Thiosulfinates: Cytotoxic and Antitumor Activity

Pharmacological value of some natural compounds makes them attractive for use in oncology. The sulfur-containing thiosulfinates found in plants of the genus Allium have long been known as compounds with various therapeutic properties, including antitumor. Over the last few years, the effect of thiosulfinates on various stages of carcinogenesis has been actively investigated. In vitro and in vivo studies have shown that thiosulfinates inhibit proliferation of cancer cells, as well as they induce apoptosis. The purpose of this review is to summarize current data on the use of natural and synthetic thiosulfinates in cancer therapy. Antitumor mechanisms and molecular targets of these promising compounds are discussed. A significant part of the review is devoted to consideration of a new strategy for treatment of oncological diseases - use of the directed enzyme prodrug therapy approach aiming to obtain antitumor thiosulfinates in situ.

An Efficient Approach for the Synthesis and Antitumor Evaluation of Novel Azo- and Anil-Linked with 3-Aminopyrazolo[3,4-b]pyridine

In this project, an effective procedure for constructing a new combination of pyrazolo[3,4-b]pyridine was depicted through the coupling of diazonium salt 2 of heterocyclic amine 1 with active methylene, enamine, and amidine moieties such as 3, 5, 7, and 9 at 0-5 °C in pyridine to afford hydrazinylhydrazonoyl derivatives 4, and diazenylheterocyclic derivatives 6, 8, and 10, respectively. Also, aminopyrazolo[3,4-b]pyridine 1 condensed with different aryl or heteroaryl aldehydes in EtOH/AcOH gave the corresponding aldimine 14, 15, 16. Compound 15 was cyclized via refluxing in DMF for 6 h to afford 18, while the transformation of compound 16 with an alkyl halide afforded 19a, b. The synthesized compounds, explicated by spectral data and elemental analysis, were examined for their antitumor activities. The in vitro cytotoxic activity of new pyrazolo[3,4-b]pyridines against the A2780CP, MCF-7, and HepG-2 cell lines was evaluated using the reference doxorubicin. Compounds 15 and 19a exhibited high reactivity against the A2780CP cell lines, with IC₅₀ values of 35 and 17.9 μM, respectively. Also, compound 28 had the cytotoxic potential for A2780CP and MCF-7 cell lines, with IC₅₀ values of 14.5, and 27.8 μM, respectively.

In Vitro Study of Cytostatic Activity of Baicalin, Baicalein, and Chlorophyllipt on HeLa-v Cell Line

Cytostatic activity of baicalin, baicalein, and neogalenical drug Chlorophyllipt was studied in vitro on HeLa-v cells. Standard samples of Eucalimin, baicalin, and baicalein, as well as Chlorophyllipt and paclitaxel (reference drug Taxacad) were used. The cell deaths were determined by MTT assay in a Multiskan FC microplate reader with incubator. The effective inhibition concentration (IC₅₀) of the tested substances were: paclitaxel (4.0±0.4 μM)-baicalein (10.5±1.1 μM)-baicalin (16.5±1.7 μM)-sum of euglobals in Chlorophyllipt (24.1±2.5 μM). Chlorophyllipt was found to exhibit cytostatic activity. Cytostatic activity of baicalein, baicalin, and Chlorophyllipt was lower than cytostatic activity of the reference drug by 2.6, 4.1, and 6 times, respectively. The prospects of further evaluation of the synergetic effect of baicalin, baicalein, and chlorophyllipt used in combinations with different cytostatic agents for finding the most effective combination have been shown.

