Anxiolytic properties of new chemical entity, 5TIO1

Bio-guided isolation of anti-leishmanial natural products from Diospyros gracilescens L. (Ebenaceae)

BACKGROUND

Plants represent an intricate and innovative source for the discovery of novel therapeutic remedies for the management of infectious diseases. The current study aimed at discovering new inhibitors of Leishmania spp., using anti-leishmanial activity-guided investigation approach of extracts from Diospyros gracilescens Gürke (1911) (Ebenaceae), targeting the extracellular (promastigotes) and intracellular (amastigotes) forms of Leishmania donovani.

METHODS

The plant extracts were prepared by maceration using H20: EtOH (30:70, v/v) and further fractionated using a bio-guided approach. Different concentrations of D. gracilescens extracts, fractions and isolated compounds were tested in triplicate against L. donovani promastigotes and amastigotes in vitro. The antileishmanial potency and cytotoxicity on RAW 264.7 cells were determined using the resazurin colorimetric assay. The time kill kinetic profile of the most active sample was also investigated. The structures of all compounds were elucidated on the basis of extensive spectroscopic analyses, including 1D and 2D NMR, and HR-ESI-MS and by comparison of their data with those reported in the literature.

RESULTS

The hydroethanolic crude extract of D. gracilescens trunk showed the most potent antileishmanial activity (IC50 = 5.84 μg/mL). Further fractionation of this extract led to four (4) fractions of which, the hexane fraction showed the most potent activity (IC50 = 0.79 μg/mL), and seven (07) compounds that exhibited moderate potency (IC50 = 13.69-241.71 μM) against L. donovani. Compound 1-deoxyinositol (7) inhibited the promastigote and amastigote forms of L. donovani with IC50 values of 241.71 μM and 120 μM respectively and also showed the highest selectivity against L. donovani promastigotes (SI > 5.04). To the best of our knowledge, the antileishmanial activity of this compound is being reported here for the first time. The promising hexane fraction showed significant inhibition of parasites growth at different concentrations, but with no evidence of cidal effect over an exposure period of 120 h.

CONCLUSIONS

The results obtained indicated that the hydroethanolic extract from the D. gracilescens trunk and the derived hexane fraction have very potent inhibitory effect on cultivated promastigotes and amastigotes of L. donovani parasite. The isolated compounds showed a lesser extent of potency and selectivity. However, further structure-activity-relationship studies of 1-deoxyinositol could lead to more potent and selective hit derivatives of interest for detailed drug discovery program against visceral leishmaniasis.

Synthesis of Tetrahydrobenzo[b]thiophene-3-carbohydrazide Derivatives as Potential Anti-cancer Agents and Pim-1 Kinase Inhibitors

BACKGROUND

Tetrahydrobenzo[b]thiophene derivatives are well known to be biologically active compounds and many of them occupy a wide range of anticancer agent drugs.

OBJECTIVE

One of the main aim of this work was to synthesize target molecules not only possessing anti-tumor activities but also kinase inhibitors. To achieve this goal, our strategy was to synthesize a series of 4,5,6,7- tetrahydrobenzo[b]thiophene-3-carbohydrazide derivatives using cyclohexan-1,4-dione and cyanoacetylhydrazine to give the 2-amino-6-oxo-4,5,6,7-tetrahydrobenzo[b]thiophene-3-carbohydrazide (3) as the key starting material for many heterocyclization reactions.

METHODS

Compound 3 was reacted with some aryldiazonium salts and the products were cyclised when reacted with either malononitrile or ethyl cyanoacetate. Thiazole derivatives were also obtained through the reaction of compound 3 with phenylisothiocyanate followed by heterocyclization with α-halocarbonyl derivatives. Pyrazole, triazole and pyran derivatives were also obtained.

RESULTS

The compounds obtained in this work were evaluated for their in-vitro cytotoxic activity against c-Met kinase, and the six typical cancer cell lines (A549, H460, HT-29, MKN-45, U87MG, and SMMC-7721). The results of anti-proliferative evaluations and c-Met kinase, Pim-1 kinse inhibitions revealed that some compounds showed high activities.

