Combination of Irinotecan and Melatonin with the Natural Compounds Wogonin and Celastrol for Colon Cancer Treatment.

Colorectal cancers are one of the leading cancers worldwide and are known for their high potential for metastasis and resistance to therapy. The aim of this study was to investigate the effect of various combination therapies of irinotecan with melatonin, wogonin, and celastrol on drug-sensitive colon cancer cells (LOVO cell line) and doxorubicin-resistant colon cancer stem-like cells (LOVO/DX cell subline). Melatonin is a hormone synthesized in the pineal gland and is responsible for circadian rhythm. Wogonin and celastrol are natural compounds previously used in traditional Chinese medicine. Selected substances have immunomodulatory properties and anti-cancer potential. First, MTT and flow cytometric annexin-V apoptosis assays were performed to determine the cytotoxic effect and the induction of apoptosis. Then, the potential to inhibit cell migration was evaluated using a scratch test, and spheroid growth was measured. The results showed important cytotoxic effects of the drug combinations on both LOVO and LOVO/DX cells. All tested substances caused an increase in the percentage of apoptotic cells in the LOVO cell line and necrotic cells in the LOVO/DX cell subline. The strongest effect on the induction of cancer cell death was observed for the combination of irinotecan with celastrol (1.25 µM) or wogonin (50 µM) and for the combination of melatonin (2000 µM) with celastrol (1.25 µM) or wogonin (50 µM). Statistically significant improvements in the effect of combined therapy were found for the irinotecan (20 µM) and celastrol (1.25 µM) combination and irinotecan (20 µM) with wogonin (25 µM) in LOVO/DX cells. Minor additive effects of combined therapy were observed in LOVO cells. Inhibition of cell migration was seen in LOVO cells for all tested compounds, while only irinotecan (20 µM) and celastrol (1.25 µM) were able to inhibit LOVO/DX cell migration. Compared with single-drug therapy, a statistically significant inhibitory effect on cell migration was found for combinations of melatonin (2000 µM) with wogonin (25 µM) in LOVO/DX cells and irinotecan (5 µM) or melatonin (2000 µM) with wogonin (25 µM) in LOVO cells. Our research shows that adding melatonin, wogonin, or celastrol to standard irinotecan therapy may potentiate the anti-cancer effects of irinotecan alone in colon cancer treatment. Celastrol seems to have the greatest supporting therapy effect, especially for the treatment of aggressive types of colon cancer, by targeting cancer stem-like cells.

Correction: Gebczak et al. Evaluation of PC12 Cells' Proliferation, Adhesion and Migration with the Use of an Extracellular Matrix (CorMatrix) for Application in Neural Tissue Engineering. Materials 2021, 14, 3858.

In the original publication [...].

Evaluation of PC12 Cells' Proliferation, Adhesion and Migration with the Use of an Extracellular Matrix (CorMatrix) for Application in Neural Tissue Engineering.

The use of extracellular matrix (ECM) biomaterials for soft tissue repair has proved extremely successful in animal models and in some clinical settings. The aim of the study was to investigate the effect of the commercially obtained CorMatrix bioscaffold on the viability, proliferation and migration of rat pheochromocytoma cell line PC12. PC12 cells were plated directly onto a CorMatrix flake or the well surface of a 12-well plate and cultured in RPMI-1640 medium and a medium supplemented with the nerve growth factor (NGF). The surface of the culture plates was modified with collagen type I (Col I). The number of PC12 cells was counted at four time points and then analysed for apoptosis using a staining kit containing annexin V conjugate with fluorescein and propidium iodide (PI). The effect of CorMatrix bioscaffold on the proliferation and migration of PC12 cells was tested by staining the cells with Hoechst 33258 solution for analysis using fluorescence microscopy. The research showed that the percentage of apoptotic and necrotic cells was low (less than 7%). CorMatrix stimulates the proliferation and possibly migration of PC12 cells that populate all levels of the three-dimensional architecture of the biomaterial. Further research on the mechanical and biochemical capabilities of CorMatrix offers prospects for the use of this material in neuro-regenerative applications.

