PASS assisted prediction and pharmacological evaluation of hesperidin against scopolamine induced amnesia in mice

Unveiling potent Schiff base derivatives with selective xanthine oxidase inhibition: In silico and in vitro approach

This research describes the synthesis by an environmentally-friendly method, microwave irradiation, development and analysis of three novel and one previously identified Schiff base derivative as a potential inhibitor of bovine xanthine oxidase (BXO), a key enzyme implicated in the progression of gout. Meticulous experimentation revealed that these compounds (10, 9, 4, and 7) have noteworthy inhibitory effects on BXO, with IC50 values ranging from 149.56 µM to 263.60 µM, indicating their good efficacy compared to that of the standard control. The validation of these results was further enhanced through comprehensive in silico studies, which revealed the pivotal interactions between the inhibitors and the catalytic sites of BXO, with a particular emphasis on the imine group (-C = N-) functionalities. Intriguingly, the compounds exhibiting the highest inhibition rates also showcase advantageous ADMET profiles, alongside encouraging initial assessments via PASS, hinting at their broad-spectrum potential. The implications of these findings are profound, suggesting that these Schiff base derivatives not only offer a new vantage point for the inhibition of BXO but also hold considerable promise as innovative therapeutic agents in the management and treatment of gout, marking a significant leap forward in the quest for more effective gout interventions.

The multifactorial role of vanillin in amelioration of aluminium chloride and D-galactose induced Alzheimer's disease in mice

The onset and progression of Alzheimer's disease (AD) are influenced by a variety of factors. These include oxidative stress, overexpression of acetylcholinesterase (AChE), depletion of acetylcholine levels, increased beta-secretase mediated conversion of Amyloid Precursor Protein (APP) to Amyloid Beta (Abeta), accumulation of Abeta oligomers, decrease in Brain Derived Neurotrophic factor (BDNF) and accelerated neuronal apoptosis due to elevated levels of caspase-3. The currently available therapeutic approaches are inadequate in affecting these pathological processes except maybe the overexpression of AChE (AChE inhibitors like donepezil, rivastigmine). There is an urgent need to develop disease modifying pharmacotherapeutic interventions which have appreciable safety and cost effectiveness. From previously reported in vitro studies and a preliminary assessment of neuroprotective effect in scopolamine induced dementia-like cognitive impairment in mice, vanillin has been used as the compound of interest in the present study. Vanillin, a phytoconstituent, has been used in humans, safely, in the form of a flavouring agent for various foods, beverages, and cosmetics. Owing to its chemical nature i.e. being a phenolic aldehyde, it has an additional antioxidant property that is congruent to the desirable characteristics that are sought in a suitable novel anti-AD agent. In our study, vanillin proved to have a nootropic effect in healthy Swiss albino mice as well as an ameliorative effect in aluminium chloride and D-galactose induced AD model in mice. Apart from tackling oxidative stress, vanillin was found to reduce the levels of AChE, beta secretase, caspase-3, enhance degradation of Abeta plaques and elevate the levels of BDNF, in cortical and hippocampal regions. Vanillin is a promising candidate for being incorporated into the search for safe and effective anti-AD molecules. However, further research might be needed to warrant its application clinically.

Neuroprotective Potentials of Flavonoids: Experimental Studies and Mechanisms of Action

Neurological and neurodegenerative diseases, particularly those related to aging, are on the rise, but drug therapies are rarely curative. Functional disorders and the organic degeneration of nervous tissue often have complex causes, in which phenomena of oxidative stress, inflammation and cytotoxicity are intertwined. For these reasons, the search for natural substances that can slow down or counteract these pathologies has increased rapidly over the last two decades. In this paper, studies on the neuroprotective effects of flavonoids (especially the two most widely used, hesperidin and quercetin) on animal models of depression, neurotoxicity, Alzheimer's disease (AD) and Parkinson's disease are reviewed. The literature on these topics amounts to a few hundred publications on in vitro and in vivo models (notably in rodents) and provides us with a very detailed picture of the action mechanisms and targets of these substances. These include the decrease in enzymes that produce reactive oxygen and ferroptosis, the inhibition of mono-amine oxidases, the stimulation of the Nrf2/ARE system, the induction of brain-derived neurotrophic factor production and, in the case of AD, the prevention of amyloid-beta aggregation. The inhibition of neuroinflammatory processes has been documented as a decrease in cytokine formation (mainly TNF-alpha and IL-1beta) by microglia and astrocytes, by modulating a number of regulatory proteins such as Nf-kB and NLRP3/inflammasome. Although clinical trials on humans are still scarce, preclinical studies allow us to consider hesperidin, quercetin, and other flavonoids as very interesting and safe dietary molecules to be further investigated as complementary treatments in order to prevent neurodegenerative diseases or to moderate their deleterious effects.