Antitumor Effects of Microencapsulated Gratiola officinalis Extract on Breast Carcinoma and Human Cervical Cancer Cells In Vitro

Flavonoid-containing Gratiola officinalis extract has been studied in relation to breast carcinoma and human cervical cancer cells in encapsulated and native form. Encapsulation was realized in polymer shells, which were formed by the layer-by-layer method using sequential adsorption of poly(allylamine hydrochloride) and poly(sodium 4-styrenesulfonate) on the destructible cores. The extract was prepared by the author's method and characterized using high performance liquid chromatography. By means of optical and fluorescent microscopy, cell changes under the action of pure and encapsulated extracts were comprehensively studied, and statistical analysis was carried out. Cells were stained with propidium iodide, acridine orange, and Hoechst 33258. A fluorescence microscope with a digital video camera were used for cell imaging. The encapsulated extract caused 100% death of breast cancer SKBR-3 cells and 34% death of cervical cancer HeLa cells and prevented the formation of autophagosomes in both cultures. Analysis of the viability and morphological features of tumor cells under the action of microencapsulated extract allows us to consider microencapsulation as an effective strategy for delivering Gratiola officinalis extract to tumor cells and a promising way to overcome the protective autophagy.

Bioactive Furanyl- or Thienyl-Substituted Nucleobases, Nucleosides and Their Analogues

Five-membered heterocycles, including furan and thiophene, play a prominent role in drug design as structural units of bioactive molecules. This review is intended to demonstrate the importance of the furan-2-yl, furan-3-yl, thien-2-yl and thien-3-yl substituents in the medicinal chemistry of purine and pyrimidine nucleobases, nucleosides and selected analogues. Data presented in the article are limited to compounds containing heteroaromatic ring connected through a bond and not fused to other systems. The impact of bioisosteric replacement of aryl substituents with heteroaryl ones on activities was assessed by comparison of the title compounds with their aryl counterparts. A total of 135 heteroaryl-substituted and 35 aryl-substituted derivatives are mentioned in the text and shown in the figures. The following classes of compounds are included in the article: (i) 5-heteroaryl-2'-deoxyuridines and related compounds; (ii) 8-heteroaryl- 2,9-disubstituted adenine derivatives; (iii) O⁶-(heteroarylmethyl)guanines; (iv) 6-heteroaryl tricyclic guanine analogues; (v) 6-heteroaryl-9-benzylpurines and analogous compounds; (vi) N⁴- furfurylcytosine, N⁶-furfuryladenine, their derivatives and analogues; (vii) 6-heteroaryl purine and 7- deazapurine ribonucleosides; (viii) 7-heteroaryl-7-deazaadenosines, their derivatives and analogues; (ix) 4-heteroaryl fused 7-deazapurine nucleosides. In most cases various modifications of the lead compound structure performed in order to obtain the most favorable activity and selectivity are briefly discussed. The reviewed structure-activity relationship studies exemplify the search for compounds with optimized antiviral, antitumor, antimycobacterial or antiparkinsonian action.

Cytostatic Activity of Combretastatin A-4 Derivatives in an In Vitro System

Cytostatic activity of combretastatin A-4, its 11 analogues, and paclitaxel (Taxacad) was evaluated in vitro on human tumor cells A549 (lung adenocarcinoma) and PC-3 (prostate adenocarcinoma) in order to find the active and stable compound as a promising antitumor agent. 5-(4-Methoxyphenyl)-4-(3,4,5-trimethoxyphenyl)-isoxazole (compound 123124) and 3-(3,4,5-trimethoxyphenyl)-4-(4-methoxyphenyl)-isoxazole (compound 29310186) demonstrated the highest cytostatic activity (IC₅₀≈8×10^-9 М). The activity of two other cytotoxic compounds (2E)-1-(7-methoxy-2H-1,3-benzodioxol-5-yl)-3-(4-methoxyphenyl)prop-2-en-1-one (compound 104815) and 4-(3-amino-4-methoxyphenyl)-5-(3,4,5-trimethoxyphenyl)-1H-pyrazole hydrochloride (compound 198732) was close to that of Taxacad: IC₅₀ 65×10^-9 and 80×10^-9 М, respectively, and are also promising active components for the development of antitumor drugs.

Two isopentenyl resorcinols from Peperomia tetraphylla

Two isopentenyl resorcinols, peperobtusin B and peperobtusin C, have been isolated from Peperomia tetraphylla. Their structures were determined on the basis of spectroscopic methods, especially ¹H NMR, ¹³C NMR, 2D NMR, and HR-TOF-MS. Two compounds were evaluated for cytostatic activity against G₂, A 549, Hela and HCT 116 cells, but cytostatic activity of both compounds is weak.

