Thymoquinone enhances the antioxidant and anticancer activity of Lebanese propolis

BACKGROUND Reactive oxygen species(ROS)are produced by multiple cellular processes and are maintained at optimal levels in normal cells by endogenous antioxidants.In recent years,the search for potential exogenous antioxidants from dietary sources has gained considerable attention to eliminate excess ROS that is associated with oxidative stress related diseases including cancer.Propolis,a resinous honeybee product,has been shown to have protective effects against oxidative stress and anticancer effects against several types of neoplasms.AIM To investigate the antioxidant and anticancer potential of Lebanese propolis when applied alone or in combination with the promising anticancer compound Thymoquinone(TQ)the main constituent of Nigella sativa essential oil.METHODS Crude extracts of Lebanese propolis collected from two locations,Rashaya and Akkar-Danniyeh,were prepared in methanol and the total phenolic content was determined by Folin–Ciocalteu method.The antioxidant activity was assessed by the ability to scavenge 2,2-diphenyl-1-picrylhydrazyl(DPPH)free radical and to inhibit H2O2-induced oxidative hemolysis of human erythrocytes.The anticancer activity was evaluated by[3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyl tetrazolium bromide]MTT assay against HCT-116 human colorectal cancer cells and MDAMB-231 human breast cancer cells.RESULTS The total phenolic content of propolis extract from Rashaya and Akkar-Danniyeh were 56.81μg and 83.503μg of gallic acid equivalent/mg of propolis,respectively.Both natural agents exhibited strong antioxidant activities as evidenced by their ability to scavenge DPPH free radical and to protect erythrocytes against H2O2-induced hemolysis.They also dose-dependently decreased the viability of both cancer cell lines.The IC50 value of each of propolis extract from Rashaya and Akkar-Danniyeh or TQ was 22.3,61.7,40.44μg/mL for breast cancer cells at 72 h and 33.3,50.9,33.5μg/mL for colorectal cancer cells at the same time point,respectively.Importantly,the inhibitory effects of propolis on DPPH radicals and cancer cell viability were achieved at half its concentration when combined with TQ.CONCLUSION Our results indicate that Lebanese propolis extract has antioxidant and anticancer potential and its combination with TQ could possibly prevent ROS-mediated diseases.

Novel therapeutic diiminoquinone exhibits anticancer effects on human colorectal cancer cells in two-dimensional and threedimensional in vitro models

BACKGROUND Colorectal cancer(CRC) is the second leading cause of cancer-related mortality.Cancer stem cells(CSCs) in CRC, which are spared by many chemotherapeutics,have tumorigenic capacity and are believed to be the reason behind cancer relapse. So far, there have been no effective drugs to target colon CSCs. Diiminoquinone(DIQ) has shown promising effects on targeting colon cancer.However, there is limited research on the effects of DIQ on eradicating CSCs in CRC.AIM To investigate the anticancer potential of DIQ on colon CSCs in two-dimensional(2D) and three-dimensional(3D) models using colonospheres and patient-derived organoids.METHODS Various 2D methods have been used to assess the effect and the mechanism of DIQ on HCT116and HT29 cell lines including cell proliferation and viability assays, migration and invasion assays,immunofluorescence staining, and flow cytometry. The potency of DIQ was also assessed in 3D culture using the sphere formation assay and colon cancer patient-derived organoid model.RESULTS Our results showed that DIQ significantly inhibited cell proliferation, migration, and invasion in HCT116 and HT29 cell lines. DIQ treatment induced apoptosis along with an accumulation of HCT116 and HT29 cancer cells in the sub-G1 region and an increase in reactive oxygen species in both CRC cell lines. DIQ reduced sphere-forming and self-renewal ability of colon cancer HCT116and HT29 stem/progenitor cells at sub-toxic doses of 1 μmol/L. Mechanistically, DIQ targets CSCs by downregulating the main components of stem cell-related-catenin, AKT, and ERK oncogenic signaling pathways. Potently, DIQ displayed a highly significant decrease in both the count and the size of the organoids derived from colon cancer patients as compared to control and 5-fluorouracil conditions.CONCLUSION This study is the first documentation of the molecular mechanism of the novel anticancer therapeutic DIQ via targeting CSC, a promising compound that needs further investigation.

