pH-responsive niosome-based nanocarriers of antineoplastic agents

Differences in pH between the tumour interstitium and healthy tissues can be used to induce conformational changes in the nanocarrier structure, thereby triggering drug release at the desired site. In the present study, novel pH-responsive nanocarriers were developed by modifying conventional niosomes with hexadecyl-poly(acrylic acid)n copolymers (HD-PAAn). Niosomal vesicles were prepared by the thin film hydration method using Span 60, Span 60/Tween 60 and cholesterol as main constituents, and HD-PAA modifiers of different concentrations (0.5, 1, 2.5, 5 mol%). Next, two model substances, a water-soluble fluorescent dye (calcein) and a hydrophobic agent with pronounced antineoplastic activity (curcumin), were loaded in the aqueous core and hydrophobic membrane of the elaborated niosomes, respectively. Physicochemical properties of blank and loaded nanocarriers such as hydrodynamic diameter (Dh), size distribution, zeta potential, morphology and pH-responsiveness were investigated in detail. The cytotoxicity of niosomal curcumin was evaluated against human malignant cell lines of different origins (MJ, T-24, HUT-78), and the mechanistic aspects of proapoptotic effects were elucidated. The formulation composed of Span 60/Tween 60/cholesterol/2.5% HD-PAA17 exhibited optimal physicochemical characteristics (Dh 302 nm; ζ potential -22.1 mV; high curcumin entrapment 83%), pH-dependent drug release and improved cytotoxic and apoptogenic activity compared to free curcumin.

The Phytochemical Profiling, In Vitro Antioxidant, and Hepatoprotective Activity of Prenanthes purpurea L. and Caffeoylquinic Acids in Diclofenac-Induced Hepatotoxicity on HEP-G2 Cells

Oxidative stress is a common phenomenon of many liver disorders; it both affects patient survival and directly influences the applicability, effectiveness, and toxicity of drugs. In the pursuit of reliable natural remedies for hepatoprotection, this study reports on the complete phytochemical characterization, antioxidant, and hepatoprotective activities of the Prenanthes purpurea methanol-aqueous extract in an in vitro model of diclofenac-induced liver injury (DILI). An ultra high-performance liquid chromatography-high-resolution mass spectrometry analysis (UHPLC-HRMS) was conducted, delineating more than 100 secondary metabolites for the first time in the species, including a series of phenolic acid-hexosides, acylquinic, acylhydroxyquinic and acyltartaric acids, and flavonoids. Quinic acid, chlorogenic, 3,5-dicaffeoylquinic and 5-feruloylhydroxyquinic acid, caffeoyltartaric and cichoric acids, eryodictiol-O-hexuronide, and luteolin O-hexuronide dominated the phytochemical profile and most likely contributed to the observed hepatoprotective activity of the studied P. purpurea leaf extract. The potency and molecular basis of cellular protection were investigated in parallel with pure caffeoylquinic acids in a series of pretreatment experiments that verified the antiapoptotic and antioxidant properties of the natural products.

Pyrenebutyrate Pt(IV) Complexes with Nanomolar Anticancer Activity

Research on platinum-based anticancer drugs continuously strives to develop new non-classical platinum complexes. Pt(IV) prodrugs are the most promising, and their activation-by-reduction mechanism of action is being explored as a prospect for higher selectivity and efficiency. Herein, we present the anticancer potency and chemical reactivity of Pt(IV) complexes formed by linking pyrene butyric acid with cisplatin. The results from cytotoxicity screening on 10 types of cancer cell lines and non-malignant cells (HEK-293) indicated IC50 values as low as 50-70 nM for the monosubstituted Pt(IV) complex against leukemia cell lines (HL-60 and SKW3) and a cisplatin-resistant derivative (HL-60/CDDP). Interestingly, the bis-substituted complex is virtually non-toxic to both healthy and cancerous cells of adherent types. Nevertheless, it shows high cytotoxicity against multidrug-resistant derivatives HL-60/CDDP and HL-60/Dox. The reactivity of the complexes with biological reductants was monitored by the NMR method. Furthermore, the platinum uptake by the treated cells was examined on two types of cellular cultures: adherent and suspension growing, and proteome profiling was conducted to track expression changes of key apoptosis-related proteins in HL-60 cells. The general conclusion points to a possible cytoskeletal entrapment of the bulkier bis-pyrene complex that could be limiting its cytotoxicity to adherent cells, both cancerous and healthy ones.

Nationwide analysis of the impact of COVID-19 in patients with a cardiovascular, oncological or chronic pulmonary disease in the context of an Eastern European country with a low vaccination rate, Bulgaria: March 2020-April 2022

OBJECTIVE

This study focused on Bulgarian patient cohorts harbouring a single documented chronic comorbidity-cardiovascular pathology, an oncological disease or a chronic pulmonary diseases (CPD) comparing the outcomes in fully vaccinated and non-vaccinated populations classified by sex and age groups in ambulatory, hospital and intensive care unit (ICU) settings at the national level.

DESIGN

Retrospective analysis SETTINGS, PARTICIPANTS AND OUTCOME MEASURES: In total, 1 126 946 patients with confirmed COVID-19, on a national level, were retrospectively analysed between March 2020 and April 2022, using data from the Ministry of Health's United Information Portal, launched in March 2020.

RESULTS

Of all the confirmed 247 441 hospitalised cases of COVID-19, 67 723 (27.3%) had documented cardiovascular disease (CVD), 2140 (0.9%) had confirmed solid malignancy (regardless of stage) and 3243 (1.3%) had established CPD as their only chronic pathology. The number of cumulative deaths in each subgroup was 10 165 (in-hospital=5812 and ICU=4353); 4.0% vaccinated (410/10 165, p<0.001), 344 (in-hospital=196 and ICU=148), 4.9% vaccinated (17/344, p<0.001), 494 (in-hospital=287 and ICU=207) and 5.2% vaccinated (26/494, p<0.001), respectively. Statistical significance (p<0.001) was obtained in favour of reduced ambulatory, hospitalisation and both in-hospital and ICU-related mortality in the vaccinated cohorts, and BNT162b2 was the most effective at preventing mortality in all age groups.

