Antitumor Potential Research Articles

Antitumor Mechanism and Therapeutic Potential of Cordycepin Derivatives.

Cordycepin has good antitumor activity, but its clinical application is limited due to the easy deamination of N6 in structure. In this study, a large lipolysis group was introduced at the cordycepin N6 to improve the problem, cordycepin derivatives (3a-4c) were synthesized, and biological evaluation of compounds was studied. In this study, the vitro antitumor activity of the compounds against MCF7 cells, HepG2 cells and SGC-7901 cells was evaluated by MTT assay. In the results, compound 4a showed the most obvious inhibitory effect on MCF7 cells with an IC50 value of 27.57 ± 0.52 μM, which was much lower than cordycepin. Compound 4a showed high selectivity between MCF7 and normal MCF-10A cells. Further biological evaluation showed that compound 4a promoted apoptosis and blocked the cell cycle in the G0/G1 phase. Then, Western Blot was used to detect related apoptotic proteins. It was found that Compound 4a could down-regulate the expression of Bcl-2 protein and up-regulate the expression of p53, Bax, Caspase-3 and Caspase-9 proteins. The mitochondrial membrane potential decreased continuously and the positive expression rate decreased. It was speculated that compound 4a induced the apoptosis of MCF7 cells through the mitochondrial pathway.

Iso-ADP-Ribose Fluorescence Polarization Probe for the Screening of RNF146 WWE Domain Inhibitors.

Poly-ADP-ribosylation is an important protein post-translational modification with diverse biological consequences. After binding poly-ADP-ribose on axis inhibition protein 1 (AXIN1) through its WWE domain, RING finger protein 146 (RNF146) can ubiquitinate AXIN1 and promote its proteasomal degradation and thus the oncogenic WNT signaling. Therefore, inhibiting the RNF146 WWE domain is a potential antitumor strategy. However, due to a lack of suitable screening methods, no inhibitors for this domain have been reported. Here, we developed a fluorescence polarization (FP)-based competition assay for the screening of RNF146 WWE inhibitors. This assay relies on a fluorescently tagged iso-ADP-ribose tracer compound, TAMRA-isoADPr. We report the design and synthesis of this tracer compound and show that it is a high-affinity tracer for the RNF146 WWE domain. This provides a convenient assay and will facilitate the development of small-molecule inhibitors for the RNF146 WWE domain.

Abstract A025: Autotaxin-lysolipid signaling suppresses a CCL11- eosinophil axis to promote pancreatic cancer progression

Abstract Among all cancer types, pancreatic ductal adenocarcinoma (PDAC) has one of the worst outcomes. In recent studies, metabolic and microenvironmental reprogramming in PDAC has been shown to facilitate tumor progression by promoting immune escape mechanisms, however these mechanisms are still poorly understood. Recently, our lab established that autotaxin (ATX) - lysophosphatidic acid (LPA) signaling in PDAC enhances tumorigenicity, but the immunomodulatory function of this signal pathway remains largely unexplored. We now show that ablation of the LPA-producing enzyme autotaxin (ATX) in PDAC cells can reduce tumor burden in mice and reprogram the tumor immune microenvironment by increasing tumor eosinophil infiltration. The functional role of eosinophils in the context of PDAC is a poorly understood area. The presence of eosinophils in pancreatic cancer has been reported in a few case reports: for example, prior studies identified neutrophils and eosinophils together as a group, expressing high levels of CD66b. We confirmed the presence of eosinophils in PDAC in mice as well as patients, and we found that rare patient samples with the highest intratumoral eosinophil abundance had the longest survival rates. Genetic or pharmacologic ATX inhibition increased intratumoral eosinophils, which promote tumor cell apoptosis locally and suppress tumor progression. When eosinophils were present, primary tumor growth was modestly reduced, but metastatic spread was greatly reduced. Mechanistically, ATX suppresses eosinophil accumulation via an autocrine feedback loop wherein ATX-LPA signaling negatively regulates activity of AP-1 transcription factor c-Jun, in turn suppressing expression of potent eosinophil chemoattractant CCL11 (Eotaxin-1). This is the first study that highlights the anti-tumor potential of eosinophils in pancreatic cancer. Citation Format: Sohinee Bhattacharyya, Chet Oon, Holly Sandborg, Terry Morgan, Mara H. Sherman. Autotaxin-lysolipid signaling suppresses a CCL11- eosinophil axis to promote pancreatic cancer progression [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Pancreatic Cancer; 2023 Sep 27-30; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(2 Suppl):Abstract nr A025.

