Pharmacological Properties of Bergapten: Mechanistic and Therapeutic Aspects.

Bergapten (BP) or 5-methoxypsoralen (5-MOP) is a furocoumarin compound mainly found in bergamot essential oil but also in other citrus essential oils and grapefruit juice. This compound presents antibacterial, anti-inflammatory, hypolipemic, and anticancer effects and is successfully used as a photosensitizing agent. The present review focuses on the research evidence related to the therapeutic properties of bergapten collected in recent years. Many preclinical and in vitro studies have been evidenced the therapeutic action of BP; however, few clinical trials have been carried out to evaluate its efficacy. These clinical trials with BP are mainly focused on patients suffering from skin disorders such as psoriasis or vitiligo. In these trials, the administration of BP (oral or topical) combined with UV irradiation induces relevant lesion clearance rates. In addition, beneficial effects of bergamot extract were also observed in patients with altered serum lipid profiles and in people with nonalcoholic fatty liver. On the contrary, there are no clinical trials that investigate the possible effects on cancer. Although the bioavailability of BP is lower than that of its 8-methoxypsoralen (8-MOP) isomer, it has fewer side effects allowing higher concentrations to be administered. In conclusion, although the use of BP has therapeutic applications on skin disorders as a sensitizing agent and as components of bergamot extract as hypolipemic therapy, more trials are necessary to define the doses and treatment guidelines and its usefulness against other pathologies such as cancer or bacterial infections.

Correction: Aljabali, A.A.A.; et al. Albumin Nano-Encapsulation of Piceatannol Enhances Its Anticancer Potential in Colon Cancer via down Regulation of Nuclear p65 and HIF-1α. Cancers 2020, 12, 113.

The authors wish to make the following corrections to this paper [...].

Albumin Nano-Encapsulation of Piceatannol Enhances Its Anticancer Potential in Colon Cancer Via Downregulation of Nuclear p65 and HIF-1α.

Piceatannol (PIC) is known to have anticancer activity, which has been attributed to its ability to block the proliferation of cancer cells via suppression of the NF-kB signaling pathway. However, its effect on hypoxia-inducible factor (HIF) is not well known in cancer. In this study, PIC was loaded into bovine serum albumin (BSA) by desolvation method as PIC-BSA nanoparticles (NPs). These PIC-BSA nanoparticles were assessed for in vitro cytotoxicity, migration, invasion, and colony formation studies and levels of p65 and HIF-1α. Our results indicate that PIC-BSA NPs were more effective in downregulating the expression of nuclear p65 and HIF-1α in colon cancer cells as compared to free PIC. We also observed a significant reduction in inflammation induced by chemical colitis in mice by PIC-BSA NPs. Furthermore, a significant reduction in tumor size and number of colon tumors was also observed in the murine model of colitis-associated colorectal cancer, when treated with PIC-BSA NPs as compared to free PIC. The overall results indicate that PIC, when formulated as PIC-BSA NPs, enhances its therpautice potential. Our work could prompt further research in using natural anticancer agents as nanoparticels with possiable human clinical trails. This could lead to the development of a new line of safe and effective therapeutics for cancer patients.

Dynamics of Prolyl Hydroxylases Levels During Disease Progression in Experimental Colitis.

Hypoxia inducible factor (HIF)-prolyl hydroxylase (PHD) inhibitors are shown to be protective in several models of inflammatory bowel disease (IBD). However, these non-selective inhibitors are known to inhibit all the three isoforms of PHD, i.e. PHD-1, PHD-2 and PHD-3. In the present report, we investigated the associated changes in levels of PHDs during the development and recovery of chemically induced colitis in mice. The results indicated that in the experimental model of murine colitis, levels of both, PHD-1 and PHD-2 were found to be increased with the progression of the disease; however, the level of PHD-3 remained the same in group of healthy controls and mice with colitis. Thus, the findings advocated that inhibitors, which inhibited all three isoforms of PHD could not be ideal therapeutics for IBD since PHD-3 is required for normal gut function. Hence, this necessitates the development of new compounds capable of selectively inhibiting PHD-1 and PHD-2 for effective treatment of IBD.

