Effect of 5-trifluoromethyl-4,5-dihydro-1H-pyrazoles on chronic inflammatory pain model in rats

PCW-1001, a Novel Pyrazole Derivative, Exerts Antitumor and Radio-Sensitizing Activities in Breast Cancer

As pyrazole and its derivatives have a wide range of biological activities, including anticancer activity, the design of novel pyrazole derivatives has emerged as an important research field. This study describes a novel pyrazole derivative that exerts antitumor and radiosensitizing activities in breast cancer both in vitro and in vivo. We synthesized a novel pyrazole compound N,N-dimethyl-N’-(3-(1-(4-(trifluoromethyl)phenyl)-1H-pyrazol-4-yl)phenyl)azanesulfonamide (PCW-1001) and showed that it inhibited several oncogenic properties of breast cancer both in vitro and in vivo. PCW-1001 induced apoptosis in several breast cancer cell lines. Transcriptome analysis of PCW-1001-treated cells showed that it regulates genes involved in the DNA damage response, suggesting its potential use in radiotherapy. Indeed, PCW-1001 enhanced the radiation sensitivity of breast cancer cells by modulating the expression of DNA damage response genes. Therefore, our data describe a novel pyrazole compound, PCW-1001, with antitumor and radiosensitizer activities in breast cancer.

Preparation of New Spiropyrazole, Pyrazole and Hydantoin Derivatives and Investigation of Their Antioxidant and Antibacterial Activities

In this study, the synthesis of new spiropyrazoles, pyrazole and hydantoin heterocycles is reported by three component reactions of parabanic acids, hydrazine derivatives, and phenacyl bromides in the presence of triphenylphosphine as a nucleophile and triethylamine as a base in good to high yields (69-91 %). Evaluation of the synthesized compounds revealed a good to excellent antioxidant activities (37.6-96.2 %) using DPPH inhibitory potency. Among these compounds, hydantoin derivatives displayed higher antioxidant activities (93.7-96.2 %) comparing with spiropyrazoles and pyrazoles. The obtained results showed that Cl and Br substituents on the phenyl ring increased antioxidant activities of the related heterocycles. The antibacterial activities of the synthesized compounds were examined against two Gram-negative (Escherichia coli and Pseudomonas aeruginosa) and two Gram-positive (Staphylococcus aureus and Bacillus subtilis) bacteria. Among the synthesized heterocycles, 2-[1,3-dimethyl-2,5-dioxo-4-(2-oxo-2-phenylethyl)imidazolidin-4-yl]hydrazine-1-carbothioamide exhibited the excellent antibacterial activity against both Gram-positive and Gram-negative bacteria.

Synthesis of pyrazoline fatty chain derivatives and its effects on melanoma cells

Skin cancer is the most common type of cancer in Brazil, representing 30% of all cases. Among these, melanoma represents only 3% of malignant neoplasms; however, it is the most serious and has a high capacity for metastasis. For this reason, it is extremely important to identify more efficient compounds and treatments that stop or decrease the proliferation of melanoma, even in its more advanced stages. This work reports the synthesis and biological evaluation of two homologous series of pyrazoline fatty chain derivatives as potent antitumoral agents in the melanoma B16F10 cell line. Cells were treated with pyrazoline fatty chain compounds (3, 30, 300, and 3000 μM) for 0, 24, 48, and 72 h. Decreased cell viability was observed when using most compounds at different concentrations and times. The structure-activity relationship (SAR) between antitumoral activity and the number of carbons and lipophilicity, as well as the oxygen-sulfur bioisosteric exchange, was evaluated. Among the tested derivatives, the lipophilic compounds 5-hydroxy-5-(trifluoromethyl)-3-undecyl-4,5-dihydro-1H-pyrazole-1-carboxamide (2d) and 5-hydroxy-5-(trifluoromethyl)-3-undecyl-4,5-dihydro-1H-pyrazole-1-thiocarboxamide (3d) showed the best results in the B16F10 cell line, as they produced the best cell viability decrease effects. The presence of fatty unbranched undecyl chain in the molecular structure appears to be important for its antimelanoma properties.