CONCLUSION

The most promising compounds 5b, 5c, 7c, 7d, 11b, 14a, 16b, 18b, 19, 21a, 23c, 23d and 23i against c-Met kinase were further investigated against the five tyrosin kinases (c-Kit, Flt-3, VEGFR-2, EGFR, and PDGFR). Compounds 5b, 5c, 7d, 7e, 11b, 11c, 16c, 16d, 18c, 19, 23e, 23k and 23m were selected to examine their Pim-1 kinase inhibitions activity where compounds 7d, 7e, 11b, 11c, 16d, 18c and 23e showed high activities. All of the synthesized compounds have no impaired effect toward the VERO normal cell line.

Early Celastrol Administration Prevents Ketamine-Induced Psychotic-Like Behavioral Dysfunctions, Oxidative Stress and IL-10 Reduction in The Cerebellum of Adult Mice

Administration of subanesthetic doses of ketamine during brain maturation represents a tool to mimic an early insult to the central nervous system (CNS). The cerebellum is a key player in psychosis pathogenesis, to which oxidative stress also contributes. Here, we investigated the impact of early celastrol administration on behavioral dysfunctions in adult mice that had received ketamine (30 mg/kg i.p.) at postnatal days (PNDs) 7, 9, and 11. Cerebellar levels of 8-hydroxydeoxyguanosine (8-OHdG), NADPH oxidase (NOX) 1 and NOX2, as well as of the calcium-binding protein parvalbumin (PV), were also assessed. Furthermore, celastrol effects on ketamine-induced alterations of proinflammatory (TNF-α, IL-6 and IL-1β) and anti-inflammatory (IL-10) cytokines in this brain region were evaluated. Early celastrol administration prevented ketamine-induced discrimination index decrease at adulthood. The same was found for locomotor activity elevations and increased close following and allogrooming, whereas no beneficial effects on sniffing impairment were detected. Ketamine increased 8-OHdG in the cerebellum of adult mice, which was also prevented by early celastrol injection. Cerebellar NOX1 levels were enhanced at adulthood following postnatal ketamine exposure. Celastrol per se induced NOX1 decrease in the cerebellum. This effect was more significant in animals that were early administered with ketamine. NOX2 levels did not change. Ketamine administration did not affect PV amount in the cerebellum. TNF-α levels were enhanced in ketamine-treated animals; however, this was not prevented by early celastrol administration. While no changes were observed for IL-6 and IL-1β levels, ketamine determined a reduction of cerebellar IL-10 expression, which was prevented by early celastrol treatment. Our results suggest that NOX inhibition during brain maturation prevents the development of psychotic-like behavioral dysfunctions, as well as the increased cerebellar oxidative stress and the reduction of IL-10 in the same brain region following ketamine exposure in postnatal life. This opens novel neuroprotective opportunities against early detrimental insults occurring during brain development.

Heterocyclization of 2-Arylidenecyclohexan-1,3-dione: Synthesis of Thiophene, Thiazole, and Isoxazole Derivatives with Potential Antitumor Activities

BACKGROUND

Thiophene, thiazole, and isoxazole derivatives are present in a wide range of natural and synthetic compounds with heterogeneous pharmacological activity. Due to their structural diversity, they are some of the most versatile classes of compounds for anticancer drug design and discovery.

OBJECTIVE

Thiophene, thiazole, and isoxazole derivatives were herein designed with a dual purpose: as antiproliferative agents and kinase inhibitors.

METHODS

The test compounds were synthesized in moderate to high yields through a simple methodology. Tetrahydrobenzo[b]thiophen-5-one derivatives 5a-f were prepared from the reaction of 2-arylidencyclohexan- 1,3-dione 3a-c with elemental sulfur and either of malononitrile (4a) or ethyl cyanoacetate (4b) in 1,4-dioxan in the presence of triethylamine. Compounds 5a,b were used for the synthesis of thiophene, thiazole, and isoxazole derivatives through their reactions with different chemical reagents.

RESULTS

Antiproliferative evaluations, c-Met kinase, and Pim-1 kinase inhibitions were performed where some compounds revealed high activities. In all cases, antiproliferative activity and the kinase inhibitions were performed against six cancer cell lines and five tyrosine kinases, respectively. Where the most cytotoxic compounds were 3c, 5d, and 16c with IC50's 0.29, 0.68, and 0.42μM, respectively, against the A549 cell line.

CONCLUSION

The anti-proliferative activities of the newly synthesized compounds were evaluated against the six cancer cell lines (A549, HT-29, MKN-45, U87MG, SMMC-7721, and H460). The most potent compounds toward the cancer cell lines (3a, 3c, 5d, 7c, 11c, 16a, and 16c) were further investigated towards the five tyrosine kinases (c-kit, FIT-3, VEGFR-2, EGFR, and PDGFR). Compounds 3c, 5d, and 16c were selected for testing of their inhibition for the Pim-1 kinase due to their anti-proliferation activities against the cancer cell lines and their high activities against the tyrosine kinases.

