxidant and anticancer properties. The methanol extract showed antioxidant properties with DDPH and ABTS radical scavenging of 84% and 94%, respectively, relative to ascorbic acid and trolox. The anticancer effects of T. purpurea subsp. apollinea against the cancer cell lines MCF7 (IC₅₀ = 102.8 ± 0.6 μg/mL), MG63 (IC₅₀ = 118.3 ± 2.5 μg/mL), T47D (IC₅₀ = 114.7 ± 1.0 μg/mL), HeLa (IC₅₀ = 196.3 ± 2.3 μg/mL), and PC3 (IC₅₀ = 117.7 ± 1.1 μg/mL) were greater than its anticancer effects against U379 (IC₅₀ = 248.4 ± 7.5 μg/mL). However, it had no adverse effects on the normal cells (WI38) (IC₅₀ = 242.9 ± 1.8 μg/mL). Therefore, the major active constituents presented in T. purpurea subsp. apollinea can be isolated and studied for their potential antioxidant and anticancer effects against breast, cervical, and prostate cancers and osteosarcoma.

Pharmacological Strategies for Overcoming Multidrug Resistance to Chemotherapy

Actual mechanisms of multidrug resistance (MDR) to chemotherapy in oncology are considered. ABC-transporters such as P-glycoprotein, BCRP protein, and MRP proteins take part in the development of resistance. The review presents the main classes of chemosensitizers, i.e., inhibitors of ABC transporters of the 1st-4th generations. Plant polyphenols, i.e., flavonoids, are commonly referred to as the last (4th) generation of MDR inhibitors. Chemosensitizers of different classes should be chosen with allowance for the patient mutation-expression profile and the receptor status of a particular tumor. The appropriate dosage of the chemosensitizer and the administration schedule can enhance the process of counteracting MDR.

Phytochemical Analysis and Profiling of Antitumor Compounds of Leaves and Stems of Calystegia silvatica (Kit.) Griseb

Anti-tumor compounds from natural products are being investigated as possible alternatives for cancer chemotherapeutics that have serious adverse effects and tumor resistance. Calystegia silvatica was collected from the north coast of Egypt and extracted via methanol and n-hexane sub-fraction. The biologically active compounds of Calystegia silvatica were identified from the methanol and n-hexane extracts from the leaves and stems of the plant using GC-MS and HPLC. The antitumor properties of both parts of the plant were investigated against cancer and non-cancer cell lines using the MTT assay, and the IC₅₀ in comparison to doxorubicin was calculated. The main compounds identified in the methanol extract were cis-vaccenic acid and trans-13-octadecenoic acid in the leaves and stems, respectively, and phenyl undecane and 3,7,11,15 tetramethyl-2-hexadeca-1-ol in the n-hexane extracts of the leaves and stems, respectively. Both parts of the plant contained fatty acids that have potential antitumor properties. The methanol extract from the stems of C. silvatica showed antitumor properties against HeLa, with an IC₅₀ of 114 ± 5 μg/mL, PC3 with an IC₅₀ of 137 ± 18 μg/mL and MCF7 with an IC₅₀ of 172 ± 15 μg/mL, which were greater than Caco2, which had an IC₅₀ of 353 ± 19 μg/mL, and HepG2, which had an IC₅₀ of 236 ± 17 μg/mL. However, the leaf extract showed weak antitumor properties against all of the studied cancer cell lines (HeLa with an IC₅₀ of 208 ± 13 μg/mL, PC3 with an IC₅₀ of 336 ± 57 μg/mL, MCF7 with an IC₅₀ of 324 ± 17 μg/mL, Caco2 with an IC₅₀ of 682 ± 55 μg/mL and HepG2 with an IC₅₀ of 593 ± 22 μg/mL). Neither part of the plant extract showed any cytotoxicity to the normal cells (WI38). Therefore, C. silvatica stems may potentially be used for the treatment of cervical, prostate and breast cancer.

