Identification of molecular interactions of pesticides with keratinase for their potential to inhibit keratin biodegradation.

The recalcitrant, fibrous protein keratin is found in the outermost layer of vertebrate skin, feathers, hair, horn, and hooves. Approximately, 10 million tons of keratin wastes are produced annually worldwide, of which around 8.5 million tons are from feather wastes. The biodegradation of keratin has been a challenge due to the lack of understanding of biological parameters that modulate the process. Few soil-borne microbes are capable of producing keratinase enzyme which has the potential to degrade the hard keratin. However, various pesticides are abundantly used for the management of poultry farms and reports suggest the presence of the pesticide residues in feather. Hence, it was hypothesized that pesticides would interact with the substrate-binding or allosteric sites of the keratinase enzyme and interferes with the keratin-degradation process. In the present study, molecular interactions of 20 selected pesticides with the keratinase enzyme were analyzed by performing molecular docking. In blind docking, 14 out of 20 pesticides showed higher inhibitory potential than the known inhibitor phenylmethylsulfonyl flouride, all of which exhibited higher inhibitory potential in site-specific docking. The stability and strength of the protein complexes formed by the top best potential pesticides namely fluralaner, teflubenzuron, cyhalothrin, and cyfluthrin has been further validated by molecular dynamic simulation studies. The present study is the first report for the preliminary investigation of the keratinase-inhibitory potential of pesticides and highlights the plausible role of these pesticides in hindering the biological process of keratin degradation and thereby their contribution in environmental pollution. Graphical abstract: Illustration depicting the hypothesis, experimental procedure, and the resultant keratinase-inhibitory potential of selected pesticides.

Isolation, identification, and molecular characterization of potential keratinolytic fungus sp. from Southern Assam: relevance to poultry wastes and its biological management.

Feather waste is a highly prevalent form of keratinous waste that is generated by the poultry industry. The global daily production of feather waste has been shown to approach 5 million tons, typically being disposed of through methods such as dumping, landfilling, or incineration which contribute significantly to environmental pollutions. The proper management of these keratinous wastes is crucial to avoid environmental contamination. The study was carried out to isolate the keratinolytic fungi from the poultry disposal sites of different region of North-East India to evaluate its potential in bioremediation of the feathers wastes. Out of 12 fungal strains isolated from the sites, the fungus showing the highest zone of hydrolysis on both the skim milk and keratin agar medium was selected for the study and the molecular identification of the isolate was performed through DNA sequence analysis by amplifying the internal transcribed spacer (ITS) region. The sequence results showed higher similarity (above 95%) with Aspergillus spp. and was named Aspergillus sp. Iro-1. The strain was further analyzed for its feather degrading potential which was performed in submerged conditions under optimized conditions. The study showed that the strain could effectively degrade the feathers validated through weight loss method, and the structural deformations in the feathers were visualized through scanning electron microscopy (SEM). Aspergillus sp. Iro-1 was obtained from the southern region of Assam. It would be of great importance as the implementation of this sp. can help in the bioremediation of feathers wastes in this region. This is the first study of identification of feather degrading fungus from southern part of Assam (Barak).

Therapeutic considerations of bioactive compounds in Alzheimer's disease and Parkinson's disease: Dissecting the molecular pathways.

Leading neurodegenerative diseases Alzheimer's disease (AD) and Parkinson's disease (PD) are characterized by the impairment of memory and motor functions, respectively. Despite several breakthroughs, there exists a lack of disease-modifying treatment strategies for these diseases, as the available drugs provide symptomatic relief and bring along side effects. Bioactive compounds are reported to bear neuroprotective properties with minimal toxicity, however, a detailed elucidation of their modes of neuroprotection is lacking. The review elucidates the neuroprotective mechanism(s) of some of the major phyto-compounds in pre-clinical and clinical studies of AD and PD to understand their potential in combating these diseases. Curcumin, eugenol, resveratrol, baicalein, sesamol and so on have proved efficient in countering the pathological hallmarks of AD and PD. Curcumin, resveratrol, caffeine and so on have reached the clinical phases of these diseases, while aromadendrin, delphinidin, cyanidin and xanthohumol are yet to be extensively explored in pre-clinical phases. The review highlights the need for extensive investigation of these compounds in the clinical stages of these diseases so as to utilize their disease-modifying abilities in the real field of treatment. Moreover, poor pharmacokinetic properties of natural compounds are constraints to their therapeutic yields and this review suggests a plausible contribution of nanotechnology in overcoming these limitations.