Synthesis of Novel Biologically Active Proflavine Ureas Designed on the Basis of Predicted Entropy Changes

A novel series of proflavine ureas, derivatives 11a–11i, were synthesized on the basis of molecular modeling design studies. The structure of the novel ureas was obtained from the pharmacological model, the parameters of which were determined from studies of the structure-activity relationship of previously prepared proflavine ureas bearing n-alkyl chains. The lipophilicity (LogP) and the changes in the standard entropy (ΔS°) of the urea models, the input parameters of the pharmacological model, were determined using quantum mechanics and cheminformatics. The anticancer activity of the synthesized derivatives was evaluated against NCI-60 human cancer cell lines. The urea derivatives azepyl 11b, phenyl 11c and phenylethyl 11f displayed the highest levels of anticancer activity, although the results were only a slight improvement over the hexyl urea, derivative 11j, which was reported in a previous publication. Several of the novel urea derivatives displayed GI₅₀ values against the HCT-116 cancer cell line, which suggest the cytostatic effect of the compounds azepyl 11b–0.44 μM, phenyl 11c–0.23 μM, phenylethyl 11f–0.35 μM and hexyl 11j–0.36 μM. In contrast, the novel urea derivatives 11b, 11c and 11f exhibited levels of cytotoxicity three orders of magnitude lower than that of hexyl urea 11j or amsacrine.

Bioactive Betulin and PEG Based Polyanhydrides for Use in Drug Delivery Systems

In the course of this study, a series of novel, biodegradable polyanhydrides based on betulin disuccinate and dicarboxylic derivatives of poly(ethylene glycol) were prepared by two-step polycondensation. These copolymers can be used as carriers in drug delivery systems, in the form of microspheres. Betulin and its derivatives exhibit a broad spectrum of biological activity, including cytotoxic activity, which makes them promising substances for use as therapeutic agents. Microspheres that were prepared from betulin based polyanhydrides show promising properties for use in application in drug delivery systems, including inhalation systems. The obtained copolymers release the active substance-betulin disuccinate-as a result of hydrolysis under physiological conditions. The use of a poly(ethylene glycol) derivative as a co-monomer increases the solubility and bioavailability of the obtained compounds. Microspheres with diameters in the range of 0.5-25 µm were prepared by emulsion solvent evaporation method and their physicochemical and aerodynamic properties were analyzed. The morphological characteristics of the microspheres depended on the presence of poly(ethylene glycol) (PEG) segment within the structure of polyanhydrides. The porosity of the particles depended on the amount and molecular weight of the PEG used and also on the speed of homogenization. The most porous particles were obtained from polyanhydrides containing 20% wt. of PEG 600 by using a homogenization speed of 18,000 rpm.

New Conjugates of Polyhydroxysteroids with Long-Chain Fatty Acids from the Deep-Water Far Eastern Starfish Ceramaster patagonicus and Their Anticancer Activity

Four new conjugates, esters of polyhydroxysteroids with long-chain fatty acids (1–4), were isolated from the deep-water Far Eastern starfish Ceramaster patagonicus. The structures of 1–4 were established by NMR and ESIMS techniques as well as chemical transformations. Unusual compounds 1–4 contain the same 5α-cholestane-3β,6β,15α,16β,26-pentahydroxysteroidal moiety and differ from each other in the fatty acid units: 5′Z,11′Z-octadecadienoic (1), 11′Z-octadecenoic (2), 5′Z,11′Z-eicosadienoic (3), and 7′Z-eicosenoic (4) acids. Previously, only one such steroid conjugate with a fatty acid was known from starfish. After 72 h of cell incubation, using MTS assay it was found that the concentrations of compounds 1, 2, and 3 that caused 50% inhibition of growth (IC₅₀) of JB6 Cl41 cells were 81, 40, and 79 µM, respectively; for MDA-MB-231 cells, IC₅₀ of compounds 1, 2, and 3 were 74, 33, and 73 µM, respectively; for HCT 116 cells, IC₅₀ of compounds 1, 2, and 3 were 73, 31, and 71 µM, respectively. Compound 4 was non-toxic against tested cell lines even in three days of treatment. Compound 2 (20 µM) suppressed colony formation and migration of MDA-MB-231 and HCT 116 cells.