Mechanistic Role of Methanolic Extract of Taraxacum officinale Roots as Cardioprotective Against Ischemia-Reperfusion Injury-Induced Myocardial Infarction in Rats

Taraxacum officinale play an important role in the prophylaxis and treatment of cardiovascular disease (CVD). Taraxacum officinale is proven as promising antioxidant in earlier studies and one of its constituent "cichoric acid" is shown to have vasorelaxant property. Therefore, present study mainly designed to investigate the cardioprotective effects of Taraxacum officinale against ischemia-reperfusion injury (I/R injury)-induced myocardial dysfunction in rats. This study not only explored the overall cardioprotective potential but also tried to explore its molecular mechanism using pharmacological inhibition via L-NAME and glibenclamide. Pretreatment of methanolic extract of Taraxacum officinale significantly attenuated (p < 0.001) increased levels of lactate dehydrogenase (LDH), creatine kinase (CK), infarct size, and thiobarbituric acid reactive substance (TBARS), while it increased the reduced levels of protein content, glutathione (GSH), and catalase (CAT) activity. Results showed that pretreatment with methanolic extract of Taraxacum officinale provides cardioprotection against I/R induced myocardial dysfunction, at least, may be mediated through the endogenous release of nitric oxide.

Ameliorative effect of vanillin on scopolamine-induced dementia-like cognitive impairment in a mouse model

BACKGROUND

Alzheimer's disease (AD) is the most common form of dementia, which is among the top five causes of death in the United States. It is a neurodegenerative disorder that causes permanent loss of memory and cognition. The current pharmacotherapy for AD is based on providing symptomatic relief only and has many side effects. There is a need for a safer, disease-modifying drug for the treatment of AD.

EXPERIMENTAL APPROACH

The PASS online software was used to screen phytoconstituents based on their predicted effects on various AD-related targets. Vanillin was selected as the compound of interest, as it has not been researched elaborately on any animal model of AD. The acetylcholinesterase inhibitory activity of vanillin was established in vitro. Thereafter, ameliorative effect of vanillin was evaluated using the exteroceptive memory model in scopolamine-induced cognitive impairment mice model.

RESULTS

Vanillin showed an acetylcholinesterase inhibitory activity in vitro, and the IC50 value was calculated to be 0.033 mM. Vanillin significantly reversed the memory and behavioral deficits caused by scopolamine as demonstrated by significant improvement in memory in negative reinforcement, elevated plus maze, and spatial learning paradigms. Vanillin also proved to have a nootropic effect. Also, vanillin proved to have significantly better antioxidant and acetylcholinesterase inhibitory effects in vivo than donepezil hydrochloride. The potential anti-AD activity of vanillin was also confirmed by the reduction in IL-6 levels and TNF-α levels.

CONCLUSION

Our results suggest that vanillin is a safe and effective natural drug candidate having a great potential for the treatment of AD. However, more research is required to evaluate its effect on A beta plaques and Tau neurofibrillary tangles in vivo.

Evaluation of apigenin-based biflavonoid derivatives as potential therapeutic agents against viral protease (3CLpro) of SARS-CoV-2 via molecular docking, molecular dynamics and quantum mechanics studies

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) is the causative agent of the pandemic COVID-19 disease that affects human respiratory function. Despite the scientific progression made in the development of the vaccine, there is an urgent need for the discovery of antiviral drugs for better performance at different stages of SARS-CoV-2 reproduction. The main protease (Mpro or 3CLpro) plays a pivotal role in the life cycle of the virus, making it an attractive target for the development of antiviral agents effective against the new strains of coronaviruses (CoVs). In this study, a series of apigenin-based natural biflavonoid derivatives as potential inhibitors of coronaviruses 3CLpro was investigated by in silico approaches. For this purpose, the molecular docking was performed to analyze the interaction of the natural biflavonoids with SARS-Cov-2 main protease and for further investigation, docking to the 3CLpro of SARS-CoV and MERS-CoV. Based on docking scores and comparison with the reference inhibitors (ritonavir and lopinavir), more than half of the biflavonoids had strong interactions with the residues of the binding pocket of the coronaviruses 3CLpro and exhibited better binding affinities toward the main protease than ritonavir and lopinavir. The top biflavonoids were further explored through molecular dynamics simulation, binding free energy calculation and residual energy contributions estimated by the MM-PBSA. Also, drug likeness property investigation by Swiss ADME tools and density functional theory (DFT) calculations were performed. The results confirmed that the 3CLpro-amentoflavone, 3CLpro-bilobetin, 3CLpro-ginkgetin, and 3CLpro-sotetsuflavone complexes possess a large amount of dynamic properties such as high stability, significant binding energy and fewer conformation fluctuations. Also, the pharmacokinetics and drug-likeness studies and HOMO-LUMO and DFT descriptor values indicated a promising result of the selected natural biflavonoids. Overall findings indicate that the apigenin-based biflavonoids may inhibit COVID-19 by significant interactions in the binding pocket and those results can pave the way in drug discovery although the effectiveness of these bioactive compounds should be further validated by in-vitro and in-vivo investigations. Communicated by Ramaswamy H. Sarma.