Hydroalcoholic extract of leaf of Arachis hypogaea L. (Fabaceae) did not induce toxic effects in the repeated-dose toxicity study in rats

Arachis hypogaea L. (peanut) leaf is traditionally used for the treatment of insomnia in Asia. However, studies describing the safety and toxicity profile for this plant preparation are limited. Thus, the goal of this study was to investigate the toxicity of peanut leaf hydroalcoholic extract (PLHE) repeated treatment. The extract was administered orally (100, 300 or 1000 mg/kg) in male and female Wistar rats for 28 days (OECD guideline 407). PLHE treatment did not cause mortality or weight variation in the animals. Also, there was no alteration on locomotor activity (open field test), motor coordination (rotarod test), or anxiety behaviour (elevated plus-maze test). Male rats had a reduction in relative liver weight (100 mg/kg) and an increase in total kidney weight (1000 mg/kg), but there was no change in biochemical and haematological parameters after PLHE treatment. Free extracellular double-stranded DNA (dsDNA) levels was also evaluated, but PLHE treatment did not increase this parameter in rat organs. Also, the dose of 1000 mg/kg of PLHE significantly increased the total thiols in the liver of females compared with the control animals. Thus, PLHE did not induce toxicity after repeated exposure for 28 days in rats.

Autophagy-regulating N-heterocycles derivatives as potential anticancer agents

As a double-edged sword, autophagy in cancer cells could either suppress or promote tumorigenesis. Nowadays, more and more natural compounds with autophagy-regulating activities exhibit therapeutic effects against various cancers. N-Heterocycle derivatives plays an important role for discovery new drugs. In this review, we summarize and classify 116 N-heterocycle derivatives with autophagy-regulating activities in the past decade into 12 classes according to structure characteristics. The structural features, bioactivities, mechanism and problems faced in this field are discussed and reported for the first time. Some of these even exhibited outstanding in vivo antitumor activities, including bisaminoquinoline (3), pancratistatin (8), 10-hydroxyevodiamine (18), lycorine (28), piperine (31) and iridium (III) complex (57), which are potential drug candidates for antitumor therapy.

A novel pseudo six-component synthesis of functionalized pyrazoles in ethanol by cascade reaction

Novel-substituted pyrazoles were synthesized using an aminal-based approach. The key steps in the synthetic strategy involve the formation of 1,1-dihydrazino-2-nitroethylene from hydrazine hydrate with nitro ketene dithioacetal and its reaction with Knoevenagel adduct derived from the corresponding aldehyde and malononitrile in ethanol media. The formation of 5-membered pyrazole ring is confirmed based on the electrostatic surface potential computed by density functional theory. This strategy can provide a concise and eco-friendly route for easy access to the highly substituted pyrazoles derivatives in excellent yields using four simple and readily available building blocks under mild conditions and particularly attractive due to features such as atom economy, high yield and mild condition.

Microwave-assisted one pot three-component synthesis of some novel pyrazole scaffolds as potent anticancer agents

Background

Pyrazoles, thiazoles and 1,3,4-thiadiazoles have been reported to possess various pharmacological activities.

Results

An efficient and a novel approach for the synthesis of some novel pyrazole based-azoles are described via multi-component reaction under controlled microwave heating conditions. The structures of the synthesized compounds were assigned on the basis of elemental analysis, IR, ¹H NMR and mass spectral data. All the synthesized compounds were tested for in vitro activities against two antitumor cell lines, human lung cancer and human hepatocellular carcinoma compared with the employed standard antitumor drug (cisplatin).

