Synthetic derivatives of chrysin and their biological activities

Design, synthesis, molecular docking, molecular dynamic simulation, and MMGBSA analysis of 7-O-substituted 5-hydroxy flavone derivatives

A series of chrysin derivatives were designed, synthesized, and evaluated for their antibacterial activity against four different bacterial strains. We have synthesized new propyl-substituted and butyl-substituted chrysin-piperazine derivatives, which show marvellous inhibition against E. coli and S. aureus. The free hydroxyl group at the C-5 position of chrysin improved therapeutic efficacy in vivo and was a beneficial formulation for chemotherapy. All synthesized compounds were confirmed by various spectroscopic techniques such as IR, NMR, HPLC, and mass spectrometry. The compounds exhibited moderate to good inhibition, and their structure-activity relationship (SAR) has also been illustrated. Among the synthesised compounds, compounds 4 and 10 were the most active against S. pyogenes and E. coli, with 12.5 g/mL MICs; additionally, compound 12 exhibits significant activity on both the S. aureus and E. coli stains. Based on the promising activity profile and docking score of compound 12, it was selected for 100 ns MD simulation and post-dynamic binding free energy analysis within the active sites of S. aureus TyrRS (PDB ID: 1JIJ) and E. coli DNA GyrB (PDB ID: 6YD9) to investigate the stability of molecular contacts and to establish how the newly synthesized inhibitors fit together in the most stable conformations.Communicated by Ramaswamy H. Sarma.

Exploring the Role of Apigenin in Neuroinflammation: Insights and Implications

Neuroinflammation, a hallmark of various central nervous system disorders, is often associated with oxidative stress and neuronal or oligodendrocyte cell death. It is therefore very interesting to target neuroinflammation pharmacologically. One therapeutic option is the use of nutraceuticals, particularly apigenin. Apigenin is present in plants: vegetables (parsley, celery, onions), fruits (oranges), herbs (chamomile, thyme, oregano, basil), and some beverages (tea, beer, and wine). This review explores the potential of apigenin as an anti-inflammatory agent across diverse neurological conditions (multiple sclerosis, Parkinson's disease, Alzheimer's disease), cancer, cardiovascular diseases, cognitive and memory disorders, and toxicity related to trace metals and other chemicals. Drawing upon major studies, we summarize apigenin's multifaceted effects and underlying mechanisms in neuroinflammation. Our review underscores apigenin's therapeutic promise and calls for further investigation into its clinical applications.

Effect of Apigenin on Neurodegenerative Diseases

Neurodegenerative diseases (NDDs), such as Alzheimer's and Parkinson's, are the most frequent age-related illnesses affecting millions worldwide. No effective medication for NDDs is known to date and current disease management approaches include neuroprotection strategies with the hope of maintaining and improving the function of neurons. Such strategies will not provide a cure on their own but are likely to delay disease progression by reducing the production of neurotoxic chemicals such as reactive oxygen species (ROS) and related inflammatory chemicals. Natural compounds such as flavonoids that provide neuroprotection via numerous mechanisms have attracted much attention in recent years. This review discusses evidence from different research models and clinical trials on the therapeutic potential of one promising flavonoid, apigenin, and how it can be helpful for NDDs in the future prospects. We have also discussed its chemistry, mechanism of action, and possible benefits in various examples of NDDs.

PEGylation of Chrysin Improves Its Water Solubility while Preserving the In Vitro Biological Activity

Chrysin is a natural flavonoid that despite having numerous biological properties, its therapeutic value is limited due to its very low solubility in aqueous media. In this work, chrysin was conjugated with methoxypolyethylene glycols (mPEGs) of different molecular weights (350, 500, 750, and 2000 g/mol), affording PEGylated chrysins with high yields and excellent purities. In all cases, an increase in the water solubility of the conjugates was observed, which was highest when 500 g/mol of mPEG was used in the PEGylation reaction. Furthermore, in aqueous solution, PEGylated chrysins formed aggregates of ellipsoid shape. Electrochemical studies showed that the redox properties were conserved after PEGylation. While in vitro antibacterial and antifungal studies probed that the intrinsic activity was conserved, in vitro antitumor activities against HepG2 (liver carcinoma cells) and PC3 (prostate cancer cell) showed that PEGylated chrysins retained the cytotoxic activity and the ability of induction of apoptosis for the evaluated human cancer cells.

