Anticancer activity of benzoxazole derivative (2015 onwards): a review

Background

According to the report published recently by the World Health Organization, the number of cancer cases in the world will increase to 22 million by 2030. So the anticancer drug research and development is taking place in the direction where the new entities are developed which are low in toxicity and are with improved activity. Benzoxazole and its derivative represent a very important class of heterocyclic compounds, which have a diverse therapeutic area. Recently, many active compounds synthesized are very effective; natural products isolated with benzoxazole moiety have also shown to be potent towards cancer.

Main text

In the last few years, many research groups have designed and developed many novel compounds with benzoxazole as their backbone and checked their anticancer activity. In the review article, the recent developments (mostly after 2015) made in the direction of design and synthesis of new scaffolds with very potent anticancer activity are briefly described. The effect of various heterocycles attached to the benzoxazole and their effect on the anticancer activity are thoroughly studied and recorded in the review.

Conclusion

These compiled data in the article will surely update the scientific community with the recent development in this area and will provide direction for further research in this area.

Stimulation of calcium influx and CK1α by NF-κB antagonist [6]-Gingerol reprograms red blood cell longevity

Chemotherapy-induced anemia (CIA) is a major obstacle in cancer management. Although the mechanisms governing CIA are poorly understood, recent efforts have identified suicidal erythrocyte (red blood cell, RBC) death as a possible cause of CIA. [6]-Gingerol (GNG), a polyphenol extracted from Zingiber officinale plant, exhibits a wide array of biological activities including antimicrobial, antioxidant, anti-inflammatory, immunomodulatory, and anticancer activities, in vitro and in vivo. However, the potential toxicity of GNG to human RBCs remains unexplored. RBCs from heparinized blood were isolated by centrifugation and exposed to antitumor concentrations (10-100 µM) of GNG for 24 hr at 37°C. Hemolysis was calculated from hemoglobin leakage in the supernatant (λ_max  = 405 nm), while cytofluorometric analysis of eryptosis employed Annexin-V-FITC to detect phosphatidylserine (PS) exposure, forward scatter (FSC) to estimate cell volume, Fluo4/AM to measure calcium activity, and H₂ DCFDA to assess oxidative stress. Moreover, zVAD(OMe)-FMK, SB203580, necrostatin-2, staurosporin, and D4476 were used to identify signaling pathways responsive to GNG. GNG induced significant hemolysis at 100 µM, independently of extracellular calcium, and increased Annexin-V-FITC fluorescence that was thoroughly abrogated without extracellular calcium. GNG also enhanced Fluo4 fluorescence and reduced FSC, but had no significant effect on DCF fluorescence. Importantly, the presence of D4476 significantly attenuated GNG-induced hemolysis. In conclusion, GNG stimulates premature RBC death characterized by loss of membrane asymmetry, elevated cytosolic calcium, cell shrinkage, and casein kinase 1α activation. Blocking the activity of calcium channels or CK1α may, therefore, ameliorate the toxic effects of GNG on RBCs. PRACTICAL APPLICATIONS: This report presents a safety assessment of GNG as a chemotherapeutic agent and highlights the novel toxicity of GNG to human RBCs. Our findings provide novel insights that may lead to more efficient utilization of GNG in chemotherapy. Specifically, our data revealed the involvement of calcium channels and casein kinase 1α in mediating GNG-induced premature RBC death, and, therefore, inverse agonists or inhibitors of either pathway may be used as pharmaceutical adjuvants to attenuate the toxic effects of GNG.

Evaluation of Kaempferol as AKT Dependent mTOR Regulator via Targeting FKBP-12 in Hepatocellular Carcinoma: An In silico Approach

Background:

Hepatocellular carcinomas (HCCs) are inherently chemotherapy-resistant tumors with about 30-50% activation of PI3K/Akt/mTOR pathway, and this pathway is not aberrant in normal cells. Therefore, targeting the PI3K/Akt/mTOR pathway has become a promising strategy in drug designing to combat liver cancer. Recently, many studies with phytochemicals suggest few classes of compounds, especially flavonoids, to be useful in down-regulating the PI3K/Akt/mTOR pathway corresponding to HCC. In the present study, an attempt is made to explore flavonoids, from which the best mTORC1 inhibitor against hepatocellular carcinoma is selected using computational molecular modeling.

Methods:

In the present study, we performed a virtual screening method with phytochemicals of flavonoid category. To ensure proper bioavailability and druggability, pharmacokinetic and interaction parameters have been used to screen the molecules. The target protein molecules have been selected from the RCSB. The interaction studies have been conducted using Biovia Discovery Studio client version 17.2.0.1.16347 and the pharmacokinetic predictions have been made through ADMET SAR. The responsiveness towards the regulation of the mTOR pathway varies from person to person, demanding a pharmacogenomic approach in the analysis. The genetic variants (Single Nucleotide Variants-SNVs) corresponding to the mutations have been identified.

Results and Discussion:

The study identified phytoconstituents with better interaction with receptor FKBP12, a Rapamycin binding domain which is the target of Rapamycin and its analogues for mTORC1 inhibition in HCC. Another protein, ‘AKT serine/threonine-protein kinase’ has been identified, which is associated with activation of mTORC1. The molecular interaction studies (docking studies) and ADMET (absorption, distribution, metabolism, excretion and toxicity) analysis were used to identify the affinity between selected phytoconstituents as mTORC1 inhibitor against Hepatocellular carcinoma. The docking studies support Kaempferol to be a potential ligand with docking score values of 33.4 (3CQU-3D structure of AKT1)] and 27.3 (2FAP-3D structure of FRB domain of mTOR) respectively as compared to that of standard drug Everolimus with 24.4 (3CQU-3D structure of AKT1) and 20.1 (2FAP-3D structure of FRB domain of mTOR) respectively. Docking studies along with ADMET results show that Kaempferol has favorable drug likeliness properties and binds to the same active site (site1) of the targeted proteins (3CQU-3D structure of AKT1) and (2FAP-3D structure of FRB domain of mTOR) where the standard drug Everolimus is known to bind.

Conclusion:

The study exhibited that Kaempferol had a better binding affinity towards the receptor FKBP12, a Rapamycin Binding Domain and AKT serine/threonine-protein kinase resulting in its better efficacy in the mTORC1 inhibition as when compared with standard drug Everolimus against HCC. To the best of our knowledge, no studies have been reported on Kaempferol as mTORC1 inhibitor against Hepatocellular carcinoma.

Importance of Fluorine in Benzazole Compounds

Fluorine-containing heterocycles continue to receive considerable attention due to their unique properties. In medicinal chemistry, the incorporation of fluorine in small molecules imparts a significant enhancement their biological activities compared to non-fluorinated molecules. In this short review, we will highlight the importance of incorporating fluorine as a basic appendage in benzothiazole and benzimidazole skeletons. The chemistry and pharmacological activities of heterocycles containing fluorine during the past years are compiled and discussed.

New perspectives of purple starthistle (Centaurea calcitrapa) leaf extracts: phytochemical analysis, cytotoxicity and antimicrobial activity

Ethnobotanical and ethnopharmacological studies of many Centaurea species indicated their potential in folk medicine so far. However, investigations of different Centaurea calcitrapa L. extracts in terms of cytotoxicity and antimicrobial activity against phytopathogens are generally scarce. The phenolic profile and broad antimicrobial activity (especially towards bacterial phytopathogens) of methanol (MeOH), 70% ethanol (EtOH), ethyl-acetate (EtOAc), 50% acetone (Me₂CO) and dichloromethane: methanol (DCM: MeOH, 1: 1) extracts of C. calcitrapa leaves and their potential toxicity on MRC-5 cell line were investigated for the first time. A total of 55 phenolic compounds were identified: 30 phenolic acids and their derivatives, 25 flavonoid glycosides and aglycones. This is also the first report of the presence of centaureidin, jaceidin, kaempferide, nepetin, flavonoid glycosides, phenolic acids and their esters in C. calcitrapa extracts. The best results were obtained with EtOAc extract with lowest MIC values expressed in µg/mL ranging from 13 to 25, while methicillin resistant Staphylococcus aureus was the most susceptible strain. The most susceptible phytopathogens were Pseudomonas syringae pv. syringae, Xanthomonas campestris pv. campestris and Agrobacterium tumefaciens. The highest cytotoxicity was recorded for EtOAc and Me₂CO extracts with the lowest relative and absolute IC₅₀ values between 88 and 102 µg/mL, while EtOH extract was the least toxic with predicted relative IC₅₀ value of 1578 µg/mL. Our results indicate that all tested extracts at concentration considered as non-toxic can be one of great importance in combat towards phytopathogenic and human pathogenic strains, as well as natural sources of antimicrobials.

