Current Molecular Pharmacology - Volume 11, Issue 2, 2018

Background: MicroRNAs (miRNAs) are small non-coding RNAs able to regulate gene expression at multiple levels. They are detected in tissues, blood, and other body fluids with high stability and have a recognized role in maintaining of tissue homeostasis. Aberrant expression profile of miRNAs has been observed in several diseases, primarily cancer. As a consequence, the analysis of miRNA signature has recognized diagnostic and prognostic role in human diseases, and the development of miRNA-based therapies is currently under investigation. Recently, emerging but controversial data have revealed the possibility that diet-derived miRNAs might be transferred from food in living organisms to regulate gene expression. Thus, exogenous dietderived miRNAs might substantially contribute to the pool of circulating miRNAs to preserve tissue homeostasis and health status in recipient's organisms, opening new perspectives for diet in heath and disease. Objective: This brief review aims at summarizing data concerning the recognized role of miRNAs as biomarkers, drugs and therapeutic targets in cancer and the detection and the activity of diet-derived miRNAs in both physiological and pathological conditions. Conclusion: MiRNAs have emerged as crucial molecules in anticancer therapies and diet-derived miRNAs might contribute to the pool of circulating miRNAs to preserve, maintain or restore health.

Background: New psychoactive substances (NPS), often referred to as “legal highs” or “designer drugs”, are derivatives and analogues of existing psychoactive drugs that are introduced in the recreational market to circumvent existing legislation on drugs of abuse. Objective: This systematic review aims to gather the state of the art regarding chemical, molecular pharmacology and toxicological information of opioid class of NPS. Methods: Chemical, pharmacological, toxicological and clinical effects of opioid class of NPS were searched in books and in PubMed (U.S. National Library of Medicine) without a limiting period. Results: Within this class, fentanyl analogues are among the most frequently abused and pose several clinical concerns and therefore will be thoroughly discussed. Other opioid sub-categories of NPS frequently misused include AH-7921, MT-45, U-47700, U-50488, desomorphine, mitragynine, tramadol, tapentadol, salvinorin A and its analogue herkinorin. Conclusion: Due to inefficient monitoring techniques, as well as limited knowledge regarding the acute and long-term effects of opioids NPS, further clinical and forensic toxicological studies are required.

Background: Diabetes mellitus (DM) is a major health problem with an increasing global prevalence. It is usually associated with an imbalance between pro-oxidant mechanisms and antioxidant defenses, contributing to oxidative-stress, and this leads to an increased susceptibility to endothelial dysfunction, atherosclerosis, insulin-resistance and impaired-pancreatic β-cell function. Objective: We have assessed the Prooxidant-antioxidant balance (PAB) and anti-hemolytic effect of Thuja orientalis L using the PAB assay and the analysis of hematological markers. Methods: The antioxidant and anti-hemolytic activity of Thuja orientalis was evaluated using the PAB assay and the inhibition of RBC hemolysis using the hydrogen peroxide hemolysis test. The percentage of anti-hemolysis was calculated from the ratio of the measurements (A-B)/B00. Results: Our results showed that the antioxidant effect of Thuja orientalis L. was greater in water than in ethyl-acetate, ethanol and methanol extract, respectively. We also observed its anti-hemolytic effect, which was higher in water, than in ethyl-acetate, methanol and ethanol extract, respectively. In particular our data showed that the H2O2-induced RBC hemolysis was inhibited in a dose-dependent manner. Conclusion: we demonstrated the antioxidant and anti-hemolytic effect of Thuja orientalis L. extracts in human serum and RBC, showing its potential property of reducing free radicals supporting further investigations to assess its functional role in larger samples size and in vivo models, as a potential antioxidant agent.

Background and Objective: The development of the tyrosine kinase inhibitor Imatinib (IM) represents a milestone in CML (Chronic Myeloid Leukemia) treatment. However, it is not curative and patients develop IM resistance. IM resistance has been previously correlated with the emergence of drug-resistant LIC/LSC (Leukemia Initiating Cell/Leukemia Stem Cell) and increased nuclear catenin levels and enhanced Wnt signaling. It has been demonstrated previously that drug resistant CML LIC/LSC can be safely eliminated both in vitro and in vivo via disruption of the CBP/catenin interaction, utilizing the highly biochemically selective small molecule CBP/catenin antagonist ICG- 001. Methods: Here, we utilized an in vitro IM selection of primary CML patients' samples to identify drug-resistant LIC/LSC populations. In this report, we characterized the drug-resistant CML LIC/LSC population using FACS, Smartchip qPCR and colony assays to analyze cell surface markers, transcriptomics and function. Results: As opposed to previous characterization of the CML leukemic stem cell population as being either CD34+CD38- or CD34+CD38+, the in vitro selected Imatinib resistant (IM-R) CML LSC population was consistently CD34-CD38-. In Long-Term Culture Initiating Cell assay (LTC-IC, a surrogate assay for long term repopulating stem cells), our results suggest that the CBP/catenin antagonist ICG- 001 sensitizes LIC/LSC to IM treatment by forced differentiative elimination of the CML LIC/LSC population. Conclusion: In vitro selected IM resistant cells are negative for both CD34 and CD38 by FACS analysis. These cells acquire CD34/CD38 expression after co-culture with stromal cells. CBP/catenin antagonist ICG-001 facilitates IM function in eliminating these cells.