Design, synthesis, antitumor activity and ct-DNA binding study of photosensitive drugs based on porphyrin framework

Photodynamic therapy is a promising novel tumor treatment method. In this study, novel porphyrin-chrysin photosensitizer derivatives were synthesized. Most of the compounds showed antitumor activity against human cervical cancer HeLa cells and human lung cancer A549 cells, among which compound 4c had the best photodynamic therapy effect on HeLa cells and A549 cells, with IC₅₀ values of 6.26 μM and 23.37 μM, respectively. Free-base porphyrin-chrysin derivatives bind to DNA through surface self-stacking, and zinc metalloporphyrin-chrysin derivatives bind to ct-DNA through intercalation. Notably, the tightness of compound binding to ct-DNA was positively correlated with its antitumor activity. What's more, three-dimensional quantitative conformation studies have shown that increasing the positive charge of the porphyrin ring and introducing a strong electron-withdrawing group at the meso position of the porphyrin ring at the para-position of the benzene ring or reducing the space volume of the compound can enhance the antitumor activity.

Formulation of Multicomponent Chrysin-Hydroxy Propyl β Cyclodextrin-Poloxamer Inclusion Complex Using Spray Dry Method: Physicochemical Characterization to Cell Viability Assessment

The work aimed to enhance chrysin (CHR) water solubility, dissolution, and in vitro antibacterial as well as cell viability. Chrysin binary, as well as ternary inclusion complex, were prepared using the spray drying method. The influence of an auxiliary component (poloxamer; PLX) was also assessed after being incorporated into the chrysin HP βCD complex (CHR-BC) and formed as a chrysin ternary complex (CHR-TC). The phase solubility investigation was carried out in order to assess the complexation efficiency and stability constant. The samples were assessed for the dissolution test, physicochemical evaluation, antibacterial activity, and cell viability tests were also assessed. The results of the phase solubility investigation showed that the stability constant for the binary system (268 M^-1) was lower than the ternary system (720 M^-1). The complex stability was validated by the greater stability constant value. The dissolution results showed that pure CHR had a limited release of 32.55 ± 1.7% in 60 min, while prepared CHR-TC and CHR-BC both demonstrated maximum CHR releases of 99.03 ± 2.34% and 71.95 ±2.1%, respectively. The dissolution study's findings revealed that the release of CHR was much improved over that of pure CHR. A study using a scanning electron microscope showed that CHR-TC contains more agglomerated and amorphous components. The higher conversion of crystalline CHR into an amorphous form is responsible for the structural alterations that are observed. After complexation, the distinctive peaks of pure CHR changed due to the complexation with HP βCD and PLX. The antimicrobial and cell viability results revealed improved antimicrobial activity as well as a lower IC50 value than pure CHR against the tested anticancer cell line (MCF7).

Propolis characterization and antimicrobial activities against Staphylococcus aureus and Candida albicans: A review