Purine and Purine Isostere Derivatives of Ferrocene: An Evaluation of ADME, Antitumor and Electrochemical Properties

Novel purine and purine isosteres containing a ferrocene motif and 4,1-disubstituted (11a-11c, 12a-12c, 13a-13c, 14a-14c, 15a-15c, 16a, 23a-23c, 24a-24c, 25a-25c) and 1,4-disubstituted (34a-34c and 35a-35c) 1,2,3-triazole rings were synthesized. The most potent cytotoxic effect on colorectal adenocarcinoma (SW620) was exerted by the 6-chloro-7-deazapurine 11c (IC₅₀ = 9.07 µM), 6-chloropurine 13a (IC₅₀ = 14.38 µM) and 15b (IC₅₀ = 15.50 µM) ferrocenylalkyl derivatives. The N-9 isomer of 6-chloropurine 13a containing ferrocenylmethylene unit showed a favourable in vitro physicochemical and ADME properties including high solubility, moderate permeability and good metabolic stability in human liver microsomes.

Novel Isoxazolidine and γ-Lactam Analogues of Homonucleosides

Homonucleoside analogues cis-16 and trans-17 having a (5-methoxycarbonyl)isoxazolidine framework were synthesized via the 1,3-dipolar cycloaddition of nucleobase-derived nitrones with methyl acrylate. Hydrogenolysis of the isoxazolidines containing thymine, dihydrouracil, theophylline and adenine moieties efficiently led to the formation of the respective γ-lactam analogues. γ-Lactam analogues having 5-bromouracil and 5-chlorouracil fragments were synthesized by treatment of uracil-containing γ-lactams with NBS and NCS. Isoxazolidine and γ-lactam analogues of homonucleosides obtained herein were evaluated for activity against a broad range of DNA and RNA viruses. None of the compounds that were tested exhibited antiviral or cytotoxic activity at concentrations up to 100 µM. The cytostatic activities of all compounds toward nine cancerous cell lines was tested. γ-Lactams trans-15e (Cl-Ura) and cis-15h (Theo) appeared the most active toward pancreatic adenocarcinoma cells (Capan-1), showing IC50 values 21.5 and 18.2 µM, respectively. Isoxazolidine cis-15e (Cl-Ura) inhibited the proliferation of colorectal carcinoma (HCT-116).

Synthesis, Biological Evaluation and Ligand Based Pharmacophore Modeling of New Aromatic Thiosemicarbazones as Potential Anticancer Agents

Two series of new aromatic thiosemicarbazone derivatives were synthesized by condensation of N-(4-cyanophenyl)hydrazine carbothioamide (I) and N-(4-methylsulfanylphenyl)hydrazine carbothioamide (II) with appropriate aromatic aldehydes in order to investigate their antiviral and cytostatic potency. The chemical structures of all compounds were fully characterized by elemental analysis and spectroscopic techniques. The results of the bioassays indicated that compounds Id, Ie, If and IIf proved inhibitory against influenza virus A (EC₅₀ = 13 – 27 μg/mL for strain H1N1 and 9.3 – 18 μg/mL for strain H3N2). Compounds Ig and IIg were the most cytostatic compounds with inhibition of HeLa cell proliferation at an IC₅₀ = 0.3 μg/mL for Ig and 1.9 μg/mL for IIg. Especially, compound Ig showed the highest cytostatic activity with IC₅₀ of 0.30, 0.70 and 2.50 μg/mL against HeLa, CEM and L1210 cell lines, respectively. This inhibition range was within the same order of magnitude as that for cisplatin. Furthermore, molecular modeling was carried out to examine the cytostatic activity and determine the best pharmacophore model as a guide for the design and development of potential prodrugs in future studies.

