Assessment of metabolic, mineral, and cytotoxic profile in pineapple leaves of different commercial varieties: A new eco-friendly and inexpensive source of bioactive compounds.

Pineapple is among the most produced and consumed fruits worldwide, and consequently, its agroindustrial production/processing generates high amounts of agricultural waste, which are routinely discarded. Thus, it is crucial to seek alternatives to reuse this agricultural waste that are in high availability. Therefore, this work aims to evaluate the chemical composition of a specific residue (leaves) of seven commercial varieties of pineapples, to attribute high added value uses, and to evaluate its potential as a source of secondary metabolites and minerals. Thereby, twenty-eight metabolites were annotated by UPLC-QTOF-MSE, including amino acids, organic acids, and phenolic compounds. The following minerals were quantitatively assessed by ICP-OES: Zn (5.30-19.77 mg kg-1), Cr, Cd, Mn (50.80-113.98 mg kg-1), Cu (1.05-4.01 mg kg-1), P (1030.77-6163.63 mg kg-1) and Fe (9.06-70.17 mg kg-1). In addition, Cr and Cd (toxic materials) present concentration levels below the limit of quantification of the analytical method (LOQCr and LOQCd = 0.02 mg kg-1) for all samples. The multivariate analysis was conceived from the chemical profile, through the tools of PCA (principal component analysis) and HCA (hierarchical cluster analysis). The results show that pineapple leaves have similarities and differences concerning their chemical composition. In addition, the cytotoxicity assays of the extracts against tumor and non-tumor strains shows that the extracts were non-toxic. This fact can corroborate and enhance the prospection of new uses and applications of agroindustrial co-products from pineapple, enabling the evaluation and use in different types of industries, such as pharmacological, cosmetic, and food, in addition to the possibility of being a potential source of bioactive compounds.

New Synthetic Sulfonamide Chalcone Induced Cell Cycle Arrest and Cell Death in Colorectal Adenocarcinoma Metastatic Cells (SW-620).

BACKGROUND: New chalcones have been developed from the insertion of organic groups, among them sulfonamides, presenting varied biological activity. OBJECTIVE: The aim of this work was to determine the antitumor potential of a new synthetic sulfonamide chalcone (SSC185) against a colorectal metastatic lymph node-derived colorectal cancer cell line (SW-620). METHODS: Synthesis and characterization, including crystallography, of SSC185 were performed. SSC185 showed a selective cytotoxic effect against colorectal cancer cell lines. Therefore, the cytotoxic effect of SSC185 against SW- 620 was further investigated. We used optical and fluorescence microscopy, flow cytometry and Western blot to determine the antitumor effects of SSC185. RESULTS: SSC185 induced cytotoxicity in SW-620 cells in a time and concentration-dependent manner. Cell cycle progression was disrupted, with increased G2/M cell number and consequent cell death, with morphological alterations associated with apoptosis and necrosis. Cell death was associated with the activation and cleavage of PARP, and with reduced expression of the pro-apoptotic Bax protein and caspase 8, depending on the SSC185 concentration tested. Expression of the necroptosis pathway proteins RIP and MLKL was also reduced. These proteins are phosphorylated during the process of necroptosis. CONCLUSION: We suggest that the mechanism involved in the cytotoxic effect of SSC185 against SW-620 in vitro may be related to the induction of cell cycle arrest in the G2/M phase and cell death by apoptosis or necroptosis, depending on the concentration used.

Antitumor Potential of the Isoflavonoids (+)- and (-)-2,3,9-Trimethoxypterocarpan: Mechanism-of-Action Studies.

Synthetically derived samples of (+)-(6aS,11aS)-2,3,9-trimethoxypterocarpan [(+)-1] and its enantiomer [(-)-1], both of which are examples of naturally occurring isoflavonoids, were evaluated, together with the corresponding racemate, as cytotoxic agents against the HL-60, HCT-116, OVCAR-8, and SF-295 tumor cell lines. As a result it was established that compound (+)-1 was particularly active with OVCAR-8 cells being the most sensitive and responding in a dose-dependent manner. A study of cell viability and drug-induced morphological changes revealed the compound causes cell death through a mechanism characteristic of apoptosis. Finally, a computational study of the interactions of compound (+)-1 and (S)-monastrol, an established, synthetically derived, potent, and cell-permeant inhibitor of mitosis, with the kinesin-type protein Eg5 revealed that both bind to this receptor in a similar manner. Significantly, compound (+)-1 binds with greater affinity, an effect attributed to the presence of the associated methoxy groups.