Propolis is a plant-based sticky substance that is produced by honeybees. It has been used traditionally by ancient civilizations as a folk medicine, and is known to have many pharmaceutical properties including antioxidant, antibacterial, antifungal, anti-inflammatory, antiviral, and antitumour effects. Worldwide, researchers are still studying the complex composition of propolis to unveil its biological potential, and especially its antimicrobial activity against a variety of multidrug-resistant microorganisms. This review explores scientific reports published during the last decade on the characterization of different types of propolis, and evaluates their antimicrobial activities against Staphylococcus aureus and Candida albicans. Propolis can be divided into different types depending on their chemical composition and physical properties associated with geographic origin and plant sources. Flavonoids, phenols, diterpenes, and aliphatic compounds are the main chemicals that characterize the different types of propolis (Poplar, Brazilian, and Mediterranean), and are responsible for their antimicrobial activity. The extracts of most types of propolis showed greater antibacterial activity against Gram-positive bacteria: particularly on S. aureus, as well as on C. albicans, as compared to Gram-negative pathogens. Propolis acts either by directly interacting with the microbial cells or by stimulating the immune system of the host cells. Some studies have suggested that structural damage to the microorganisms is a possible mechanism by which propolis exhibits its antimicrobial activity. However, the mechanism of action of propolis is still unclear, due to the synergistic interaction of the ingredients of propolis, and this natural substance has multi-target activity in the cell. The broad-spectrum biological potentials of propolis present it as an ideal candidate for the development of new, potent, and cost-effective antimicrobial agents.

Promising Protective Effects of Chrysin in Cardiometabolic Diseases

Cardiometabolic diseases (CMD) have a great burden in terms of morbidity and mortality worldwide. The vicious cycle of CMD consists of type II diabetes, hypertension, dyslipidemia, obesity, and atherosclerosis interacting and feedbacking each other. The natural flavonoid chrysin has been displayed to own a broad spectrum of therapeutic impacts for human health. Herein, we did an in-depth investigation of the novel mechanisms of chrysin's cardioprotection against cardiometabolic disorder. Studies have shown that chrysin protects the cardiovascular system by enhancing the intrinsic antioxidative defense system. This antioxidant boost by chrysin protects against several risk factors of cardiometabolic disorders including atherosclerosis, vascular inflammation and dysfunction, platelet aggregation, hypertension, dyslipidemia, cardiotoxicity, myocardial infarction, injury and remodeling, diabetes-induced injuries, and obesity. Chrysin also exhibited anti-inflammatory mechanisms through inhibiting pro-inflammatory pathways including NF-κB, MAPK, and PI3k/Akt. Furthermore, chrysin modulated NO pathway, RAS system, AGE/RAGE pathway, PPARs pathway which contributed to the risk factors of cardiometabolic disorders. Taken together, the mechanisms in which chrysin protects against cardiometabolic disorder are more than merely antioxidation and anti-inflammation in the cardiovascular system.

Chrysin Inhibits Pseudo-allergic Reaction by Suppressing Mitochondrial STAT3 Activation via MAS-Related GPR Family Member X2

Chrysin, one of the most pharmacologically active natural flavonoids, has been extracted from various plants. Mast cells are an important part of innate immunity-mediating anaphylaxis. Pseudo-allergic reactions are currently believed to be associated with the MAS-related GPR family member X2 (MrgX2). In this study, the anti-pseudo allergy effect of chrysin and its underlying mechanisms were studied in vitro and in vivo. Chrysin inhibited passive cutaneous anaphylaxis and systemic pseudo-allergy in vivo. LAD2 cell degranulation, calcium ion (Ca²⁺) influx, and adenosine 5'-triphosphate (ATP) content were significantly suppressed in a dose-dependent manner. Chrysin suppressed pseudo-allergic reactions through the PLC/IP3/Ca²⁺ and ERK/STAT3 serine 727 pathways downstream of MrgX2. Therefore, mitochondrial ATP, but not glycolysis, is vital for pseudo-allergic reactions mediated by MrgX2. This study provides new insights for the treatment of pseudo-allergy.