SAHAquines, Novel Hybrids Based on SAHA and Primaquine Motifs, as Potential Cytostatic and Antiplasmodial Agents

We report the synthesis of SAHAquines and related primaquine (PQ) derivatives. SAHAquines are novel hybrid compounds that combine moieties of suberoylanilide hydroxamic acid (SAHA), an anticancer agent with weak antiplasmodial activity, and PQ, an antimalarial drug with low antiproliferative activity. The preparation of SAHAquines is simple, cheap, and high yielding. It includes the following steps: coupling reaction between primaquine and a dicarboxylic acid monoester, hydrolysis, a new coupling reaction with O-protected hydroxylamine, and deprotection. SAHAquines 5 a-d showed significant reduction in cell viability. Among the three human cancer cell lines (U2OS, HepG2, and MCF-7), the most responsive were the MCF-7 cells. The antibodies against acetylated histone H3K9/H3K14 in MCF-7 cells revealed a significant enhancement following treatment with N-hydroxy-N'-{4-[(6-methoxyquinolin-8-yl)amino]pentyl}pentanediamide (5 b). Ethyl (2E)-3-({4-[(6-methoxyquinolin-8-yl)amino]pentyl}carbamoyl)prop-2-enoate (2 b) and SAHAquines were the most active compounds against both the hepatic and erythrocytic stages of Plasmodium parasites, some of them at sub-micromolar concentrations. The results of our research suggest that SAHAquines are promising leads for new anticancer and antimalarial agents.

Asymmetric Primaquine and Halogenaniline Fumardiamides as Novel Biologically Active Michael Acceptors

Novel primaquine (PQ) and halogenaniline asymmetric fumardiamides 4a⁻f, potential Michael acceptors, and their reduced analogues succindiamides 5a⁻f were prepared by simple three-step reactions: coupling reaction between PQ and mono-ethyl fumarate (1a) or mono-methyl succinate (1b), hydrolysis of PQ-dicarboxylic acid mono-ester conjugates 2a,b to corresponding acids 3a,b, and a coupling reaction with halogenanilines. 1-[bis(Dimethylamino)methylene]-1H-1,2,3-triazolo[4,5-b]pyridinium 3-oxide hexafluorophosphate (HATU) was used as a coupling reagent along with Hünig's base. Compounds 4 and 5 were evaluated against a panel of bacteria, several Mycobacterium strains, fungi, a set of viruses, and nine different human tumor cell lines. p-Chlorofumardiamide 4d showed significant activity against Staphylococcus aureus,Streptococcus pneumoniae and Acinetobacter baumannii, but also against Candida albicans (minimum inhibitory concentration (MIC) 6.1⁻12.5 µg/mL). Together with p-fluoro and p-CF₃ fumardiamides 4b,f, compound 4d showed activity against Mycobacterium marinum and 4b,f against M. tuberculosis. In biofilm eradication assay, most of the bacteria, particularly S. aureus, showed susceptibility to fumardiamides. m-CF₃ and m-chloroaniline fumardiamides 4e and 4c showed significant antiviral activity against reovirus-1, sindbis virus and Punta Toro virus (EC50 = 3.1⁻5.5 µM), while 4e was active against coxsackie virus B4 (EC50 = 3.1 µM). m-Fluoro derivative 4a exerted significant cytostatic activity (IC50 = 5.7⁻31.2 μM). Acute lymphoblastic leukemia cells were highly susceptible towards m-substituted derivatives 4a,c,e (IC50 = 6.7⁻8.9 μM). Biological evaluations revealed that fumardiamides 4 were more active than succindiamides 5 indicating importance of Michael conjugated system.