Pisosterol Induces G2/M Cell Cycle Arrest and Apoptosis via the ATM/ATR Signaling Pathway in Human Glioma Cells.

BACKGROUND: Pisosterol, a triterpene derived from Pisolithus tinctorius, exhibits potential antitumor activity in various malignancies. However, the molecular mechanisms that mediate the pisosterol-specific effects on glioma cells remain unknown. OBJECTIVE: This study aimed to evaluate the antitumoral effects of pisosterol on glioma cell lines. METHODS: The 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) and trypan blue exclusion assays were used to evaluate the effect of pisosterol on cell proliferation and viability in glioma cells. The effect of pisosterol on the distribution of the cells in the cell cycle was performed by flow cytometry. The expression and methylation pattern of the promoter region of MYC, ATM, BCL2, BMI1, CASP3, CDK1, CDKN1A, CDKN2A, CDKN2B, CHEK1, MDM2, p14ARF and TP53 was analyzed by RT-qPCR, western blotting and bisulfite sequencing PCR (BSP-PCR). RESULTS: Here, it has been reported that pisosterol markedly induced G2/M arrest and apoptosis and decreased the cell viability and proliferation potential of glioma cells in a dose-dependent manner by increasing the expression of ATM, CASP3, CDK1, CDKN1A, CDKN2A, CDKN2B, CHEK1, p14ARF and TP53 and decreasing the expression of MYC, BCL2, BMI1 and MDM2. Pisosterol also triggered both caspase-independent and caspase-dependent apoptotic pathways by regulating the expression of Bcl-2 and activating caspase-3 and p53. CONCLUSION: It has been, for the first time, confirmed that the ATM/ATR signaling pathway is a critical mechanism for G2/M arrest in pisosterol-induced glioma cell cycle arrest and suggests that this compound might be a promising anticancer candidate for further investigation.

Response of preantral follicles exposed to quinoxaline: A new compound with anticancer potential.

The culture of preantral follicles as an in vitro model to evaluate the toxicity of new anticancer drug has being established. Therefore, the aim of this study was to evaluate the effect of quinoxaline derivative the 2 2- (XYZC 6H 3 -CH=N-NH)-quinoxaline, 1 (QX) on caprine preantral follicles. We evaluate the follicular morphology and activation, proliferation and apoptosis of granulosa cells and finally the protein (ABCB1) and genes expression (cyclin/Cdks), respectively involved in multidrug resistance and cell cycle progression. Ovarian fragments containing primordial and developing follicles were exposed (in vitro culture) to different concentrations of QX (QX1.5, QX3.0 or QX6.0 µM/mL) during 6 days. To evaluate the effect of QX, the ovarian tissue was exposed to Paclitaxel 0.1 µg/mL (PTX - negative control) or in culture media without QX (MEM). At the end of exposure time, we realized that the QX (all concentrations) increased (P < .05) the normal morphology of preantral follicles compared to control (not treated ovarian tissue) or MEM. However, QX6.0 showed a enhanced (P < .05) on follicular activation (burnout) and apoptosis than QX1.5 and QX3.0. Expression of ABCB1 was similar between QX1.5 and QX6.0 and both were lower than control, MEM and PTX. Interestingly, the apoptosis rate in QX3.0 was similar to control and MEM and lower then QX1.5; QX6.0 and PTX. We conclude that quinoxaline may be a promising chemotherapeutic agent, however, other concentrations within a defined range (2-5.5 µM) could be widely investigated.

Metabolomic profile of Schinopsis brasiliensis via UPLC-QTOF-MS for identification of biomarkers and evaluation of its cytotoxic potential.