Docking, synthesis, and anticancer assessment of novel quinoline-amidrazone hybrids

A group of new amidrazone compounds that include a quinoline component was produced through the reaction of hydrazonyl chloride, derived from 6-aminoquinoline, with appropriate secondary cyclic amines. The new compounds were confirmed through 1H-NMR, 13C-NMR, FTIR, and HRMS, and further verified by single-crystal X-ray diffraction. The antitumor potential of the synthesized compounds was tested against lung cancer (A549) and breast cancer (MCF-7) cell lines. Among the compounds, the ethyl carboxylate and o-hydroxy phenyl piperazine derivatives (10d and 10g) exhibited the strongest activity against both cell lines, with IC50 values of 43.1 and 59.1 μM for the lung and breast cancer cell lines, respectively. Moreover, the most potent compounds were subsequently docked into the c-Abl kinase binding site (PDB code: 1IEP) as a possible anticancer mechanism. In-silico ADMET study shows acceptable pharmacokinetic properties, and the toxicity profile for the most potent compounds is non-carcinogenic.

Investigation of Epilobium hirsutum L. Optimized Extract's Anti-Inflammatory and Antitumor Potential.

Epilobium hirsutum L., commonly known as hairy willowherb, is a perennial herbaceous plant native to Europe and Asia. In Romania, the Epilobium genus includes 17 species that are used in folk medicine for various purposes. This study aimed to investigate the anti-inflammatory and antitumor potential of the optimized extract of Epilobium hirsutum (EH) in animal models. The first study investigated the anti-inflammatory properties of EH optimized extract and the model used was carrageenan-induced paw inflammation. Wistar rats were divided into three groups: negative control, positive control treated with indomethacin, and a group treated with the extract. Oxidative stress markers, cytokine levels, and protein expressions were assessed. The extract demonstrated anti-inflammatory properties comparable to those of the control group. In the second study, the antitumor effects of the extract were assessed using the tumor model of Ehrlich ascites carcinoma. Swiss albino mice with Ehrlich ascites were divided into four groups: negative, positive treated with cyclophosphamide (Cph), Group 3 treated with Cph and EH optimized extract, and Group 4 treated with extract alone. Samples from the ascites fluid, liver, and heart were analyzed to evaluate oxidative stress, inflammation, and cancer markers. The extract showed a reduction in tumor-associated inflammation and oxidative stress. Overall, the EH optimized extract exhibited promising anti-inflammatory and antitumor effects in the animal models studied. These findings suggest its potential as a natural adjuvant therapeutic agent for addressing inflammation and oxidative stress induced by different pathologies.

A novel enemy of cancer: recent investigations into protozoan anti-tumor properties.

Cancer remains a significant global health issue, despite advances in screening and treatment. While existing tumor treatment protocols such as surgery, chemotherapy, radiotherapy, targeted therapy, and immunotherapy have proven effective in enhancing the prognosis for some patients, these treatments do not benefit all patients. Consequently, certain types of cancer continue to exhibit a relatively low 5-year survival rate. Therefore, the pursuit of novel tumor intervention strategies may help improve the current effectiveness of tumor treatment. Over the past few decades, numerous species of protozoa and their components have exhibited anti-tumor potential via immune and non-immune mechanisms. This discovery introduces a new research direction for the development of new and effective cancer treatments. Through in vitro experiments and studies involving tumor-bearing mice, the anti-tumor ability of Toxoplasma gondii, Plasmodium, Trypanosoma cruzi, and other protozoa have unveiled diverse mechanisms by which protozoa combat cancer, demonstrating encouraging prospects for their application. In this review, we summarize the anti-tumor ability and anti-tumor mechanisms of various protozoa and explore the potential for their clinical development and application.