Galectin-3 enhances monocyte-derived macrophage efferocytosis of apoptotic granulocytes in asthma.

BACKGROUND: Galectin-3 is a 32 kDa protein secreted by macrophages involved in processes such as cell activation, chemotaxis and phagocytosis. Galectin-3 has previously been shown to improve the ability of airway macrophages to ingest apoptotic cells (efferocytosis) in chronic obstructive pulmonary disease (COPD) and may be of interest in non-eosinophilic asthma (NEA) which is also characterised by impaired efferocytosis. It was hypothesised that the addition of exogenous galectin-3 to monocyte-derived macrophages (MDMs) derived from donors with NEA would enhance their ability to engulf apoptotic granulocytes. METHODS: Eligible non-smoking adults with asthma (n = 19), including 7 with NEA and healthy controls (n = 10) underwent a clinical assessment, venepuncture and sputum induction. MDMs were co-cultured with apoptotic granulocytes isolated from healthy donors with or without exogenous recombinant galectin-3 (50 µg/mL) and efferocytosis was assessed by flow cytometry. Galectin-3 expression and localisation in MDMs was visualised by immunofluorescence staining and fluorescence microscopy. Galectin-3, interleukin (IL)-6 and CXCL8 secretion were measured in cell culture supernatants by ELISA and cytometric bead array. RESULTS: Baseline efferocytosis (mean (±standard deviation)) was lower in participants with asthma (33.2 (±17.7)%) compared with healthy controls (45.3 (±15.9)%; p = 0.081). Efferocytosis did not differ between the participants with eosinophilic asthma (EA) (31.4 (±19.2)%) and NEA (28.7 (±21.5)%; p = 0.748). Addition of galectin-3 significantly improved efferocytosis in asthma, particularly in NEA (37.8 (±18.1)%) compared with baseline (30.4 (±19.7)%; p = 0.012). Efferocytosis was not associated with any of the clinical outcomes but was negatively correlated with sputum macrophage numbers (Spearman r = - 0.671; p = 0.017). Galectin-3 was diffusely distributed in most MDMs but formed punctate structures in 5% of MDMs. MDM galectin-3 secretion was lower in asthma (9.99 (2.67, 15.48) ng/mL) compared with the healthy controls (20.72 (11.28, 27.89) ng/mL; p = 0.044) while IL-6 and CXCL8 levels were similar. CONCLUSIONS: Galectin-3 modulates macrophage function in asthma, indicating a potential role for galectin-3 to reverse impaired efferocytosis in NEA.

Role of microRNAs (miRNAs) in the pathophysiology of diabetes mellitus.

Diabetes mellitus is becoming the critical problem among the entire world and it is difficult to understand the molecular mechanism representing the concept of diabetic pathology. Recently the knowledge of the involvement of genetics in type 2 diabetes mellitus (T2DM) susceptibility has sketched a great concentration towards the transcriptional activity of ß cells within the pancreas. This disease becomes the leading cause of death, so it is necessary to study the molecular pathogenesis, phenotypes, and characteristics to design the therapeutic parameters. Here in this review role of miRNA is being illustrated as it plays a crucial role in the pathogenesis, progression, and fate of beta cells of pancreas regulating the insulin secretion. Here in this review, we try to include the effects and pathophysiology of various miRNA in diabetes mellitus and on the various sites of the human body.

Nephrotoxicity in Rats Exposed to Paracetamol: The Protective Role of Moralbosteroid, a Steroidal Glycoside.

Paracetamol (PCM) has an acceptable safety profile when used at prescribed doses. However, it is now understood that paracetamol can damage the kidneys when administered as an overdose. In addition, oxidative stress can play a major role in causing nephrotoxicity. This investigation studies the efficacy of moralbosteroid isolated from M. alba stem bark. Nephrotoxicity was induced with administration of paracetamol. Nephroprotection was studied using two doses of the extract. The experimental animals were divided into four groups (n = 6). Two groups served as positive and negative controls, respectively, and two received the test substances. All of the contents were orally administered. Significant reductions in nephrotoxicity and oxidative damages were observed in the treatment groups. There was a marked decrease in blood levels of urea, creatinine, and lipid peroxidation. Furthermore, it was found that glutathione levels in the blood increased dramatically after treatment. Histological findings confirmed the potent renoprotective potential of moralbosteroid. This was evidenced by the minimized intensity of nephritic cellular destruction. In animal studies, moralbosteroid exhibited dose-dependent activity, which is thought to be mediated through its antioxidant potential.