Improved neuroprotective activity of Fisetin through SNEDDS in ameliorating the behavioral alterations produced in rotenone-induced Parkinson's model

Fisetin is a polyphenolic flavonoid reported to have antioxidant, anti-inflammatory, and anti-cancer activities. However, it loses its importance as an effective phytochemical due to its poor water solubility and lower bioavailability. In the present study, the self-nanoemulsifying drug delivery system (SNEDDS) of fisetin was developed in order to improve its pharmacological activity. The developed SNEDDS of fisetin was evaluated for improving the rotenone-induced behavioral changes in the rats, and its efficacy was compared with naïve fisetin. It was noticed that fisetin loaded in the SNEDDS formulation significantly (p < 0.001) ameliorated the rotenone-induced alteration in the body weight, grip strength, beam walk, postural instability, etc., in rats when compared to the effect of naïve fisetin. Naïve fisetin significantly (p < 0.05) ameliorated the effect of rotenone on the level of dopamine only at a higher dose. Whereas, SNEDDS of fisetin produced a significant (p < 0.05) effect at both dose levels when compared with the diseased group as well as also produced a significant (p < 0.05) effect when compared with the naïve fisetin group. The results of histopathological examination revealed about the neuroprotective effect of SNEDDS loaded with fisetin as observed through the protection of neuronal damage. From this study, it was concluded that SNEDDS improved the anti-Parkinsonian activity of fisetin by improving the behavioral alteration produced by rotenone due to enhancement in its solubility and bioavailability.

Pharmacological evaluation of vanillic acid in rotenone-induced Parkinson's disease rat model

In the present study, we investigated the anti-Parkinson's effect of vanillic acid (VA) (12 mg/kg, 25 mg/kg, 50 mg/kg p.o.) against rotenone (2 mg/kg s.c.) induced Parkinson's disease (PD) in rats. The continuous administration of rotenone for 35 days resulted in rigidity in muscles, catalepsy, and decrease in locomotor activity, body weight, and rearing behaviour along with the generation of oxidative stress in the brain (rise in the TBARS, and SAG level and reduced CAT, and GSH levels). Co-treatment of VA and levodopa-carbidopa (100 mg/kg + 25 mg/kg p.o.) lead to a significant (P < 0.001) reduction in the muscle rigidity and catalepsy along with a significant (P < 0.001) increase in body weight, rearing behaviour, locomotion and muscle activity as compared to the rotenone-treated group in the dose dependent manner, showing maximum effect at the 50 mg/kg. It also showed reversal of levels of oxidative stress parameters thus, reducing the neuronal oxidative stress. The level of DA was also estimated which showed an increase in the level of DA in the VA plus standard drug treated animals as compared to rotenone treated group. Histopathological evaluation showed a high number of eosinophilic lesions in the rotenone group which were found to be very less in the VA co-treated group. The study thus proved that co-treatment of VA and levodopa-carbidopa, significantly protected the brain from neuronal damage due to oxidative stress and attenuated the motor defects indicating the possible therapeutic potential of VA as a neuroprotective in PD.

Hesperidin as a Neuroprotective Agent: A Review of Animal and Clinical Evidence

Neuroprotection is the preservation of function and networks of neural tissues from damages caused by various agents, as well as neurodegenerative diseases such as Parkinson's, Alzheimer's, Huntington's diseases, and multiple sclerosis. Hesperidin, a flavanone glycoside, is a natural phenolic compound with a wide range of biological effects. Mounting evidence has demonstrated that hesperidin possesses inhibitory effect against development of neurodegenerative diseases. Our review discusses neuropharmacological mechanisms for preventive and therapeutic effects of hesperidin in neurodegenerative diseases. In addition, the review examines clinical evidence confirming its neuroprotective function. Various cellular and animal models specific to neurodegenerative diseases have been conducted to evaluate the underlying neuropharmacological mechanisms of hesperidin. Neuroprotective potential of this flavonoid is mediated by improvement of neural growth factors and endogenous antioxidant defense functions, diminishing neuro-inflammatory and apoptotic pathways. Despite the various preclinical studies on the role of hesperidin in the neurodegenerative diseases, less is known about its definite effect on humans. A limited number of clinical trials showed that hesperidin-enriched dietary supplements can significantly improve cerebral blood flow, cognition, and memory performance. Further clinical trials are also required for confirming neuroprotective efficacy of this natural flavonoid and evaluating its safety profile.