Alternative Options for Skin Cancer Therapy via Regulation of AKT and Related Signaling Pathways

Global environmental pollution has led to human exposure to ultraviolet (UV) radiation due to the damaged ozone layer, thereby increasing the incidence and death rate of skin cancer including both melanoma and non-melanoma. Overexpression and activation of V-akt murine thymoma viral oncogene homolog (AKT, also known as protein kinase B) and related signaling pathways are major factors contributing to many cancers including lung cancer, esophageal squamous cell carcinoma and skin cancer. Although BRAF inhibitors are used to treat melanoma, further options are needed due to treatment resistance and poor efficacy. Depletion of AKT expression and activation, and related signaling cascades by its inhibitors, decreases the growth of skin cancer and metastasis. Here we have focused the effects of AKT and related signaling (PI3K/AKT/mTOR) pathways by regulators derived from plants and suggest the need for efficient treatment in skin cancer therapy.

Effectiveness of ginger on pain following periodontal surgery - A randomized cross-over clinical trial

Background

Ibuprofen is one of the generally prescribed Non-steroidal anti-inflammatory drugs (NSAIDs) for postoperative pain after periodontal surgery, but are contraindicated in certain patients. Ginger, which is the rhizome of Zingiber officinale, being a common herbal drug having anti-inflammatory as well as analgesic activities can be an efficient substitute for synthetic agents like Ibuprofen.

Objectives

To compare the effectiveness of ibuprofen and dried ginger powder on pain and gingival inflammation following open flap debridement.

Materials and methods

Ten systemically healthy individuals with chronic generalized periodontitis were selected for this single-blinded randomized cross-over clinical trial and underwent open flap debridement in at least two quadrants. Each quadrant was randomly allocated to receive either Ibuprofen (400 mg) or Ginger powder capsules (400 mg) thrice daily for three days. Subjects were requested to note down the pain score on the Visual Analogue Scale (VAS) provided in a printed format, for the first eight hours after surgery and on the following two days, and gingival inflammation was assessed after one week, using Modified Gingival Index (MGI).

Result

The difference in the VAS score and MGI between the two groups was not of statistical significance.

Conclusion

Effectiveness of ginger powder for the management of pain and gingival inflammation following open flap debridement is comparable to that of ibuprofen.

Kaempferol-Mediated Sensitization Enhances Chemotherapeutic Efficacy of Sorafenib Against Hepatocellular Carcinoma: An In Silico and In Vitro Approach

Purpose: Sorafenib is the sole FDA approved drug conventionally used for the treatment of advanced hepatocellular carcinoma (HCC). Despite of the beneficial use of sorafenib in the treatment of HCC, multidrug resistance still remains a challenge. HCC is inherently known as chemotherapy resistant tumor due to P-glycoprotein (P-gp)-mediated multidrug resistance. Methods: We studied the interaction energy of kaempferol with human multidrug resistance protein-1 (RCSB PDB ID: 2CBZ) using in silico method with the help of BIOVIA Discovery Studio. HepG2 and N1S1 liver cancer cell lines were treated in suitable cell culture media to evaluate the efficacy of kaempferol in chemo-sensitizing liver cancer cells towards the effect of sorafenib. Cell viability study was performed by MTT assay. Results: In silico analysis of kaempferol showed best docking score of 23.14 with Human Multi Drug Resistant Protein-1 (RCSB PDB ID: 2CBZ) compared with positive control verapamil. Inin-vitro condition, combination of sub-toxic concentrations of both kaempferol and sorafenib produced 50% cytotoxicity with concentration of 2.5 µM each which indicates that kaempferol has the ability to reverse the MDR by decreasing the over-expression of P-gp. Conclusion: Kaempferol is able to sensitize the HepG2 and N1S1 against the sub-toxic concentration of sorafenib. Hence, we consider that the efficacy of sorafenib chemotherapy can be enhanced by the significant approach of combining the sub-toxic concentrations of sorafenib with kaempferol. Thus, kaempferol can be used as a better candidate molecule along with sorafenib for enhancing its efficacy, if validated through preclinical studies.

Phenolic Extraction of Moringa Oleifera Leaves Induces Caspase-Dependent and Caspase-Independent Apoptosis through the Generation of Reactive Oxygen Species and the Activation of Intrinsic Mitochondrial Pathway in Human Melanoma Cells

Moringa oleifera Lam. has long been used to treat many diseases, including diabetes, aging, inflammatory, and cancer. Many studies have revealed that the crude extract of Moringa oleifera Lam. leaves possesses anticancer property. Therefore, in this study, the extract of Moringa oleifera leaves was fractionated using different solvents to figure out the most effective fraction for anti-proliferative effect on melanoma cells. Methanol extract (MO-ME), hexane fraction (MO-HE), chloroform fraction (MO-CH), ethyl acetate fraction (MO-EA), and water-soluble fraction (MO-WA) of Moringa oleifera leaves were prepared. Total phenolic and flavonoid contents were determined. The anti-proliferative activity on melanoma cells and normal cells was investigated using WST-1 assay. The apoptotic activity was assessed by testing DNA condensation, DNA fragmentation, and phosphatidylserine (PS) externalization. The expression of apoptosis-related genes, the mitochondrial depolarization, and reactive oxygen species (ROS) were then examined to clarify the underlying molecular mechanisms. In this regard, MO-ME, MO-EA, and MO-CH inhibited the proliferation of both A375 human melanoma cells and A2058 human melanoma cells, but had little effect on WS1 normal human skin fibroblasts and primary normal human dermal fibroblasts (NHDF). Among fractions, the phenolic-rich MO-EA markedly inhibited the growth of A375 cells in a dose- and time-dependent manner. The anti-proliferation was supposed to be mediated via apoptosis, which was demonstrated by the significant increase of condensed chromatin, DNA fragmentation, and PS externalization. The apoptosis was stimulated by enhanced ROS production and reduction of mitochondrial membrane potential. MO-EA activated Bax while reducing Bcl-2 expression, leading to an increase in Bax/Bcl-2 ratio. The mechanisms of cell death involved in activation of Caspase-3/7 and Caspase-9 (Caspase-dependent pathway), activation, and translocation of apoptosis-inducing factor (AIF) into the nucleus (Caspase-independent pathway). Our study indicated that the phenolic-rich fraction exerted significant anticancer effects on melanoma cells in vitro which involved in Caspase-dependent and Caspase-independent apoptosis pathways mediated by mitochondrial ROS. These results provided a fundament for the using of phenolic-rich fraction of Moringa oleifera leaves to treat skin cancer effectively.

Bioinformatics and experimental studies of anti-leukemic activity from 6-gingerol demonstrate its role in p53 mediated apoptosis pathway

6-gingerol is a traditional medicine that possesses anti-cancer activity against several types of cancer. However, the mechanism of action still remains unclear. Therefore, this study explored the effects of 6-gingerol on anti-leukemic mechanisms in NB4, MOLT4, and Raji leukemic cell. Results indicated that 6-gingerol inhibited cell proliferation and induced cell apoptosis in these 3 cell lines. Moreover, 6-gingerol was shown to increase the mRNA expression of the caspase family thereby suggesting that 6-gingerol induced apoptosis through the caspase-dependent pathway. To explore the signaling pathway regulating 6-gingerol induced apoptosis, we utilized and integrated the network pharmacology approach together with experimental investigations. Targets of 6-gingerol were identified from ChEMBL and STITCH databases, which were used for constructing the protein-protein interaction (PPI) network. Results from the PPI network indicated that p53 was a key regulator. Moreover, it was found that 6-gingerol could increase the levels of p53 mRNA in all leukemic cell lines. Thus, 6-gingerol has shown to have anti-cancer activity. In addition, p53, BAX and BCL2 could be involved in the apoptosis pathway of these leukemic cells. This study is anticipated to be useful for the development of 6-gingerol as an anti-leukemic drug in the future.

