New Formulation of a Methylseleno-Aspirin Analog with Anticancer Activity towards Colon Cancer.

Aspirin (ASA) has attracted wide interest of numerous scientists worldwide thanks to its chemopreventive and chemotherapeutic effects, particularly in colorectal cancer (CRC). Incorporation of selenium (Se) atom into ASA has greatly increased their anti-tumoral efficacy in CRC compared with the organic counterparts without the Se functionality, such as the promising antitumoral methylseleno-ASA analog (1a). Nevertheless, the efficacy of compound 1a in cancer cells is compromised due to its poor solubility and volatile nature. Thus, 1a has been formulated with native α-, ß- and γ-cyclodextrin (CD), a modified ß-CD (hydroxypropyl ß-CD, HP-ß-CD) and Pluronic F127, all of them non-toxic, biodegradable and FDA approved. Water solubility of 1a is enhanced with ß- and HP- ß-CDs and Pluronic F127. Compound 1a forms inclusion complexes with the CDs and was incorporated in the hydrophobic core of the F127 micelles. Herein, we evaluated the cytotoxic potential of 1a, alone or formulated with ß- and HP- ß-CDs or Pluronic F127, against CRC cells. Remarkably, 1a formulations demonstrated more sustained antitumoral activity toward CRC cells. Hence, ß-CD, HP-ß-CD and Pluronic F127 might be excellent vehicles to improve pharmacological properties of organoselenium compounds with solubility issues and volatile nature.

A review on gentisic acid as a plant derived phenolic acid and metabolite of aspirin: Comprehensive pharmacology, toxicology, and some pharmaceutical aspects.

Beneficial therapeutic effects of phenolic acids have been proven in various research projects including in vivo and in vitro studies. Gentisic acid (GA) is a phenolic acid that has been associated with useful effects on human health, such as antiinflammatory, antigenotoxic, hepatoprotective, neuroprotective, antimicrobial, and especially antioxidant activities. It is an important metabolite of aspirin and also widely distributed in plants as a secondary plant product such as Gentiana spp., Citrus spp., Vitis vinifera, Pterocarpus santalinus, Helianthus tuberosus, Hibiscus rosa-sinensis, Olea europaea, and Sesamum indicum and in fruits such as avocados, batoko plum, kiwi fruits, apple, bitter melon, black berries, pears, and some mushrooms. This study was undertaken to review the pharmacological effects, pharmacokinetic properties as well as toxicity and pharmaceutical applications of GA.

Synthesis of halogenated azo-aspirin analogues from natural product derivatives as the potential antibacterial agents.

Chemical modification of medicines from natural product-based molecules has become of interest in recent years. In this study, a series of halogenated azo derivatives 1a-d were synthesised via coupling reaction, followed by Steglich esterification with aspirin (a natural product derivative) to form azo derivatives 2a-d. While, halogenated azo-aspirin 3a-d were synthesised via direct coupling reaction of aspirin and diazonium salt. Bacteriostatic activity was demonstrated against E. coli and S. aureus via turbidimetric kinetic method. Compound 3a-d showed excellent antibacterial activities against E. coli (MIC 75-94 ppm) and S. aureus (MIC 64-89 ppm) compared to ampicillin (MIC 93 and 124 ppm respectively), followed by 1a-d and 2a-d. The presence of reactive groups of -OH, N=N, C=O and halogens significantly contribute excellent interaction towards E. coli and S. aureus. Molecular dockings analysis of 3a against MIaC protein showed binding free energy of -7.2 kcal/mol (E. coli) and -6.6 kcal/mol (S. aureus).

Effects of Panax Notoginseng Saponins on Esterases Responsible for Aspirin Hydrolysis In Vitro.