CONCLUSIONS

This retrospective analysis shows that patients vaccinated against COVID-19 demonstrated trends of reduced hospitalisations and premature mortality in patients with CVD, solid malignancy or CPD as a single comorbidity.

Phytochemical Profiling, Antioxidant and Cognitive-Enhancing Effect of Helichrysum italicum ssp. italicum (Roth) G. Don (Asteraceae)

This study aimed at the evaluation of the antioxidant and cognitive-enhancing effect of methanol-aqueous extract from Helichrysum italicum ssp. italicum aerial parts. Significant radical scavenging activity (110.33 ± 3.47 and 234.70 ± 5.21 mg TE/g for DPPH and ABTS) and reducing power (354.23 ± 17.51 and 210.24 ± 8.68 mg TE/g for CUPRAC and FRAP) were observed. The extract showed average acetylcholinesterase and low butyrylcholinesterase inhibitory potential. H. italicum extract (200 mg/kg/po) administered in combination with galantamine (3 mg/kg/po) for 12 days significantly improved the memory and learning process compared with galantamine alone in the passive avoidance test. The effect was comparable to that of Ginkgo biloba extract (100 mg/kg/po). In deep secondary metabolite annotation of the extract by UHPLC-HRMS, more than 90 hydroxybenzoic and hydroxicinnamic acid-glycosides, phenylethanoid glycosides, a series of acylquinic and caffeoylhexaric acids, methoxylated derivatives of scutellarein, quercetagetin and 6-hydroxyluteolin, and prenylated phloroglucinol-α-pyrones were reported for the first time in H. italicum. Fragmentation patterns of four subclasses of heterodimer-pyrones were proposed. In-depth profiling of the pyrones revealed 23 compounds undescribed in the literature. Pyrones and acylphloroglucinols together with acylquinic acids could account for memory improvement. The presented research advanced our knowledge of H. italicum, highlighting the species as a rich source of secondary metabolites with cognitive-enhancing potential.

Pharmacological Activities of Schiff Bases and Their Derivatives with Low and High Molecular Phosphonates

This review paper is focused on the design of anthracene and furan-containing Schiff bases and their advanced properties as ligands in complex transition metal ions The paper also provides a brief overview on a variety of biological applications, namely, potent candidates with antibacterial and antifungal activity, antioxidant and chemosensing properties. These advantageous properties are enhanced upon metal complexing. The subject of the review has been extended with a brief discussion on reactivity of Schiff bases with hydrogen phosphonates and the preparation of low and high molecular phosphonates, as well as their application as pharmacological agents. This work will be of interest for scientists seeking new challenges in discovering advanced pharmacological active molecules gaining inspiration from the versatile families of imines and aminophosphonates.

Fused Triazinobenzimidazoles Bearing Heterocyclic Moiety: Synthesis, Structure Investigations, and In Silico and In Vitro Biological Activity

[1,3,5]Triazino[1,2-a]benzimidazole-2-amines bearing heterocyclic moiety in 4-position were synthesized. The compounds were characterized by elemental analysis, IR, ¹H-NMR, ¹³C-NMR, and HRMS spectroscopy. The molecular geometry and electron structure of these molecules were theoretically studied using density functional theory (DFT) methods. The molecular structure of the synthesized fused triazinobenzimidazole was confirmed to correspond to the 3,4-dihydrotriazinobenzimidazole structure through the analysis of spectroscopic NMR data and DFT calculations. The antinematodic activity was evaluated in vitro on isolated encapsulated muscle larvae (ML) of Trichinella spiralis. The results showed that the tested triazinobenzimidazoles exhibit significantly higher efficiency than the conventional drug used to treat trichinosis, albendazole, at a concentration of 50 μg/mL. The compound 3c substituted with a thiophen-2-yl moiety exhibited the highest anthelmintic activity, with a larvicidal effect of 58.41% at a concentration of 50 μg/mL after 24 h of incubation. Following closely behind, the pyrrole analog 3f demonstrated 49.90% effectiveness at the same concentration. The preliminary structure-anti-T. spiralis activity relationship (SAR) of the analogues in the series was discussed. The cytotoxicity of the benzimidazole derivatives against two normal fibroblast cells (3T3 and CCL-1) and two cancer human cell lines (MCF-7 breast cancer cells and chronic myeloid leukemia cells AR-230) was evaluated using the MTT-dye reduction assay. The screening results indicated that the compounds showed no cytotoxicity against the tested cell lines. An in silico study of the physicochemical and pharmacokinetic characteristics of the novel synthesized fused triazinobenzimidazoles showed that they were characterized by a significant degree of drug-likeness and optimal properties for anthelmintic agents.

Ferrocene modified analogues of imatinib and nilotinib as potent anti-cancer agents

The unique features of ferrocene and the need for development of targeted anticancer drugs inspired the design, synthesis and biological evaluation of ferrocenyl modified tyrosine kinase inhibitors by replacing the pyridyl moiety in imatinib and nilotinib generalized structures with a ferrocenyl group. A series of seven new ferrocene analogues were synthesized and evaluated for their anticancer activity in a panel of bcr-abl positive human malignant cell lines using imatinib as a reference drug. The metallocenes exhibited a dose-dependent inhibition on malignant cell growth with varying antileukemic activity. The most potent analogues were compounds 9 and 15a showing comparable or even superior efficacy to the reference. Their cancer selectivity indices suggest a favorable selectivity profile, indicating a 250 times higher preferential activity of 15a towards malignantly transformed K-562 cells and an even twice greater one (500) of 9 in the LAMA-84 leukemic model as compared to the normal murine fibroblast cell line.