Traversing through the cell signaling pathways of neuroprotection by betanin: therapeutic relevance to Alzheimer's Disease and Parkinson's Disease.

Modulation of cell signaling pathways is the key area of research towards the treatment of neurodegenerative disorders. Altered Nrf2-Keap1-ARE (Nuclear factor erythroid-2-related factor 2-Kelch-like ECH-associated protein 1-Antioxidant responsive element) and SIRT1 (Sirtuin 1) cell signaling pathways are considered to play major role in the etiology and pathogenesis of Alzheimer's disease (AD) and Parkinson's disease (PD). Strikingly, betanin, a betanidin 5-O-ß-D-glucoside compound is reported to show commendable anti-oxidative, anti-inflammatory and anti-apoptotic effects in several disease studies including AD and PD. The present review discusses the pre-clinical studies demonstrating the neuroprotective effects of betanin by virtue of its potential to ameliorate oxidative stress, neuroinflammation, abnormal protein aggregation and cell death. It highlights the direct linkage between the neuroprotective abilities of betanin and upregulation of the Nrf2-Keap1-ARE and SIRT1 signaling pathways. The review further hypothesizes the involvement of the betanin-Nrf2-ARE route in the inhibition of beta-amyloid aggregation through beta-site amyloid precursor protein cleaving enzyme 1 (BACE1), one of the pivotal hallmarks of AD. The present review hereby for the first time elaborately discusses the reported neuroprotective abilities of betanin and decodes the Nrf2 and SIRT1 modulating potential of betanin as a primary mechanism of action behind, hence highlighting it as a novel drug candidate for the treatment of neurodegenerative diseases in the near future.

Garcinia morella extract confers dopaminergic neuroprotection by mitigating mitochondrial dysfunctions and inflammation in mouse model of Parkinson's disease.

Dopaminergic neuroprotection is the main interest in designing novel therapeutics against Parkinson's disease (PD). In the process of dopaminergic degeneration, mitochondrial dysfunctions and inflammation are significant. While the existing drugs provide symptomatic relief against PD, a therapy conferring total neuroprotection by targeting multiple degenerative pathways is still lacking. Garcinia morella is a common constituent of Ayurvedic medication and has been used for the treatment of inflammatory disorders. The present study investigates whether administration of G. morella fruit extract (GME) in MPTP mouse model of PD protects against dopaminergic neurodegeneration, including the underlying pathophysiologies, and reverses the motor behavioural abnormalities. Administration of GME prevented the loss of dopaminergic cell bodies in the substantia nigra and its terminals in the corpus striatum of PD mice. Subsequently, reversal of parkinsonian behavioural abnormalities, viz. akinesia, catalepsy, and rearing, was observed along with the recovery of striatal dopamine and its metabolites in the experimental model. Furthermore, reduced activity of the mitochondrial complex II in the nigrostriatal pathway of brain of the mice was restored after the administration of GME. Also, MPTP-induced enhanced activation of Glial fibrillary acidic protein (GFAP) and neuronal nitric oxide synthase (nNOS) in the nigrostriatal pathway, which are the markers of inflammatory stress, were found to be ameliorated on GME treatment. Thus, our study presented a novel mode of dopaminergic neuroprotection by G. morella in PD by targeting the mitochondrial dysfunctions and neuroinflammation, which are considered to be intricately associated with the loss of dopaminergic neurons.