Design and Synthesis of N-Substituted 3,4-Pyrroledicarboximides as Potential Anti-Inflammatory Agents.

In the present paper, we describe the biological activity of the newly designed and synthesized series N-substituted 3,4-pyrroledicarboximides 2a-2p. The compounds 2a-2p were obtained in good yields by one-pot, three-component condensation of pyrrolo[3,4-c]pyrrole scaffold (1a-c) with secondary amines and an excess of formaldehyde solution in C2H5OH. The structural properties of the compounds were characterized by 1H NMR, 13C NMR FT-IR, MS, and elemental analysis. Moreover, single crystal X-ray diffraction has been recorded for compound 2h. The colorimetric inhibitor screening assay was used to obtain their potencies to inhibit COX-1 and COX-2 enzymes. According to the results, all of the tested compounds inhibited the activity of COX-1 and COX-2. Theoretical modeling was also applied to describe the binding properties of compounds towards COX-1 and COX-2 cyclooxygenase isoform. The data were supported by QSAR study.

New 1,3,4-Oxadiazole Derivatives of Pyridothiazine-1,1-Dioxide with Anti-Inflammatory Activity.

Numerous studies have confirmed the coexistence of oxidative stress and inflammatory processes. Long-term inflammation and oxidative stress may significantly affect the initiation of the neoplastic transformation process. Here, we describe the synthesis of a new series of Mannich base-type hybrid compounds containing an arylpiperazine residue, 1,3,4-oxadiazole ring, and pyridothiazine-1,1-dioxide core. The synthesis was carried out with the hope that the hybridization of different pharmacophoric molecules would result in a synergistic effect on their anti-inflammatory activity, especially the ability to inhibit cyclooxygenase. The obtained compounds were investigated in terms of their potencies to inhibit cyclooxygenase COX-1 and COX-2 enzymes with the use of the colorimetric inhibitor screening assay. Their antioxidant and cytotoxic effect on normal human dermal fibroblasts (NHDF) was also studied. Strong COX-2 inhibitory activity was observed after the use of TG6 and, especially, TG4. The TG11 compound, as well as reference meloxicam, turned out to be a preferential COX-2 inhibitor. TG12 was, in turn, a non-selective COX inhibitor. A molecular docking study was performed to understand the binding interaction of compounds at the active site of cyclooxygenases.

Design, synthesis, biological evaluation and in silico studies of novel pyrrolo[3,4-d]pyridazinone derivatives withpromising anti-inflammatory and antioxidant activity.

Novel Mannich base analogues of pyrrolo[3,4-d]pyridazinone 7a,b-13a,b are designed and synthesized as potential anti-inflammatory agents. The title compounds are obtained via convenient one-pot synthesis with good yields. Their structures and properties are described by spectroscopic techniques and elemental analyses. The aim of this study is to evaluate the inhibitory activity of the new derivatives against both cyclooxygenase isoforms COX1 and COX2 as well as their cytotoxicity. The results clearly indicate that the tested compounds 7a,b-13a,b are not toxic, all show better affinity towards isoform COX-2, and some of them act as selective COX-2 inhibitors. Moreover, every examined derivative of pyrrolo[3,4-d]pyridazinone demonstrates better inhibitory activity towards COX-2 and a superior COX-2/COX-1 selectivity ratio compared to the reference drug meloxicam. Molecular docking studies confirm that compounds 7a,b-13a,b preferably bind COX-2 and all of them bind to the active site of cyclooxygenase in a way very similar to meloxicam. Subsequently, taking into account that inflammation is strongly correlated with oxidative stress and both of these processes can potentiate each other, synthesized Mannich bases are evaluated for potential antioxidant activity. Most of the investigated derivatives reduce induced oxidative and nitrosative stress. Moreover, compounds 7a,b, 8a, 10a,b, 11b, 12a,b-13a,b protect chromatin from oxidative stress and decrease the number of DNA strand breaks caused by intracellular growth of free radicals. Finally, a study of the binding mechanism between compounds 7a,b-13a,b and bovine serum albumin (BSA) was carried out. According to spectroscopic and molecular docking studies, all examined derivatives interact with BSA, which suggests their potential long half-life in vivo.