Design, Synthesis and Cytotoxic Activity of Novel Salicylaldehyde Hydrazones against Leukemia and Breast Cancer

Despite the significant advancements in complex anticancer therapy, the search for new and more efficient specific anticancer agents remains a top priority in the field of drug discovery and development. Here, based on the structure-activity relationships (SARs) of eleven salicylaldehyde hydrazones with anticancer activities, we designed three novel derivatives. The compounds were tested in silico for drug-likeness, synthesized, and evaluated in vitro for anticancer activity and selectivity on four leukemic cell lines (HL-60, KE-37, K-562, and BV-173), one osteosarcomic cell line (SaOS-2), two breast adenocarcinomic cell lines (MCF-7 and MDA-MB-231), and one healthy cell line (HEK-293). The designed compounds were found to have appropriate drug likeness and showed anticancer activities in all cell lines tested; particularly, two of them exhibited remarkable anticancer activity in nanomolar concentrations on the leukemic cell lines HL-60 and K-562 and the breast cancer MCF-7 cells and extraordinary selectivity for the same cancer lines ranging between 164- and 1254-fold. The study also examined the effects of different substituents on the hydrazone scaffold and found that the 4-methoxy salicylic moiety, phenyl, and pyridinyl rings are the most appropriate for anticancer activity and selectivity of this chemical class.

Cytotoxic and Antibacterial Prenylated Acylphloroglucinols from Hypericum olympicum L

Two new bicyclo[3.3.1]nonane type bicyclic polyprenylated acylphloroglucinol derivatives (BPAPs), olympiforin A and B as well as three known prenylated phloroglucinols, were isolated from the aerial parts of Hypericum olympicum L. The structures of the isolated compounds were established by means of spectral techniques (HRESIMS and 1D and 2D NMR). All compounds were tested on a panel of human tumor (MDA-MB-231, EJ, K-562, HL-60 and HL-60/DOX) and non- tumorigenic (HEK-293 and EA.hy926) cell lines using the MTT assay. All tested compounds exerted significant in vitro cytotoxicity with IC₅₀ values ranging from 1.2 to 24.9 μM and from 0.9 to 34 μM on tumor and non-cancerous cell lines, respectively. Most of the compounds had good selectivity and were more cytotoxic to the tumor cell lines than to the normal ones. A degradation of the precursor caspase 9 for some of the compounds was observed; therefore, the intrinsic pathway of apoptosis is the most likely mechanism of cytotoxic activity. The BPAPs were examined for antibacterial and antibiofilm activity through the broth microdilution method and the protocol of Stepanović. They showed a moderate effect against Enterococcus faecalis and Streptococcus pyogenes but a very profound activity against Staphylococcus aureus with minimum inhibitory concentrations (MIC) in the range of 0.78-2 mg/L. Olympiforin B also had a great effect against methicillin-resistant S. aureus (MRSA) with an MIC value of 1 mg/L and a very significant antibiofilm activity on that strain with a minimum biofilm inhibition concentration (MBIC) value of 0.5 mg/L. The structures of the isolated compounds were in silico evaluated using ADME and drug likeness tests.

Intake and Contribution of Food Groups to Vitamin D Intake in Adults with Overweight and Obesity

The aim of the present study is to investigate the dietary intake of vitamin D in normal-weight and overweight individuals, establishing its correlation with specific food groups. Two hundred and sixty-four individuals were studied, of which 41.3% men and 58.9% women between 19 and 60 years of age. Nutritional assessment was carried out applying 24-h recall in the months January to April in 2014 and 2015. Nutritional status was assessed by means of anthropometric indicators – anthropometric indicators and indices, whereas weight and body composition were measured by professional bioelectrical impedance using a Tanita 420 BC MA device. It was established that the average daily intake of vitamin D for the entire group of studied individuals was 6.6 µg/day (women – 5.6 µg/day and men – 10.4 µg/day). Main dietary sources of vitamin D in the diet of adults were meat and meat products, fish and fish products, eggs and milk and dairy products. In the groups based upon BMI category of participants, meat and meat products were found to be the main source of vitamin D in all groups. Average daily intake of vitamin D has values significantly below the recommended average daily intake. A policy to promote the consumption of foods rich in vitamin D in order to reduce the relative share of individuals not meeting the recommendations is required.

In silico and In vitro Determination of Antiproliferative Activity of Series N-Pyrrolyl Hydrazide-Hydrazones and Evaluation of their Effects on Isolated Rat Mycrosomes and Hepatocytes

BACKGROUND

The significant increase in patients suffering from different types of cancer, guides scientists to take prompt measures in the development of novel and effective antiproliferative agents, where the intercalation of heterocyclic fragments in the designed molecules has proven to be a useful practice.

OBJECTIVE

The newly synthesized compounds were obtained from the corresponding 1,4-dicarbonyl derivative through multicomponent reactions to produce biologically active target molecules and assessed by in silico and in vitro assays for their possible antitumor activity.

METHODS

The pharmacological bioassay was conducted in the panel of human tumor cell lines (i) SKW-3 (ACC 53) - human T-cell leukemia and (ii) HL-60 (ACC 3) - human acute myeloid leukemia (AML). The statistical processing of MTT data included the paired Student's t-test with p ≤ 0.05 set as significance level.

RESULTS

All evaluated structures displayed a higher cytotoxic effect against the acute myeloid leukemia HL-60 with 11o and 11p as the most active compared to the activity against SKW-3 cell line. Throughout the cytotoxicity screening two molecules, 11l and 12o, displayed comparable chemosensitivity on both cell lines. The corresponding hepatotoxicity on isolated rat hepatocytes and microsomes was also established, identifying 11, 12 and 12a as the least toxic and 11x, 11d, 12x and 12d as the most toxic derivatives.

CONCLUSION

As the most promising compound is underlined ethyl 1-(2-(2-((1-acetyl-1H-indol-3-yl)methylene)hydrazinyl)-2- oxoethyl)-5-(4-bromophenyl)-2-methyl-1H-pyrrole-3-carboxylate (11l) demonstrating highest activity on both evaluated tumor cell lines, decreased hepatotoxicity on all evaluated parameters and docking score of -7.517 kcal/mol.