Antiproliferation effect of imatinib mesylate on MCF7, T-47D tumorigenic and MCF 10A nontumorigenic breast cell lines via PDGFR-β, PDGF-BB, c-Kit and SCF genes

Recent cancer molecular therapies are targeting main functional molecules to control applicable process of cancer cells. Attractive targets are established by receptor tyrosine kinases, such as platelet-derived growth factor receptors (PDGFRs) and c-Kit as mostly irregular signaling, which is due to either over expression or mutation that is associated with tumorigenesis and cell proliferation. Imatinib mesylate is a selective inhibitor of receptor tyrosine kinase, including PDGFR-β and c-Kit. In this research, we studied how imatinib mesylate would exert effect on MCF7 and T-47D breast cancer and MCF 10A epithelial cell lines, the gene and protein expression of PDGFR-β, c-Kit and their relevant ligands platelet-derived growth factor (PDGF)-BB and stem cell factor (SCF). The MTS assay was conducted in therapeutic relevant concentration of 2–10 µM for 96, 120 and 144 h treatment. In addition, apoptosis induction and cytostatic activity of imatinib mesylate were investigated with the terminal deoxynucleotidyl transferase dUTP nick end labeling TUNEL and cell cycle assays, respectively, in a time-dependent manner. Comparative real-time PCR and Western blot analysis were conducted to evaluate the expression and regulation of imatinib target genes and proteins. Our finding revealed that imatinib mesylate antiproliferation effect, apoptosis induction and cytostatic activity were significantly higher in breast cancer cell lines compared to MCF 10A. This effect might be due to the expression of PDGFR-β, PDGF-BB, c-Kit and SCF, which was expressed by all examined cell lines, except the T-47D cell line which was not expressed c-Kit. However, examined gene and proteins expressed more in cancer cell lines. Therefore, imatinib mesylate was more effective on them. It is concluded that imatinib has at least two potential targets in both examined breast cancer cell lines and can be a promising drug for targeted therapy to treat breast cancer.

Design, Synthesis and Biological Evaluation of Novel Primaquine-Cinnamic Acid Conjugates of the Amide and Acylsemicarbazide Type

In this paper design and synthesis of a scaffold comprising primaquine (PQ) motif and cinnamic acid derivatives (CADs) bound directly (compounds 3a-k) or via a spacer (compounds 7a-k) are reported. In the first series of compounds, PQ and various CADs were connected by amide bonds and in the second series by acylsemicarbazide functional groups built from the PQ amino group, CONHNH spacer and the carbonyl group originating from the CADs. PQ-CAD amides 3a-k were prepared by a simple one-step condensation reaction of PQ with a series of CAD chlorides (method A) or benzotriazolides 2 (method B). The synthesis of acylsemicarbazides 7a-k included activation of PQ with benzotriazole, preparation of PQ-semicarbazide 6 and its condensation with CAD chlorides 4. All synthesized PQ-CAD conjugates were evaluated for their anticancer, antiviral and antioxidative activities. Almost all compounds from series 3 were selective towards the MCF-7 cell line and active at micromolar concentrations. The o-fluoro derivative 3h showed high activity against HeLa, MCF-7 and in particular against the SW 620 cell line, while acylsemicarbazide 7f with a benzodioxole ring and 7c, 7g and especially 7j with methoxy-, chloro- or trifluoromethyl-substituents in the para position showed high selectivity and high inhibitory activity against MCF-7 cell line at micromolar (7c, 7f, 7g) and nanomolar (7j) levels. Acylsemicarbazide derivatives with trifluoromethyl group(s) 7i, 7j and 7k showed specific activity against human coronavirus (229E) at concentrations which did not alter the normal cell morphology. The same compounds exerted the most potent reducing activity in the DPPH test, together with 7d and 7g, while methoxy (compounds 7c-e), benzodioxole (7f), p-Cl (7g) and m-CF₃ (7i) acylsemicarbazides and amide 3f presented the highest LP inhibition (83%-89%). The dimethoxy derivative 7d was the most potent LOX inhibitor (IC50 = 10 μΜ). The performed biological tests gave evidence of acylsemicarbazide functional group as superior binding group in PQ-CAD conjugates.