GABA and 5-HT Systems Are Involved in the Anxiolytic Effect of Gan-Mai-Da-Zao Decoction

The Gan-Mai-Da-Zao (GMDZ) decoction is one of the most famous Chinese medicine prescriptions to treat emotional diseases in China. Here we examined the anxiolytic-like effects of the GMDZ decoction in mice. The mice were orally administered with GMDZ decoction (1, 2, and 4 g/kg, respectively) for 7 days, diazepam (2 mg/kg, p.o.) and buspirone (5 mg/kg, p.o.) were used as positive controls. Then, elevated plus maze (EPM) test, light/dark box (LDB) test, and marble burying (MB) test, open field (OF) test and rota-rod test were performed. We found that GMDZ treatment (2 and 4 g/kg) significantly increased the percentage of open arm entries and time spent on the open arms in EPM as compared to the control. GMDZ treatment also significantly increased the time spent in the light box and the number of light box entries in LDB and reduced the number of marbles buried in MB. Similarly to those observed with diazepam and buspirone. In contrast, GMDZ did not affect the locomotor activity in the OF and motor coordination in the rota-rod test. Furthermore, the anxiolytic-like effects induced by GMDZ were inhibited by the γ-aminobutyric acid-A (GABA_A) receptor antagonist flumazenil and 5-hydroxytryptamine-1A (5-HT_1A) receptor antagonist WAY-100635. These results showed that GMDZ possesses anxiolytic-like effects in animal models, and its mechanism of action might be modulated by 5-HT_1A and GABA_A receptors.

Uses of Cyclohexan-1,4-dione for the Synthesis of 2-Amino-4,5-dihydrobenzo[b]thiophen-6(7H)-one Derivatives with Anti-proliferative and Pim-1 Kinase Activities

The reaction of cyclohexan-1,4-dione with elemental sulfur and any of the 2-cyano-N-arylacetamide derivatives 2a-c gave the 2-amino-4,5-dihydrobenzo[b]thiophen-6(7H)-one derivatives 3a-c to be used in some heterocyclization reactions. The multicomponent reactions of any of compounds 3a-c with aromatic aldehydes 6a-c and either of malononitrile or ethylcyanoacetate gave the 5,9-dihydro-4H-thieno[2,3-f]chromene derivatives 9a-r, respectively. The anti-proliferative evaluation of the newly synthesized compounds against the six cancer cell lines A549, HT-29, MKN-45, U87MG, SMMC-7721 and H460 showed that the nine compounds 3c, 5c, 9e, 9h, 9i, 9j, 9l, 9q, 11e and 13e with highest cytotoxcity. Toxicity of these compounds against shrimp larvae revealed that compounds 3c, 9j, 9q, and 13e showed no toxicity against the tested organisms. The c-Met kinase inhibition of the most potent compounds showed that compounds 9j, 9q, 10e, 12e and 13e have the highest activities. Compounds 9j, 9l, 9q and 11e showed high activity towards tyrosine kinases. Moreover, compounds 9j, 9q and 13e showed the highest inhibitor activity towards Pim-1 kinase.

Platonia insignis Mart., a Brazilian Amazonian Plant: The Stem Barks Extract and Its Main Constituent Lupeol Exert Antileishmanial Effects Involving Macrophages Activation

Platonia insignis Mart., popularly known as “bacurizeiro,” is used in traditional medical practices based on its diverse biological properties. This study was aimed at evaluating the antileishmanial effects of the ethanol extract (EtOH-Ext), hexane fraction (Hex-F), and its main isolated Lupeol obtained from stem barks of P. insignis against Leishmania (Leishmania) amazonensis, as well as their cytotoxicity and possible mechanisms of action. The EtOH-Ext, Hex-F, and Lupeol inhibited the growth of L. amazonensis promastigote forms at IC₅₀ of 174.24, 45.23, and 39.06 µg/mL, respectively, as well as L. amazonensis axenic amastigote forms at IC₅₀ of 40.58, 35.87, and 44.10 µg/mL, respectively. The mean cytotoxic concentrations for macrophages (CC₅₀) were higher than those for amastigotes (341.95, 71.65, and 144.0 µg/mL, resp.), indicating a selective cytotoxicity towards the parasite rather than the macrophages. Interestingly, all treatments promoted antileishmanial effect against macrophage-internalized amastigotes at concentrations lower than CC₅₀. Furthermore, increases of lysosomal volume of macrophages treated with EtOH-Ext, Hex-F, and Lupeol were observed. On the other hand, only Lupeol stimulated increase of phagocytic capability of macrophages, suggesting this compound might be characterized as the biomarker for the antileishmanial effect of P. insignis stem bark, as well as the involvement of immunomodulatory mechanisms in this effect.