Therapeutic potential of thymoquinone in combination therapy against cancer and cancer stem cells

The long-term success of standard anticancer monotherapeutic strategies has been hampered by intolerable side effects,resistance to treatment and cancer relapse.These monotherapeutic strategies shrink the tumor bulk but do not effectively eliminate the population of self-renewing cancer stem cells(CSCs)that are normally present within the tumor.These surviving CSCs develop mechanisms of resistance to treatment and refuel the tumor,thus causing cancer relapse.To ensure durable tumor control,research has moved away from adopting the monotreatment paradigm towards developing and using combination therapy.Combining different therapeutic modalities has demonstrated significant therapeutic outcomes by strengthening the anti-tumor potential of monotreatment against cancer and cancer stem cells,mitigating their toxic adverse effects,and ultimately overcoming resistance.Recently,there has been growing interest in combining natural products from different sources or with clinically used chemotherapeutics to further improve treatment efficacy and tolerability.Thymoquinone(TQ),the main bioactive constituent of Nigella sativa,has gained great attention in combination therapy research after demonstrating its low toxicity to normal cells and remarkable anticancer efficacy in extensive preclinical studies in addition to its ability to target chemoresistant CSCs.Here,we provide an overview of the therapeutic responses resulting from combining TQ with conventional therapeutic agents such as alkylating agents,antimetabolites and antimicrotubules as well as with topoisomerase inhibitors and non-coding RNA.We also review data on anticancer effects of TQ when combined with ionizing radiation and several natural products such as vitamin D3,melatonin and other compounds derived from Chinese medicinal plants.The focus of this review is on two outcomes of TQ combination therapy,namely eradicating CSCs and treating various types of cancers.In conclusion,the ability of TQ to potentiate the anticancer activity of many chemotherapeutic agents and sensitize cancer cells to radiotherapy makes it a promising molecule that could be used in combination therapy to overcome resistance to standard chemotherapeutic agents and reduce their associated toxicities.

Micelles as potential drug delivery systems for colorectal cancer treatment

Despite the significant progress in cancer therapy,colorectal cancer(CRC)remains one of the most fatal malignancies worldwide.Chemotherapy is currently the mainstay therapeutic modality adopted for CRC treatment.However,the long-term effectiveness of chemotherapeutic drugs has been hampered by their low bioavailability,non-selective tumor targeting mechanisms,non-specific biodistribution associated with low drug concentrations at the tumor site and undesirable side effects.Over the last decade,there has been increasing interest in using nanotechnology-based drug delivery systems to circumvent these limitations.Various nanoparticles have been developed for delivering chemotherapeutic drugs among which polymeric micelles are attractive candidates.Polymeric micelles are biocompatible nanocarriers that can bypass the biological barriers and preferentially accumulate in tumors via the enhanced permeability and retention effect.They can be easily engineered with stimuli-responsive and tumor targeting moieties to further ensure their selective uptake by cancer cells and controlled drug release at the desirable tumor site.They have been shown to effectively improve the pharmacokinetic properties of chemotherapeutic drugs and enhance their safety profile and anticancer efficacy in different types of cancer.Given that combination therapy is the new strategy implemented in cancer therapy,polymeric micelles are suitable for multidrug delivery and allow drugs to act concurrently at the action site to achieve synergistic therapeutic outcomes.They also allow the delivery of anticancer genetic material along with chemotherapy drugs offering a novel approach for CRC therapy.Here,we highlight the properties of polymeric micelles that make them promising drug delivery systems for CRC treatment.We also review their application in CRC chemotherapy and gene therapy as well as in combination cancer chemotherapy.

Antioxidative, cytotoxic, and anti-metastatic potentials of Laurencia obtusa and Ulva lactuca seaweeds

Objective:To investigate the antioxidant and cytotoxic properties of the most active extracts from Ulva lactuca and Laurencia obtusa against colon and cervical cancer cell lines.Methods:The antioxidant radical scavenging activity of the algal extracts was estimated using the 2,2-diphenyl-1-picrylhydrazyl colorimetric assay.Moreover,the cytotoxic potential of these bioactive extracts was studied against HCT-116 and HeLa cells by 3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyltetrazolium bromide assay.Wound healing analysis was adopted to evaluate the antimetastatic effects of protein extracts from both algae.Cell cycle analysis was performed by flow cytometry,and apoptotic bodies were detected using 4′,6-diamidino-2-phenylindole fluorescent staining.Amino acids of hydrolyzed protein extract were separated and identified chromatographically by high performance liquid chromatography.Results:The green algae Ulva lactuca had higher lipid content than Laurencia obtusa,whereas the latter had higher protein content with high antioxidant capacity.Protein extracts had significant dose-and time-dependent cytotoxicity and anti-metastatic activity against HCT-116 cells.Protein b extracts of both algae obtained from the chloroform:hexane solvent lipid-free residue caused morphological changes and induced apoptosis of HCT-116 cells.Further analysis revealed that apoptosis induced upon Laurencia obtusa protein b treatment was triggered via the ROS pathway,causing a significant increase in the sub-G_(1) population.Glycine and arginine(5.94 and 5.47μM,respectively)were the most common amino acids in Laurencia obtusa protein b extract.Conclusions:Proteins of Laurencia obtusa and Ulva lactuca could be considered as an adjuvant nutraceutical source of pro-apoptotic and anti-metastatic biomolecules against colon cancer.