Modulation Effect on Tubulin Polymerization, Cytotoxicity and Antioxidant Activity of 1H-Benzimidazole-2-Yl Hydrazones

1H-benzimidazol-2-yl hydrazones with varying hydroxy and methoxy phenyl moieties were designed. Their effect on tubulin polymerization was evaluated in vitro on porcine tubulin. The compounds elongated the nucleation phase and slowed down the tubulin polymerization comparably to nocodazole. The possible binding modes of the hydrazones with tubulin were explored by molecular docking at the colchicine binding site. The anticancer activity was evaluated against human malignant cell lines MCF-7 and AR-230, as well as against normal fibroblast cells 3T3 and CCL-1. The compounds demonstrated a marked antineoplastic activity in low micromolar concentrations in both screened in vitro tumor models. The most active were the trimethoxy substituted derivative 1i and the positional isomers 1j and 1k, containing hydroxy and methoxy substituents: they showed IC₅₀ similar to the reference podophyllotoxin in both tumor cell lines, accompanied with high selectivity towards the malignantly transformed cells. The compounds exerted moderate to high ability to scavenge peroxyl radicals and certain derivatives-1l containing metha-hydroxy and para-methoxy group, and 1b-e with di/trihydroxy phenyl moiety, revealed HORAC values high or comparable to those of well-known phenolic antioxidants. Thus the 1H-benisimidazol-2-yl hydrazones with hydroxy/methoxy phenyl fragments were recognized as new agents exhibiting promising combined antioxidant and antineoplastic action.

Establishment and Biochemical Characterization of a Multidrug-resistant Promyelocytic Leukemia Cell Line HL-60/CDDP

The present study reports on the establishment, validation and biochemical characterization of a novel chemoresistant variant of the HL-60 acute myeloid leukemia (AML) cell line developed at the Laboratory of Experimental Chemotherapy at the Faculty of Pharmacy of MU-Sofia. Selection of the chemoresistant strain (HL-60/CDDP) has been carried out by prolonged serial exposures of the parent chemosensitive HL-60 cell line to gradually increasing concentrations of the metal complex. In its final variant, the resultant HL-60/CDDP test system showed significantly altered chemosensitivity profiles to the Pt(II)-based drugs cisplatin, carboplatin, oxaliplatin and was maintained in an RPMI-1640 medium containing 25 μM cisplatin. The promyelocytic cells also showed diminished susceptibility to differentiation therapy with arsenic trioxide As2O3. The emergence of the multiresistant phenotype is suggested to be most likely due to common biochemical properties of the screened compounds, including their strong affinity and high reactivity with sulfhydryl SH-groups. The presented study is focused on elucidating the multidrug resistance patterns in the newly established leukemic model that can be used as a potential test system for exploring the drug-resistance reversal capacity of various drugs and experimental compounds.

Peptide-based targeted cancer therapeutics: design, synthesis and biological evaluation

Cancer is the leading cause for human mortality together with cardiovascular diseases. Abl (Abelson) tyrosine kinases play a fundamental role in transducing various signals that control proliferation, survival, migration and invasion in several cancers such as Chronic Myeloid Leukemia (CML), breast cancer and brain cancer. For these reasons Abl tyrosine kinases are considered important biological targets in drug discovery. In this study a series of lysine-based oligopeptides with expected Abl inhibitory activity were designed resembling the binding of FDA-approved drugs (i.e. of Imatinib and Nilotinib), synthesized, purified by High Performance Liquid Chromatography (HPLC), analyzed by mass spectrometry (MS) and biologically tested in vitro in CML (AR-230 and K-562), breast cancers (MDA-MB 231 and MDA-MB 468) and glioblastoma cell lines (U87 and U118). The solid-phase peptide synthesis (SPPS) by Fmoc (9-fluorenylmethoxycarbonyl) chemistry was used to synthesize target compounds. AutoDock Vina was applied for simulation binding to Abl. The biological activities were measured evaluating cytotoxic effect, induction of apoptosis and inhibition of cancer cells migration. The new peptides exhibited different concentration-dependent antiproliferative effect against the tumor cell lines after 72 h treatment. The most promising results were obtained with the U87 glioblastoma cell line where a significant reduction of the migration ability was detected with one compound (H-Lys¹-Lys²-Lys³-NH₂).

GC-MS analysis of Amaryllidaceae and Sceletium-type alkaloids in bioactive fractions from Narcissus cv. Hawera

RATIONALE

Narcissus cv. Hawera has been found to biosynthesize some Sceletium-type alkaloids with antidepressant and anxiolytic activities. This ornamental plant has been poorly studied as a source of bioactive alkaloids including some contraversive reports on in vitro and intact plants. In this study, a detailed GC-MS characterization of its alkaloid fractions is presented.

METHODS

GC-MS was used for the identification of compounds in the alkaloid fractions. Both underivatized and silylated samples were analyzed simultaneously. Elevated plus maze and tail suspension tests were used to assay the anxiolytic and antidepressant activities. Ellman's and MTT-dye reduction assays were used to evaluate the acetylcholinesterase (AChE) inhibitory and cytotoxicity activities, respectively.

RESULTS

Of the 29 alkaloids, 13 of Sceletium-type were detected. Two new alkaloids were identified as 2-oxo-mesembrine and 2-oxo-epi-mesembrenol. Lycorine was found as a major compound (43.5%) in the crude silylated methanol extract. After the elimination of lycorine by pre-crystallization, the major alkaloids were 40.8% 6-epi-mesembranol, 16.2% 6-epi-mesembrenol, and 13.8% sanguinine. This fraction showed anxiolytic and antidepressant-like activities as well as potent AChE inhibitory and antineoplastic activities.

CONCLUSIONS

Silylation of the alkaloid fractions from Narcissus cv. Hawera provides better separation, structural information, and improved sensitivity for compounds with two and more hydroxyl groups. The lycorine-free alkaloid fraction shows a great potential for further pharmacological studies.