Herb⁻drug interactions strongly challenge the clinical combined application of herbs and drugs. Herbal products consist of complex pharmacological-active ingredients and perturb the activity of drug-metabolizing enzymes. Panax notoginseng saponins (PNS)-based drugs are often combined with aspirin in vascular disease treatment in China. PNS was found to exhibit inhibitory effects on aspirin hydrolysis using Caco-2 cell monolayers. In the present study, a total of 22 components of PNS were separated and identified by UPLC-MS/MS. Using highly selective probe substrate analysis, PNS exerted robust inhibitory potency on human carboxylesterase 2 (hCE2), while had a minor influence on hCE1, butyrylcholinesterase (BChE) and paraoxonase (PON). These effects were also verified through molecular docking analysis. PNS showed a concentration-dependent inhibitory effect on hydrolytic activity of aspirin in HepaRG cells. The protein level of hCE2 in HepaRG cells was suppressed after PNS treatment, while the level of BChE or PON1 in the extracellular matrix were elevated after PNS treatment. Insignificant effect was observed on the mRNA expression of the esterases. These findings are important to understand the underlying efficacy and safety of co-administration of PNS and aspirin in clinical practice.

Interaction study between antiplatelet agents, anticoagulants, thyroid replacement therapy and a bioavailable formulation of curcumin (Meriva®).

OBJECTIVE: The objective of this clinical study is to evaluate possible interactions between antiplatelet agents, anticoagulants, thyroid hormone replacement therapy and a formulation of curcumin (Meriva®) that resulted effective for the complementary treatment of osteoarthritis. PATIENTS AND METHODS: Interaction between antiplatelet agents and Meriva® was evaluated by measuring anti-platelet activity with the in-vivo bleeding-time (BT) in patients assuming acetylsalicylic acid or ticlopidine or clopidogrel from at least 2 years. The BT was evaluated before and after 10 days of supplementation with Meriva®. The interaction between anticoagulants and Meriva® was evaluated in patients using warfarin or dabigatran for previous venous thrombosis. The INR level was evaluated before and after 10 days of supplementation with the curcumin formulation. Thyroid function tests in hypothyroid patients using LT4 replacement therapy (Eutirox®) were evaluated before and after 15 days of supplementation with Meriva®. Similarly, levels of glycemia and glycated hemoglobin were evaluated in diabetic patients in treatment with metformin, before and after 10 days of supplementation with the studied product. RESULTS: After 10 days of supplementation with Meriva® the average BT value was not significantly different for patients assuming acetylsalicylic acid, ticlopidine or clopidogrel at standard dosages. Similarly, after 10 days of Meriva® treatment, the INR level in the two groups of patients assuming warfarin or dabigatran was not statistically different from that observed at baseline. In the analyzed patients assuming LT4 or metformin, no interactions between the therapy and Meriva® were observed. CONCLUSIONS: Results from this non-interaction clinical study suggest that Meriva® does not interfere with the antiplatelet activity of the most common antiplatelet agents nor alters the INR values in stable patients assuming warfarin or dabigatran. Similarly, dosages of LT4 or metformin do not need to be adjusted in case of complementary treatment with Meriva®.

Chitosan/waste coffee-grounds composite: An efficient and eco-friendly adsorbent for removal of pharmaceutical contaminants from water.

Waste coffee-grounds (WCG), a poorly explored source of biocompounds, were combined with chitosan (Cs) and poly(vinyl alcohol) (PVA) in order to obtain composites. Overall, WCG showed a good interaction with the polymeric matrix and good dispersibility up to 10 wt-%. At 5 wt-% WCG, the composite exhibited a noticeable enhancement (from 10 to 44%) of the adsorption of pharmaceuticals (metamizol (MET), acetylsalicylic acid (ASA), acetaminophen (ACE), and caffeine (CAF)) as compared to the pristine sample. The highest removal efficiency was registered at pH 6 and the removal followed the order ASA > CAF > ACE > MET. For all pharmaceuticals, the adsorption kinetics was found to follow the pseudo-second order model, while the adsorption mechanism was explained by the Freundlich isotherm. Reuse experiments indicated that the WCG-containing composite has an attractive cost-effectiveness since it presented a remarkable reusability in at least five consecutive adsorption/desorption cycles.

Inhibitory Influence of Panax notoginseng Saponins on Aspirin Hydrolysis in Human Intestinal Caco-2 Cells.