Heightened Plasma Levels of Transforming Growth Factor Beta (TGF-β) and Increased Degree of Systemic Biochemical Perturbation Characterizes Hepatic Steatosis in Overweight Pediatric Patients: A Cross-Sectional Study

Nonalcoholic Fatty Liver Disease (NAFLD) is a common cause of chronic liver disease in childhood and strongly associated with obesity. Routine biochemical non-invasive tests remain with low accuracy for diagnosis of NAFLD. We performed a cross-sectional study to examine potential associations between anthropometric and biochemical parameters, specially TGF-β, a prognosis marker for hepatic steatosis (HS). Between May and October 2019, seventy-two overweight adolescents were enrolled, of which 36 had hepatic steatosis. Hepatic, lipidic and glycemic profiles, and levels of vitamin D, ferritin and TGF-β were analyzed. Hierarchical cluster and a discriminant model using canonical correlations were employed to depict the overall expression profile of biochemical markers and the biochemical degree of perturbation. Median values of alanine aminotransferase (ALT), gamma glutamyl transpeptidase (GGT), and TGF-β were higher in the adolescents with HS. Values of body mass index (BMI)/age and ALT, but not of TGF-β, were gradually increased proportionally to augmentation of steatosis severity. In a multivariate analysis, TGF-β plasma concentrations were associated with occurrence of hepatic steatosis independent of other covariates. Discriminant analysis confirmed that TGF-β concentrations can identify HS cases. Our data reveal that HS patients exhibit a distinct biosignature of biochemical parameters and imply TGF-β as an important biomarker to evaluate risk of steatosis development.

Biological Activity of Some Aromatic Plants and Their Metabolites, with an Emphasis on Health-Promoting Properties

The biological activities of four aromatic plants, namely frankincense, myrrh, ginger, and turmeric, were reviewed in the current study. The volatile fraction (essential oil) as well as the nonvolatile fraction of these four plants showed different promising biological activities that are displayed in detail. These activities can include protection from and/or alleviation of some ailment, which is supported with different proposed mechanisms of action. This review aimed to finally help researchers to get a handle on the importance of considering these selected aromatic plants, which have not been thoroughly reviewed before, as a potential adjuvant to classical synthetic drugs to enhance their efficiency. Moreover, the results elicited in this review encourage the consumption of these medicinal plants as an integrated part of the diet to boost the body's overall health based on scientific evidence.

A stilbene dimer and flavonoids from the aerial parts of Chromolaena odorata with proprotein convertase subtilisin/kexin type 9 expression inhibitory activity

Investigation of components of the chloroform-soluble and ethyl acetate-soluble extracts of the aerial parts of Chromolaena odorata L. selected by PCSK9 mRNA expression monitoring assay in HepG2 cells led to the isolation of a new stilbene dimer, (+)-8b-epi-ampelopsin A (1), and 30 known compounds (2-31). The structures of the isolates were established by interpretation of NMR spectroscopic data and the stereochemistry of the new stilbene (1) was proposed based on ECD and NMR calculations. Among the isolates, 1, 5,6,7,4'-tetramethoxyflavanone (6), 5,6,7,3',4'-pentamethoxyflavanone (7), acacetin (18), and uridine (21) were found to inhibit PCSK9 mRNA expression with IC₅₀ values of 20.6, 21.4, 31.7, 15.0, and 13.7 µM, respectively. Furthermore, the most abundant isolate among the selected compounds, 6, suppressed PCSK9 and low-density lipoprotein receptor protein expression in addition to downregulating the mRNA expression of HNF-1α.

10-gingerol induces oxidative stress through HTR1A in cumulus cells: in-vitro and in-silico studies

Background We investigated whether 10-gingerol is able to induce oxidative stress in cumulus cells. Methods For the in-vitro research, we used a cumulus cell culture in M199, containing 10-gingerol in various concentrations (0, 12, 16, and 20 µM), and detected oxidative stress through superoxide dismutase (SOD) activity and malondialdehyde (MDA) concentrations, with incubation periods of 24, 48, 72, and 96 h. The obtained results were confirmed by in-silico studies. Results The in-vitro data revealed that SOD activity and MDA concentration increased with increasing incubation periods: SOD activity at 0 µM (1.39 ± 0.24i), 12 µM (16.42 ± 0.35ab), 16 µM (17.28 ± 0.55ab), 20 µM (17.81 ± 0.12a), with a contribution of 71.1%. MDA concentration at 0 µM (17.82 ± 1.39 l), 12 µM (72.99 ± 0.31c), 16 µM (79.77 ± 4.19b), 20 µM (85.07 ± 2.57a), with a contribution of 73.1%. Based on this, the in-silico data uncovered that 10-gingerol induces oxidative stress in cumulus cells by inhibiting HTR1A functions and inactivating GSK3B and AKT-1. Conclusions 10-gingerol induces oxidative stress in cumulus cells through enhancing SOD activity and MDA concentration by inhibiting HTR1A functions and inactivating GSK3B and AKT-1.

Antitumoral effects of [6]-gingerol [(S)-5-hydroxy-1-(4-hydroxy-3-methoxyphenyl)-3-decanone] in sarcoma 180 cells through cytogenetic mechanisms

BACKGROUND

[6]-Gingerol [(S)-5-hydroxy-1-(4-hydroxy-3-methoxyphenyl)-3-decanone] is a phenolic substance reported for several ethnopharmacological usage by virtue of its antioxidant, antiemetic, anti-inflammatory and anticancer properties. This study assessed the antitumoral effects of [6]-Gingerol in primary cells of Sarcoma 180 as well as in peripheral blood lymphocytes of mice.

METHODS

The effect of [6]-Gingerol was assessed by applying cytogenetic biomarkers as indicative of genotoxicity, mutagenicity and apoptosis. Ascitic liquid cells were treated with [6]-Gingerol at concentrations of 21.33, 42.66 and 85.33 μM and subjected to the cytotoxicity assays using Trypan blue test and the comet assay, as well as the cytokinesis-block micronucleus assay. Doxorubicin (6 μM) and hydrogen peroxide (85.33 μM) were used as positive controls.

RESULTS

[6]-Gingerol, especially at concentrations of 42.66 and 85.33 μM, showed notable cytotoxicity in Sarcoma 180 cells by reducing cell viability and cell division rates via induction of apoptosis. Genotoxicity at the concentrations used was punctuated by the increase in the index and frequency of DNA damage in tested groups. [6]-Gingerol, at all concentrations tested, did not induce significant aneugenic and/or clastogenic effects. It did, however, induced other nuclear abnormalities, such as nucleoplasmic bridges, nuclear buds and apoptosis. The genotoxic effects observed in the cotreatment with H₂O₂ (challenge assay) employing neoplastic and healthy cells, indicated that [6]-Gingerol may induce oxidative stress.

CONCLUSIONS

Observations suggest that [6]-Gingerol may be a candidate for pharmaceutical antitumoral formulations due to its cytotoxicity and to mechanisms associated with genetic instability generated by nuclear alterations especially by apoptosis.

SNRPB promotes cervical cancer progression through repressing p53 expression

Cervical cancer is still a leading cause of tumor death in women across the world. Small nuclear ribonucleoprotein polypeptides B and B1 (SNRPB) gene encodes the components of the core spliceosomal machinery, and regulates the development of several types of cancers. However, its function in cervical cancer progression remains unclear. In the study, we found that SNRPB was highly expressed in human cervical cancer tissues and in cervical cancer cell lines. Meanwhile, SNRPB knockdown using shRNA in cervical cancer cells markedly reduced the cell proliferation, migration and invasion. Furthermore, the increased percentage of cells in G2/M phase and apoptotic cell death was detected in cervical cancer cells with SNRPB knockdown, suggesting that SNRPB might contribute to cervical cancer growth. Moreover, we found that SNRPB could directly interact with p53, and the interaction showed an essential role in modulating cervical cancer cell proliferation, migration, invasion and apoptosis. In xenograft model, the knockdown of SNRPB exerted effectively anti-cervical cancer ability characterized by the reduced tumor volume and weight, and a remarkable reduction in KI-67 expression. Improved expression of p53 validated the in vitro findings. Therefore, SNRPB might be a potent therapeutic target in cervical cancer through interacting with p53.