Suggesting 7,8-dihydroxyflavone as a promising nutraceutical against CNS disorders.

7,8-dihydroxyflavone (DHF), a naturally-occurring plant-based flavone, is a high-affinity tyrosine kinase receptor B (TrkB) agonist and a bioactive molecule of therapeutic interest for neuronal survival, differentiation, synaptic plasticity and neurogenesis. In the family of neurotrophic factors, this small BDNF-mimetic molecule has attracted considerable attention due to its oral bioavailability and ability to cross the blood-brain barrier. Recent evidences have shed light on the neuroprotective role of this pleiotropic flavone against several neurological disorders, including Alzheimer's disease, Parkinson's disease, cerebral ischemia, Huntington's disease, and other CNS disorders. DHF also elicits potent protective actions against toxins-induced insults to brain and neuronal cells. DHF shows promising anti-oxidant and anti-inflammatory properties in ameliorating the neurodegenerative processes affecting the CNS. This review provides an overview of the significant neuroprotective potentials of DHF and discusses how it exerts its multitudinous beneficial effects by modulating different pathways linked with the pathophysiology of CNS disorders, and thus proposes it to be a nutraceutical against a broad spectrum of neurological disorders.

Natural Products and Their Therapeutic Effect on Autism Spectrum Disorder.

Autism is a complex neurodevelopmental disorder that is evident in early childhood and can persist throughout the entire life. The disease is basically characterized by hurdles in social interaction where the individuals demonstrate repetitive and stereotyped interests or patterns of behavior. A wide number of neuroanatomical studies with autistic patients revealed alterations in brain development which lead to diverse cellular and anatomical processes including atypical neurogenesis, neuronal migration, maturation, differentiation, and degeneration. Special education programs, speech and language therapy, have been employed for the amelioration of behavioral deficits in autism. Although commonly prescribed antidepressants, antipsychotics, anticonvulsants, and stimulants have revealed satisfactory responses in autistic individuals, adverse side effects and increased risk of several other complications including obesity, dyslipidemia, diabetes mellitus, thyroid disorders, etc. have compelled the researchers to turn their attention toward herbal remedies. Alternative approaches with natural compounds are on continuous clinical trial to confirm their efficacy and to understand their potential in autism treatment. This chapter aims to cover the major plant-based natural products which hold promising outcomes in the field of reliable therapeutic interventions for autism.

Neuroprotective attributes of L-theanine, a bioactive amino acid of tea, and its potential role in Parkinson's disease therapeutics.

Meta-analyses of tea consumption and reduced risk of Parkinson's disease have thrown light in the pathway of exploring beneficial properties of tea components. On the basis of dry mass, a typical black or green tea beverage contains approximately 6% of free amino acids, which impart high quality, taste and distinctive aroma to the tea infusion. L-theanine (chemically known as γ-glutamylethylamide) is a non-proteinogenic amino acid of tea that takes part in the biosynthesis of its polyphenols. Recently discovered neuroprotective effects of L-theanine can be attributed to its structural analogy with glutamate, the principal excitatory neurotransmitter in brain. This unique amino acid also bears a potential to ameliorate the pathophysiological changes associated with Parkinson's disease as it displays antioxidant and anti-inflammatory properties, improves motor behavioral abnormalities, increases dopamine availability and may cause a favorable downshift in neurodegeneration due to glutamate excitotoxicity. To gain an explicit understanding of the role of L-theanine, this review article is the first one to focus on its mechanism of neuromodulatory action and to critically evaluate the possibilities of employing this bioactive amide in the forage of anti-Parkinsonian medication. We also hypothesize the idea of L-theanine being a potent natural agent against L-DOPA induced dyskinesia, since long-term reliance on dopamine replacement therapy is linked with elevation in glutamate receptor activity.