Recent Updates Regarding the Antiproliferative Activity of Galium verum Extracts on A375 Human Malignant Melanoma Cell Line.

The biological activity of Galium verum herba was exerted on various tumor cell lines with incredible results, but their potential effect on malignant melanoma has not been established yet. Therefore, the current study was structured in two directions: (i) the investigation of the phytochemical profile of diethyl ether (GvDEE) and butanol (GvBuOH) extracts of G. verum L. and (ii) the evaluation of their biological profile on A375 human malignant melanoma cell line. The GvDEE extract showed an FT-IR profile different from the butanol one, with high antioxidant capacity (EC50 of GvDEE = 0.12 ± 0.03 mg/mL > EC50 of GvBuOH = 0.18 ± 0.05 mg/mL). The GvDEE extract also showed antimicrobial potential, especially against Gram-positive bacteria strains, compared to the butanol extract, which has no antimicrobial activity against any bacterial strain tested. The results regarding the antitumor potential showed that both extracts decreased A375 cell viability largely (69% at a dose of 55 µg/mL of the GvDEE extract). Moreover, both extracts induce nuclear fragmentation by forming apoptotic bodies and slight chromatin condensation, which is more intense for GvDEE. Considering the results, one can state that the Galium verum herba possesses antitumor effects on the A375 human malignant melanoma cell line, a promising phytocompound for the antitumor approach to skin cancer.

A bispecific antibody targeting HER2 and CLDN18.2 eliminates gastric cancer cells expressing dual antigens by enhancing the immune effector function.

Gastric cancer (GC) is widely regarded as one of the toughest cancers to treat. Trastuzumab, which targets the human epidermal growth factor receptor 2 (HER2) for GC treatment, has demonstrated clinical success. However, these patients have a high likelihood of developing resistance. Additionally, Claudin18.2 (CLDN18.2) is a promising emerging target for GC treatment. Therefore, therapies that simultaneously target both HER2 and CLDN18.2 targets are of great significance. Here, we constructed a bispecific antibody targeting both HER2 and CLDN18.2 (HC-2G4S; BsAb), which displayed satisfactory purity, thermostability and enhancing antibody-dependent cell-mediated cytotoxicity (ADCC) activity. In a tumor spheroids model of GC, BsAb demonstrated greater therapeutic efficacy than monoclonal antibodies (mAb) or combination treatment strategies. We propose that the enhanced anti-tumor potency of BsAbs in vivo is due to the monovalent binding of single-chain antibodies to more targets due to weaker affinity, resulting in a more potent immune effect function. Therefore, HC-2G4S could be a productive agent for treating GC that is HER2-positive, CLDN18.2-positive, or both, with the potential to overcome trastuzumab resistance and provide significant clinical benefits and expanded indications.

Furanocoumarins as Enhancers of Antitumor Potential of Sorafenib and LY294002 toward Human Glioma Cells In Vitro.

Furanocoumarins are naturally occurring compounds in the plant world, characterized by low molecular weight, simple chemical structure, and high solubility in most organic solvents. Additionally, they have a broad spectrum of activity, and their properties depend on the location and type of attached substituents. Therefore, the aim of our study was to investigate the anticancer activity of furanocoumarins (imperatorin, isoimperatorin, bergapten, and xanthotoxin) in relation to human glioblastoma multiforme (T98G) and anaplastic astrocytoma (MOGGCCM) cell lines. The tested compounds were used for the first time in combination with LY294002 (PI3K inhibitor) and sorafenib (Raf inhibitor). Apoptosis, autophagy, and necrosis were identified microscopically after straining with Hoechst 33342, acridine orange, and propidium iodide, respectively. The levels of caspase 3 and Beclin 1 were estimated by immunoblotting and for the blocking of Raf and PI3K kinases, the transfection with specific siRNA was used. The scratch test was used to assess the migration potential of glioma cells. Our studies showed that the anticancer activity of furanocoumarins strictly depended on the presence, type, and location of substituents. The obtained results suggest that achieving higher pro-apoptotic activity is determined by the presence of an isoprenyl moiety at the C8 position of the coumarin skeleton. In both anaplastic astrocytoma and glioblastoma, imperatorin was the most effective in induction apoptosis. Furthermore, the usage of imperatorin, alone and in combination with sorafenib or LY294002, decreased the migratory potential of MOGGCCM and T98G cells.