Steroidal glycosides with antiproliferative activities from Digitalis trojana

The phytochemical investigation of Digitalis trojana led to the isolation of two cardiac glycosides (1, 2), one pregnane glycoside (3), three furostanol type saponins (4-6), along with three cleroindicins (7-9), four phenylethanoid glycosides (10-13), two flavonoids (14, 15) and two phenolic acid derivatives (16, 17). The structure elucidation of the isolates was carried out by NMR experiments as well as ESI-MS. The cytotoxic activity of compounds 1-13 against a small panel of cancer cell lines, namely MCF-7, T98G, HT-29, PC-3, A375 and SH-SY5Y, was investigated. Compounds 1-6 showed antiproliferative activity against human breast MCF-7 and colon HT-29 cancer cell lines with IC50 values ranging from 8.3 to 50 μM. In order to understand the mechanism involved in the cell death, the active compounds were tested as pro-apoptotic agents using propidium iodide staining by flow cytometry method. No significant increase was observed in the apoptosis of the MCF-7 and HT-29 cancer cells. Moreover, the effects of the active compounds on cell proliferation were assessed on the same cancer cell lines by cell cycle analysis of DNA content using flow cytometry. No significative changes were observed in the cell cycle of MCF-7, while significant changes in G2 /M cell cycle phase of HT-29 cells were observed after treatment with digitalin (1), cariensoside (3) and 22-O-methylparvispinoside B (6) at 10 μM.

Novel NSAID 1-acyl-4-cycloalkyl/arylsemicarbazides and 1-acyl-5-benzyloxy/hydroxy carbamoylcarbazides as potential anticancer agents and antioxidants

The novel 1-acyl-4-cycloalkyl/arylsemicarbazides (5a-y) and 1-acyl-5-benzyloxy/hydroxycarbamoylcarbazides (8a-f) derived from the nonsteroidal anti-inflammatory drugs ibuprofen, fenoprofen and reduced ketoprofen were prepared, fully chemically characterized and evaluated for their cytostatic, antiviral and antioxidant activities. Compounds 5 and 8 consist of a region rich in electronegative atoms (five to nine nitrogen and oxygen atoms) framed by aryl or cycloalkyl residues on one or both terminal ends. The synthetic pathways applied for the preparation of the title compounds involved a benzotriazole as a synthetic auxiliary in several steps. Three of the tested compounds, namely 4-benzhydryl-1-[2-(3-phenoxyphenyl)propanoyl]semicarbazide (5l), 4-benzhydryl-1-[2-(3-benzylphenyl)propanoyl]semicarbazide (5s), and 4-benzhydryl-1-[2-(4-isobutylphenyl)propanoyl]semicarbazide (5f) showed pronounced antiproliferative activity in vitro against six cancer cell lines (IC(50)=3-23 μM). The same compounds highly inhibited soybean lipoxygenase (IC(50)=60 and 51.5 μM) and lipid peroxidation as well (99, 88 and 74%, respectively). 4-Benzyloxy-1-[2-(4-isobutylphenyl)propanoyl]semicarbazide (5t) and 5-benzyloxycarbamoyl-1-[2-(3-benzylphenyl)propanoyl]carbazide (8c) exerted complete lipid peroxidation inhibition. Semicarbazides 5w-y and carbazides 8d-f bearing a hydroxamic acid/hydroxyurea moiety showed a modest antiradical activity in DPPH test, while the best radical scavenger was 1-(1-benzotriazolecarbonyl)-4-benzyloxysemicarbazide (7). None of the compounds were inhibitory to a broad panel of DNA and RNA viruses in the cell culture at subtoxic concentrations.

Norsesquiterpenoids from the leaves of Croton tiglium

Two new compounds, badounoids A (1) and B (2), together with 13 known norsesquiterpenes, were isolated from the leaves of Croton tiglium L. The structures of the new compounds were established by means of spectroscopic methods. The absolute configuration of badounoid B was determined by single-crystal X-ray diffraction analysis. All the known compounds were isolated from Croton plants for the first time which added a new chemical facet for this genus. The selected compounds were evaluated for their cytostatic activity against several cancer cell lines. None of them was found to be active.

