Design, synthesis, and pharmacological evaluation of novel 1,2,4-triazol-3-amine derivatives as potential agonists of GABAA subtype receptors with anticonvulsant and hypnotic effects

Synthesis and In Vitro α-Amylase and α-Glucosidase Dual Inhibitory Activities of 1,2,4-Triazole-Bearing bis-Hydrazone Derivatives and Their Molecular Docking Study

There is an increasing prevalence of diabetes mellitus throughout the world, and new compounds are necessary to combat this. The currently available antidiabetic therapies are long-term complicated and side effect-prone, and this has led to a demand for more affordable and more effective methods of tackling diabetes. Research is focused on finding alternative medicinal remedies with significant antidiabetic efficacy as well as low adverse effects. In this research work, we have focused our efforts to synthesize a series of 1,2,4-triazole-based bis-hydrazones and evaluated their antidiabetic properties. In addition, the precise structures of the synthesized derivatives were confirmed with the help of various spectroscopic techniques including ¹H-NMR, ¹³C-NMR, and HREI-MS. To find the antidiabetic potentials of the synthesized compounds, in vitro α-glucosidase and α-amylase inhibitory activities were characterized using acarbose as the reference standard. From structure-activity (SAR) analysis, it was confirmed that any variation found in inhibitory activities of both α-amylase and α-glucosidase enzymes was due to the different substitution patterns of the substituent(s) at variable positions of both aryl rings A and B. The results of the antidiabetic assay were very encouraging and showed moderate to good inhibitory potentials with IC₅₀ values ranging from 0.70 ± 0.05 to 35.70 ± 0.80 μM (α-amylase) and 1.10 ± 0.05 to 30.40 ± 0.70 μM (α-glucosidase). The obtained results were compared to those of the standard acarbose drug (IC₅₀ = 10.30 ± 0.20 μM for α-amylase and IC₅₀ = 9.80 ± 0.20 μM for α-glucosidase). Specifically, compounds 17, 15, and 16 were found to be significantly active with IC₅₀ values of 0.70 ± 0.05, 1.80 ± 0.10, and 2.10 ± 0.10 μM against α-amylase and 1.10 ± 0.05, 1.50 ± 0.05, and 1.70 ± 0.10 μM against α-glucosidase, respectively. These findings reveal that triazole-containing bis-hydrazones act as α-amylase and α-glucosidase inhibitors, which help develop novel therapeutics for treating type-II diabetes mellitus and can act as lead molecules in drug discovery as potential antidiabetic agents.

In silico molecular modeling, neuro-behavioral profile, and toxicity assessment of the essential oil of Ferula gummosa Boiss. as an anti-seizure agent

ETHNOPHARMACOLOGICAL RELEVANCE

Ferula gummosa Boiss., known in Persian as "Baridje," belongs to the Apiaceae family. All parts of this plant, especially the root, contain galbanum. Galbanum, the oleo-gum resin of F. gummosa, is one of the essential traditional herbal medicines in Iran, which is used as a tonic for epilepsy and chorea, memory enhancement, gastrointestinal diseases, and wound healing.

AIM OF THE STUDY

We investigated the toxicity, anticonvulsant effects, and molecular modeling of the essential oil (EO) distilled from the oleo-gum resin of F. gummosa.

MATERIALS AND METHODS

Gas chromatography-mass spectrometry was used to identify the EO components. The cytotoxicity of EO on HepG2 cell lines was assessed by the MTT method. Male mice were arranged as follows: negative control groups (sunflower oil (10 ml/kg, i.p.) or saline (10 ml/kg, p.o.)), EO groups (0.5, 1, 1.5, and 2.5 ml/kg, p.o.), and positive control groups (ethosuximide (150 mg/kg, p.o.) or diazepam (1.0 or 2 mg/kg, i.p.)). The motor coordination and neurotoxicity of EO were studied using the rota-rod test. Open-field, novel object recognition, and passive avoidance learning tests were used to investigate the effect of EO on locomotor activity and memory function. An acute pentylenetetrazole-induced seizure model was utilized to evaluate the anticonvulsant properties of the EO. The interaction of the EO main components with the GABA_A receptor was investigated by coarse-grained molecular dynamics simulations.

RESULTS

β-pinene, sabinene, α-pinene, and ρ-cymene were the main components of EO. The IC₅₀ of the EO at 24, 48, and 72 h was found to be 59.90, 12.96, and 3.93 μl/ml, respectively. No adverse effects were observed in memory, motor coordination, and locomotor activity in mice treated with EO. Administration of EO (1, 1.5, and 2.5 ml/kg) improved survival rates in mice receiving pentylenetetrazole (PTZ; to induce an epileptic seizure). Sabinene was able to bind to the binding site of benzodiazepines at the GABA_A receptor.

CONCLUSIONS

Acute treatment with the EO of F. gummosa caused antiepileptic effects and could effectively increase the survival rate in PTZ-treated mice with no significant toxicity.