Antiproliferative activity of extract from in vitro callus cultures of Astragalus vesicarius ssp. carniolicus (A. Kern.) Chater

Five isoflavonoids, i.e. 5-hydroxy-7-methoxy-2’, 5’-dihydroxyisoflavone (AV4), 5, 7-dihydroxy-4’-methoxyisoflavone (AV6), 7-methoxy-5-hydroxy-4’-methoxy-2’-hydroxyisoflavone (AV7), 8-pregnyl genistein (AV9), 5,7-dihydroxy-8-pregnyl-4’-methoxy-2’-hydroxyisoflavone (AV10) and one coumarochromone – sophorophenolone (AV8) were isolated from EtOAc of in vitro callus cultures of Astragalus vesicarius ssp. carniolicus, after enzymatic hydrolysis with β-glucosidase. Their structures were tentatively elucidated by spectroscopic mean (1H NMR and HR-ESI-MS spectra). Antiproliferative activity of EtOAc extract and isolated aglycones against chemosensitive human promyelocyte cell line HL-60 and its multidrug-resistant variant HL-60/Dox was assessed in vitro. Despite the strong activity of EtOAc (IC50 8.8 µg/mL (HL-6, 72 h) to 11.8 µg/mL (HL-60/Dox, 72 h)), prenylated compound AV9 showed also antiproliferative activity – 36.1 µg/mL (HL-60 and HL-60/Dox, 72 h).

Tamoxifen Delivery System Based on PEGylated Magnetic MCM-41 Silica

Magnetic iron oxide containing MCM-41 silica (MM) with ~300 nm particle size was developed. The MM material before or after template removal was modified with NH2- or COOH-groups and then grafted with PEG chains. The anticancer drug tamoxifen was loaded into the organic groups' modified and PEGylated nanoparticles by an incipient wetness impregnation procedure. The amount of loaded drug and the release properties depend on whether modification of the nanoparticles was performed before or after the template removal step. The parent and drug-loaded samples were characterized by XRD, N2 physisorption, thermal gravimetric analysis, and ATR FT-IR spectroscopy. ATR FT-IR spectroscopic data and density functional theory (DFT) calculations supported the interaction between the mesoporous silica surface and tamoxifen molecules and pointed out that the drug molecule interacts more strongly with the silicate surface terminated by silanol groups than with the surface modified with carboxyl groups. A sustained tamoxifen release profile was obtained by an in vitro experiment at pH = 7.0 for the PEGylated formulation modified by COOH groups after the template removal. Free drug and formulated tamoxifen samples were further investigated for antiproliferative activity against MCF-7 cells.

The pharmacological basis for application of cannabidiol in cancer chemotherapy

Chemotherapy is one of the therapeutic approaches for cancer treatment and has demonstrated great success with the introduction of selectively acting molecules against specific biomarkers of some types of tumors. Despite this success there is a large unmet need for novel therapies that provide effective control on the progression of advanced or drug-resistant cancer diseases. In this review, we briefly summarized our knowledge of cannabinoids and the endocannabinoid system, as possible agents for cancer therapy. We analyzed the anticancer properties and mechanism of action of cannabidiol (CBD), the main non-psychoactive cannabinoid received from hemp of Cannabis plant. Despite of data for pleiotropic effects of CBD, we here present the results for the efficacy of CBD in the modulation of different stages of cancer development. The analysis of the anticancer properties of CBD is made in relation to the proposed or newly discovered molecular targets of action. Thereafter, we consider the specific effects of CBD on primary tumors, their invasiveness and metastases, whether the influence on identified tumor markers in different types of tumors reflect the therapeutic potential of CBD. The studies reviewed herein indicate that CBD elicit activity through the cannabinoid receptor dependent and independent pathways. The processes such as ceramide production, ER-stress, autophagy and apoptosis, angiogenesis and matrix remodeling also appear to regulate the anticancer activity of CBD. So, the pharmacological basis for therapeutic application of CBD is constructed on the scientific data for its antitumor activity, extensively provided studies in vitro and in vivo in animal tumor models, and available data on the safety profile of clinically approved CBD products. We also try to reduce the deficits of our understanding in relation of pharmacological synergistic interactions of CBD with cytostatic drugs, where data remains limited. It is recognized that more studies for defining the specific molecular and signaling mechanisms of anticancer action of cannabinoids, particularly CBD, requires further evaluation. We believe that the therapeutic advantages of CBD are associated not only with its non-psychoactive behavior, but also are related to its influence on the important biochemical pathways and signal molecules, defining the genome instability and specific changes of the malignant tumor cells.

Enhanced cellular uptake of platinum by a tetracationic Pt(II) nanocapsule and its implications to cancer treatment

Despite the known limitations of cisplatin chemotherapy, the treatment of cancer by platinum-based drugs remains the method of choice for many oncologists. The advancement in drug delivery formulations and protocols of combined treatments provided effective tools to ameliorate the side effects of platinum-based therapies. Another approach to improve the pharmacological profiles of anticancer platinum drugs is to properly modify their structure and composition, which has produced numerous platinum complexes with improved therapeutic effect. Recently, we have demonstrated the strong anticancer potency of supramolecular nanocapsules that form by self-assembly of four bis-anthracene ligands with two metal ions, either Pt(II) or Pd(II). Herein, we focus our study on the Pt(II) nanocapsule and its uptake by two types of cancer cells, suspension cultures of HL-60 cells and the adherent cancer cells HT-29. Comparison of the platinum uptake by cancer cells treated with the nanocapsule and with cisplatin evidenced superior uptake of platinum caused by the nanocapsule, which in HT-29 and HL-60 cells prevails by 21 and 31 times, respectively. Morphological changes in the HL-60 cells induced by the Pt(II) nanocapsule were studied by transmission electron microscopy (TEM) which provided plausible explanation of the uptake results. These data corroborate also with the known nanocapsule's very high cytotoxicity, better selectivity, and lack of cross-resistance with cisplatin. Additionally, our estimations of the drug-drug interactions in combined treatments established the propensity of the nanocapsule to exert supra-additive cytotoxicity in combination with cisplatin against the bladder cancer T-24 cells. All these findings define the scope for more detailed pharmacological characterization of the presented Pt(II) nanocapsule.

Three new prenyloxy chromanones from aerial parts of Hypericum aucheri

Three new prenyloxy chromanone derivatives, aucherine A-C (6, 7 and 9) as well as six known prenylated phloroglucinols (1-5 and 8) were isolated from the aerial parts of Hypericum aucheri Jaub. Et Spach. The structures of the isolated compounds were established by means of spectral techniques (HRESIMS, 1D and 2D NMR). The new compounds were tested on а panel of human tumor cell line using MTT assay. All tested compounds exerted moderate cytotoxicity with IC₅₀ values ranging from 19.6 to 57.8 μM. The influence of the new compounds on some key signaling molecules (procaspase-9 and Bcl-xL), implicated in the regulation of programmed cell death was assessed by Western blot analysis.