Sputum colour can identify patients with neutrophilic inflammation in asthma.

INTRODUCTION: Sputum colour is associated with neutrophilic inflammation in chronic bronchitis and chronic obstructive pulmonary disease (COPD). Neutrophilia and sputum expectoration is notable in asthma, but whether sputum colour is associated with and predicts the presence of neutrophilic inflammation in asthma is unknown. The objective of the study is to assess the ability of sputum colour in distinguishing asthma inflammatory phenotypes. METHODS: Induced sputum samples collected from 271 adults with stable asthma were retrospectively assessed. Sputum colour was determined using the BronkoTest sputum colour chart and correlated to differential cell counts and CXCL-8 concentration. Neutrophilic inflammation was defined as an age-corrected sputum neutrophil proportion (≥61.6% for age 20-40 years; ≥63.2% for age 40-60 and ≥67.2% for age >60 years), whereas neutrophilic bronchitis (NB) was defined as high total cell count (≥5.1×106 cells/mL) plus an increased age-corrected neutrophil proportion. The optimal cut-off for sputum colour to predict neutrophilic inflammation and NB was determined using receiver operator characteristic curve analysis. RESULTS: A sputum colour score of ≥3 represented and predicted neutrophilic inflammation with modest accuracy (area under the curve (AUC)=0.64; p<0.001, specificity=78.4%, sensitivity=49.2%). Participants with a sputum colour score of ≥3 had significantly (p<0.05) higher CXCL-8, total cells and neutrophil number and proportion. Sputum colour score was also positively correlated with these factors. Sputum colour score ≥3 predicted NB with reasonably good accuracy (AUC=0.79, p<0.001, specificity=79.3%, sensitivity=70.7%). CONCLUSIONS: Visual gradation of sputum colour in asthma relates to high total cell count and neutrophilic inflammation. Assessment of sputum colour can identify adults with asthma who are likely to have NB without the need for sputum processing and differential cell count, which may facilitate asthma management.

Pharmacological Evaluation of the Recuperative Effect of Morusin Against Aluminium Trichloride (AlCl3)-Induced Memory Impairment in Rats.

BACKGROUND: Elevation in brain levels of aluminium can be neurotoxic and can cause learning and memory deficiencies. In Chinese medicine, Morus alba is used as a neuroprotective herb. The current study was intended to discover the recuperative effect of morusin against aluminium trichloride (AlCl3)-induced memory impairment in rats along with biochemical mechanism of its protective action. METHODS: Memory deficiency was produced by AlCl3 (100 mg/kg; p.o.) in experimental animals. Learning and memory activity was measured using Morris water maze (MWM) test model. Central cholinergic activity was evaluated through the measurement of brain acetylcholinesterase (AChE) activity. In addition to the above, oxidative stress was determined through assessment of brain thiobarbituric acid-reactive species (TBARS) and glutathione (GSH) levels. RESULTS: AlCl3 administration prompted significant deficiency of learning and memory in rats, as specified by a noticeable reduction in MWM presentation. AlCl3 administration also produced a significant deterioration in brain AChE action and brain oxidative stress (increase in TBARS and decrease in GSH) levels. Treatment with morusin (5.0 and 10.0 mg/kg, dose orally) significantly overturned AlCl3- induced learning and memory shortages along with diminution of AlCl3-induced rise in brain AChE activity and brain oxidative stress levels. CONCLUSION: It may be concluded that morusin exerts a memory-preservative outcome in mental discrepancies of rats feasibly through its various activities.

The Extracellular Surface of the GLP-1 Receptor Is a Molecular Trigger for Biased Agonism.