Targeted Radium Alpha Therapy in the Era of Nanomedicine: In Vivo Results.

Targeted alpha-particle therapy using radionuclides with alpha emission is a rapidly developing area in modern cancer treatment. To selectively deliver alpha-emitting isotopes to tumors, targeting vectors, including monoclonal antibodies, peptides, small molecule inhibitors, or other biomolecules, are attached to them, which ensures specific binding to tumor-related antigens and cell surface receptors. Although earlier studies have already demonstrated the anti-tumor potential of alpha-emitting radium (Ra) isotopes-Radium-223 and Radium-224 (223/224Ra)-in the treatment of skeletal metastases, their inability to complex with target-specific moieties hindered application beyond bone targeting. To exploit the therapeutic gains of Ra across a wider spectrum of cancers, nanoparticles have recently been embraced as carriers to ensure the linkage of 223/224Ra to target-affine vectors. Exemplified by prior findings, Ra was successfully bound to several nano/microparticles, including lanthanum phosphate, nanozeolites, barium sulfate, hydroxyapatite, calcium carbonate, gypsum, celestine, or liposomes. Despite the lengthened tumor retention and the related improvement in the radiotherapeutic effect of 223/224Ra coupled to nanoparticles, the in vivo assessment of the radiolabeled nanoprobes is a prerequisite prior to clinical usage. For this purpose, experimental xenotransplant models of different cancers provide a well-suited scenario. Herein, we summarize the latest achievements with 223/224Ra-doped nanoparticles and related advances in targeted alpha radiotherapy.

Synthesis, characterization, DNA/BSA-binding affinity and biological activity of dinuclear palladium(II) complexes with aromatic N-heterocyclic bridging ligand

Dinuclear palladium(II) complexes, [{Pd(en)Cl}2(μ-L)](NO3)2 (L is bridging ligand pirazine (Pd1), pyrimidine (Pd2), pyridazine (Pd3), phenazine (Pd4) and en is ethylenediamine), were synthesized and characterized. The interactions of the synthesized palladium(II) complexes with biomolecules such as DNA and BSA were studied using UV–Vis spectroscopy and fluorescence spectroscopy. Analysis of tumoricidal activity of investigated complexes, tested on several tumor cell lines of human and mouse origin, revealed that Pd1 and Pd2 exhibited weak cytotoxic potential at lower concentrations. However, Pd3 showed higher cytotoxicity effects on the human MDA-MB 468 breast carcinoma and A375 melanoma cell lines, while Pd4 exhibited tumoricidal potential against MDA-MB 468 cells and A549 human lung adenocarcinoma cells. Interestingly, A375 human melanoma cells were highly sensitive to Pd4 treatment similarly to the effect of cisplatin. Further, the antimicrobial effects of tested compounds were evaluated using different species of Gram-positive and Gram-negative bacteria, as well as yeasts. Pd1–Pd4 showed variable antimicrobial activity depending on the microorganism species. Among tested complexes, Pd4 exhibited the highest antimicrobial activity. The obtained data suggest that palladium(II) complexes might be further investigated as potential antitumor and antimicrobial agents.

Structures, Biosynthesis, and Bioactivity of Oligomycins from the Marine-Derived Streptomyces sp. FXY-T5.