Conclusions

All the newly synthesized compounds were evaluated for their anticancer activity against human lung cancer and human hepatocellular carcinoma cell lines using MTT assay. The results obtained exploring the high potency of six of the tested compounds compared with cisplatin. Graphical abstract

Urea/thiourea: efficient, inexpensive and reusable catalysts for the synthesis of pyrazole derivatives with 2-iminothiazolidin-4-one and 2,4-thiazolidinediones under solvent-free conditions

An efficient and green synthesis of pyrazolyl-2,4-thiazolidinediones/pyrazolyl-2-iminothiazolidine-4-ones 7(a-j) has been developed using urea/thiourea as catalyst. Two methods (A and B) have been introduced for the synthesis of these compounds. Method A performed well for the condensation of pyrazole-4-carboxaldehydes 4(a-e) with 2-iminothiazolidin-4-one 5a and with 2,4-thiazolidinedione 5b at 110 [Formula: see text] for 16-20 min to furnish (Z)-5-((1,3-diphenyl-1H-pyrazol-4-yl)methylene)thiazolidine-2,4-diones 7(a-j) in excellent yields. In method B, the pyrazole-4-carboxaldehydes 4(a-e) were condensed with urea/thiourea at 110 [Formula: see text] for 10 min to give key intermediates 6(a-j) which were later condensed with 5a and 5b to afford 7(a-j) via the elimination of urea/thiourea rather than the formation of a Biginelli product. These two protocols are inexpensive, eco-friendly and high yielding to provide the final products. The synthesis of compound 7f.

A Comparative Investigation of the Analgesic Effects of Metamizole and Paracetamol in Rats

BACKGROUND

This study investigated the effects of metamizole and paracetamol on pain and oxidative stress induced by scalpel incision and carrageenan in rats.

MATERIALS AND METHODS

Total of 144 rats were divided into groups of 12 animals. Six groups each were used for scalpel incision and carrageenan tests. Pain was inflicted by applying a scalpel incision or carrageenan. Pain-created groups by scalpel incision received metamizole (SIM) or paracetamol (SIP) at doses of 250 or 500 mg/kg. Pain-created groups by carrageenan received metamizole (CAM) or paracetamol (CAP) at doses of 250 or 500 mg/kg. Analgesic activity was determined by Basile Algesimeter. The COX-2 and MPO gene expressions were determined, and malondialdehyde and tGSH were measured in rat paws.

RESULTS

In the scalpel incision test, pain was reduced in groups of SIM-250 and SIM-500 in the first hour by 65.2% and 91.3%, respectively, and in the third hour by 51.9% and 77.8%, respectively, compared with the SIC group. In SIP-250 and SIP-500 groups, pain was reduced in the first hour by 43% and 74%, respectively, and by 33.4% and 59.3%, respectively, in the third hour compared with the SIC group. In the carrageenan test, in groups CAM-250 and CAM-500, pain was reduced in the first hour by 72.3% and 86.1%, respectively, and by 65.8% and 71.4%, respectively, in the third hour compared with the CCG group. In groups CAP-250 and CAP-500, pain was reduced in the first hour by 52.8% and 69.4%, respectively, and by 28.6% and 25.8%, respectively, in the third hour compared with the CCG group. Metamizole inhibited COX-2 gene expression at a dose of 500 mg/kg in the carrageenan test. At doses of 250 and 500 mg/kg, metamizole reduced COX-2 and MPO gene expressions and oxidative stress induced by scalpel incision or carrageenan. But both doses of paracetamol were unable to suppress that parameters.

CONCLUSIONS

Our results show that metamizole is more effective than paracetamol for treating surgical trauma-related pain, inflammation, and oxidative stress and hence may be a preferential drug to paracetamol.

Novel ibuprofenate- and docusate-based ionic liquids: emergence of antimicrobial activity

Six new ionic-liquid-based active pharmaceutical ingredients (IL-APIs) were prepared and their molecular structures characterized.

Effect of Uncaria tomentosa extract on purinergic enzyme activities in lymphocytes of rats submitted to experimental adjuvant arthritis model

BACKGROUND

Considering that adjuvant arthritis is an experimental model of arthritis widely used for preclinical testing of numerous anti-arthritic agents, which were taken by a large number of patients worldwide, it is of great interest to investigate the therapeutic action of compounds with anti-inflammatory properties, such as Uncaria tomentosa extract. Moreover, there are no studies demonstrating the effect of U. tomentosa on the metabolism of adenine nucleotides published so far. Thus, the purpose of the present study is to investigate the effects of U. tomentosa extract on E-NTPDase and E-ADA activities in lymphocytes of Complete Freund's Adjuvant (CFA) arthritis induced rats.