Synthesis of New N1Arylpiperazine Substituted Xanthine Derivatives and Evaluation of their Antioxidant and Cytotoxic Effects

Background:

Cancer is one of the leading causes of morbidity and mortality worldwide, with approximately 14 million new cases in 2012, with most of the clinically used drugs being ineffective. Methylxanthines have raised more interest in research on modifying their structure because of their diverse biological activity. In addition, the piperazine nucleus is one of the most important heterocycles exhibiting remarkable pharmacological activities.

Methods:

The structure of the obtained compounds was characterized and elucidated by IR, 1H and 13C NMR and LCMS spectral analysis. The purity of the substances was proven by corresponding melting points and elemental analysis. The antioxidant activity was evaluated by four common methods – DPPH, ABTS, FRAP and lipid peroxidation assay. The cytotoxic effects of the tested series were evaluated using the standard MTT-dye reduction assay on three tumour cell lines.

Results:

A series of new xanthine derivatives comprising an arylpiperazine moiety at N1 were synthesized. The cytotoxicity against human T-cell leukemia cell SKW-3, human acute myeloid leukemia HL-60 and human Bcell precursor leukemia cell REH was evaluated. The relationship between the structure and citotoxicity of the compounds was investigated by quantitative structure-activity relationship (QSAR) analysis and the important structural parameters were drawn.

Conclusion:

The highest antioxidant activity was demonstrated by compound 6c. The highest cytotoxic effect was observed for compound 6f. It was found that cytotoxicity against SKW-3 depends on the electron density distribution in the structures. Branching of the molecular skeleton and introduction of heteroatoms like fluorine and sulfur in the structures also significantly improved the antiproliferative activity of the compounds.

Superior proapoptotic activity of curcumin-loaded mixed block copolymer micelles with mitochondrial targeting properties

Targeting tumor cell mitochondria is a prospective strategy for highly effective anticancer therapy. Consequently, the development of potent systems for the targeted delivery of mitochondria-acting therapeutics to mitochondria has the potential to boost this sector of nanomedicine. In this study, a functional mixed micellar system based on two co-assembled triblock copolymers, poly(2-(dimethylamino)ethyl methacrylate)-b-poly(ε-caprolactone)-b-poly(2-(dimethylamino)ethyl methacrylate) bearing triphenylphosphonium ligands (PDMAEMA(TPP+)20-b-PCL70-b-PDMAEMA(TPP+)20) and poly(ethylene oxide)-b-poly(ε-caprolactone)-b-poly(ethylene oxide) (PEO113-b-PCL70-b-PEO113), was assessed for the mitochondria targeted delivery of curcumin. The high proapoptotic activity of the system and the sub-cellular mechanisms of cytotoxicity were demonstrated using a chemosensitive HL-60 cell line and its resistant alternative HL-60/DOX. Next, the successful localization of nanocarriers in mitochondria was proved by fluorescence microscopy with the aid of DAPI (4',6-diamidino-2-phenylindole) as a cellular localization tracker. The in vitro experiments revealed the great potential of the functional system developed for the targeted delivery of curcumin to mitochondria, causing programmed tumor cell death.

Determination of the Antiproliferative Activity of New Theobromine Derivatives and Evaluation of Their In Vitro Hepatotoxic Effects

A new series of N-substituted 1-benzyltheobromine-8-thioacetamides were designed and synthesized. Their anti-proliferative activity against human chronic myelocytic leukemia cell K562, human T-cell leukemia cell SKW-3 and human acute myeloid leukemia HL-60 was evaluated. For the tested compounds a concentrationdependent cytotoxic activity was observed, with 7g outlined as the most active compound within the series. The targed compounds were obtained in yields of 56 to 85% and their structures were elucidated by FTIR, (1)H NMR, (13)C NMR and microanalyses. The compounds purity was proven by elemental analysis and spectral data. In general, the compounds showed low hepatotoxicity on sub-cellular and cellular level. On isolated rat microsomes only 7d showed toxic effect while theobromine, 1-benzyl-theobromine-thioacetic acid (BTTA) and the other new theobromine derivatives were devoid of toxicity. In isolated rat hepatocytes, when compared to theobromine and BTTA, 7f showed lower cytotoxic effects, and 7d exerted higher cytotoxicity. The results indicate 7g as a promising structure for the design of future compounds with low hepatotoxicity and good antiproliferative activity.

Synthesis, antimycobacterial activity and docking study of 2-aroyl-[1]benzopyrano[4,3-c]pyrazol-4(1H)-one derivatives and related hydrazide-hydrazones

A new convenient method for preparation of 2-aroyl-[1]benzopyrano[4,3-c]pyrazol-4(1H)-one derivatives 5b-g and coumarin containing hydrazide-hydrazone analogues 4a-e was presented. The antimycobacterial activity against reference strain Mycobacterium tuberculosis H37Rv and cytotoxicity against the human embryonic kidney cell line HEK-293 were tested in vitro. All compounds demonstrated significant minimum inhibitory concentrations (MIC) ranging 0.28-1.69μM, which were comparable to those of isoniazid. The cytotoxicity (IC₅₀>200µM) to the "normal cell" model HEK-293T exhibited by 2-aroyl-[1]benzopyrano[4,3-c]pyrazol-4(1H)-one derivatives 5b-e, was noticeably milder compared to that of their hydrazone analogues 4a-e (IC₅₀ 33-403µM). Molecular docking studies on compounds 4a-e and 5b-g were also carried out to investigate their binding to the 2-trans-enoyl-ACP reductase (InhA) enzyme involved in M. tuberculosis cell wall biogenesis. The binding model suggested one or more hydrogen bonding and/or arene-H or arene-arene interactions between hydrazones or pyrazole-fused coumarin derivatives and InhA enzyme for all synthesized compounds.