Oligomycins are potent antifungal and antitumor agents. Mass spectrometry (MS)- and nuclear magnetic resonance (NMR)-based metabolomic fingerprinting analysis of marine-derived actinomycetes in our in-house library provided an oligomycin-producing strain, Streptomyces sp. FXY-T5. Chemical investigation led to the discovery of five new oligomycins, 24-lumooligomycin B (1), 4-lumooligomycin B (2), 6-lumooligomycin B (3), 40-homooligomycin B (4), and 15-hydroxy-oligomycin B (5), together with seven biosynthetically related known derivatives. Their structures were assigned by MS, NMR, electronic circular dichroism (ECD), and single-crystal X-ray diffraction analyses. The biosynthesis pathway of oligomycins was first proposed based on the analysis of a type I modular polyketide synthase (PKS) system and targeted gene disruption. As expected, the isolated oligomycins showed significant antiagricultural fungal pathogen activity and antiproliferative properties from which the possible structure-activity relationships were first suggested. More importantly, oligomycins induced significant G1-phase cell cycle arrest on cancer cells and significantly attenuated their Cyclin D1 and PCNA expression through a β-catenin signaling pathway.

CP41, a novel curcumin analogue, induces apoptosis in endometrial cancer cells by activating the H3F3A/ proteasome-MAPK signaling pathway and enhancing oxidative stress

AimsCurcumin is a natural compound and has good antitumor properties, but its clinical use is limited by its low bioavailability. We constructed the derivative CP41 (3,5-bis(2-chlorobenzylidene)-1-piperidin-4-one) by enhancing the bioavailability of curcumin while retaining its antitumor properties. Main methodsCCK-8 (Cell Counting Kit-8) was used to detect the effect of CP41 on cell proliferation; Western blotting, immunofluorescence, immunoprecipitation, quantitative PCR and enzyme-linked immunosorbent assay were used to evaluate the expression of subcutaneous tumor-related molecules in cells and mice. Key findingsOur results showed that CP41 inhibited the proliferation of endometrial cancer cells by suppressing the proliferation of AN3CA and HEC-1-B cells. We found that CP41 significantly increased H3F3A and inhibited proteasome activity, which activated MAPK signaling and led to apoptosis. Further experiments showed that H3F3A is a potential target of CP41. Correlation analysis showed that H3F3A was positively correlated with the sensitivity to chemotherapeutic agents in endometrial cancer. CP41 significantly induced reactive oxygen species (ROS) levels and activated endoplasmic reticulum stress, which led to apoptosis. The safety profile of CP41 was also evaluated, and CP41 did not cause significant drug toxicity in mice. SignificanceCP41 showed stronger antitumor potency than curcumin, and its antitumor activity may be achieved by inducing ROS and activating H3F3A-mediated apoptosis.

Phytochemistry Profile, Antimicrobial and Antitumor Potential of the Methanolic Extract of Tabernaemontana catharinensis A DC and Eragrostis plana NEES.

Natural compounds that have the potential to act as antimicrobials and antitumors are a constant search in the field of pharmacotherapy. Eragrostis plana NEES (Poaceae) is a grass with high allelopathic potential. Allelopathy is associated with compounds generated in the primary and secondary metabolism of the plant, which act to protect it from phytopathogens. Tabernaemontana catharinensis A DC (Apocynaceae), a tree in which its leaves and bark are used for the preparation of extracts and infusions that have anti-inflammatory and antinociceptive effects, is attributed to its phytochemical constitution. The objective of this study was to elucidate the phytochemical constitution, the antibacterial potential, the toxicity against immune system cells, hemolytic potential, and antitumor effect of methanolic extracts of E. plana and T. catharinensis. The phytochemical investigation was carried out using the UHPLC-QTOF MS equipment. The antibacterial activity was tested using the broth microdilution plate assay, against Gram-negative and Gram-positive strains, and cytotoxicity assays were performed on human peripheral blood mononuclear cells (PBMC) and in vitro hemolysis. Antitumor activity was performed against the colon cancer cell line (CT26). Results were expressed as mean and standard deviation and analyzed by ANOVA. p < 0.05 was considered significant. More than 19 possible phytochemical constituents were identified for each plant, with emphasis on phenolic compounds (acids: vanillic, caffeic, and quinic) and alkaloids (alstovenine, rhyncophylline, amezepine, voacangine, and coronaridine). Both extracts showed antibacterial activity at concentrations below 500 µg/mL and were able to decrease the viability of CT26 at concentrations below 2000 µg/mL, without showing cytotoxic effect on PBMCs and in vitro hemolysis at the highest concentration tested. This is the first report of the activity of E. plana and T. catharinensis extracts against colon cancer cell line (CT26). Studies should be carried out to verify possible molecular targets involved in the antitumor effect in vivo.