METHODS

To evaluate the effect of U. tomentosa extract on the activity of E-NTPDase and ADA in lymphocytes, the rats were submitted to an experimental adjuvant arthritis model. Peripheral lymphocytes were isolated and E-NTPDase and E-ADA activities were determined. Data were analyzed by a one- or two-way ANOVA. Post hoc analyses were carried out by the Student-Newman-Keuls (SNK) Multiple Comparison Test.

RESULTS

E-NTPDase activity was increased in arthritic untreated. Arthritic rats which received U. tomentosa extract, presented similar results to the control group. However, results obtained for adenosine hydrolysis by E-ADA were not altered in arthritic rats. U. tomentosa extract did not alter E-NTPDase and E-ADA activity in healthy animals.

CONCLUSIONS

The present investigation supports the hypothesis that the increased E-NTPDase activity verified in arthritic rats might be an attempt to maintain basal levels of ATP and ADP in the extracellular medium, since the arthritis induction causes tissue damage and, consequently, large amounts of ATP are released into this milieu. Also, it highlights the possibility to use U. tomentosa extract as an adjuvant to treat arthritis.

Involvement of the NO/cGMP/KATP pathway in the antinociceptive effect of the new pyrazole 5-(1-(3-fluorophenyl)-1H-pyrazol-4-yl)-2H-tetrazole (LQFM-021)

The pyrazol compounds are known to possess antipyretic, analgesic and anti-inflammatory activities. This study was conducted to investigate the peripheral antinociceptive effect of the pyrazole compound 5-(1-(3-Fluorophenyl)-1H-pyrazol-4-yl)-2H-tetrazole (LQFM-021) and involvement of opioid receptors and of the NO/cGMP/K(ATP) pathway. The oral treatments in mice with LQFM-021 (17, 75 or 300 mg/kg) decreased the number of writhing. In the formalin test, the treatments with LQFM-021 at doses of 15, 30 and 60 mg/kg reduced the licking time at both neurogenic and inflammatory phases of this test. The treatment of the animals with LQFM-021 (30 mg/kg) did not have antinociceptive effects in the tail-flick and hot plate tests. Furthermore, pre-treatment with naloxone (3 mg/kg i.p.), L-name (10 mg/kg i.p.), ODQ (10 mg/kg i.p.) or glibenclamide (3 mg/kg i.p.) antagonized the antinociceptive effect of LQFM-021 in both phases of the formalin test. In addition, it was also demonstrated that the treatments of mice with LQFM-021(15, 30 and 60 mg/kg) did not compromise the motor activity of the animals in the chimney test. Only the highest dose used in the antinociceptive study promoted changes in the open field test and pentobarbital-induced sleep test, thus ruling out possible false positive effects on nociception tests. Our data suggest that the peripheral antinociception effects of the LQFM-021 were mediated through the peripheral opioid receptors with activation of the NO/cGMP/KATP pathway.

Mechanisms involved in abdominal nociception induced by either TRPV1 or TRPA1 stimulation of rat peritoneum

Abdominal pain is a frequent symptom of peritoneal cavity irritation, but little is known about the role of the receptors for irritant substances, transient receptor potential vanilloid 1 (TRPV1) and ankyrin 1 (TRPA1), in this painful condition. Thus, we investigated the abdominal nociception caused by peritoneal stimulation with TRPV1 (capsaicin) and TRPA1 (allyl isothiocyanate, AITC) agonists and their mechanisms in rats. The intraperitoneal (i.p.) injection of either capsaicin or AITC (0.03-10 mg/kg) induced short-term (up to 20 min) and dose-dependent abdominal nociception, and also produced c-fos expression in spinal afferents of the dorsal horn. TRPV1 antagonism prevented (94 ± 4% inhibition) nociception induced by capsaicin but not by AITC. In contrast, the TRPA1 antagonism almost abolished AITC-induced nociception (95 ± 2% inhibition) without altering the capsaicin response. Moreover, nociception induced by either capsaicin or AITC was reduced by the desensitisation of TRPV1-positive sensory fibres with resiniferatoxin (73 ± 18 and 76 ± 15% inhibitions, respectively) and by the NK1 receptor antagonist aprepitant (56 ± 5 and 53 ± 8% inhibitions, respectively). Likewise, the i.p. injections of capsaicin or AITC increased the content of substance P in the peritoneal fluid. Nevertheless, neither the mast cell membrane stabiliser cromoglycate, nor the H1 antagonist promethazine, nor depletion of peritoneal macrophages affected abdominal nociception induced either by capsaicin or AITC. Accordingly, neither capsaicin nor AITC increased the histamine content in the peritoneal fluid or provoked peritoneal mast cell degranulation in vitro. Collectively, our findings suggest that TRPV1 and TRPA1 stimulation in the peritoneum produces abdominal nociception that is mediated by sensory fibres activation.