Protective Effects of [6]-Gingerol Against Chemical Carcinogens: Mechanistic Insights

[6]-Gingerol from ginger has received considerable attention as a potential cancer therapeutic agent because of its chemopreventive and chemotherapeutic effects, as well as its safety. In the current study, we examined [6]-gingerol as a natural scavenger of nine ultimate chemical carcinogens to which we are frequently exposed: glycidamide, styrene oxide, aflatoxin B1 exo-8,9-epoxide, β-propiolactone, ethylene oxide, propylene oxide, 2-cyanoethylene oxide, chloroethylene oxide, and vinyl carbamate epoxide. To evaluate [6]-gingerol efficacy, we expanded our research with the examination of glutathione-the strongest natural scavenger in human cells. The corresponding activation free energies were calculated using Hartree-Fock method with three flexible basis sets and two implicit solvation models. According to our results, [6]-gingerol proves to be an extremely effective scavenger of chemical carcinogens of the epoxy type. On the other hand, with the exception of aflatoxin B1 exo-8,9-epoxide, glutathione represents a relatively poor scavenger, whose efficacy could be augmented by [6]-gingerol. Moreover, our quantum mechanical study of the alkylation reactions of chemical carcinogens with [6]-gingerol and glutathione provide valuable insights in the reaction mechanisms and the geometries of the corresponding transition states. Therefore, we strongly believe that our research forms a solid basis for further computational, experimental and clinical studies of anticarcinogenic properties of [6]-gingerol as well as for the development of novel chemoprophylactic dietary supplements. Finally, the obtained results also point to the applicability of quantum chemical methods to studies of alkylation reactions related to chemical carcinogenesis.

A, Bava SV, Sundaram S, Retnakumari AP, Chittalakkottu S, Anto RJ. Pre-clinical evidences for the efficacy of tryptanthrin as a potent suppressor of skin cancer

OBJECTIVE

Clinical trials have demonstrated the efficacy of indigo naturalis, a traditional Chinese medicine ingredient, against psoriasis, a skin disease characterized by keratinocyte hyperproliferation and inflammation. The present study investigates the efficacy of tryptanthrin, a bioactive compound in indigo naturalis, against non-melanoma skin cancer (NMSC) and the signalling events involved.

METHODS

Efficacy of tryptanthrin against NMSC was assessed using DMBA/PMA-induced skin carcinogenesis model in Swiss albino mice. Immunostaining for PCNA and ki-67 was used to mark proliferating cells in tissues. Haematoxylin and eosin staining and toluidine staining were employed to assess inflammation, and TUNEL assay was used to detect apoptosis in tissues. The signalling events were evaluated using Western blot, imunohistochemistry and immunofluorescence staining. MTT assay and clonogenic assay were performed to assess the viability and proliferation of cancer cells, in vitro.

RESULTS

In mice, topical application of tryptanthrin suppressed skin carcinogenesis. It attenuated inflammation, impeded the proliferation of hair follicle (HF) cells and suppressed the activation of β-catenin, a major driver of HF cell proliferation. Additionally tryptanthrin suppressed the activation of ERK1/2 and p38, both of which promote β-catenin activation and lowered the expression of c-Myc and cyclin-D1. Tryptanthrin suppressed the proliferation of the human NMSC cell line, A431 and abrogated EGF-induced activation of β-catenin and subsequent cytoskeletal rearrangement.

CONCLUSION

The study demonstrates with molecular evidence that tryptanthrin is an effective suppressor of NMSC.

6-Gingerol induces cell-cycle G1-phase arrest through AKT-GSK 3β-cyclin D1 pathway in renal-cell carcinoma

Purpose

6-Gingerol, a major biochemical and pharmacological active ingredient of ginger, has shown anti-inflammatory and antitumor activities against various cancers. Searching for natural products with fewer side effects for developing adjunctive therapeutic options is necessary.

Methods

The effects of 6-gingerol on proliferation, colony formation, and cell cycle in RCC cells were detected by a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, colony formation assay, and propidium iodide (PI) staining, respectively. Western blotting, an immunofluorescence assay, and immunohistochemical staining were performed to assess the expression of relevant proteins. A subcutaneous tumor model was set up to investigate the 6-gingerol effects on tumor growth in vivo, and the pharmacokinetics of 6-gingerol in mice were detected by LC/MS assays.

Results

6-Gingerol treatment exerted time- and dose-dependent inhibition of the growth and colony formation of ACHN, 786-O, and 769-P cells, leading to a concomitant induction of cell-cycle G1-phase arrest and decrease in Ki-67 expression in the cell nucleus. Western-blotting results showed that 6-gingerol reduces phosphorylation of protein kinase B (AKT) Ser 473, cyclin-dependent kinases (CDK4), and cyclin D1 and, meanwhile, increases glycogen synthase kinase (GSK 3β) protein amount. Furthermore, the efficacy of 6-gingerol was demonstrated in an in vivo murine model of 786-O.

Conclusion

The above results indicate that 6-gingerol can induce cell-cycle arrest and cell-growth inhibition through the AKT–GSK 3β–cyclin D1 signaling pathway in vitro and in vivo, suggesting that 6-gingerol should be useful for renal-cell carcinoma treatment.

Electronic supplementary material

The online version of this article (10.1007/s00280-019-03999-9) contains supplementary material, which is available to authorized users.

Dietary delphinidin inhibits human colorectal cancer metastasis associating with upregulation of miR-204-3p and suppression of the integrin/FAK axis

Delphinidin is a flavonoid belonging to dietary anthocyanidin family that has been reported to possess diverse anti-tumoral activities. However, the effects of delphinidin on colorectal cancer (CRC) cells and the underlying mechanisms are not fully understood. Thus, we aimed to investigate the anti-cancer activity of delphinidin in CRC cells and the underlying molecular mechanisms. The effects of delphinidin on the viability, metastatic characteristics, signaling, and microRNA (miR) profile of human CRC cell lines used were analyzed. In vivo metastasis was also evaluated using xenograft animal models. Our findings showed that delphinidin (<100 μM) inhibited the colony formation of DLD-1, SW480, and SW620 cells, but non-significantly affected cell viability. Delphinidin also suppressed the migratory ability and invasiveness of the tested CRC cell lines, downregulated integrin αV/β3 expression, inhibited focal adhesion kinase (FAK)/Src/paxillin signaling, and interfered with cytoskeletal construction. Analysis of the miR expression profile revealed a number of miRs, particularly miR-204-3p, that were significantly upregulated and downregulated by delphinidin. Abolishing the expression of one upregulated miR, miR-204-3p, with an antagomir restored delphinidin-mediated inhibition of cell migration and invasiveness in DLD-1 cells as well as the αV/β3-integrin/FAK/Src axis. Delphinidin also inhibited the lung metastasis of DLD-1 cells in the xenograft animal model. Collectively, these results indicate that the migration and invasion of CRC cells are inhibited by delphinidin, and the mechanism may involve the upregulation of miR-204-3p and consequent suppression of the αV/β3-integrin/FAK axis. These findings suggest that delphinidin exerts anti-metastatic effects in CRC cells by inhibiting integrin/FAK signaling and indicate that miR-204-3p may play an important role in CRC metastasis.

Gingers and Their Purified Components as Cancer Chemopreventative Agents

Chemoprevention by ingested substituents is the process through which nutraceuticals and/or their bioactive components antagonize carcinogenesis. Carcinogenesis is the course of action whereby a normal cell is transformed into a neoplastic cell. This latter action involves several steps, starting with initiation and followed by promotion and progression. Driving these stages is continued oxidative stress and inflammation, which in turn, causes a myriad of aberrant gene expressions and mutations within the transforming cell population and abnormal gene expressions by the cells within the surrounding lesion. Chemoprevention of cancer with bioreactive foods or their extracted/purified components occurs primarily via normalizing these inappropriate gene activities. Various foods/agents have been shown to affect different gene expressions. In this review, we discuss how the chemoprevention activities of gingers antagonize cancer development.