Fraisinib: a calixpyrrole derivative reducing A549 cell-derived NSCLC tumor in vivo acts as a ligand of the glycine-tRNA synthase, a new molecular target in oncology.

Background and purpose: Lung cancer is the leading cause of death in both men and women, constituting a major public health problem worldwide. Non-small-cell lung cancer accounts for 85%-90% of all lung cancers. We propose a compound that successfully fights tumor growth in vivo by targeting the enzyme GARS1. Experimental approach: We present an in-depth investigation of the mechanism through which Fraisinib [meso-(p-acetamidophenyl)-calix(4)pyrrole] affects the human lung adenocarcinoma A549 cell line. In a xenografted model of non-small-cell lung cancer, Fraisinib was found to reduce tumor mass volume without affecting the vital parameters or body weight of mice. Through a computational approach, we uncovered that glycyl-tRNA synthetase is its molecular target. Differential proteomics analysis further confirmed that pathways regulated by Fraisinib are consistent with glycyl-tRNA synthetase inhibition. Key results: Fraisinib displays a strong anti-tumoral potential coupled with limited toxicity in mice. Glycyl-tRNA synthetase has been identified and validated as a protein target of this compound. By inhibiting GARS1, Fraisinib modulates different key biological processes involved in tumoral growth, aggressiveness, and invasiveness. Conclusion and implications: The overall results indicate that Fraisinib is a powerful inhibitor of non-small-cell lung cancer growth by exerting its action on the enzyme GARS1 while displaying marginal toxicity in animal models. Together with the proven ability of this compound to cross the blood-brain barrier, we can assess that Fraisinib can kill two birds with one stone: targeting the primary tumor and its metastases "in one shot." Taken together, we suggest that inhibiting GARS1 expression and/or GARS1 enzymatic activity may be innovative molecular targets for cancer treatment.

Deciphering the Glycosylation Steps in the Biosynthesis of P-1894B and Grincamycin Isolated from Marine-Derived Streptomyces lusitanus SCSIO LR32.

Recently, we re-isolated the glycosylated angucycline antibiotics P-1894B (1) and grincamycin (1') from the marine-derived Streptomyces lusitanus SCSIO LR32 as potent antitumor agents and identified their biosynthesis gene cluster gcn. Both P-1894B (1) and grincamycin (1') possess a trisaccharide and a disaccharide moiety comprised of five deoxysugars. In this work, three genes encoding glycosyltransferases (GcnG1, GcnG2, and GcnG3) responsible for the assembly of deoxysugars into angucycline aglycone were identified from the biosynthesis gene cluster gcn. Gene inactivations of gcnG1, gcnG2, gcnG3, and gcnG1G2 by lambda-RED-mediated gene replacements led to the construction of four mutants, in which the glycosyltransferase genes were disrupted, respectively. The metabolites from the mutants were purified and identified, including two new analogues designated as grincamycin U (3a) and V (3'). The sequential glycosylation steps in the biosynthesis of P-1894B (1) and grincamycin (1') catalyzed by GcnG3, GcnG1, and GcnG2 were elucidated.

Identification of a Sonically Activated Degrader of Methionine Adenosyltransferase 2A by an in Silico Approach Assisted with the Hole-Electron Analysis.