Ligand-directed signal bias offers opportunities for sculpting molecular events, with the promise of better, safer therapeutics. Critical to the exploitation of signal bias is an understanding of the molecular events coupling ligand binding to intracellular signaling. Activation of class B G protein-coupled receptors is driven by interaction of the peptide N terminus with the receptor core. To understand how this drives signaling, we have used advanced analytical methods that enable separation of effects on pathway-specific signaling from those that modify agonist affinity and mapped the functional consequence of receptor modification onto three-dimensional models of a receptor-ligand complex. This yields molecular insights into the initiation of receptor activation and the mechanistic basis for biased agonism. Our data reveal that peptide agonists can engage different elements of the receptor extracellular face to achieve effector coupling and biased signaling providing a foundation for rational design of biased agonists.

Detection and quantification of allosteric modulation of endogenous m4 muscarinic acetylcholine receptor using impedance-based label-free technology in a neuronal cell line.

Allosteric modulators of G protein-coupled receptors have the potential to achieve greater receptor subtype selectivity compared with ligands targeting the orthosteric site of this receptor family. However, the high attrition rate in GPCR drug discovery programs has highlighted the need to better characterize lead compounds in terms of their allosteric action, as well as the signals they elicit. Recently, the use of label-free technologies has been proposed as an approach to overcome some limitations of endpoint-based assays and detect global changes in the ligand-stimulated cell. In this study, we assessed the ability of an impedance-based label-free technology, xCELLigence, to detect allosteric modulation in a neuronal cell line natively expressing rodent M4 muscarinic acetylcholine receptors. We were able to demonstrate that positive allosteric modulation of the endogenous M4 muscarinic acetylcholine receptor can be detected using this technology. Importantly, the allosteric parameters estimated from the label-free approach are comparable to those estimated from endpoint-based assays.

Recent advances in understanding GLP-1R (glucagon-like peptide-1 receptor) function.

Type 2 diabetes is a major global health problem and there is ongoing research for new treatments to manage the disease. The GLP-1R (glucagon-like peptide-1 receptor) controls the physiological response to the incretin peptide, GLP-1, and is currently a major target for the development of therapeutics owing to the broad range of potential beneficial effects in Type 2 diabetes. These include promotion of glucose-dependent insulin secretion, increased insulin biosynthesis, preservation of ß-cell mass, improved peripheral insulin sensitivity and promotion of weight loss. Despite this, our understanding of GLP-1R function is still limited, with the desired spectrum of GLP-1R-mediated signalling yet to be determined. We review the current understanding of GLP-1R function, in particular, highlighting recent contributions in the field on allosteric modulation, probe-dependence and ligand-directed signal bias and how these behaviours may influence future drug development.

Comportamiento de la disolución de aceclofenaco-PVP coprecipitados / Dissolution behaviour of aceclofenac-PVP coprecipitates

Objetivo: El objetivo de esta investigación fue estudiar el efecto del PVP en la disolución in vitro del aceclofenaco en coprecipitados. Material y métodos: Se prepararon diferentes coprecipitados de aceclofenaco con distintas cargas de droga y se llevaron a cabo los estudios in vitro de disolución de la droga pura, mezclas físicas y coprecipitados. Resultados: Los coprecipitados de aceclofenaco con PVP mostraron un considerable incremento de la tasa de disolución en comparación con las mezclas físicas y la droga pura en HCl 0,1 N y tampón fosfato con pH 7,4. Los coprecipitados con proporción 1:2 mostraron una tasa máxima de disolución en comparación con otras proporciones. La naturaleza amorfa de la droga en coprecipitados fue confirmada con microscopia electrónica de barrido así cómo el descenso de la entalpia de fusión de los coprecipitados con respecto a la droga pura. Los estudios de espectrometría FT-IR y calorimetría diferencial de barrido indicaron que no hubo interacción entre el aceclofenaco y el PVP en estado sólido. La mejora de la disolución se atribuyó al descenso de la cristalinidad y humedad de la droga, la formación del eutéctico y el efecto solubilizante del soporte de los coprecipitados de aceclofenaco. Conclusión: La disolución del aceclofenaco puede ser mejorada con el uso de los soportes hidrófílicos como el PVP(AU)