Effect of new olivacine derivatives on p53 protein level.

BACKGROUND: The p53 protein is a transcription factor for many genes, including genes involved in inhibiting cell proliferation and inducing apoptosis in genotoxically damaged and tumor-transformed cells. In more than 55% of cases of human cancers, loss of the essential function of p53 protein is found. In numerous reports, it has been shown that small molecules (chemical compounds) can restore the suppressor function of the mutant p53 protein in tumor cells. The aim of this study was to evaluate the potential anticancer activity of three newly synthesized olivacine derivatives. METHODS: The study was performed using two cell lines-CCRF/CEM (containing the mutant p53 protein) and A549 (containing a non-mutant, wild-type p53 protein). The cells were incubated with olivacine derivatives for 18 h and then assays were carried out: measurement of the amount of p53 and p21 proteins, detection of apoptosis, cell cycle analysis, and rhodamine 123 accumulation assay (evaluation of P-glycoprotein inhibition). Multiple-criteria decision analysis was used to compare the anticancer activity of the tested compounds. RESULTS: Each tested compound caused the reconstitution of suppressor activity of the p53 protein in cells with the mutant protein. In addition, one of the compounds showed significant antitumor activity in both wild-type and mutant cells. For all compounds, a stronger effect on the level of the p53 protein was observed than for the reference compound-ellipticine. CONCLUSIONS: The observed effects of the tested new olivacine derivatives (pyridocarbazoles) suggest that they are good candidates for new anticancer drugs.

COX-1/COX-2 inhibition activities and molecular docking study of newly designed and synthesized pyrrolo[3,4-c]pyrrole Mannich bases.

In the present paper we describe the biological activity of newly designed and synthesized series of pyrrolo[3,4-c]pyrrole Mannich bases (7a-n). The Mannich bases were obtained in good yields by one-pot, three-component condensation of pyrrolo[3,4-c]pyrrole scaffold (6a-c) with secondary amines and an excess of formaldehyde solution in C2H5OH. The chemical structures of the compounds were characterized by 1H NMR, 13C NMR, FT-IR, and elemental analysis. Moreover, single crystal X-ray diffraction has been recorded for compound 7l. All synthesized derivatives were investigated for their potencies to inhibit COX-1 and COX-2 enzymes by colorimetric inhibitor screening assay. In order to analyse the intermolecular interactions between theligands and cyclooxygenase, experimental data were supported with the results of molecular docking simulations. According to the results, all of the tested compounds inhibited the activity of COX-1 and COX-2.

Biological Evaluation and Molecular Docking Studies of Dimethylpyridine Derivatives.

Cyclooxygenase inhibitors as anti-inflammatory agents can be used in chemoprevention. Many in vitro and in vivo studies on human and animal models have explained the mechanisms of the chemopreventive effect of COX inhibitors such as: induction of apoptosis, inhibition of neoplasia, angiogenesis suppression, induction of cell cycle inhibition and inhibition of the expression of peroxisome proliferator-activated receptors. Here, biological evaluation of twelve different Schiff base derivatives of N-(2-hydrazine-2-oxoethyl)-4,6-dimethyl-2-sulfanylpyridine- 3-carboxamide are presented. Their in vitro anti-COX-1/COX-2, antioxidant and anticancer activities were studied. The molecular docking study was performed in order to understand the binding interaction of compounds in the active site of cyclooxygenases. Compounds PS18 and PS33 showed a significant inhibitory activity on COX-1 at lower concentrations compared to meloxicam and piroxicam. The IC50 of COX-1 of these compounds was 57.3 µM for PS18 and 51.8 µM for PS33. Out of the tested compounds, the highest therapeutic index was demonstrated by PS18, PS19, PS33, PS40 and PS41. Lower molar concentrations of these compounds inhibit the growth of cancer cells while not inhibiting the healthy cells. Compounds PS18, PS19 and PS33 simultaneously demonstrated a statistically-significant inhibition of COX-1 or COX-2. This opens up the possibility of applying these compounds in the chemoprevention of cancer.