Herb-drug interactions are important safety concerns in clinical practice. The interactions occur firstly in the intestinal absorption for orally administered drugs. Aspirin and Panax notoginseng saponins (PNS)-based drugs are often combined in China to prevent larger-artery atherosclerosis. Here, we aimed to characterize the aspirin transport across Caco-2 cell monolayers, a model of the intestinal absorption, and further to evaluate the influence of PNS on aspirin hydrolysis and the relating mechanisms. Transcellular transport of aspirin and the influence of PNS were explored using Caco-2 cell monolayers. The protein expression of human carboxylesterase 1 (hCE1) and hCE2 in Caco-2 cells after PNS treatment was analyzed by ELISA, and the mRNA level were determined by qRT-PCR. In the study, Caco-2 cells showed high level of hydrolase activity, and most aspirin was hydrolyzed inside the cells during the transport process. Interestingly, PNS were demonstrated to inhibit the esterase activities responsible for aspirin hydrolysis in Caco-2 cells. PNS could also decrease the protein expression of hCE1 and hCE2, whereas exhibited minor effect on the mRNA expression. These results indicated that oral administration of PNS-based drugs might inhibit the hydrolysis of aspirin during intestinal absorption thus promoting its bioavailability.

Effect of Calcium Ions on the Disintegration of Enteric-Coated Solid Dosage Forms.

To investigate the effect of calcium ions on the disintegration of enteric-coated dosage forms, disintegration testing was performed on enteric-coated aspirin tablets in the presence and absence of calcium in the test media. The results show that the presence of calcium ions retards the disintegration of enteric-coated dosage forms. This finding, which has not been reported in scientific literature, sheds light on the importance of conducting well-designed detailed investigations into the potential of calcium from dietary sources, calcium supplements, antacids, and/or phosphate binders affecting the absorption of drugs formulated into enteric-coated dosage forms. Moreover, it shows the necessity to investigate the potential of the occurrence of additional nutrient-excipient interactions.

Human GAPDH Is a Target of Aspirin's Primary Metabolite Salicylic Acid and Its Derivatives.

The plant hormone salicylic acid (SA) controls several physiological processes and is a key regulator of multiple levels of plant immunity. To decipher the mechanisms through which SA's multiple physiological effects are mediated, particularly in immunity, two high-throughput screens were developed to identify SA-binding proteins (SABPs). Glyceraldehyde 3-Phosphate Dehydrogenase (GAPDH) from plants (Arabidopsis thaliana) was identified in these screens. Similar screens and subsequent analyses using SA analogs, in conjunction with either a photoaffinity labeling technique or surface plasmon resonance-based technology, established that human GAPDH (HsGAPDH) also binds SA. In addition to its central role in glycolysis, HsGAPDH participates in several pathological processes, including viral replication and neuronal cell death. The anti-Parkinson's drug deprenyl has been shown to suppress nuclear translocation of HsGAPDH, an early step in cell death and the resulting cell death induced by the DNA alkylating agent N-methyl-N'-nitro-N-nitrosoguanidine. Here, we demonstrate that SA, which is the primary metabolite of aspirin (acetyl SA) and is likely responsible for many of its pharmacological effects, also suppresses nuclear translocation of HsGAPDH and cell death. Analysis of two synthetic SA derivatives and two classes of compounds from the Chinese medicinal herb Glycyrrhiza foetida (licorice), glycyrrhizin and the SA-derivatives amorfrutins, revealed that they not only appear to bind HsGAPDH more tightly than SA, but also exhibit a greater ability to suppress translocation of HsGAPDH to the nucleus and cell death.

Low cost microfluidic cell culture array using normally closed valves for cytotoxicity assay.