Novel Chrysin-De-Allyl PAC-1 Hybrid Analogues as Anticancer Compounds: Design, Synthesis, and Biological Evaluation

New chrysin-De-allyl-Pac-1 hybrid analogues, tethered with variable heterocyclic systems (4a–4o), were rationally designed and synthesized. The target compounds were screened for in vitro antiproliferative efficacy in the triple-negative breast cancer (TNBC) cell line, MDA-MB-231, and normal human mammary epithelial cells (HMECs). Two compounds, 4g and 4i, had the highest efficacy and selectivity towards MDA-MB-231 cells, and thus, were further evaluated by mechanistic experiments. The results indicated that both compounds 4g and 4i induced apoptosis by (1) inducing cell cycle arrest at the G2 phase in MDA-MB-231 cells, and (2) activating the intrinsic apoptotic pathways in a concentration-dependent manner. Physicochemical characterizations of these compounds suggested that they can be further optimized as potential anticancer compounds for TNBC cells. Overall, our results suggest that 4g and 4i could be suitable leads for developing novel compounds to treat TNBC.

Chrysin-Loaded Chitosan Nanoparticles Potentiates Antibiofilm Activity against Staphylococcus aureus

The application of nanotechnology in medicine is gaining popularity due to its ability to increase the bioavailability and biosorption of numerous drugs. Chrysin, a flavone constituent of Orocylumineicum vent is well-reported for its biological properties. However, its therapeutic potential has not been fully exploited due to its poor solubility and bioavailability. In the present study, chrysin was encapsulated into chitosan nanoparticles using TPP as a linker. The nanoparticles were characterized and investigated for their anti-biofilm activity against Staphylococcus aureus. At sub-Minimum Inhibitory Concentration, the nanoparticles exhibited enhanced anti-biofilm efficacy against S. aureus as compared to its bulk counterparts, chrysin and chitosan. The decrease in the cell surface hydrophobicity and exopolysaccharide production indicated the inhibitory effect of the nanoparticles on the initial stages of biofilm development. The growth curve analysis revealed that at a sub-MIC, the nanoparticles did not exert a bactericidal effect against S. aureus. The findings indicated the anti-biofilm activity of the chrysin-loaded chitosan nanoparticles and their potential application in combating infections associated with S. aureus.

In silico design, synthesis and activity of potential drug-like chrysin scaffold-derived selective EGFR inhibitors as anticancer agents

BACKGROUND & OBJECTIVE

Epidermal growth factor receptor (EGFR) signaling pathway is one of the promising and well-established targets for anticancer therapy. The objective of the present study was to identify new EGFR inhibitors using ligand and structure-based drug designing methods, followed by a synthesis of selected inhibitors and evaluation of their activity.

METHODS

A series of C-7-hydroxyproton substituted chrysin derivatives were virtually drawn to generate a small compound library that was screened using 3D QSAR model created from forty-two known EGFR tyrosine kinase inhibitors. Next, the obtained hits with fitness score ≥ 1.0 were subjected to molecular docking analysis. Based on the predicted activity and XP glide score, three EGFR inhibitors were synthesized and characterized using ¹H-NMR, ¹³C-NMR and MS. Finally, comparative in vitro investigation of the biological activity of synthesized inhibitors was performed with that of the parent molecule, chrysin.

RESULTS

The data depicted a 3.2-fold enhanced cytotoxicity of chrysin derivative, CHM-04 against breast cancer cells as compared with chrysin as well as its binding with EGFR protein. Furthermore, the biological activity of CHM-04 was comparable to the standard EGFR inhibitor, AG1478 in increasing apoptosis and decreasing the migratory potential of triple-negative breast cancer cells as well as significantly lowering the mammosphere forming ability of breast cancer stem cells.

CONCLUSION

The present study suggests CHM-04, an EGFR inhibitor possessing drug-like properties as a plausible therapeutic candidate against breast cancer.