Schinopsis brasiliensis is a plant typically found in the caatinga biome (northeastern Brazil). Its leaves and bark have been used for the treatment of health dysfunctions such as cough, influenza, diarrhea, throat inflammation, and sexual impotence. However, there is a lack of knowledge regarding the chemical composition and pharmacological activities of this plant. High-performance liquid chromatography coupled to high-resolution mass spectrometry (UPLC-QTOF-MSE) allowed the partial identification of 33 compounds, including isomers from leaf, branch, and bark samples, with 16 compounds reported for the first time (corilagin, chlorogenic acid, and quercetin derivatives) in S. brasiliensis. Principal component analysis efficiently distinguished the respective parts of the plant. Orthogonal partial least squares discriminatory analysis, together with the variable importance in projection and S-Plot graphs were used to identify 23 biomarker compounds associated with cytotoxic activity against a colorectal cancer cell line.

Annonalide and derivatives: Semisynthesis, cytotoxic activities and studies on interaction of annonalide with DNA.

The cytotoxic activity of the pimarane diterpene annonalide (1) and nine of its semisynthetic derivatives (2-10) was investigated against the human tumor cell lines HL-60 (leukemia), PC-3 (prostate adenocarcinoma), HepG2 (hepatocellular carcinoma), SF-295 (glioblastoma) and HCT-116 (colon cancer), and normal mouse fibroblast (L929) cells. The preparation of 2-10 involved derivatization of the side chain of 1 at C-13. Except for 2, all derivatives are being reported for the first time. Most of the tested compounds presented IC50s below 4.0 µM, being considered potential antitumor agents. The structures of all new compounds were elucidated by spectroscopic analyses including 2D NMR and HRMS. Additionally, the interaction of annonalide (1) with ctDNA was evaluated using spectroscopic techniques, and the formation of a supramolecular complex with the macromolecule was confirmed. Competition assays with fluorescent probes (Hoechst and ethidium bromide) and theoretical studies confirmed that 1 interacts preferentially via DNA intercalation with stoichiometric ratio of 1:1 (1:ctDNA). The ΔG value was calculated as -28.24 kJ mol-1, and indicated that the interaction process occurs spontaneously. Docking studies revealed that van der Walls is the most important interaction in 1-DNA and EB-DNA complexes, and that both ligands (1 and EB) interact with the same DNA residues (DA6, DA17 and DT19).

Preliminary in vitro evaluation of the anti-proliferative activity of guanylhydrazone derivatives.

Guanylhydrazones have shown promising antitumor activity in preclinical tumor models in several studies. In this study, we aimed at evaluating the cytotoxic effect of a series of synthetic guanylhydrazones. Different human tumor cell lines, by including HCT-8 (colon carcinoma), MDA-MB-435 (melanoma) and SF-295 (glioblastoma) were continuous exposed to guanylhydrazone derivatives for 72 hours and growth inhibition of tumor cell lines and macrophages J774 was measured using tetrazolium salt (MTT) assay. Compounds 7, 11, 16 and 17 showed strong cytotoxic activity with IC50 values lower than 10 µmol L(-1) against four tumor cell lines. Among them, 7 was less toxic to non-tumor cells. Finally, obtained data suggest that guanylhydrazones may be regarded as potential lead compounds for the design of novel anticancer agents.

Cytotoxic epimeric withaphysalins from leaves of Acnistus arborescens.

Phytochemical analysis of the leaves of Acnistus arborescens (Solanaceae) resulted in the isolation of two new epimeric withaphysalins (17S,20R,22R)-5beta,6beta: 18,20-diepoxy-4beta,18-dihydroxy-1-oxowitha-24-enolide (2, 18R and 18S), together with the known withaphysalin F (1, 18R and 18S). Their structures were established by spectroscopic methods, including 2D NMR data and comparison with literature data. Compounds 1 and 2 dis-played potent cytotoxic activities against several cancer cell lines with IC50 values in the range of 0.20 to 1.46 microg/mL for 1 and 0.89 to 8.08 microg/mL for 2. The strong cytotoxicity presented by 1 suggests that in this series of compounds, the 2,3-unsaturated ketone moiety is an important pharmacophoric unit. The cytotoxic activity seemed to be related to DNA synthesis inhibition, as revealed by the reduction of 5-bromo-2'-deoxyuridine incorporation after 24 hours of incubation on leukemic cells.