Reconciling the Gap between Medications and their Potential Leads: The Role of Marine Metabolites in the Discovery of New Anticancer Drugs: A Comprehensive Review

One-third of people will be diagnosed with cancer at some point in their lives, making it the second leading cause of death globally each year after cardiovascular disease. The complex anticancer molecular mechanisms have been understood clearly with the advent of improved genomic, proteomic, and bioinformatics. Our understanding of the complex interplay between numerous genes and regulatory genetic components within cells explaining how this might lead to malignant phenotypes has greatly expanded. It was discovered that epigenetic resistance and a lack of multitargeting drugs were highlighted as major barriers to cancer treatment, spurring the search for innovative anticancer treatments. It was discovered that epigenetic resistance and a lack of multitargeting drugs were highlighted as major barriers to cancer treatment, spurring the search for innovative anticancer treatments. Many popular anticancer drugs, including irinotecan, vincristine, etoposide, and paclitaxel, have botanical origins. Actinomycin D and mitomycin C come from bacteria, while bleomycin and curacin come from marine creatures. However, there is a lack of research evaluating the potential of algae-based anticancer treatments, especially in terms of their molecular mechanisms. Despite increasing interest in the former, and the promise of the compounds to treat tumours that have been resistant to existing treatment, pharmaceutical development of these compounds has lagged. Thus, the current review focuses on the key algal sources that have been exploited as anticancer therapeutic leads, including their biological origins, phytochemistry, and the challenges involved in converting such leads into effective anticancer drugs.

Phytochemistry and Anticancer Effects of Mangrove (Rhizophora mucronata Lam.) Leaves and Stems Extract against Different Cancer Cell Lines

The biologically active components of the methanol extracts of R. mucronata were identified using GC/MS. The anticancer effects of each methanol extract from the leaves and stem were evaluated against cancer and non-cancer cell lines. The MTT assay was used in order to evaluate cell viability, and the IC₅₀ and the selectivity indices were calculated in relation to a positive control (doxorubicin). The results showed that 11 and 8 different chemical compounds were found in the methanol extracts from the leaves and stems of R. mucronata, respectively. The active constituents of R. mucronata leaves and stems had anticancer effects against colon cancer (CaCo-2), with IC₅₀ levels of 127 ± 4 μg/mL and 107 ± 6 μg/mL, respectively, and on breast cancer (MCF-7), with IC₅₀ levels of 158 ± 10 μg/mL and 138 ± 4 μg/mL, respectively. These were both greater than their effects on prostate cancer (PC-3), for which they showed IC₅₀ levels of 480 ± 14 μg/mL and 294 ± 3 μg/mL, respectively. However, the anticancer effect of the stems on lung cancer (A549) (IC₅₀ = 155 ± 10 μg/mL) was greater than that of the leaves (IC₅₀ = 376 ± 9 μg/mL) in comparison with doxorubicin. Neither the stems nor the leaves of R. mucronata showed any cytotoxicity against normal cells (WI-38), with the IC₅₀ being 932 ± 30 μg/mL for the leaves and 629 ± 3 μg/mL for the stems.

Remodeling tumor microenvironment with natural products to overcome drug resistance

With cancer incidence rates continuing to increase and occurrence of resistance in drug treatment, there is a pressing demand to find safer and more effective anticancer strategy for cancer patients. Natural products, have the advantage of low toxicity and multiple action targets, are always used in the treatment of cancer prevention in early stage and cancer supplement in late stage. Tumor microenvironment is necessary for cancer cells to survive and progression, and immune activation is a vital means for the tumor microenvironment to eliminate cancer cells. A number of studies have found that various natural products could target and regulate immune cells such as T cells, macrophages, mast cells as well as inflammatory cytokines in the tumor microenvironment. Natural products tuning the tumor microenvironment via various mechanisms to activate the immune response have immeasurable potential for cancer immunotherapy. In this review, it highlights the research findings related to natural products regulating immune responses against cancer, especially reveals the possibility of utilizing natural products to remodel the tumor microenvironment to overcome drug resistance.