New quinoline-based triazole hybrid analogs as effective inhibitors of α-amylase and α-glucosidase: Preparation, in vitro evaluation, and molecular docking along with in silico studies

The 7-quinolinyl-bearing triazole analogs were synthesized (1d–19d) and further assessed in vitro for their inhibitory profile against α-amylase andα-glucosidase. The entire analogs showed a diverse range of activities having IC₅₀ values between 0.80 ± 0.05 µM to 40.20 ± 0.70 µM (α-amylase) and 1.20 ± 0.10 µM to 43.30 ± 0.80 µM (α-glucosidase) under the positive control of acarbose (IC₅₀ = 10.30 ± 0.20 µM) (IC₅₀ = 9.80 ± 0.20 µM) as the standard drug. Among the synthesized scaffolds, seven scaffolds 12d, 10d, 8d, 9d, 11d, 5d, and 14d showed excellent α-amylase and α-glucosidase inhibitory potentials with IC₅₀ values of 4.30 ± 0.10, 2.10 ± 0.10, 1.80 ± 0.10, 1.50 ± 0.10, 0.80 ± 0.05, 5.30 ± 0.20, and 6.40 ± 0.30 µM (against α-amylase) and 3.30 ± 0.10, 2.40 ± 0.10, 1.20 ± 0.10, 1.90 ± 0.10, 8.80 ± 0.20, 7.30 ± 0.40, and 5.50 ± 0.10 µM (against α-glucosidase), respectively, while the remaining 12 scaffolds 19d, 8d, 17d, 16d, 15d, 7d, 4d, 3d, 1d, 2d, 13d and 6 d showed less α-amylase and α-glucosidase inhibitory potentials than standard acarbose but still found to be active. Structure–activity connection studies also showed that scaffolds with electron-withdrawing groups like -Cl, -NO₂, and -F linked to the phenyl ring had higher inhibitory potentials for -amylase and -glucosidase than scaffolds with -OCH₃, -Br, and -CH₃ moieties. In order to better understand their binding sites, the powerful scaffolds 11d and 9d were also subjected to molecular docking studies. The results showed that these powerful analogs provide a number of important interactions with the active sites of both of these targeted enzymes, including conventional hydrogen bonding, pi–pi stacking, pi–sulfur, pi–anion, pi–pi, pi–sigma, T-shaped, and halogen (fluorine). Furthermore, various techniques (spectroscopic), including 1H, ¹³C-NMR, and HREI-MS mass, were used to explore the correct structure of newly afforded hybrid scaffolds based on quinoline-bearing triazole ring.

Sedative-hypnotic, anxiolytic and possible side effects of Salvia limbata C. A. Mey. Extracts and the effects of phenological stage and altitude on the rosmarinic acid content

ETHNOPHARMACOLOGICAL RELEVANCE

Salvia limbata C. A. Mey. (Persian name: Maryam Goli-e-labeh dar) has been used for treating central nervous disorders such as insomnia, anxiety and depression in Persian traditional medicine. S. limbata is known for its pharmacological activities which could be at least in a part, upon the presence of rosmarinic acid (RA). However, the sedative-hypnotic effect, anxiolytic activity, possible side effects, and the mechanism of action of S. limbata extract has not yet been examined.

AIM OF THE STUDY

In the current study the sedative-hypnotic effect, anxiolytic activity, possible side effects, and the mechanism of action of S. limbata extracts were evaluated. Besides, the effects of altitude and phenological stage on the RA content of S. limbata were investigated.

MATERIALS AND METHODS

Sedative-hypnotic and anxiolytic effects were evaluated through the pentobarbital induced loss of righting reflex test and open field test, respectively. Flumazenil was used to reveal the mechanism of action. Possible side effects were investigated in the passive avoidance and grip strength tests. Besides, the effects of altitude and phenological stage (vegetative, flowering, and seed setting) on the RA content of S. limbata were evaluated using reversed-phase high-performance liquid chromatography (RP-HPLC).

RESULTS

Following behavioral tests, sedative-hypnotic and anxiolytic effects were observed. Since the observed effects were reversed by flumazenil and no side effect on the memory and muscle strength was reported, modulation of the α1-containing GABA-A receptors could be proposed as one of the involved mechanisms. According to the RP-HPLC analysis, harvesting S. limbata in the vegetative stage at the altitude of 2500 m led to the highest content of RA (8.67 ± 0.13 mg/g dry matter). Among different extract of the plant samples collected in the vegetative stage at the altitude of 2500 m, the hydroalcoholic extract showed the highest rosmarinic acid content.

CONCLUSION

The obtained results help to find the optimum situation to gain the highest content of RA as well as the pharmacological activity that could be economically important for the pharmaceutical industries.

Chalcones reverse the anxiety and convulsive behavior of adult zebrafish

In the treatment of anxiety and seizures, drugs of the benzodiazepine (BZD) class are used, which act on the Central Nervous System (CNS) through the neurotransmitter gamma-aminobutyric acid (GABA). Flavonoids modulate GABAA receptors. The aim of this study was to evaluate the anxiolytic and anticonvulsant effects of synthetic chalcones and their mechanisms of action via the GABAergic system, using adult zebrafish (ZFa). The animals were treated with chalcones (4.0 or 20 or 40 mg/kg; 20 µL; i.p) and submitted to the open field and 96 h toxicity test. Chalcones that cause locomotor alteration were evaluated in the light and dark anxiolytic test. The same doses of chalcones were evaluated in the anticonvulsant test. The lowest effective dose was chosen to assess the possible involvement in the GABAA receptor by blocking the flumazenil (fmz) antagonist. No chalcone was toxic and altered ZFa's locomotion. All chalcones had anxiolytic and anticonvulsant effects, mainly chalcones 1, where all doses showed effects in both tests. These effects were blocked by Fmz (antagonist GABAA), where it shows evidence of the performance of these activities of the GABA system. Therefore, this study demonstrated in relation to structure-activity, that the position of the substituents is important in the intensity of activities and that the absence of toxicity and the action of these compounds in the CNS, shows the pharmacological potential of these molecules, and, therefore, the insights are designed for the development of new drugs.