Thymoquinone anticancer activity is enhanced when combined with royal jelly in human breast cancer

BACKGROUND Breast cancer is the most common cause of the majority of cancer-related deaths in women,among which triple-negative breast cancer is the most aggressive type of breast cancer diagnosed with limited treatment options.Thymoquinone(TQ),the main bioactive constituent of Nigella sativa,has been extensively studied as a potent anticancer molecule against various types of cancers.Honeybee products such as the royal jelly(RJ),the nutritive secretion fed to honeybee queens,exhibit a variety of biological activities besides its anticancer effect.However,the anticancer activity of the combination of TQ and RJ against breast cancer is still unknown.AIM To investigate cytotoxicity of RJ in FHs 74 Int cells and the anticancer effects of TQ,RJ,and their combinations in the MDA-MB-231 cell line.METHODS Cells were treated with TQ,RJ,and their combinations for 24 h.Using 3-(4,5 dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay,we determined the half-maximal inhibitory concentration of TQ.Trypan blue and 3-(4,5 dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assays were then performed to assess the cell viability in response to different treatment conditions.Cell death and cycle regulation were investigated using propidium iodide deoxyribonucleic acid staining followed by flow cytometry in response to a single dose of TQ,RJ,and their combination.Immunostaining for cleaved caspase 3 and Ki67 expression was used to determine apoptosis induction and changes in cell proliferation.RESULTS TQ alone inhibited cell viability in a dose-dependent manner at concentrations below and above the half-maximal inhibitory concentration.RJ exhibited relatively nontoxic effects against MDA-MB-231 cells and FHs 74 Int small intestinal cells at concentrations below 5μg/mL.High doses of RJ(200μg/mL)had greater toxicity against MDA-MB-231 cells.Interestingly,the inhibition of cell viability was most pronounced in response to 15μmol/L TQ and 5μg/mL RJ.A dose of 15μmol/L TQ caused a significant increase in the PreG1 population,while a more pronounced effect on cell viability inhibition and PreG1 increase was observed in response to TQ and RJ combinations.TQ was the main inducer of caspase 3-dependent apoptosis when applied alone and in combination with RJ.In contrast,no significant regulation of Ki67 expression was observed,indicating that the decrease in cell viability was due to apoptosis induction rather than to inhibition of cell proliferation.CONCLUSION This study is the first to report enhanced anticancer effects of TQ and RJ combination against MDA-MB-231 breast cancer cells,which could confer an advantage for cancer therapy.

Potential role of micro ribonucleic acids in screening for anal cancer in human papilloma virus and human immunodeficiency virus related malignancies

Despite advances in antiretroviral treatment(ART),human immunodeficiency virus(HIV)continues to be a major global public health issue owing to the increased mortality rates related to the prevalent oncogenic viruses among people living with HIV(PLWH).Human papillomavirus(HPV)is the most common sexually transmitted viral disease in both men and women worldwide.High-risk or oncogenic HPV types are associated with the development of HPV-related malignancies,including cervical,penile,and anal cancer,in addition to oral cancers.The incidence of anal squamous cell cancers is increasing among PLWH,necessitating the need for reliable screening methods in this population at risk.In fact,the currently used screening methods,including the Pap smear,are invasive and are neither sensitive nor specific.Investigators are interested in circulatory and tissue micro ribonucleic acids(miRNAs),as these small non-coding RNAs are ideal biomarkers for early detection and prognosis of cancer.Multiple miRNAs are deregulated during HIV and HPV infection and their deregulation contributes to the pathogenesis of disease.Here,we will review the molecular basis of HIV and HPV co-infections and focus on the pathogenesis and epidemiology of anal cancer in PLWH.The limitations of screening for anal cancer and the need for a reliable screening program that involves specific miRNAs with diagnostic and therapeutic values is also discussed.