A reusable low cost microfluidic cell culture array device (MCCAD) integrated with a six output concentration gradient generator (cGG) and 4×6 arrays of microchamber elements, addressed by a series of row and columnar pneumatically actuated normally closed (NC) microvalves was fabricated for cell-based screening of chemotherapeutic compounds. The poly(dimethylsiloxane) (PDMS) device consists of three layers: fluidic, control and membrane which are held by surface contact and made leak-proof by clamping pressure. The NC valves are actuated by a thick PDMS membrane that was created by a novel method based on the self-assembly of PDMS pre-polymer molecules over a denser calcium chloride solution. The membrane actuated the valves reliably and particulates such as alumina particles (3 µm) and MCF-7 cells (20-24 µm) (2×10(5) cells/mL) were flowed through the valves without causing blockage or leakage and consequently avoiding contamination of the different cell culture elements. The MCCAD was cast and assembled in a standard laboratory without specialist equipment and demonstrated for performing quantitative cell-based cytotoxicity assays of pyocyanine on human breast cancer (MCF-7) cells and assessed for toxic effect on human hepatocyte carcinoma (HepG2) cells as an indicator for liver injury. Then, the MCCAD was demonstrated for sequential drug combinatorial screening involving gradient generation of paclitaxel doses followed by treatment with aspirin doses on the viability of MCF-7 cells. The interaction between paclitaxel and aspirin was evaluated by using the Bliss independence predictive model and results showed reasonable agreement with the model. A robust, portable, easily fabricated and low cost device is therefore shown to conveniently carry out culturing of multiple cell lines for high throughput screening of anti-cancer compounds using minimal reagents.

Quality and antioxidant properties on sweet cherries as affected by preharvest salicylic and acetylsalicylic acids treatments.

The effects of salicylic acid (SA) or acetylsalicylic acid (ASA) treatments during on-tree cherry growth and ripening on fruit quality attributes, especially those related with the content on bioactive compounds and antioxidant activity were analysed in this research. For this purpose, two sweet cherry cultivars, 'Sweet Heart' and 'Sweet Late', were used and SA or ASA treatments, at 0.5, 1.0 and 2.0mM concentrations, were applied at three key points of fruit development (pit hardening, initial colour changes and onset of ripening). These treatments increased fruit weight and ameliorated quality attributes at commercial harvest, and led to cherries with higher concentration in total phenolics and in total anthocyanins, as well as higher antioxidant activity, in both hydrophilic and lipophilic fractions. Thus, preharvest treatments with SA or ASA could be promising tools to improve sweet cherry quality and health beneficial effects for consumers.

Comparative evaluation of gastroulcerogenic potential of nitrogen isoforms of salicyl alcohol and aspirin in rats: biochemical and histological study.

The aim of the current study was to explore in vivo any relative gastroulcerogenic prospective propensity of newly synthesized nitrogen containing derivatives of salicyl alcohol; compound (I) [1-(2-hydroxybenzyl)piperidinium chloride], compound (II) [4-carbamoyl-1-(2-hydroxybenzyl)piperidinium chloride] and aspirin in albino rats. The experimental groups received the following oral treatments daily for 6 days: group I saline control; group II, standard (aspirin) treatment group [150 mg/kg of body weight]; group III, test (compound I) treatment group [100, 150 mg/kg]; group IV, test (compound II) treatment group [100, 150 mg/kg]. The results showed that in the case of the aspirin treated group and compound (I) [150 mg/kg], there was a significant increase in gastric volume, free acidity, total acidity, ulcer score and a decrease in gastric pH. Furthermore, histopathological examination of gastric mucosa of these treated groups revealed detectable morphological changes. Utilizing the same protocol, synthetic compound (I) [100 mg/kg] and (II) [100, 150 mg/kg] exhibited no statistically significant ulcerogenic or cytotoxic properties. A cyclooxygenase (COX) selectivity test indicated the preferential inhibition of COX-I and COX-II enzymes by compounds (I) and (II). This study therefore indicates that these synthetic compounds may possess reduced ulcerogenic potential and could be a functional substitute to aspirin.

Over the counter drugs (and dietary supplement) exercise: a team-based introduction to biochemistry for health professional students.