Sulfonylpiperazines based on a flavone as antioxidant and cytotoxic agents

Chrysin-based sulfonylpiperazines 7a-k were synthesized and investigated for their in vitro free radical scavenging potential as well as cytotoxic efficacies against selected cancer cell lines. Cytotoxicity of the new compounds toward noncancer cells was confirmed using the SRB assay against Madin-Darby Canine Kidney cells. Reaction of piperazine with different substituted benzenesulfonyl chlorides in triethylamine furnished sulfonylpiperazines (3a-k), which were then allowed to react with 7-(4-bromobutoxy)-5-hydroxy-2-phenyl-4H-chromen-4-one (6) prepared reacting chrysin with 1,4-dibromobutane to give the final derivatives 7a-k. The results concluded that chrysin-sulfonylpiperazines exerted better antioxidant and anticancer efficacies than previously studied chrysin-piperazine precursors. For example, compounds 7h, 7j, and 7k with 4-OCF₃ , 4-OCH₃ , and 2,4-diOCH₃ groups exhibited the best antioxidant potential against 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radicals. Moreover, halogenated analogues (7b, 7c, 7g, and 7h) demonstrated promising anticancer potential against SK-OV3, HeLa, and HT-29 cell lines, whereas those bearing a methoxy functional group (7j and 7k) had beneficial effects against the cell lines A-549 and HT-29. Thus, it can be confirmed from the bioassay results that the overall structural design as well as proper substitution is crucial to deliver the anticipated biological effects. Spectroscopic techniques such as FT-IR, ¹ H NMR, ¹³ C NMR, mass and elemental analysis (CHN) were carried out to confirm the final structures.

The new buzz: Investigating the antimicrobial interactions between bioactive compounds found in South African propolis

ETHNOPHARMACOLOGICAL RELEVANCE

Propolis, a resinous substance produced by the Apis mellifera bee, contains a number of flavonoids sourced from plants found in the surrounding region. Whilst bees use this substance to seal off and protect the beehive, humans have used propolis therapeutically for centuries, making use of its antibacterial, antiseptic, antipyretic and wound healing properties, among others. South African propolis is rich in the flavonoids pinocembrin, galangin, and chrysin and very little previous research has been conducted on the antimicrobial effects of these compounds.

AIM OF THE STUDY

To obtain an understanding of the antimicrobial activity of the compounds pinocembrin, galangin, and chrysin, both independently and in combination.

MATERIALS AND METHODS

The compounds pinocembrin, galangin and chrysin were investigated for interactive antimicrobial activity by determining the minimum inhibitory concentrations (MIC), minimum bactericidal concentrations (MBC), anti-quorum sensing activity, biofilm studies, and toxicity studies (brine shrimp lethality assay).

RESULTS

Minimum inhibitory concentration results demonstrated that combinations of compounds showed better inhibitory activity than single compounds. When the flavonoids were tested in combination using the MIC assay, synergy was noted for 22% of the 1:1 ratio combinations and for 66% of the triple 1:1:1 ratio combinations. Similarly, MBC results showed bactericidal activity from selected combinations, while the compounds on their own demonstrated no cidal activity. Quorum sensing studies showed that compound combinations are more effective at inhibiting bacterial communication than the individual compounds. Biofilm assays showed that the highest percentage inhibition was observed for the triple combination against E. coli at 24 h. Finally, brine shrimp lethality studies revealed that combinations of the three compounds had reduced cytotoxicity when compared to the individual compounds.

CONCLUSION

The results obtained in this study demonstrate that the compounds found in South African propolis work synergistically to achieve an optimal antimicrobial effect, whilst simultaneously minimizing cytotoxicity.