Aim: The objective of the present investigation was to study the effect of PVP on in vitro dissolution of aceclofenac from coprecipitates. Materials and Methods: Aceclofenac coprecipitates (CP) with different drug loadings were prepared and in vitro dissolution studies of pure drug, physical mixtures and coprecipitates were carried out. Results: Coprecipitates of aceclofenac with PVP showed considerable increase in the dissolution rate in comparison with physical mixture and pure drug in 0.1 N HCl, pH1.2 and phosphate buffer, pH, 7.4. Coprecipitates in 1:2 ratio showed maximum dissolution rate in comparison to other ratios. Amorphous nature of the drug in coprecipitates was confirmed by scanning electron microscopy and a decrease in enthalpy of drug melting in coprecipitates compared to the pure drug. FT-IR spectroscopy and differential scanning calorimetry studies indicated no interaction between aceclofenac and PVP in coprecipitates in solid state. Dissolution enhancement was attributed to decreased crystallinity of the drug and to the wetting, eutectic formation and solubilizing effect of the carrier from the coprecipitates of aceclofenac. Conclusion: dissolution of aceclofenac can be enhanced by the use of hydrophilic carriers like PVP(AU)

Dissolution behavior of ß-cyclodextrin molecular inclusion complexes of aceclofenac.

The objective of the present investigation was to study the effect of ß-cyclodextrin (ß-CD) on the in vitro dissolution of aceclofenac (AF) from molecular inclusion complexes. Aceclofenac molecular inclusion complexes in 1:1 and 1:2 M ratio were prepared using a kneading method. The in vitro dissolution of pure drug, physical mixtures, and cyclodextrin inclusion complexes was carried out. Molecular inclusion complexes of AF with ß-CD showed a considerable increase in the dissolution rate in comparison with the physical mixture and pure drug in 0.1 N HCl, pH 1.2, and phosphate buffer, pH 7.4. Inclusion complexes with a 1:2 M ratio showed the maximum dissolution rate in comparison to other ratios. Fourier transform infrared spectroscopy and differential scanning calorimetry studies indicated no interaction between AF and ß-CD in complexes in solid state. Molecular modeling results indicated the relative energetic stability of the ß-CD dimer-AF complex as compared to ß-CD monomer-AF. Dissolution enhancement was attributed to the formation of water soluble inclusion complexes with ß-CD. The in vitro release from all the formulations was best described by first-order kinetics (R(2) = 0.9826 and 0.9938 in 0.1 N HCl and phosphate buffer, respectively) followed by the Higuchi release model (R(2) = 0.9542 and 0.9686 in 0.1 N HCl and phosphate buffer, respectively). In conclusion, the dissolution of AF can be enhanced by the use of a hydrophilic carrier like ß-CD.

Minocycline attenuates the development of diabetic neuropathic pain: possible anti-inflammatory and anti-oxidant mechanisms.

Painful neuropathy, a common complication of diabetes mellitus is characterized by allodynia and hyperalgesia. Recent studies emphasized on the role of non-neuronal cells, particularly microglia in the development of neuronal hypersensitivity. The purpose of the present study is to evaluate the effect of minocyline, a selective inhibitor of microglial activation to define the role of neuroimmune activation in experimental diabetic neuropathy. Cold allodynia and thermal and chemical hyperalgesia were assessed and the markers of inflammation and oxidative and nitrosative stress were estimated in streptozotocin-induced diabetic rats. Chronic administration of minocycline (40 and 80 mg/kg, i.p.) for 2 weeks started 2 weeks after diabetes induction attenuated the development of diabetic neuropathy as compared to diabetic control animals. In addition, minocyline treatment reduced the levels of interleukin-1ß and tumor necrosis factor-α, lipid peroxidation, nitrite and also improved antioxidant defense in spinal cords of diabetic rats as compared to diabetic control animals. In contrast, minocycline (80 mg/kg, per se) had no effect on any of these behavioral and biochemical parameters assessed in age-matched control animals. The results of the present study strongly suggest that activated microglia are involved in the development of experimental diabetic neuropathy and minocycline exerted its effect probably by inhibition of neuroimmune activation of microglia. In addition, the beneficial effects of minocycline are partly mediated by its anti-inflammatory effect by reducing the levels of proinflammatory cytokines and in part by modulating oxidative and nitrosative stress in the spinal cord that might be involved in attenuating the development of behavioral hypersensitivity in diabetic rats.