For successful delivery of basic science topics for health-professional students, it is critical to reduce apprehension and illustrate relevance to clinical settings and everyday life. At the beginning of the Biochemistry course for Physician Assistants, a team-based assignment was designed to develop an understanding of the mechanism of action, effectiveness, and toxicity of five common over the counter (OTC) drugs and dietary supplements, and place these familiar medicines in a political and historical context. The objectives of this exercise were to stimulate interest in biochemistry; to provide basic information on enzymes and enzyme inhibitors related to these drugs to be expanded upon later in the course; and to encourage active and interactive learning. Teams of five students were formed, and each student was given an information sheet on aspirin, alpha-galactosidase, orlistat, dextromethorphan, or simvastatin, a low dose statin, which was previously available without prescription at pharmacies in the UK. After each member of the team acquired information on one OTC drug/dietary supplement by reading an assigned information sheet, the team was asked to go through a series of questions, and then submit answers to a quiz as a group. A high rate of success on the quiz, an overwhelmingly positive response on formal course evaluations, and enthusiastic exchanges during class suggested this team-based session accomplished its goals.

Modified tamarind kernel polysaccharide: a novel matrix for control release of aspirin.

pH dependent hydrogels of modified tamarind kernel polysaccharide (TKP) were synthesized by grafting with polyacrylamide chains on TKP backbone in presence of microwave irradiation and initiator. The present study is carried out to design oral controlled drug delivery systems for aspirin using synthesized hydrogels as carrier in form of tablets. TKP-g-PAM based hydrogels show significant enhancement for control release of aspirin. Release behavior of aspirin has been evaluated using USP type I apparatus in 900 mL of buffer solutions (pH 1.2, 6.8, 7.4), maintained at 37°C at 100 rpm. It is observed that with increase in percentage of grafting (% G), swelling of matrices increases whereas erosion and rate of drug release decrease. The effect of % G onto t50 value (time taken for release of 50% drug) has also been discussed. The release characteristics from the matrices under study show non-Fickian diffusion mechanism, suggesting the controlled release of aspirin.

Resolvin D3 and aspirin-triggered resolvin D3 are potent immunoresolvents.

Resolvins are a family of n-3 lipid mediators initially identified in resolving inflammatory exudates that temper inflammatory responses to promote catabasis. Here, temporal metabololipidomics with self-limited resolving exudates revealed that resolvin (Rv) D3 has a distinct time frame from other lipid mediators, appearing late in the resolution phase. Using synthetic materials prepared by stereocontrolled total organic synthesis and metabololipidomics, we established complete stereochemistry of RvD3 and its aspirin-triggered 17R-epimer (AT-RvD3). Both synthetic resolvins potently regulated neutrophils and mediators, reducing murine peritonitis and dermal inflammation. RvD3 and AT-RvD3 displayed leukocyte-directed actions, e.g., blocking human neutrophil transmigration and enhancing macrophage phagocytosis and efferocytosis. These results position RvD3 uniquely within the inflammation-resolution time frame to vantage and contribute to the beneficial actions of aspirin and essential n-3 fatty acids.

Evaluation of the in vivo anti-inflammatory and analgesic activity of a highly water-soluble aspirin conjugate.

Glucose-aspirin (GA) was synthesized by conjugating aspirin (ASA) to the 3-carbon of glucose to produce a stable water-soluble aspirin derivative. The in vivo activities were compared with those of aspirin. The mouse tail flick assay showed that at 120 min., both aspirin and GA showed the maximum possible effect, and the higher dose (200 mg/kg) generally had less of an effect than the lower dose (100 mg/kg). Per cent inhibition of paw oedema was 63% and 69% for ASA and GA at 100 mg/kg, respectively. In the tail immersion test, the increase in reaction time was significantly greater with GA as compared to aspirin (100 mg/kg) at 60 min. In conclusion, there was significant anti-inflammatory and analgesic activity for GA at the doses studied under the experimental conditions.

Evaluation of analgesic activity of P. domestica L.

This research study was conducted to investigate acute oral toxicity and analgesic activity of ethanol extract of P. domestica fruit by using tail flick analgesiometer at 300 and 500mg/kg doses in animal models. Acute oral toxicity results showed that crude extract is safe up to the dose of 5g/kg body weight of animals. The analgesic activity revealed that P. domestica extract at 500mg/kg dose possesses highest significant and prolonged analgesic activity in dose dependent manner as compared to standard and control groups. Aspirin 300mg/kg body weight was used as standard drug. Phytochemical analysis was also carried out which showed the presence of certain phytochemicals constituents in test drug that are responsible for analgesic activity. Therefore the results are justified.