HPLC-UV and LC-MS Analyses of Acylquinic Acids in Geigeria alata (DC) Oliv. & Hiern. and their Contribution to Antioxidant and Antimicrobial Capacity

INTRODUCTION

Geigeria alata is a traditional plant used in Sudanese folk medicine for treatment of diabetes, cough, epilepsy and intestinal complaints.

OBJECTIVE

To analyze phenolic acids in Geigeria alata roots and leaves and to evaluate their antioxidant and antimicrobial activities.

METHODOLOGY

Phenolic acids in the aqueous-methanol extracts were identified by LC-MS. Major compounds were isolated using low-pressure liquid chromatography. The quantitative analysis of phenolic acids was performed by a validated HPLC-UV method with limits of detection ranging from 0.04 to 0.57 μg/mL. 2,2-Diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azinobis-(3-ethylbenzothiazine-6-sulphonic acid) (ABTS) and ferric reducing antioxidant power (FRAP) methods were used for antioxidant activity evaluation. In addition, the minimal inhibitory concentration and the minimal bactericidal concentration against a panel of pathogenic bacteria and fungi were determined by the broth microdilution test.

RESULTS

For the first time protocatechuic, caffeic, p-coumaroylquinic, caffeoylsinapoylquinic, caffeoylferuloylquinic, three feruloylquinic, six caffeoylquinic acids, and a caffeic acid hexoside were detected in Geigeria alata roots by LC-MS. HPLC-UV analyses showed that 3,5-dicaffeoylquinic acid (25.96 ± 2.08 mg/g dry weight (DW)) was the most abundant phenolic acid in roots, while 4,5-dicaffeoylquinic acid (8.99 ± 0.56 mg/g DW) was the main compound present in leaves. 3,5-Dicaffeoylquinic acid demonstrated stronger radical scavenging activity and reducing power compared with the crude extracts and the positive control 5-caffeoylquinic acid. 3,4,5-Tricaffeoylquinic acid revealed the highest antibacterial potential against the penicillin sensitive and resistant Staphylococcus aureus strains, as well as methicillin-resistant S. aureus.

CONCLUSION

The caffeoylquinic acids content of up to 6.22% in Geigeria alata roots establishes this species as a new source rich in these bioactive molecules. Copyright © 2016 John Wiley & Sons, Ltd.

3-methoxy aroylhydrazones - free radicals scavenging, anticancer and cytoprotective potency

OBJECTIVE

This study aimed to determine the capability of newly designed 3-methoxy derivatives of salicylaldehyde benzoylhydrazone to influence the oxidative stress processes and to test their in vitro cytotoxicity.

METHODS

We have used chemiluminescent and spectrophotometric model systems containing different types of reactive oxygen species (OH^●, OCl^─ and O₂^─●). The hydrazones effect on the viability of Hep-G2, HEK-293 and SH-SY5Y cell lines was determined via MTT assay.

RESULTS

The comparative analysis of the C₅₀ values of the chemiluminescent investigation demonstrated moderate activity against the hydroxyl radicals (C₅₀ > 50 μmol/L) and remarkable reactivity in the systems containing a superoxide radical and a hypochlorous anion (C₅₀ < 3.7 μmol/L). Further experiments in the spectrophotometric system of UV-induced OH^● generation and consequent 2'-deoxyribose oxidative damage excluded the possibility of quenching effect and proved the direct interaction of the studied compounds with that generated in the system reactive oxygen species (ROS). The encapsulation of the studied derivatives into chitosan-alginate particles led to the protection and stabilization of their antioxidant activity as revealed by a one-month study using the ABTS ^●+ method. The cytotoxic study revealed less pronounced effects against the non-malignant cell line (HEK-293) compared to Hep-G2 and SH-SY-5Y cells.

DISCUSSION

The incorporation of a hydroxyl group in the hydrazide part of a parent molecule which relates to better antioxidant effect in most of the studied systems is associated with higher IC₅₀ values in all cytotoxicity experiments and relates to the cytoprotective effect against N-methyl-D-aspartate-induced excitotoxicity in SH-SY5Y human neuronal cells.

Preparation of efficient quercetin delivery system on Zn-modified mesoporous SBA-15 silica carrier

Mesoporous silica material type SBA-15 was modified with different amounts of Zn (2 and 4wt.%) by incipient wetness impregnation method in ethanol. The parent, Zn-modified and quercetin loaded samples, were characterized by XRD, N₂ physisorption, TEM, thermal gravimetric analysis, UV-vis and FT-IR spectroscopies and in vitro release of quercetin at pH5.5 which is typical of dermal formulations. By this loading method anhydrous quercetin was formed on the silica carrier It was found that the different hydrate forms of quercetin (dihydrate, monohydrate, anhydrite) significantly influence the physico-chemical properties of the delivery system. It was found that hydrate forms of quercetin can be differentiated by XRD and by FT-IR spectroscopic methods. Thus, by evaluating the interaction of the drug with the silica carrier the changes due to its hydration state always have to be taken into account. Formation of Zn-quercetin complex was evidenced on zinc modified SBA-15 silica by FT-IR spectroscopy. High quercetin loading capacity (over 40wt.%) could be achieved on the parent and Zn-containing SBA-15 samples. The in-vitro release process at pH=5.5 showed slower quercetin release from Zn-modified SBA-15 samples compared to the parent one. Additionally, the comparative cytotoxic experiments evidenced that quercetin encapsulated in Zn-modified silica carriers has superior antineoplastic potential against HUT-29 cells compared to free drug. Zn-modified SBA-15 silica particles could be promising carriers for dermal delivery of quercetin.

M2L4 coordination capsules with tunable anticancer activity upon guest encapsulation

Guest encapsulation can modulate the cytotoxicity of anthracene-based nano-capsules and broaden their applications from metallodrugs to biocompatible delivery systems.

Functional block copolymer nanocarriers for anticancer drug delivery

We present a synthetic strategy towards functional polymer-based nanocarriers for potential anticancer drug delivery.