Potential proapoptotic phytochemical agents for the treatment and prevention of colorectal cancer

Colorectal cancer (CRC) is one of the leading causes of mortality among men and women. Chemo-resistance, adverse effects and disease recurrence are major challenges in the development of effective cancer therapeutics. Substantial literature on this subject highlights that populations consuming diets rich in fibers, fruits and vegetables have a significantly reduced incidence rate of CRC. This chemo-preventive effect is primarily associated with the presence of phytochemicals in the dietary components. Plant-derived chemical agents act as a prominent source of novel compounds for drug discovery. Phytochemicals have been the focus of an increasing number of studies due to their ability to modulate carcinogenic processes through the alteration of multiple cancer cell survival pathways. Despite promising results from experimental studies, only a limited number of phytochemicals have entered into clinical trials. The purpose of the current review is to compile previously published pre-clinical and clinical evidence of phytochemicals in cases of CRC. A PubMed, Google Scholar and Science Direct search was performed for relevant articles published between 2008-2018 using the following key terms: 'Phytochemicals with colorectal cancers', 'apoptosis', 'cell cycle', 'reactive oxygen species' and 'clinical anticancer activities'. The present review may aid in identifying the most investigated phytochemicals in CRC cells, and due to the limited number of studies that make it from the laboratory bench to clinical trial stage, may provide a novel foundation for future research.

Toxic, cytogenetic and antitumor evaluations of [6]-gingerol in non-clinical in vitro studies

Gingerol - [6]-gingerol ((S)-5-hydroxy-1-(4-hydroxy-3-methoxyphenyl)-3-decanone; [6]-G) - is a phenolic compound with several pharmacological properties. Herein, the aim of the study was to evaluate the toxicogenic effects of [6]-G on Artemia salina nauplii, Allium cepa, HL-60 cell line and Sarcoma 180 (S-180) ascitic fluid cells.For toxic and genotoxic analysis, it was used [6]-G concentrations of 5, 10, 20 and 40 μg mL-1. For cytotoxic evaluation using the MTT test (3- [4,5-dimethyl-thiazol-2-yl] -2,5-diphenyl tetrazolium bromide), serial [6]-G dilutions (1.56-100 μg mL-1) were performed, and S-180, HL-60 and peripheral blood mononuclear cells (PBMC) were treated for 72 h. The IC50 of [6]-G were 1.14, 5.73 and 11.18 μg mL-1 for HL-60, S-180 and PBMC, respectively, indicating a possible selectivity against tumor cell lines. At higher concentrations (>10 μg mL^-1), toxicity and genotoxicity were observed in the A. cepa test, especially at 40 μg mL^-1. Mechanisms indicating apoptosis, such as toxicity, cytotoxicity and nuclear abnormalities (bridges, fragments, delays, loose chromosomes and micronuclei) suggest that [6]-G has potential for antitumor pharmaceutical formulations.

A Review Exploring Therapeutic Worth of 1,3,4-Oxadiazole Tailored Compounds

1,3,4-Oxadiazole, a five-membered aromatic ring can be seen in a number of synthetic molecules. The peculiar structural feature of 1,3,4-oxadiazole ring with pyridine type of nitrogen atom is beneficial for 1,3,4-oxadiazole derivatives to have effective binding with different enzymes and receptors in biological systems through numerous weak interactions, thereby eliciting an array of bioactivities. Research in the area of development of 1,3,4-oxadiazole-based derivatives has become an interesting topic for the scientists. A number of 1,3,4-oxadiazole based compounds with high therapeutic potency are being extensively used for the treatment of different ailments, contributing to enormous development value. This work provides a systematic and comprehensive review highlighting current developments of 1,3,4-oxadiazole based compounds in the entire range of medicinal chemistry such as anticancer, antifungal, antibacterial, antitubercular, anti-inflammatory, antineuropathic, antihypertensive, antihistaminic, antiparasitic, antiobesity, antiviral, and other medicinal agents. It is believed that this review will be of great help for new thoughts in the pursuit for rational designs for the development of more active and less toxic 1,3,4-oxadiazole based medicinal agents.

Isolation of Tryptanthrin and Reassessment of Evidence for Its Isobaric Isostere Wrightiadione in Plants of the Wrightia Genus

A series of Wrightia hanleyi extracts was screened for activity against Mycobacterium tuberculosis H37Rv. One active fraction contained a compound that initially appeared to be either the isoflavonoid wrightiadione or the alkaloid tryptanthrin, both of which have been previously reported in other Wrightia species. Characterization by NMR and MS, as well as evaluation of the literature describing these compounds, led to the conclusion that wrightiadione (1) was misidentified in the first report of its isolation from W. tomentosa in 1992 and again in 2015 when reported in W. pubescens and W. religiosa. Instead, the molecule described in these reports and in the present work is almost certainly the isobaric (same nominal mass) and isosteric (same number of atoms, valency, and shape) tryptanthrin (2), a well-known quinazolinone alkaloid found in a variety of plants including Wrightia species. Tryptanthrin (2) is also accessible synthetically via several routes and has been thoroughly characterized. Wrightiadione (1) has been synthesized and characterized and may have useful biological activity; however, this compound can no longer be said to be known to exist in Nature. To our knowledge, this misidentification of wrightiadione (1) has heretofore been unrecognized.

Cytotoxic Properties of Damiana (Turnera diffusa) Extracts and Constituents and A Validated Quantitative UHPLC-DAD Assay

In our continuing search for new cytotoxic agents, we assayed extracts, fractions, and pure compounds from damiana (Turnera diffusa) against multiple myeloma (NCI-H929, U266, and MM1S) cell lines. After a first liquid-liquid solvent extraction, the ethyl acetate layer of an acetone (70%) crude extract was identified as the most active fraction. Further separation of the active fraction led to the isolation of naringenin (1), three apigenin coumaroyl glucosides 2–4, and five flavone aglycones 5–9. Naringenin (1) and apigenin 7-O-(4″-O-p-E-coumaroyl)-glucoside (4) showed significant cytotoxic effects against the tested myeloma cell lines. Additionally, we established a validated ultra-high performance liquid chromatography diode array detector (UHPLC-DAD) method for the quantification of the isolated components in the herb and in traditional preparations of T. diffusa.

Steroidal glycoalkaloids from Solanum nigrum target cytoskeletal proteins: an in silico analysis

Background

Solanum nigrum (black nightshade; S. nigrum), a member of family Solanaceae, has been endowed with a heterogeneous array of secondary metabolites of which the steroidal glycoalkaloids (SGAs) and steroidal saponins (SS) have vast potential to serve as anticancer agents. Since there has been much controversy regarding safety of use of glycoalkaloids as anticancer agents, this area has remained more or less unexplored. Cytoskeletal proteins like actin play an important role in maintaining cell shape, synchronizing cell division, cell motility, etc. and along with their accessory proteins may also serve as important therapeutic targets for potential anticancer candidates. In the present study, glycoalkaloids and saponins from S. nigrum were screened for their interaction and binding affinity to cytoskeletal proteins, using molecular docking.

Methods

Bioactivity score and Prediction of Activity Spectra for Substances (PASS) analysis were performed using softwares Molinspiration and Osiris Data Explorer respectively, to assess the feasibility of selected phytoconstituents as potential drug candidates. The results were compared with two standard reference drugs doxorubicin hydrochloride (anticancer) and tetracycline (antibiotic). Multivariate data obtained were analyzed using principal component analysis (PCA).

Results

Docking analysis revealed that the binding affinities of the phytoconstituents towards the target cytoskeletal proteins decreased in the order coronin>villin>ezrin>vimentin>gelsolin>thymosin>cofilin. Glycoalkaloid solasonine displayed the greatest binding affinity towards the target proteins followed by alpha-solanine whereas amongst the saponins, nigrumnin-I showed maximum binding affinity. PASS Analysis of the selected phytoconstituents revealed 1 to 3 violations of Lipinski’s parameters indicating the need for modification of their structure-activity relationship (SAR) for improvement of their bioactivity and bioavailability. Glycoalkaloids and saponins all had bioactivity scores between −5.0 and 0.0 with respect to various receptor proteins and target enzymes. Solanidine, solasodine and solamargine had positive values of druglikeness which indicated that these compounds have the potential for development into future anticancer drugs. Toxicity potential evaluation revealed that glycoalkaloids and saponins had no toxicity, tumorigenicity or irritant effect(s). SAR analysis revealed that the number, type and location of sugar or the substitution of hydroxyl group on alkaloid backbone had an effect on the activity and that the presence of α-L-rhamnopyranose sugar at C-2 was critical for a compound to exhibit anticancer activity.