Simple di- and trivanillates exhibit cytostatic properties toward cancer cells resistant to pro-apoptotic stimuli

A series of 33 novel divanillates and trivanillates were synthesized and found to possess promising cytostatic rather than cytotoxic properties. Several compounds under study decreased by >50% the activity of Aurora A, B, and C, and WEE1 kinase activity at concentrations <10% of their IC(50) growth inhibitory ones, accounting, at least partly, for their cytostatic effects in cancer cells and to a lesser extent in normal cells. Compounds 6b and 13c represent interesting starting points for the development of cytostatic agents to combat cancers, which are naturally resistant to pro-apoptotic stimuli, including metastatic malignancies.

Role of culture supernatant of cytotoxic/cytostatic macrophages in activation of murine resident peritoneal macrophages

Peritoneal macrophages elicited by Lactobacillus casei YIT9018 (LCEPM) were incubated in culture for 18 h with L. casei; the culture supernatant (LCM) was then harvested and tested for its ability to increase the cytostatic activity of resident peritoneal macrophages (RPM) and LCEPM. Treatment of RPM with LCM induced activation of macrophages to a cytostatic state against L929, Colon 26, P815, P388D1 and L1210 cells. A combination of recombinant human tumor necrosis factor (rhTNF), recombinant mouse TNF (rmTNF), recombinant human interleukin-1 (rhIL-1) or bacterial lipopolysaccharide with recombinant mouse interferon gamma (rmIFN-gamma) resulted in the synergistic induction of cytostatic activity in RPM. Recombinant mouse granulocyte-macrophage colony-stimulating factor (rmGM-CSF) plus rhTNF increased the cytostatic activity of RPM a little but rmGM-CSF or rhTNF combined with rhIL-1 or alone had no effect. The effect of LCM on RPM was not inhibited by polymyxin B, anti-mTNF antiserum or below 20 U/ml monoclonal anti-rmIFN-gamma antibody (anti-rmIFN-gamma) but was inhibited by more than 40 U/ml anti-rmIFN-gamma, and LCM did not have any interferon antiviral activity. These results suggest that the cytostatic activity of RPM was augmented by the LCM, and that the effect of the LCM may be not due to IFN-gamma, TNF, GM-CSF, IL-1 or a small amount of contaminating lipopolysaccharide.

Antimetastatic effect of immunomodulators from Nocardia opaca in mice and rats activation of peritoneal macrophages by these fractions

Nocardia delipidated cell mitogen (NDCM), a particulate fraction prepared from Nocardia opaca, injected i.p. in an oil/water emulsion to F6 rhabdomyosarcoma-bearing rats, inhibited the development of pulmonary metastases; 6 out of 10 rats were protected. Repeated i.p. administration of emulsified NDCM and of two other compounds, a Nocardia water soluble mitogen (NWSM a hydrosoluble fraction) and purified cell walls (CW, an insoluble macromolecular fraction) in Lewis lung carcinoma (LLC)-bearing mice resulted in a significant reduction of lung metastases. The efficiency of these fractions was enhanced by association with monokines. A combination regimen of NDCM, NWSM, and CW (100 micrograms/0.1 ml) and monokines (0.1 ml), injected i.p. in LLC-bearing mice, yielded a greater antimetastatic effect than either therapy alone. Peritoneal macrophages from mice which had been injected i.p. with NWSM or CW, when triggered either by TPA (tetradecanoyl phorbol acetate) or by zymosan, released large quantities of hydrogen peroxide and had a high rate of glucose consumption. These macrophages were activated as judged by their cytostatic activity against syngeneic P815 mastocytoma growth; they expressed biochemical markers which have been reported to characterize the activated state. Incubation of thioglycollate-elicited peritoneal macrophages with NWSM, and monokines for 72 h resulted in a cytotoxic activity against labeled LLC cells; addition of macrophage activating factor significantly increased the cytotoxic capacity of these macrophages. In view of this we postulate that the antimetastatic effect of soluble and insoluble N. opaca fractions and monokines might be mediated by activated peritoneal macrophages.