Design, Synthesis, and Pharmacological Evaluation of Novel Tacrine Derivatives as Multi-target ANTI-Alzheimer's Agents In Rat Models

BACKGROUND

Alzheimer's disease is a progressive neurodegenerative disorder for which no curative drugs are available and treatment available is just palliative.

OBJECTIVES

Current research focused on design of Tacrine-Flavone hybrids as multitargeted cholinesterase and monoamine oxidase B inhibitors.

METHODS

A total of 10 Tacrine- Flavone hybrids were designed, synthesized and characterized. The in vitro neurotoxicity and hepatotoxicity of the synthesized compounds determined using SHSY5Y cell line and HEPG2 cell line. One most active compound (AF1) with least toxicity in in vitro studies was chosen for in vivo studies. Acute and subacute toxicity of the novel compound AF1 conducted on Wistar rats according to OECD guideline 423 and 407. The LD50 value of the novel compound calculated according to Finney's method using Probit analysis. Anti-Alzheimer's activity studies conducted on male Wistar rats. Behavioral studies conducted and AChE and MAO-B activity determined in rat brain.

RESULTS AND DISCUSSION

All the compounds exhibited good inhibitory effect on MAO B and AChE. The neurotoxicity studies of the active compound AF1 did not show toxicity up to 100μg. The hepatotoxicity study of the most active compound AF1, showed the compound to be safe up to 200μg. The LD 50 value of the novel compound after a single oral administration was found to be 64 mg/kg bodyweight in rats. Subacute toxicity studies did not show any remarkable toxicity in the vital organs up to 40 mg/kg. Activity studies showed comparable results with standard at 20 mg/kg.

CONCLUSION

The results showed that the novel Tacrine-Flavone hybrids are multitarget-directed ligands, which are safe and active compared to tacrine and can be a promising lead molecule for further study.

Autistic Effects of Nootropic Drug Brahmi against Propionic Acid-induced Behavior and Memory Impairment in Rat Model

Aims: To evaluate the hydro alcoholic effect of Brahmi against propionic acid-induced behavior and memory impairment in rat model. Study Design: This includes preclinical study on Sprague Dawley rats in which Propionic acid induced and evaluation of in vivo and in vitro models were performed. Place and Duration of Study: Department of Pharmacology, C L Baid Metha College of Pharmacy Jan 2019 to June 2021. Methodology: We include a total of 27 adult Sprague Dawley Rats and induced propionic acid intracerebroventricular route to induce autism. Drug treatment using hydro alcoholic extract of Bacopa monnieri was given in 250 mg/kg and 500 mg/kg was compared with negative group rats and control groups. In vivo parameters like Actophotometer and marble burying test was done, In vitro analysis of Serotonin and Glutamate was estimated in the above treated groups. Results: The locomotor activity of rat was recorded individually for each animal using Actophotometer. HAEBM (250 mg/kg and 500 mg/kg) treated rat produced an increase in the level of significance (P<0.0001) on day one. In marble burying test Rats were located for thirty minutes in a standard cage covered with 5 cm depth of wood chip bedding with ten marbles evenly spaced. HAEBM (250 mg/kg and 500 mg/kg) showed significant (P<0.001) level of burying when compared to group-II rats (P<0.01). In this research study 5HT level showed a significant (P<0.001) increase in Group III, Group IV when compared with group-II (P<0.01). Glutamate is an excitatory Neurotransmitter. Group II showed significant increase (P<0.001) in the level of Glutamate but on drug treated groups III and IV shows decrease in concentration of glutamate. Conclusion: The present study findings showed that the hydro alcoholic root extract of brahmi possesses neuroprotective activity with significant nootropic effects. The hydro alcoholic root extract of Bacopa monnieri. L showed the presence of various Gabapentin and flavonoids phenols may be the reason for its neuroprotection and memory improvement effects.

Neuroprotective effects of Clitoria ternatea L. against propionic acid-induced behavior and memory impairment in autistic rat model

Background

Autism spectrum disorder is primarily characterized by complex behavioral and altered memory as a consequence of neuronal development abnormalities. The treatment of autism is highly challenging because of the lack of knowledge about its exact etiopathology. In the Ayurvedic system of medicine, there are group of plants named ‘Medhya drugs' because of their ability to improve brain- and neuron-related activities like learning and memory. Clitoria ternatea L. is one of the listed ‘Medhya drugs’ which have been proved for its memory enhancement effects; in the present study, the ethanolic root extract of Clitoria ternatea L. was evaluated for its neuroprotective ability against propionic acid-induced memory and behavior impairments in an autistic rat model. The variation in behavior and memory were investigated by utilizing different procedures like rat elevated plus maze and novel object recognition test. In vitro assays for the estimations of glutamate and serotonin were also performed in isolated rat brain tissue homogenate.