The Relationship between Pharmacological Properties and Structure- Activity of Chrysin Derivatives

Chrysin is a natural product of a flavonoid compound. Chemically, chrysin consists of two phenyl rings (A and B) and a heterocyclic ring (C). Biologically, chrysin exerts many different physiological activities. In recent years, with the in-depth development for more active drugs, the synthesis and biological activities of chrysin derivatives have been well studied. Besides, structure-activity relationship of chrysin revealed that the chemical construction meets the critical chemical structural necessities of flavonoids for numerous pharmacological activities. It is generally believed that modified chrysin could be more potent than unmodified chrysin. Different modification in the rings of chrysin could possess various degrees of biological activities. This review aims to summarize the mechanism for the activities of chrysin and its derivatives in different rings. We also explored the relationship between biological function and structure-activity of substituted chrysin derivatives with different functional groups. The influence of chrysin derivatives on the proliferation and apoptosis of cancer cells is also investigated. Development of novel drugs based on the biological functions of chrysin could better improve clinical outcomes of affected population, especially for tumor patients and diabetic patients.

Modulation of S. aureus and P. aeruginosa biofilm: an in vitro study with new coumarin derivatives

Coumarin is an important heterocyclic molecular framework of bioactive molecules against broad spectrum pathological manifestations. In the present study 18 new coumarin derivatives (CDs) were synthesized and characterized for antibiofilm activity against two model bacteria such as Staphylococcus aureus and Pseudomonas aeruginosa. It was observed that all the CDs executed significant effect in moderating activities against both planktonic and biofilm forms of these selected bacteria. Hence, to interpret the underlying probable reason of such antibiofilm effect, in-silico binding study of CDs with biofilm and motility associated proteins of these organisms were performed. All CDs have shown their propensity for occupying the native substrate binding pocket of each protein with moderate to strong binding affinities. One of the CDs such as CAMN1 showed highest binding affinity with these proteins. Interestingly, the findings of in-silico studies coincides the experimental results of antibiofilm and motility affect of CDs against both S. aureus and P. aeruginosa. Moreover, in-silico studies suggested that the antibiofilm activity of test CDs may be due to the interference of biofilm and motility associated proteins of the selected model organisms (PilT from P. aeruginosa and TarK, TarO from S. aureus). The detailed synthesis, characterization, methodology and results of biological screening along with computational studies have been reported. This study could be of greater interest in the context of the development of new anti-bacterial agent in the future.

Chrysin functionalized NHC–Au(i) complexes: synthesis, characterization and effects on the nematode Caenorhabditis elegans

The synthesis and biological effects on the nematodeCaenorhabditis elegansof chrysin functionalized Au(i)–NHC complexes are reported.

Kazakh Ziziphora Species as Sources of Bioactive Substances

Ziziphora species represent the prototypical example of the Lamiaceae family. The phytochemicals present in Ziziphora include monoterpenic essential oils, triterpenes and phenolic substances belonging to the flavonoids. In Kazakh traditional medicine, Ziziphora species possess several medicinal uses. In particular, Z. bungeana Lam. and Z. clinopodioides Lam. are used for the treatment of illnesses related to the cardiovascular system or to combat different infections. Unfortunately, the majority of the information about the complex Ziziphora species is only available in Russian and Chinese language, therefore, we decided gather all available information on Kazakhstan Ziziphora, namely its content compounds, medicinal uses and published patents, to draw the attention of scientists to this very interesting plant with high medicinal potential.