Conclusion

The present study revealed some cytoskeletal target(s) for S. nigrum phytoconstituents by docking analysis that have not been previously reported and thus warrant further investigations both in vitro and in vivo.

Ginger: A Novel Strategy to Battle Cancer through Modulating Cell Signalling Pathways: A Review

Numerous studies have been performed in understanding the development of cancer. Though, the mechanism of action of genes in the development of cancer remains to be explained. The current mode of treatment of cancer shows adverse effects on normal cells and also alter the cell signalling pathways. However, ginger and its active compound have fascinated research based on animal model and laboratories during the past decade due to its potentiality in killing cancer cells. Ginger is a mixture of various compounds including gingerol, paradol, zingiberene and shogaol and such compounds are the main players in diseases management. Most of the health-promoting effects of ginger and its active compound can be attributed due to its antioxidant and anti-tumour activity. Besides, the active compound of ginger has proven its role in cancer management through its modulatory effect on tumour suppressor genes, cell cycle, apoptosis, transcription factors, angiogenesis and growth factor. In this review, the role of ginger and its active compound in the inhibition of cancer growth through modulating cell signalling pathways will be reviewed and discussed.

Design and synthesis of benzothiazole/thiophene-4H-chromene hybrids

A library of 4H-chromene derivatives with heterocyclic substituent's at the 3 and 4-positions was synthesized in a convenient DBU catalysed three component synthesis between salicylaldehyde, acetonitrile derivatives and thiazolidinedione to afford 2-amino-3-benzothiazole-4-heterocycle-4H-chromenes and 2-amino-3-thiophenoyl-4-heterocycle-4H-chromenes derivatives in ethanol and a mixture of ethanol and water (1 : 1) at room temperature. The significance of this protocol is the feasibility of incorporating substituents simultaneously at the 3 and 4 positions of 4H-chromenes in an efficient three component reaction.

Protective and therapeutic potential of ginger (Zingiber officinale) extract and [6]-gingerol in cancer: A comprehensive review

Natural dietary agents have attracted considerable attention due to their role in promoting health and reducing the risk of diseases including cancer. Ginger, one of the most ancient known spices, contains bioactive compounds with several health benefits. [6]-Gingerol constitutes the most pharmacologically active among such compounds. The aim of the present work was to review the literature pertaining to the use of ginger extract and [6]-gingerol against tumorigenic and oxidative and inflammatory processes associated with cancer, along with the underlying mechanisms of action involved in signaling pathways. This will shed some light on the protective or therapeutic role of ginger derivatives in oxidative and inflammatory regulations during metabolic disturbance and on the antiproliferative and anticancer properties. Data collected from experimental (in vitro or in vivo) and clinical studies discussed in this review indicate that ginger extract and [6]-gingerol exert their action through important mediators and pathways of cell signaling, including Bax/Bcl2, p38/MAPK, Nrf2, p65/NF-κB, TNF-α, ERK1/2, SAPK/JNK, ROS/NF-κB/COX-2, caspases-3, -9, and p53. This suggests that ginger derivatives, in the form of an extract or isolated compounds, exhibit relevant antiproliferative, antitumor, invasive, and anti-inflammatory activities.

Daikenchuto (Da-Jian-Zhong-Tang) ameliorates intestinal fibrosis by activating myofibroblast transient receptor potential ankyrin 1 channel

AIM

To investigate the anti-fibrotic effects of the traditional oriental herbal medicine Daikenchuto (DKT) associated with transient receptor potential ankyrin 1 (TRPA1) channels in intestinal myofibroblasts.

METHODS

Inflammatory and fibrotic changes were detected in a 2,4,6-trinitrobenzenesulfonic acid (TNBS) chronic colitis model of wild-type and TRPA1-knockout (TRPA1-KO) mice via pathological staining and immunoblotting analysis. Ca²⁺ imaging experiments examined the effects of DKT and its components/ingredients on intestinal myofibroblast (InMyoFib) cell TRPA1 channel function. Pro-fibrotic factors and transforming growth factor (TGF)-β1-associated signaling were tested in an InMyoFib cell line by qPCR and immunoblotting experiments. Samples from non-stenotic and stenotic regions of the intestines of patients with Crohn’s disease (CD) were used for pathological analysis.

RESULTS

Chronic treatment with TNBS caused more severe inflammation and fibrotic changes in TRPA1-KO than in wild-type mice. A one-week enema administration of DKT reduced fibrotic lesions in wild-type but not in TRPA1-KO mice. The active ingredients of DKT, i.e., hydroxy α-sanshool and 6-shogaol, induced Ca²⁺ influxes in InMyoFib, and this was antagonized by co-treatment with a selective TRPA1 channel blocker, HC-030031. DKT counteracted TGF-β1-induced expression of Type I collagen and α-smooth muscle actin (α-SMA), which were accompanied by a reduction in the phosphorylation of Smad-2 and p38-mitogen-activated protein kinase (p38-MAPK) and the expression of myocardin. Importantly, 24-h incubation with a DKT active component Japanese Pepper increased the mRNA and protein expression levels of TRPA1 in InMyoFibs, which in turn negatively regulated collagen synthesis. In the stenotic regions of the intestines of CD patients, TRPA1 expression was significantly enhanced.

CONCLUSION

The effects of DKT on the expression and activation of the TRPA1 channel could be advantageous for suppressing intestinal fibrosis, and benefit inflammatory bowel disease treatment.

What Has Come out from Phytomedicines and Herbal Edibles for the Treatment of Cancer?

Several modern treatment strategies have been adopted to combat cancer with the aim of minimizing toxicity. Medicinal plant-based compounds with the potential to treat cancer have been widely studied in preclinical research and have elicited many innovations in cutting-edge clinical research. In parallel, researchers have eagerly tried to decrease the toxicity of current chemotherapeutic agents either by combining them with herbals or in using herbals alone. The aim of this article is to present an update of medicinal plants and their bioactive compounds, or mere changes in the bioactive compounds, along with herbal edibles, which display efficacy against diverse cancer cells and in anticancer therapy. It describes the basic mechanism(s) of action of phytochemicals used either alone or in combination therapy with other phytochemicals or herbal edibles. This review also highlights the remarkable synergistic effects that arise between certain herbals and chemotherapeutic agents used in oncology. The anticancer phytochemicals used in clinical research are also described; furthermore, we discuss our own experience related to semisynthetic derivatives, which are developed based on phytochemicals. Overall, this compilation is intended to facilitate research and development projects on phytopharmaceuticals for successful anticancer drug discovery.

Emerging themes of regulation of oncogenic proteins by Solanum nigrum and its bioactive molecules in different cancers

Research over the decades has sequentially and systematically provided a near-complete resolution of multifaceted and therapeutically challenging nature of cancer. Drug discovery from plants has enjoyed a renaissance in the past few years. Natural products have provided many of the lead structures, which are currently being used as templates for the design and synthesis of novel compounds with biologically enhanced properties. With the maturity and diversification of technologies, there is a growing need to design high-throughput functional assays for the evaluation of the myriad of compounds being catalogued. This review sheds light on the tumor suppressive properties of Solanum nigrum and its bioactive ingredients. Several worthy of mention include uttroside B, solanine, solamargine, and physalins, which have been tested for efficacy in cancer cell lines and xenografted mice. We have summarized the most recent findings related to S. nigrum-mediated regulation of intracellular protein network in different cancers. α-Solanine, an active component of S. nigrum, is involved in the regulation of microRNA-21 (miRNA-21) (oncogenic) and miRNA-138 (tumor suppressor) in prostate cancer. However, this is the only available evidence that gives us a clue related to the tumor suppressive effects exerted by components of S. nigrum at a posttranscriptional level. More interestingly, S. nigrum and its components exerted inhibitory effects on different pathways including PI3K/AKT, JAK-STAT, VEGF/VEGFR, and matrix metalloproteinases in different cancers. We also provide an overview of new tools, methodologies, and approaches, which will allow researchers to extract as much information as possible out of the tremendous data sets currently being generated. The use of computational tools will be helpful in processing structurally complex natural products and also in prediction of their macromolecular targets.