Small molecules capable of modulating methionine adenosyltransferase 2A (MAT2A) are of significant interest in precise cancer therapeutics. Herein, we raised the hole-electron Coulombic attraction as a reliable molecular descriptor for predicting the reactive oxygen generation capacity of MAT2A inhibitors, based on which we discovered compound H3 as a sonically activated degrader of MAT2A. Upon sonication, H3 can generate reactive oxygen species to specifically degrade cellular MAT2A via rapid oxidative reactions. Combination of H3 and sonication induced 87% MAT2A depletion in human colon cancer cells, thus elevating its antiproliferation effects by 8-folds. In vivo, H3 had a favorable pharmacokinetic profile (bioavailability = 77%) and ADME properties. Owing to the MAT2A degradation merits, H3 at a dosage of 10 mg/kg induced 31% tumor regression in xenograft colon tumor models. The significantly boosted antitumor potency can potentially alleviate the toxicity of high-dose MAT2A inhibitors to normal cells and tissues, especially to the liver.

Exploring the potential of tannin-rich tree bark extracts in combating foodborne diseases and gastric cancer

The objective of this study was to perform chemical characterization of tannin-rich extracts obtained from the bark of woody species and to assess their bioactive potential for the treatment of foodborne diseases and gastric cancer. The barks of Anacardium occidentale, Stryphnodendron adstringens, and a commercial tannin from Acacia mearnsii were used to prepare the extracts. HPLC was employed to determine the profile and quantity of phenolic compounds present in the extracts, while FTIR was utilized to identify their functional groups. The antioxidant activity was assessed using the DPPH assay, while the antimicrobial activity was evaluated by the disk diffusion method and measurement of minimum inhibitory concentration and minimum bactericidal concentration. Additionally, the antitumor activity was evaluated using the MTT-tetrazolium assay. The phenolic profile of the extracts revealed the presence of ten compounds, with gallic acid and catechin being the most abundant for all species. Hydroxyl (OH) was the recurrent functional group in all the analyzed extracts. At a concentration of 25 μg/mL, the extracts exhibited DPPH free radical scavenging activity of 90%. The extracts had significant antitumor potential, inhibiting the growth of human gastric adenocarcinoma cells (AGS) by 90% at 200 μg/mL. Listeria monocytogenes was the most sensitive bacterium to the use of the extracts, while Escherichia coli was the most resistant. In conclusion, the results obtained in this study demonstrated the promising potential of tannin-rich extracts from the studied species as antioxidant, antimicrobial, and anticancer agents.

Antitumoral Potential of Artepillin C, a Compound Derived from Brazilian Propolis, against Breast Cancer Cell Lines.

Breast cancer is the most commonly diagnosed cancer among women worldwide with limited treatment options. Artepillin C (3,5-diprenyl-4-hydroxycinnamic acid) is one of the main constituents of Brazilian propolis presenting different activities, including antitumoral effects against various types of cancer. We evaluated the antitumoral potential and mechanisms of action of artepillin C against two distinct human breast cancer cell lines, MCF-7 and MDA-MB-231, to explore a new therapeutic candidate. Cell viability was assessed by MTT assay and the long-term cytotoxicity was performed by clonogenic assay. The morphological changes were observed by light microscopy, analysis of cell death pathway by Annexin V FITC/propidium iodide (PI), lactate dehydrogenase (LDH) by colorimetry, DNA fragmentation by agarose gel and senescence by β-galactosidase. Detection of total reactive oxygen species (ROS) by fluorescence microscopy and determination of mitochondrial transmembrane potential by flow cytometry were also performed. Artepillin C presented a strong and dose-time-dependent cytotoxic effect on MCF-7 and MDA-MB-231 cell lines, with cytotoxicity more evident in MCF-7. In both cancer cell lines, the clonogenic potential was significantly reduced and the morphology of the cells was changed. The treatment also induced death by necrosis and late apoptosis in MCF-7 and MDA-MB-231 and induced cell senescence in MCF-7. Also, artepillin C increased total ROS in both cancer cells and decreased mitochondrial membrane potential in MDA-MB-231 cells. Artepillin C presented antitumoral potential in two human breast cancer cell lines, MCF-7, and MDA-MB-231, suggesting a new promising option for the treatment and/or chemopreventive strategy for breast cancer.

Triterpenoids Isolated from Cassia fistula can be a Potent Anti-Tumor Agent: A Review

Triterpenoids Isolated from Cassia fistula can be a Potent Anti-Tumor Agent: A Review