Background and Objective: The objective of present study is to explore multiple effects of the compound MG17 and relate them to achieve better therapeutic potential against neuroinflammation related disorders. We examined whether our compound is acting through regulating neuroinflammatory mediators. Methods: We have done some preliminary behavioral studies to shortlist the derivatives using rodent models of peripheral nerve injury in our earlier publication and now we extended our screening studies to explore the test compounds efficacy on other related peripheral neurological disorders such as Streptozotocin- induced diabetic peripheral neuropathy (DPN) and methyl mercury (MeHg) induced neurodegeneration in rats. Pro-inflammatory cytokines interleukin-1β (IL-1β), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) were quantified with RT-qPCR studies and histopathology studies were performed taking tissue samples from MeHg induced neurodegeneration rats. The effect of MG17 was assessed on local and acute inflammation through carrageenan-induced rat paw edema model. Results: We observed the reduction in nociceptive responses in DPN rats. Pain threshold was reduced greater than 50% in various pain assessment modules. Upregulated pro-inflammatory cytokines which are thought to have a prominent role in neuroinflammation was controlled near to normal level quantified by RT-PCR studies. However, MG17 was able to regulate IL-6 and TNF-α but not IL-1β. Conclusion: Our results clearly suggest the beneficial potential of compound MG17 through inhibition of pro-inflammatory cytokines upregulation. MG17 could be an intriguing therapeutic approach in diabetesrelated neuro-pathophysiological conditions.

Background and Objective: The high degree of malignancy of tumour cells is linked to alterations of many physiological parameters like the intracellular pH (pHi). The pHi in cancer cell line is regulated by the carbonic anhydrase IX (CA IX). The main enzymatic function of the CA IX protein is to catalyze the hydration of carbon dioxide into bicarbonate ions and protons. CA IX expression in a broad variety of human tumor tissues is associated with resistance to therapy. One promising approach is to target the mechanism regulating pH homeostasis with carbonic anhydrase inhibitors like sulfamides and coumarins families. Methods: In this work we have evaluated effects of umbelliferone and acetazolamide in a high resistant melanoma cell line (A375) over expressing CA IX. Impact of effective doses of CA IX inhibitors on apoptosis, intracellular pH (pHi), CA IX protein expression and functionality have been investigated. Determination of effective doses of CA IX inhibitors was performed with MTT tests. We also evaluated sensitization effect of CA inhibitors to conventional therapy as dacarbazin. Results: We have used 10 μM Umbelliferone and 100 μM Acetazolamide as effective doses for 24h. These doses did not induce any apoptosis. Umbelliferone induced a more important pHi decrease than Acetalozamide from 7.3 to 7.08 and to 7.12 respectively, and a more important decrease in s-CA IX fraction showing a decrease in CA IX function. We have demonstrated that pre-treatment with umbelliferone or acetazolamide allows a better dacarbazin efficacy. Conclusion: We have demonstrated that inhibitors modify intracellular pH and CAIX functionality and sensitize cells to Dacarbazin. These original results complete the knowledge on Sulfamide CA IX inhibitors, bring new insights about Coumarin compounds and offer new possibilities in high grade melanoma therapies.

Background: Modafinil (MOD) is a waking-promoting compound that is used for the treatment of sleep disorders such as sleepiness and narcolepsy. Despite its efficiency, there are missing pieces of evidence regarding the mechanism of action of MOD at molecular level. For example, current data have demonstrated that MOD induces alertness by activating several wake-related neurotransmitter receptors, including dopamine 1 (D1) receptor. Nevertheless, an intriguing point highlights that MOD might be activating intracellular elements bounded to D1 receptor, such as cAMP response element-binding (CREB) or mitogen-activated protein kinase (MAP-K) expression. Objective: We tested whether administrations of MOD induce phosphorylation of either CREB or MAPK in wake-related brain areas, such as dorsomedial hypothalamic nucleus (DM) and tuberomammillary nucleus (TMN) in rats. Methods: Rats that received a systemic injection of MOD (30 or 150 mg/Kg) were sacrificed and brains were processed for immunohistochemical analysis of phospho-CREB or phospho-MAP-K staining. Results: MOD dose-dependently enhanced phospho-CREB and phospho-MAP-K immunoreactivity in DM and TMN. Moreover, the statistical analysis revealed that MOD increased the number of phospho- CREB and phospho-MAP-K immunoreactive neurons in these brain areas studied. Conclusion: These findings provide significative insights regarding the possible molecular mechanism of action of MOD engaging the activation of phospho-CREB and phospho-MAP-K in wake-linked brain areas. Indeed, further studies are required to fully understand the molecular mechanism of action of MOD.