Chemical Composition of Aqueous Ethanol Extract of Luffa cylindrica Leaves and Its Effect on Representation of Caspase-8, Caspase-3, and the Proliferation Marker Ki67 in Intrinsic Molecular Subtypes of Breast Cancer in Vitro

Breast cancer constitutes the second most prevalent cancer in Egypt, the problem needs more trends in treatment and treatment development either by regimen modification or introducing new drugs, and the main objective of this study is to screen the effects of the aqueous ethanol herbal extract of Luffa cylindrica leaves on different types of breast cancer cell lines representing different molecular subtypes of the disease. The major active constituents of the extract were tentatively identified by LC/MS which revealed the presence of phenolic compound derivatives and saponin that may be responsible in part for the activity of the extract. The emphasis was laid on the main apoptotic pathways as well as the extract effect on the normal cell line. Results of phytochemical investigation, cell cycle analysis, and molecular analysis of apoptotic and proliferative markers have shown effective anticancer activity against MCF-7, BT-474, and MDA-MB-231 cell lines which represent three subtypes of breast cancer, luminal A, luminal B, and triple negative, respectively. On the other hand, the effects on normal lung fibroblast cell line are less prominent at the dose used for treating breast cancer cell lines.

Autophagy-dependent apoptosis is triggered by a semi-synthetic [6]-gingerol analogue in triple negative breast cancer cells

Triple negative breast cancer (TNBC) is very aggressive and lacks specific therapeutic targets, having limited treatment options and poor prognosis. [6]-gingerol is the most abundant and studied compound in ginger, presenting diverse biological properties such as antitumor activity against several types of cancer, including breast cancer. In this study, we show that the semi-synthetic analogue SSi6, generated after chemical modification of the [6]-gingerol molecule, using acetone-2,4-dinitrophenylhydrazone (2,4-DNPH) reagent, enhanced selective cytotoxic effects on MDA-MB-231 cells. Remarkably, unlike the original [6]-gingerol molecule, SSi6 enabled autophagy followed by caspase-independent apoptosis in tumor cells. We found a time-dependent association between SSi6-induced oxidative stress, autophagy and apoptosis. Initial SSi6-induced reactive oxygen species (ROS) accumulation (1h) led to autophagy activation (2-6h), which was followed by caspase-independent apoptosis (14h) in TNBC cells. Additionally, our data showed that SSi6 induction of ROS plays a key role in the promotion of autophagy and apoptosis. In order to investigate whether the observed cell death induction was dependent on preceding autophagy in MDA-MB-231 cells, we used siRNA to knock down LC3B prior to SSi6 treatment. Our data show that LC3B downregulation decreased the number of apoptotic cells after treatment with SSi6, indicating that autophagy is a key initial step on SSi6-induced caspase-independent apoptosis. Overall, the results of this study show that structural modifications of natural compounds can be an interesting strategy for developing antitumor drugs, with distinct mechanisms of actions, which could possibly be used against triple negative breast cancer cells that are resistant to canonical apoptosis-inducing drugs.

Interspecies Anticancer and Antimicrobial Activities of Genus Solanum and Estimation of Rutin by Validated UPLC-PDA Method

Solanaceae is one of the highly diverse plant families of which Solanum is the largest genera (1700 species) containing several pharmacological properties like anticancer and antimicrobial. This motivated us to explore the anticancer (against HepG2, HEK-293, and MCF-7 cells) and antimicrobial (against S. aureus, E. coli, P. aeruginosa, and C. albicans) properties of S. schimperianum, S. villosum, S. coagulans, S. glabratum, S. incanum, and S. nigrum along with rutin estimation by UPLC-PDA method. Of the studied Solanum extracts, S. nigrum exhibited significant cytotoxic property against HepG2 (IC50: 20.4 μg/mL) and MCF-7 (IC50: 30.1 μg/mL); S. coagulans showed toxicity against HepG2 (IC50: 28.4 μg/mL) and HEK-293 cells (IC50: 25.7 μg/mL) compared to 5-Fluorouracil (standard). Compared to these, extracts of S. coagulans and S. glabratum exhibited relatively high antimicrobial potency (MIC: 0.4-1.6 mg/mL). Nonetheless, all Solanum extracts significantly reduced the biofilm against PAO1-strain. Rutin was detected in all extracts with the highest content (53.79 μg/mg) in S. coagulans that supported its strong antimicrobial and anticancer properties. Molecular docking analysis showing strong binding of rutin with human DNA and proteins (DNA Topoisomerase IIα and E. coli DNA gyrase B) supported the anticancer and antimicrobial activities of Solanum species.

Probing the interaction of the phytochemical 6-gingerol from the spice ginger with DNA

6-Gingerol [5-hydroxy-1-(4-hydroxy-3-methoxyphenyl) decan-3-one], the bio-active ingredient of the popular Indian spice ginger (Zingiber officinale Roscoe), is well-known for its pharmacological and physiological actions. The potent antioxidant, antiemetic, antiulcer, antimicrobial, analgesic, hypoglycemic, antihypertensive, antihyperlipidemic, immunostimulant, anti-inflammatory, cardiotonic, and cancer prevention activities of 6-Gingerol has been investigated and explored. 6-Gingerol is a good candidate for the treatment of various cancers including prostrate, pancreatic, breast, skin, gastrointestinal, pulmonary, and renal cancer. In this study we report for the first time the molecular recognition of 6-Gingerol with calf thymus DNA (ctDNA) through experimental and molecular modeling techniques confirming a minor groove binding mode of 6-Gingerol with ctDNA. Fluorescence and UV-vis spectroscopic studies confirm the complex formation of 6-gingerol with ctDNA. The energetics and thermodynamics of the interaction of 6-Gingerol with ctDNA was explored by Isothermal Titration Calorimetry (ITC) and Differential Scanning Calorimetry (DSC). The ctDNA helix melting upon 6-Gingerol binding was examined by melting temperature Tm analysis. Further the electrophoretic mobility shift assay confirms a possible groove binding of 6-Gingerol with ctDNA. Molecular docking and Molecular dynamics (MD) studies provide a detailed understanding on the interaction of 6-Gingerol binding in the minor groove of DNA which supports experimental results.

Crystal structure of (E)-N'-[1-(4-amino-phen-yl)ethyl-idene]-2-hy-droxy-5-iodo-benzohydrazide methanol monosolvate

In the title compound, C15H14IN3O2·CH3OH, two aromatic rings are linked by an N-substituted hydrazide function. The dihedral angle between the aromatic rings is 10.53 (8)°. The stereochemistry about the imine function is E. The methanol mol-ecule forms an O-H⋯O hydrogen bond to the hydrazide O atom. In the crystal, chains of mol-ecules running along the c-axis direction are formed by O-H⋯O hydrogen bonds. Adjacent chains are linked through N-H⋯O hydrogen bonds and π-π stacking inter-actions. The inter-molecular inter-actions in the crystal packing were investigated using Hirshfeld surface analysis, which indicated that the most significant contacts are H⋯H (38.2%), followed by C⋯H/H⋯C (20.6%), O⋯H/H⋯O (11.1%) and I⋯H/H⋯I (9.7%).