Synthesis, COX-1/2 inhibition and antioxidant activities of new oxicam analogues designed as potential chemopreventive agents.

Oxicams (e.g. piroxicam, meloxicam) are widely used nonsteroidal anti-inflammatory drugs (NSAIDs). A large body of evidence from epidemiological and preclinical studies has shown that NSAIDs have a chemopreventive effect on different types of cancer, especially in colorectal cancer. Moreover, mounting evidence from preclinical and clinical studies suggests that persistent inflammation functions as a driving force in the journey to cancer. What is more, inflammation induces reactive oxygen and nitrogen species, which cause damage to important cellular components (e.g., DNA, proteins and lipids), which can directly or indirectly contribute to malignant cell transformation. In this study, we discuss the synthesis and the resultant newly synthesized oxicam derivatives which are potentially chemopreventive, and at the same time antioxidant. Compound 9c, with the highest therapeutic index in the LoVo cancer cell line, was found to be the most efficient in ROS scavenging activity under conditions of oxidative stress.

Synthesis, COX-1/2 inhibition activities and molecular docking study of isothiazolopyridine derivatives.

One of the main challenges for nowadays medicine is drugs selectivity. In COX-1 and COX-2, the active sites are composed of the same group of amino acids with the exception of the only one residue in position 523, in COX-1 is an isoleucine, while in COX-2 is a valine. Here, we presented a series of isothiazolopyridine/benzisothiazole derivatives substituted differently into an isothiazole ring, which were synthesized and investigated for their potencies to inhibit COX-1 and COX-2 enzymes by colorimetric inhibitor screening assay. All the tested compounds inhibited the activity of COX-1, the effect on COX-2 activity was differential. The mode of binding was characterized by a molecular docking study. Comparing biological activity of the investigated compounds, it was observed that compounds sharing the most similar position to flurbiprofen and meloxicam, representing the two main enzyme subdomains, achieved higher biological activity than others. It is directly related to the fit to the enzyme's active site, which prevents too early dissociation of the compounds.

FLAX OIL FROM TRANSGENIC LINUM USITATISSIMUM SELECTIVELY INHIBITS IN VITRO PROLIFERATION OF HUMAN CANCER CELL LINES.

Emulsions made of oils from transgenic flaxseeds significantly decreased in vitro proliferation of six tested human cancer cell lines in 48-h cultures, as assessed with the standard sulforhodamine assay. However, the emulsions also increased proliferation rate of normal human dermal fibroblasts and, to a lower extend, of keratinocytes. Both inhibition of in vitro proliferation of human cancer cell lines and stimulation of proliferation of normal dermal fibroblasts and keratinocytes were especially strong with the emulsion type B and with emulsion type M. Oils from seeds of transgenic flax type B and M should be considered as valuable adjunct to standard cytostatic therapy of human cancers and also could be applied to improve the treatment of skin lesions in wound healing.

Emulsions Made of Oils from Seeds of GM Flax Protect V79 Cells against Oxidative Stress.

Polyunsaturated fatty acids, sterols, and hydrophilic phenolic compounds are components of flax oil that act as antioxidants. We investigated the impact of flax oil from transgenic flax in the form of emulsions on stressed Chinese hamster pulmonary fibroblasts. We found that the emulsions protect V79 cells against the H2O2 and the effect is dose dependent. They reduced the level of intracellular reactive oxygen species and protected genomic DNA against damage. The rate of cell proliferation increased upon treatment with the emulsions at a low concentration, while at a high concentration it decreased significantly, accompanied by increased frequency of apoptotic cell death. Expression analysis of selected genes revealed the upregulatory impact of the emulsions on the histones, acetylases, and deacetylases. Expression of apoptotic, proinflammatory, and anti-inflammatory genes was also altered. It is thus suggested that flax oil emulsions might be useful as a basis for biomedical products that actively protect cells against inflammation and degeneration. The beneficial effect on fibroblast resistance to oxidative damage was superior in the emulsion made of oil from transgenic plants which was correlated with the quantity of antioxidants and squalene. The emulsions from transgenic flax are promising candidates for skin protection against oxidative damage.