Chrysin-piperazine conjugates as antioxidant and anticancer agents

Synthesis of 7-(4-bromobutoxy)-5-hydroxy-2-phenyl-4H-chromen-4-one intermediate treating chrysin with 1,4-dibromobutane facilitated combination of chrysin with a wide range of piperazine moieties which were equipped via reacting the corresponding amines with bis(2-chloroethyl)amine hydrochloride in diethylene glycol monomethyl ether solvent. Free radical scavenging potential of prepared products was analyzed in vitro adopting DPPH and ABTS bioassay in addition to the evaluation of in vitro anticancer efficacies against cervical cancer cell lines (HeLa and CaSki) and an ovarian cancer cell line SK-OV-3 using SRB assay. Bearable toxicity of 7a-w was examined employing Madin-Darby canine kidney (MDCK) cell line. In addition, cytotoxic nature of the presented compounds was inspected utilizing Human bone marrow derived mesenchymal stem cells (hBM-MSCs). Overall, 7a-w indicated remarkable antioxidant power in scavenging DPPH(·) and ABTS(·+), particularly analogs 7f, 7j, 7k, 7l, 7n, 7q, 7v, 7w have shown promising free radical scavenging activity. Analogs 7j and 7o are identified to be highly active candidates against HeLa and CaSki cell lines, whereas 7h and 7l along with 7j proved to be very sensitive towards ovarian cancer cell line SKOV-3. None of the newly prepared scaffolds showed cytotoxic nature toward hBM-MSCs cells. From the structure-activity point of view, nature and position of the electron withdrawing and electron donating functional groups on the piperazine core may contribute to the anticipated antioxidant and anticancer action. Different spectroscopic techniques (FT-IR, (1)H NMR, (13)C NMR, Mass) and elemental analysis (CHN) were utilized to confirm the desired structure of final compounds.

Chrysin-benzothiazole conjugates as antioxidant and anticancer agents

7-(4-Bromobutoxy)-5-hydroxy-2-phenyl-4H-chromen-4-one, obtained from chrysin with 1,4-dibromobutane, was combined with a wide range of 6-substituted 2-aminobenzthiazoles, which had been prepared from the corresponding anilines with potassium thiocyanate. Free radical scavenging efficacies of newer analogues were measured using DPPH and ABTS assays, in addition to the assessment of their anticancer activity against cervical cancer cell lines (HeLa and CaSki) and ovarian cancer cell line (SK-OV-3) implementing the SRB assay. Cytotoxicity of titled compounds was checked using Madin-Darby canine kidney (MDCK) non-cancer cell line. Overall, 6a-r indicated remarkable antioxidant power as DPPH and ABTS(+) scavengers; particularly the presence of halogen(s) (6g, 6h, 6j-6l) was favourable with IC50 values comparable to the control ascorbic acid. Unsubstituted benzothiazole ring favored the activity of resultant compounds (6a and 6r) against HeLa cell line, whereas presence of chlorine (6g) or a di-fluoro group (6k) was a key to exert strong action against CaSki. Moreover, a mono-fluoro (6j) and a ketonic functionality (6o) were beneficial to display anticipated anticancer effects against ovarian cancer cell line SK-OV-3. The structural assignments of the new products were done on the basis of IR, (1)H NMR, (13)C NMR spectroscopy and elemental analysis.

Caffeic Acid phenethyl ester and ethanol extract of propolis induce the complementary cytotoxic effect on triple-negative breast cancer cell lines

Chemotherapy of breast cancer could be improved by bioactive natural substances, which may potentially sensitize the carcinoma cells’ susceptibility to drugs. Numerous phytochemicals, including propolis, have been reported to interfere with the viability of carcinoma cells. We evaluated the in vitro cytotoxic activity of ethanol extract of propolis (EEP) and its derivative caffeic acid phenethyl ester (CAPE) towards two triple-negative breast cancer (TNBC) cell lines, MDA-MB-231 and Hs578T, by implementation of the MTT and lactate dehydrogenase (LDH) assays. The morphological changes of breast carcinoma cells were observed following exposure to EEP and CAPE. The IC₅₀ of EEP was 48.35 µg∙mL⁻¹ for MDA-MB-23 cells and 33.68 µg∙mL⁻¹ for Hs578T cells, whereas the CAPE IC₅₀ was 14.08 µM and 8.01 µM for the MDA-MB-231 and Hs578T cell line, respectively. Here, we report that propolis and CAPE inhibited the growth of the MDA-MB-231 and Hs578T lines in a dose-dependent and exposure time-dependent manner. EEP showed less cytotoxic activity against both types of TNBC cells. EEP and, particularly, CAPE may markedly affect the viability of breast cancer cells, suggesting the potential role of bioactive compounds in chemoprevention/chemotherapy by potentiating the action of standard anti-cancer drugs.