Concordance and incongruence in preclinical anxiety models: Systematic review and meta-analyses

Rodent defense behavior assays have been widely used as preclinical models of anxiety to study possibly therapeutic anxiety-reducing interventions. However, some proposed anxiety-modulating factors - genes, drugs and stressors - have had discordant effects across different studies. To reconcile the effect sizes of purported anxiety factors, we conducted systematic review and meta-analyses of the literature on ten anxiety-linked interventions, as examined in the elevated plus maze, open field and light-dark box assays. Diazepam, 5-HT1A receptor gene knockout and overexpression, SERT gene knockout and overexpression, pain, restraint, social isolation, corticotropin-releasing hormone and Crhr1 were selected for review. Eight interventions had statistically significant effects on rodent anxiety, while Htr1a overexpression and Crh knockout did not. Evidence for publication bias was found in the diazepam, Htt knockout, and social isolation literatures. The Htr1a and Crhr1 results indicate a disconnect between preclinical science and clinical research. Furthermore, the meta-analytic data confirmed that genetic SERT anxiety effects were paradoxical in the context of the clinical use of SERT inhibitors to reduce anxiety.

Wen-dan decoction improves negative emotions in sleep-deprived rats by regulating orexin-a and leptin expression

Wen-Dan Decoction (WDD), a formula of traditional Chinese medicine, has been clinically used for treating insomnia for approximately 800 years. However, the therapeutic mechanisms of WDD remain unclear. Orexin-A plays a key role in the sleep-wake cycle, while leptin function is opposite to orexin-A. Thus, orexin-A and leptin may be important factors in sleep disorders. In this study, 48 rats were divided into control, model, WDD-treated, and diazepam-treated groups. The model of insomnia was produced by sleep deprivation (SD) for 14 days. The expressions of orexin-A, leptin, and their receptors in blood serum, prefrontal cortex, and hypothalamus were detected by enzyme-linked immunosorbent assay, immunohistochemistry, and real time PCR. Open field tests showed that SD increased both crossing movement (Cm) and rearing-movement (Rm) times. Orexin-A and leptin levels in blood serum increased after SD but decreased in brain compared to the control group. mRNA expressions of orexin receptor 1 and leptin receptor after SD were decreased in the prefrontal cortex but were increased in hypothalamus. WDD treatment normalized the behavior and upregulated orexin-A, leptin, orexin receptor 1 and leptin receptor in brain. The findings suggest that WDD treatment may regulate SD-induced negative emotions by regulating orexin-A and leptin expression.

Is oxidative stress in mice brain regions diminished by 2-[(2,6-dichlorobenzylidene)amino]-5,6-dihydro-4H-cyclopenta[b]thiophene-3-carbonitrile?

2-[(2,6-Dichlorobenzylidene)amino]-5,6-dihydro-4H-cyclopenta[b]thiophene-3-carbonitrile, 5TIO1, is a new 2-aminothiophene derivative with promising pharmacological activities. The aim of this study was to evaluate its antioxidant activity in different areas of mice central nervous system. Male Swiss adult mice were intraperitoneally treated with Tween 80 dissolved in 0.9% saline (control group) and 5TIO1 (0.1, 1, and 10 mg kg(-1)). Brain homogenates-hippocampus, striatum, frontal cortex, and cerebellum-were obtained after 24 h of observation. Superoxide dismutase and catalase activities, lipid peroxidation and nitrite content were measured using spectrophotometrical methods. To clarify the 5TIO1's mechanism on oxidative stress, western blot analysis of superoxide dismutase and catalase was also performed. 5TIO1 decreased lipid peroxidation and nitrite content in all brain areas and increased the antioxidant enzymatic activities, specially, in cerebellum. The data of Western blot analysis did not demonstrate evidence of the upregulation of these enzymes after the administration of this compound. Our findings strongly support that 5TIO1 can protect the brain against neuronal damages regularly observed during neuropathologies.