The antinociceptive and anti-inflammatory effects of the crude extract of Jatropha isabellei in a rat gout model

ETHNOPHARMACOLOGICAL RELEVANCE

Jatropha isabellei Müll Arg. (Euphorbiaceae) is a medicinal plant that has been used in South American folk medicine for the treatment of arthritic diseases, particularly gout.

AIM OF THE STUDY

This study was designed to verify the antinociceptive, anti-inflammatory and hypouricemic potential of Jatropha isabellei.

MATERIALS AND METHODS

Rats were orally administered with the crude extract (100-300 mg/kg) or a fraction that is rich in alkaloids (0.15 mg/kg) of Jatropha isabellei. An intra-articular (i.a.) injection of 50 μl of monosodium urate (MSU) crystals (1.25mg/site) was used to generate the gout model to assess the effect of the treatment on nociception (thermal and mechanical hyperalgesia) and inflammation (oedema and neutrophil infiltration). The effect of Jatropha isabellei on the serum levels of uric acid was evaluated in a model of hyperuricaemia induced by the intraperitoneal injection of potassium oxonate (250 mg/kg). The side effects were analysed using an open-field test, gastric lesion assessment and by measuring the levels of the ALT and AST enzymes.

RESULTS

Our study demonstrated that the crude extract of Jatropha isabellei and a fraction rich in alkaloids were able to prevent the thermal hyperalgesia, mechanical allodynia, oedema and neutrophil infiltration induced by intra-articular MSU injection in rats. On the other hand, treatment with Jatropha isabellei did not alter the uric acid levels increased by potassium oxonate in the hyperuricaemia model. In addition, Jatropha isabellei did not induce gastric lesions or liver damage and did not alter spontaneous locomotor activity.

CONCLUSION

The crude extract of Jatropha isabellei and its fraction rich in alkaloid presents antinociceptive and anti-inflammatory effects in a rat gout model, similar to that observed after treatment with colchicine, supporting the traditional use of this plant in gouty patients.

Synthesis of modified steroids as a novel class of non-ulcerogenic, anti-inflammatory and anti-nociceptive agents

The identification of compounds able to treat both pain and inflammation with limited side effects is one of the prominent goals in biomedical research. This study aimed at the synthesis of new modified steroids with structures justifying non-ulcerogenic, anti-inflammatory and anti-nociceptive activities. The steroid derivatives were synthesized via straightforward and efficient methods and their structures were established based on the analytical and spectral data. The in vivo anti-inflammatory, anti-nociceptive and anti-ulcerogenic activities of some of these compounds were studied. The newly synthesized compounds 8b, 19b, 24 and 31a showed anti-inflammatory, anti-nociceptive and anti-ulcerogenic activity with various intensities. Oedema was significantly reduced by either dose 25 or 50 mg/kg of all tested compounds at 3 and 4 h post-carrageenan. Compound 19b was the most effective in alleviating thermal pain. The analgesic activity of either dose of the compounds 8b, 24, 31a as well as the high dose 19b was significantly higher than that for indomethacin (IND). Gastric mucosal lesions caused in the rats by the administration of 96% EtOH and IND were inhibited by all tested compounds administered at (50 mg/kg) dose in the study.