Synthesis, structure and in vitro cytotoxicity testing of some 1,3,4-oxadiazoline derivatives from 2-hydroxy-5-iodobenzoic acid

The syntheses of nine new 5-iodosalicylic acid-based 1,3,4-oxadiazoline derivatives starting from methyl salicylate are described. These compounds are 2-[4-acetyl-5-methyl-5-(3-nitrophenyl)-4,5-dihydro-1,3,4-oxadiazol-2-yl]-4-iodophenyl acetate (6a), 2-[4-acetyl-5-methyl-5-(4-nitrophenyl)-4,5-dihydro-1,3,4-oxadiazol-2-yl]-4-iodophenyl acetate (6b), 2-(4-acetyl-5-methyl-5-phenyl-4,5-dihydro-1,3,4-oxadiazol-2-yl)-4-iodophenyl acetate, C₁₉H₁₇IN₂O₄ (6c), 2-[4-acetyl-5-(4-fluorophenyl)-5-methyl-4,5-dihydro-1,3,4-oxadiazol-2-yl]-4-iodophenyl acetate, C₁₉H₁₆FIN₂O₄ (6d), 2-[4-acetyl-5-(4-chlorophenyl)-5-methyl-4,5-dihydro-1,3,4-oxadiazol-2-yl]-4-iodophenyl acetate, C₁₉H₁₆ClIN₂O₄ (6e), 2-[4-acetyl-5-(3-bromophenyl)-5-methyl-4,5-dihydro-1,3,4-oxadiazol-2-yl]-4-iodophenyl acetate (6f), 2-[4-acetyl-5-(4-bromophenyl)-5-methyl-4,5-dihydro-1,3,4-oxadiazol-2-yl]-4-iodophenyl acetate (6g), 2-[4-acetyl-5-methyl-5-(4-methylphenyl)-4,5-dihydro-1,3,4-oxadiazol-2-yl]-4-iodophenyl acetate (6h) and 2-[5-(4-acetamidophenyl)-4-acetyl-5-methyl-4,5-dihydro-1,3,4-oxadiazol-2-yl]-4-iodophenyl acetate (6i). The compounds were characterized by mass, ¹H NMR and ¹³C NMR spectroscopies. Single-crystal X-ray diffraction studies were also carried out for 6c, 6d and 6e. Compounds 6c and 6d are isomorphous, with the 1,3,4-oxadiazoline ring having an envelope conformation, where the disubstituted C atom is the flap. The packing is determined by C-H...O, C-H...π and I...π interactions. For 6e, the 1,3,4-oxadiazoline ring is almost planar. In the packing, Cl...π interactions are observed, while the I atom is not involved in short interactions. Compounds 6d, 6e, 6f and 6h show good inhibiting abilities on the human cancer cell lines KB and Hep-G2, with IC₅₀ values of 0.9-4.5 µM.

Dioscorea bulbifera induced apoptosis through inhibition of ERK 1/2 and activation of JNK signaling pathways in HCT116 human colorectal carcinoma cells

Dioscorea bulbifera, also known as air potato, has been cultivated as food crop mainly in tropical countries in Asia and Australia. The tubers are edible and have often been used in Traditional Chinese Medicine (TCM) and Ayurvedic medicine to treat cancer, diabetes, thyroid disease, and inflammation. This study aimed to investigate the effects of D. bulbifera on HCT116 human colorectal carcinoma cells and to unravel the plausible mechanisms underlying its apoptotic effects. The ethanol crude and fractions (hexane, ethyl acetate and water) of D. bulbifera were subjected to cell viability MTT assay against various cancer cell lines. The lowest IC50 of the extract and fractions on selected cancer cells were selected for further apoptosis assay and western blot analysis. HCT116 cancer cells were treated with D. bulbifera and stained with Annexin/PI or Hoechst 33342/PI for preliminary confirmation of apoptosis. The dissipation of mitochondria membrane potential (MMP) was determined by flow cytometry. The protein expressions of apoptosis-related proteins such as Bcl-2 family, caspases, Fas, PARP, ERK1/2 and JNK were detected by western blot analysis. Moreover, the HCT116 cells were treated with UO126 and SP600125 inhibitors to verify the involvement of ERK1/2 and JNK protein expressions in inducing apoptotic cell death. Based on the result, D. bulbifera ethyl acetate fraction (DBEAF) exhibited the most compelling cytotoxicity on HCT116 cells with an IC50 of 37.91 ± 1.30 µg/mL. The induction of apoptosis was confirmed by phosphatidylserine externalization and chromatin condensation. Depolarization of MMP further conferred the induction of apoptosis was through the regulation of Bcl-2 family proteins. Activation of caspase cascades (caspase-3, -9, -8 and -10) was elicited followed by the observation of cleaved PARP accumulation in DBEAF-treated cells. Furthermore, death receptor, Fas was activated upon exposure to DBEAF. Collective apoptotic evidences suggested the involvement of intrinsic and extrinsic pathways by DBEAF in HCT116 cells. Interestingly, the attenuation of ERK1/2 phosphorylation accompanied by the activation of JNK was detected in DBEAF-treated cells. In conclusion, the findings revealed that DBEAF induced apoptosis through intrinsic and extrinsic pathways involving ERK1/2 and JNK.

Cardamonin reduces chemotherapy resistance of colon cancer cells via the TSP50/NF-κB pathway in vitro

It has previously been reported that cardamonin is able to regulate glycometabolism and vasodilation whilst also exhibiting anti-inflammatory and antitumor properties. The antitumor effect of cardamonin is multifaceted, and so it is necessary to investigate the antitumor mechanisms of cardamonin at the molecular level. Cardamonin alters chemotherapy-resistant colon cancer cell growth; however, the underlying mechanism is unknown. The present study was conducted to investigate the effect of cardamonin on chemotherapy-resistant colon cancer cells and the possible mechanisms of action. Cardamonin significantly suppressed the growth of chemotherapy-resistant colon cancer cells, induced apoptosis and promoted caspase-3/9 activity and Bax protein expression in 5-fluorouracil (5-FU)-resistant HCT-116 cells. Cardamonin significantly suppressed c-MYC, octamer-binding transcription factor 4, cyclin E, testes-specific protease 50 and nuclear factor-κB protein expression in 5-FU-resistant HCT-116 cells. The findings of the present study demonstrate that cardamonin suppresses chemotherapy-colon cancer cell via the NF-κB pathway in vitro.

Heteronemin, a marine natural product, sensitizes acute myeloid leukemia cells towards cytarabine chemotherapy by regulating farnesylation of Ras

Cytarabine is a conventionally used chemotherapeutic agent for treating acute myeloid leukemia (AML). However, chemoresistance, toxic side-effects and poor patient survival rates retard the efficacy of its performance. The current study deals with the chemosensitization of AML cells using heteronemin, a marine natural product towards cytarabine chemotherapy. Heteronemin could effectively sensitize HL-60 cells towards sub-toxic concentration of cytarabine resulting in synergistic toxicity as demonstrated by MTT assay and [3H] thymidine incorporation studies, while being safe towards healthy blood cells. Flow cytometry for Annexin-V/PI and immunoblotting for caspase cleavage proved that the combination induces enhancement in apoptosis. Heteronemin being a farnesyl transferase inhibitor (FTI) suppressed cytarabine-induced, farnesyl transferase-mediated activation of Ras, as assessed by Ras pull-down assay. Upon pre-treating cells with a commercial FTI, L-744,832, the synergism was completely lost in the combination, confirming the farnesyl transferase inhibitory activity of heteronemin as assessed by thymidine incorporation assay. Heteronemin effectively down-regulated cytarabine-induced activation of MAPK, AP-1, NF-κB and c-myc, the down-stream targets of Ras signaling, which again validated the role of Ras in regulating the synergism. Hence we believe that the efficacy of cytarabine chemotherapy can be improved to a significant extent by combining sub-toxic concentrations of cytarabine and heteronemin.

Endophytic Paraconiothyrium sp. from Zingiber officinale Rosc. Displays Broad-Spectrum Antimicrobial Activity by Production of Danthron

The bioactivity spectrum of fungal endophytes isolated from Zingiber officinale was analyzed against clinical pathogens and against the phytopathogen Pythium myriotylum, which causes Pythium rot in ginger. One of the isolates GFM13 showed broad bioactivity against various pathogens tested including P. myriotylum. The spore suspension as well as the culture filtrate of the endophytic fungal isolate was found to effectively protect ginger rhizomes from Pythium rot. By molecular identification, the fungal endophyte was identified as Paraconiothyrium sp. The bioactive compound produced by the isolate was separated by bioactivity-guided fractionation and was identified by GC-MS as danthron, an anthraquinone derivative. PCR amplification showed the presence of non-reducing polyketide synthase gene (NR-PKS) in the endophyte GFM13, which is reported to be responsible for the synthesis of anthraquinones in fungi. This is the first report of danthron being produced as the biologically active component of Paraconiothyrium sp. Danthron is reported to have wide pharmaceutical and agronomic applications which include its use as a fungicide in agriculture. The broad-spectrum antimicrobial activity of danthron and the endophytic origin of Paraconiothyrium sp. offer immense applications of the study.