Background: The ubiquitous nuclear receptor PPARβ/δ is increasingly being studied in regards to numerous diseases including diabetes following on the finding that PPARβ/δ agonist GW0742 controls Type 1 Diabetes in rats. Studies have shown that GW0742 has off target, non- PPARβ/δ effects in the cell although there are some key questions that remain to be addressed in respect to the significance of this control on vascular tone. Methods: Using isometric organ baths, rat aorta rings were exposed to ROCK inhibitors and the changes in contraction and dilation measured. Results: Our data shows that the PPARβ/δ agonist GW0742 (10^-7M) inhibits contractile responses to U46619 and phenylephrine, and that these responses are similar in normal and Streptozotocin (STZ) diabetic rat aorta. ROCK inhibitors Fasudil and Y27632 significantly reduced GW0742 mediated dilation of naïve rat aorta, but Fasudil had no effect on GW0742 dilation in STZ diabetic rat aorta. In contrast, STZ diabetic rat aorta pre-contracted with high [K⁺] Krebs lacked a dilatory response to GW0742, which taken together indicates that the mechanism of action of GW0742 mediated dilation changes in the diabetic state compared to non-diabetic state. Conclusion: This is the first direct evidence demonstrating the non- PPARβ/δ effect of GW0742 on contraction is irrespective to the diabetic state, and that GW0742 has the potential to induce vasodilation via multiple off-target mechanisms.

Background and Objective: Imipenem has played an important role in the treatment of broad-spectrum bacterial infection. However, nephrotoxicity due to imipenem remains an important clinical challenge. The aim of this study is to test the hypothesis stating that N-acetyl-L-cysteine (NAC) and atorvastatin possess a nephroprotective effect against imipenem-induced nephrotoxicity. Methods: Adult Sprague Dawley rats were randomly assigned into six groups (n=8-10 rats/group; total n=55). The groups were (control, imipenem only, NAC only, atorvastatin only, NAC with imipenem, and atorvastatin with imipenem). Rats were treated with NAC or atorvastatin for six weeks. Serum and urinary creatinine and blood urea nitrogen (BUN) levels were measured. Additionally, urinary protein, urinary glucose and kidney levels of oxidants/antioxidants biomarkers were measured. Results: The administration of 300mg/kg/d imipenem induced nephrotoxicity as indicated by the significant reduction of serum creatinine, serum BUN and calculated GFR in the imipenem only-treated group compared to the control. These effects of imipenem were normalized by either NAC or atorvastatin. Moreover, the levels of catalase, superoxide dismutase and glutathione peroxidase were significantly reduced in the imipenem group. However, pre-administration of NAC and atorvastatin neutralized the levels of these enzymes and protected against imipenem-induced nephrotoxicity. Conclusion: We concluded that the pre-administration of either NAC or atorvastatin protects the kidneys from imipenem-induced nephrotoxicity, through their antioxidant effects.

Background and Objective: Gamma-decanolactone (GD) is a monoterpene effective against seizures induced by pentylenetetrazole. The mechanism of action of GD is likely to be via glutamate antagonism. GD also inhibits intracellular reactive oxygen species (ROS) generation and the lipopolysaccharide-induced expression of inducible nitric oxide synthase (iNOS) and tumor necrosis factor-alpha (TNF-α) in vitro. Considering the neuropharmacological profile of GD studied so far, we investigated the effect of intraperitoneal administration of GD 100 and 300 mg/kg on pilocarpine (PIL)-induced status epilepticus (SE) in mice. Methods: GD was administered 30 min before PIL. Behavioral (latency to first seizure and the percentage of clonic forelimb seizures), biochemical, and oxidative stress parameters were evaluated. DNA damage in the cerebral cortex of mice was assessed using the comet assay and mutagenic activity of GD was evaluated using Salmonella/microsome assay in TA100, TA98, TA97a, TA102, and TA1535 strains, with and without metabolic activation (S9 mix). Results: The behavioral results showed that only the latency to the first clonic seizure increased in the groups treated with GD 300 mg/kg, but not when the animals received GD 100 mg/kg. Both GD doses were able to increase superoxide dismutase and catalase activities, inducing a decrease in ROS and nitrite production and in DNA damage in the cerebral cortex. GD was not able to induce base pair substitution and frameshift mutations in the absence or in the presence of metabolic activation. Conclusion: These findings demonstrate that GD does not improve behavioral parameters in the PIL model, but it was able to protect seizure-related oxidative stress and DNA damage in mice, without inducing gene mutations.