Aceclofenac topical dosage forms: in vitro and in vivo characterization.

Aceclofenac is a new generation non-steroidal anti-inflammatory drug showing effective anti-inflammatory and analgesic properties. It is available in the form of tablets of 100 mg. Importance of aceclofenac as a NSAID has inspired development of topical dosage forms. This mode of administration may help avoid typical side effects associated with oral administration of NSAIDs, which have led to its withdrawal. Furthermore, aceclofenac topical dosage forms can be used as a supplement to oral therapy for better treatment of conditions such as arthritis. Ointments, creams, and gels containing 1% (m/m) aceclofenac have been prepared. They were tested for physical appearance, pH, spreadability, extrudability, drug content uniformity, in vitro diffusion and in vitro permeation. Gels prepared using Carbopol 940 (AF2, AF3) and macrogol bases (AF7) were selected after the analysis of the results. They were evaluated for acute skin irritancy, anti-inflammatory and analgesic effects using the carrageenan-induced thermal hyperalgesia and paw edema method. AF2 was shown to be significantly (p < 0.05) more effective in inhibiting hyperalgesia associated with inflammation, compared to AF3 and AF7. Hence, AF2 may be suggested as an alternative to oral preparations.

Evaluation of extemporaneously manufactured topical gels containing aceclofenac on inflammation and hyperalgesia in rats.

The systemic use of non-steroidal anti-inflammatory drugs (NSAIDs) which act by inhibiting cyclooxygenase (COX) is severely hampered by gastric and peptic ulcers. The topical delivery of NSAIDs has the advantages of avoiding gastric and peptic ulcers and delivering the drug to the inflammation site. Importance of aceclofenac as a new generational NSAID has inspired the development of topical dosage forms. This mode of administration may help to avoid typical side effects of NSAIDs associated with oral and systemic administration such as gastric irritation, particularly diarrhoea, nausea, abdominal pain and flatulence. The aim of this study was to formulate topical gel containing 1% of aceclofenac in carbopol and PEG base and to evaluate it for analgesic and antiinflammatory activity using carrageenan-induced thermal hyperalgesia and paw oedema in rats. Carrageenan administration into the hind paw produced a significant inflammation associated with hyperalgesia as shown by decreased rat paw withdrawal latency in response to a thermal stimulus (47+/-0.5 degrees C) 4 h after carrageenan injection. Topical application of AF1 significantly attenuated the development of hypersensitivity to thermal stimulus as compared to control (P<0.05) and other formulation treated groups (P<0.05). All the AF semisolid formulations, when applied topically 2 h before carrageenan administration, inhibited paw edema in a timedependent manner with maximum percent edema inhibition of 80.33+/-2.52 achieved with AF1 after 5 h of carrageenan administration However, topical application of AF2 markedly prevented the development of edema as compared to other formulation (AF2 and AF3) treated groups (P<0.05). Among all the semisolid formulations, Carbopol gel base was found to be most suitable dermatological base for aceclofenac.

Investigation of enhancement of solubility of norfloxacin beta-cyclodextrin in presence of acidic solubilizing additives.

The present study is aimed at improving the solubility of a poorly water-soluble drug, norfloxacin by incorporating solubilizing additives such as ascorbic acid and citric acid into the beta-cyclodextrin complexes. Norfloxacin, being amphoteric in nature, exhibits a higher solubility at pH below 4 and above 8. Addition of substances like ascorbic acid and citric acid in beta-cyclodextrin complexes reduces the pH of the immediate microenvironment of the drug below pH 4. In the present work, beta-cyclodextrin complexes of norfloxacin were prepared along with solubilizing additives such as citric acid and ascorbic acid in various proportion and the dissolution profile was performed in both HCl buffer, pH 1.2 and phosphate buffer, pH 7.4. The results have shown an enhanced dissolution rate in both media. DSC and IR spectral studies performed on the solid complexes have shown that there is no interaction of the drug with the additives and beta-cyclodextrin. Disc diffusion studies have shown larger diameters of zone of inhibition indicating a greater diffusivity of the drug into the agar medium.