Curcumin loaded pH-sensitive hybrid lipid/block copolymer nanosized drug delivery systems

Curcumin is a perspective drug candidate with pleiotropic antineoplastic activity, whose exceptionally low aqueous solubility and poor pharmacokinetic properties have hampered its development beyond the preclinical level. A possible approach to overcome these limitations is the encapsulation of curcumin into nano-carriers, incl. liposomes. The present contribution is focused on feasibility of using hybrid pH-sensitive liposomes, whereby curcumin is entrapped as a free drug and as a water soluble inclusion complex with PEGylated tert-butylcalix[4]arene, which allows the drug to occupy both the phospholipid membranes and the aqueous core of liposomes. The inclusion complexes were encapsulated in dipalmithoylphosphathydilcholine:cholesterol liposomes, whose membranes were grafted with a poly(isoprene-b-acrylic acid) diblock copolymer to confer pH-sensitivity. The liposomes were characterized by DLS, ζ-potential measurements, cryo-TEM, curcumin encapsulation efficacy, loading capacity, and in vitro release as a function of pH. Free and formulated curcumin were further investigated for cytotoxicity, apoptosis-induction and caspase-8, and 9 activation in chemosensitive HL-60 and its resistant sublines HL-60/Dox and HL-60/CDDP. Formulated curcumin was superior cytotoxic and apoptogenic agent vs. the free drug. The mechanistic assay demonstrated that the potent proapoptotic effects of pH-sensitive liposomal curcumin presumably mediated via recruitment of both extrinsic and intrinsic apoptotic pathways in both HL-60 and HL-60/CDDP cells.

Polyprenylated Phloroglucinols from Hypericum maculatum

A detailed phytochemical investigation of the dichloromethane extract of the aerial parts of Hypericum maculatum Crantz. led to the isolation of four new (2-5) and six known (1a/b, 6-10) polyprenylated phloroglucinol derivatives. The new compounds were identified by means of spectral methods (MS, NMR, IR, UV) as ( E)-4-(3,7-dimethylocta-2,6-dien-1-yl)-5-hydroxy-2-(3-methylbut-2-en-1-yl)-3,6-dioxocyclohexa-1,4-dien-1-yl isobutyrate (2), ( E)-2-(3,7-dimethylocta-2,6-dien-1-yl)-5-hydroxy-4-(3-methylbut-2-en-1-yl)-3,6-dioxocyclohexa-1,4-dien-1-yl isobutyrate (3), ( E)-4-(3,7-dimethylocta-2,6-dien-1-yl)-5-hydroxy-2-(3-methylbut-2-en-1-yl)-3,6-dioxocyclohexa-1,4-dien-1-yl 2-methylbutanoate (4) and ( E)-2-(3,7-dimethylocta-2,6-dien-1-yl)-5-hydroxy-4-(3-methylbut-2-en-1-yl)-3,6-dioxocyclohexa-1,4-dien-1-yl 2-methylbutanoate (5). The known compounds have been identified as hyperpolyphyllirin/hyperibine J (1a/b), erectquione A (6), ( E)-1-(3-(3,7-dimethylocta-2,6-dien-1-yl)-2,4,6-trihydroxyphenyl)-2-methylpropan-1-one (7), ( E)-1-(3-(3,7-dimethylocta-2,6-dien-1-yl)-2,4,6-trihydroxyphenyl)-2-methylbutan-1-one (8), 1-(5,7-dihydroxy-2-methyl-2-(4-methylpent-3-en-1-yl)chroman-8-yl)-2-methylpropan-1-one (9) and 1-(6,8-dihydroxy-1,1,4a-trimethyl-2,3,4,4a,9,9a-hexahydro-1H-xanthen-5-yl)-2-methylpropan-1-one (10). The stereochemistry of 1a is described for the first time. The cytotoxicity of 1-6 on SKW-3, BV-173 and K-562 tumor cell lines was determined using MTT based assays.

Polyprenylated Phloroglucinols from Hypericum maculatum

A detailed phytochemical investigation of the dichloromethane extract of the aerial parts of Hypericum maculatum Crantz. led to the isolation of four new (2-5) and six known (1a/b, 6-10) polyprenylated phloroglucinol derivatives. The new compounds were identified by means of spectral methods (MS, NMR, IR, UV) as (E)-4-(3,7-dimethylocta-2,6-dien-1-yl)-5-hydroxy-2-(3-methylbut-2-en-1-yl)-3,6-dioxocyclohexa-1,4-dien-1-yl isobutyrate (2), (E)-2-(3,7-dimethylocta-2,6-dien-1-yl)-5-hydroxy-4-(3-methylbut-2-en-1-yl)-3,6-dioxocyclohexa-1,4-dien-1-yl isobutyrate (3), (E)-4-(3,7-dimethylocta-2,6-dien-1-yl)-5-hydroxy-2-(3-methylbut-2-en-1-yl)-3,6-dioxocyclohexa-1,4-dien-1-yl 2-methylbutanoate (4) and (E)-2-(3,7-dimethylocta-2,6-dien-1-yl)-5-hydroxy-4-(3-methylbut-2-en-1-yl)-3,6-dioxocyclohexa-1,4-dien-1-yl 2-methylbutanoate (5). The known compounds have been identified as hyperpolyphyllirin/hyperibine J (1a/b), erectquione A (6), (E)-1-(3-(3,7-dimethylocta-2,6-dien--yl)-2,4,6-trihydroxyphenyl)-2-methylpropan-1-one (7), (E)-1-(3-(3,7-dimethylocta-2,6-dien-1-yl)- 2,4,6-trihydroxyphenyl)-2-methylbutan-1-one (8), 1-(5,7-dihydroxy-2-methyl-2-(4-methylpent-3-en-1-yl)chroman-8-yl)-2-methylpropan-1-one (9) and 1-(6,8-dihydroxy-1,1,4a-trimethyl-2,3,4,4a,9,9a-hexahydro-1H-xanthen-5-yl)-2-methylpropan-1-one (10). The stereochemistry of 1a is described for the first time. The cytotoxicity of 1-6 on SKW-3, BV-173 and K-562 tumor cell lines was determined using MTT based assays.