Results

The object recognition and elevated plus maze test were showed the promising effects of Clitoria ternatea L. ethanolic root extract against the propionic acid-induced autism. In this study, the propionic acid infused rats (Group II) fail to recognize and explore the novel object compared to Group I (infused with phosphate-buffered saline) animals; extract treatment at two different doses (250 mg/kg and 500 mg/kg) (Groups III & IV, respectively) prevented these damage significantly (p < 0.001) so that extract-treated groups showed significant improvement in novel object recognition in a dose-dependent manner. Similarly, the effect of extract treatment on learning and memory of rats was investigated using transfer latency as a parameter for acquisition and retention of memory process on elevated plus maze; this further proved the memory enhancement ability of Clitoria ternatea L. Extract treatment also significantly reduced the concentration of different neurotransmitters like serotonin and glutamate in rat brain homogenate (Groups III &IV) in a dose-dependent manner as compared with the Group II.

Conclusion

The ethanolic root extract of Clitoria ternatea L. proved to be effective against propionic acid-induced memory and behavior impairments in an autistic rat model.

Microwave hydrothermal synthesis of α-MnMoO4 nanorods for high electrochemical performance supercapacitors

Pristine α-MnMoO₄ nanorods were facilely prepared via co-precipitation (Cp) and microwave hydrothermal (MH) methods. X-ray diffraction (XRD) patterns showed pure monoclinic crystalline phase α-MnMoO₄ for the heat treated powder at 500 °C. Fourier Transform Infrared (FTIR) spectra showed that the chemical bond structure of α-MnMoO₄ corresponds to the strong vibrational modes of Mo–O–Mo, Mo–O and Mo Created by potrace 1.16, written by Peter Selinger 2001-2019 ]]> O. Raman spectra showed the structural bonding and crystalline nature of α-MnMoO₄. Field Emission Scanning Electron Microscope (FE-SEM) images exposed the nanorod shape of the α-MnMoO₄ powder, with diameters of ∼200 nm and lengths of ∼1.6 μm. Electrochemical studies of the Cp- and MH-MnMoO₄ nanorods with 2 M NaOH as the electrolyte showed specific capacitances of 143 F g⁻¹ and 551 F g⁻¹, respectively, at a 1 A g⁻¹ constant discharge current density. Cyclic voltammetric (CV) studies of the MH-MnMoO₄ nanorods at various scan rates revealed the presence of redox pairs, suggesting a pseudocapacitive nature. The structural stability at different current densities demonstrated the high rate performances and good reversible capacity retention of the calcined MH-MnMoO₄ nanorods. A cycling life stability study of MH-MnMoO₄ demonstrated a good capacity retention of 89% of the initial specific capacitance at 5 A g⁻¹ after 1000 cycles.

Pristine α-MnMoO₄ nanorods were facilely prepared via co-precipitation (Cp) and microwave hydrothermal (MH) methods.

Ultrathin spinel LiMn2O4 nanowires as high power cathode materials for Li-ion batteries

Ultrathin LiMn(2)O(4) nanowires with cubic spinel structure were synthesized by using a solvothermal reaction to produce α-MnO(2) nanowire followed by solid-state lithiation. LiMn(2)O(4) nanowires have diameters less than 10 nm and lengths of several micrometers. Galvanostatic battery testing showed that LiMn(2)O(4) nanowires deliver 100 and 78 mAh/g at very high rate (60C and 150C, respectively) in a larger potential window with very good capacity retention and outstanding structural stability. Such performances are due to both the favorable morphology and the high crystallinity of nanowires.

Spinel LiMn2O4 nanorods as lithium ion battery cathodes

Spinel LiMn2O4 is a low-cost, environmentally friendly, and highly abundant material for Li-ion battery cathodes. Here, we report the hydrothermal synthesis of single-crystalline beta-MnO2 nanorods and their chemical conversion into free-standing single-crystalline LiMn2O4 nanorods using a simple solid-state reaction. The LiMn2O4 nanorods have an average diameter of 130 nm and length of 1.2 microm. Galvanostatic battery testing showed that LiMn2O4 nanorods have a high charge storage capacity at high power rates compared with commercially available powders. More than 85% of the initial charge storage capacity was maintained for over 100 cycles. The structural transformation studies showed that the Li ions intercalated into the cubic phase of the LiMn2O4 with a small change of lattice parameter, followed by the coexistence of two nearly identical cubic phases in the potential range of 3.5 to 4.3 V.