Spectroscopic studies of the interaction of aspirin and its important metabolite, salicylate ion, with DNA, A·T and G·C rich sequences.

Among different biological effects of acetylsalicylic acid (ASA), its anticancer property is controversial. Since ASA hydrolyzes rapidly to salicylic acid (SA), especially in the blood, interaction of both ASA and SA (as the small molecules) with ctDNA, oligo(dA·dT)15 and oligo(dG·dC)15, as a possible mechanism of their action, is investigated here. The results show that the rate of ASA hydrolysis in the absence and presence of ctDNA is similar. The spectrophotometric results indicate that both ASA and SA cooperatively bind to ctDNA. The binding constants (K) are (1.7±0.7)×10(3) M(-1) and (6.7±0.2)×10(3) M(-1) for ASA and SA, respectively. Both ligands quench the fluorescence emission of ethidium bromide (Et)-ctDNA complex. The Scatchard plots indicate the non-displacement based quenching (non-intercalative binding). The circular dichroism (CD) spectra of ASA- or SA-ctDsNA complexes show the minor distortion of ctDNA structure, with no characteristic peaks for intercalation of ligands. Tm of ctDNA is decreased up to 3°C upon ASA binding. The CD results also indicate more distortions on oligo(dG·dC)15 structure due to the binding of both ASA and SA in comparison with oligo(dA·dT)15. All data indicate the more affinity for SA binding with DNA minor groove in comparison with ASA which has more hydrophobic character.

Inhibition of arachidonic acid metabolism and its implication on cell proliferation and tumour-angiogenesis.

Arachidonic acid (AA) and its metabolites have recently generated a heightened interest due to growing evidence of their significant role in cancer biology. Thus, inhibitors of the AA cascade, first and foremost COX inhibitors, which have originally been of interest in the treatment of inflammatory conditions and certain types of cardiovascular disease, are now attracting attention as an arsenal against cancer. An increasing number of investigations support their role in cancer chemoprevention, although the precise molecular mechanisms that link levels of AA, and its metabolites, with cancer progression have still to be elucidated. This article provides an overview of the AA cascade and focuses on the roles of its inhibitors and their implication in cancer treatment. In particular, emphasis is placed on the inhibition of cell proliferation and neo-angiogenesis through inhibition of the enzymes COX-2, 5-LOX and CYP450. Downstream effects of inhibition of AA metabolites are analysed and the molecular mechanisms of action of a selected number of inhibitors of catalytic pathways reviewed. Lastly, the benefits of dietary omega-3 fatty acids and their mechanisms of action leading to reduced cancer risk and impeded cancer cell growth are mentioned. Finally, a proposal is put forward, suggesting a novel and integrated approach in viewing the molecular mechanisms and complex interactions responsible for the involvement of AA metabolites in carcinogenesis and the protective effects of omega-3 fatty acids in inflammation and tumour prevention.

Polycyclic cage structures as carrier molecules for neuroprotective non-steroidal anti-inflammatory drugs.

The blood-brain barrier is formed by the brain capillary endothelium and plays the predominant role in controlling the passage of substances between the blood and the brain. Recent studies on polycyclic structures, i.e. pentacyclo[5.4.0.0(2,6).0(3,10).0(5,9)]undecane and amantadine, indicated favourable distribution thereof to the brain and it was concluded that these polycyclic structures and their derivatives penetrate the blood-brain barrier readily. A series of novel polycyclic prodrugs incorporating the well known non-steroidal anti-inflammatory drugs (NSAIDs), acetylsalicylic acid and ibuprofen, were synthesised and screened for blood-brain barrier permeability and antioxidant activity. Increased levels of both NSAIDs were detected in the brain tissue of C57BL/6 mice after administration of the synthesised prodrugs, indicating favourable blood-brain barrier permeation. Results from a lipid peroxidation assay indicated that the ester and amide prodrugs significantly increased the ability of the drugs to attenuate lipid peroxidation. These novel prodrugs thus readily penetrate the blood-brain barrier and exhibit increased antioxidant activity when compared to the free NSAIDs.