Garcinol, a multifaceted sword for the treatment of Parkinson's disease.

Garcinol, the principal phytoconstituent of plants belonging to the genus Garcinia, is known for its anti-oxidant as well as anti-inflammatory properties, which can be extended to its possible neuroprotective role. Recent reports disseminate the capacity of garcinol to influence neuronal growth and survival, alter the neurochemical status in brain, as well as regulate memory and cognition. The concomitant neuro-rescue property of garcinol may render it as an effective compound in Parkinson's disease (PD) therapeutics since it is capable of ameliorating the related pathophysiological changes. Emerging pieces of evidence linking histone acetylation defects to the progression of neurodegenerative diseases provide an effective basis for targeting PD. Hyperacetylation of histones has been reported in Parkinsonian brain, which demands the use of pharmacological inhibitors of histone acetyltransferases (HAT). Garcinol serves as a potent natural HAT inhibitor and has unveiled promising results in molecular interaction studies against Monoamine oxidase B (MAO-B) and Catechol-O-Methyltransferase (COMT), as well as in L-DOPA induced dyskinesia. This review highlights the prospective implications of garcinol as a novel anti-Parkinsonian agent, and establishes a bridge between histone acetylation defects and the pathological aspects of PD.

Garcinol, an effective monoamine oxidase-B inhibitor for the treatment of Parkinson's disease.

Loss of dopamine containing neurons in the substantia nigra pars compacta of midbrain, and resultant depletion of dopamine in the striatum is the cause of Parkinson's disease (PD), which is associated with motor abnormalities. Replenishment of dopamine by oral supplementation of its precursor, the levodopa (L-DOPA), remains the primary mode of treatment of PD, despite its potential side-effects after prolonged use in patients. To reduce the daily dosing of L-DOPA in patients, inhibitors of dopamine catabolizing enzymes, particularly monoamine oxidase-B (MAO-B), are prescribed. The most widely used MAO-B inhibitor to maintain the bioavailability of dopamine in the brain of PD patients is L-deprenyl, despite of its potential side-effects. The present study identified Garcinol as a potential candidate in the treatment paradigm of PD by virtue of its exorbitant MAO-B inhibitory potential. The inhibitory potential is comparable to the known MAO-B inhibitors, which was evaluated using molecular docking technique. Owing to its known antioxidant, anti-inflammatory and catechol-o-methyl transferase inhibitory potential, the molecule would confer neuroprotection as well, and thus, the present study is of immense significance in the treatment paradigm of PD.

Accumulation of Cholesterol and Homocysteine in the Nigrostriatal Pathway of Brain Contributes to the Dopaminergic Neurodegeneration in Mice.

Elevated levels of cholesterol (hypercholesterolemia) and homocysteine (hyperhomocysteinemia, HHcy) in blood have been linked with the pathology of Parkinson's disease. However, the impact of their combined effect on brain is unknown. The present study aims to investigate the effect of HHcy on dopaminergic neurons in brain of mice with hypercholesterolemia. Mice were subjected to a high-cholesterol diet for 12 weeks to develop hypercholesterolemia, and were administered with homocysteine (250 mg/kg, b.w., i.p., 60 days) daily starting from 24th day of the high-cholesterol diet for induction of HHcy. The animals were subjected to Parkinsonian motor behavioral tests and sacrificed to estimate the levels of cholesterol, homocysteine and dopamine in brain, and to assess dopaminergic neuronal status. There occurred elevation in cholesterol and homocysteine levels in nigrostriatum of hypercholesterolemic animals with HHcy. Injection of homocysteine in hypercholesterolemic mice exacerbated the motor abnormalities as well as caused depletion of striatal dopamine level significantly, which was supported by a significant decrease in tyrosine hydroxylase (TH) immunoreactivity in striatum. While neither hypercholesterolemia nor HHcy caused significant changes in the number of TH-positive neurons, hypercholesterolemia in combination with HHcy resulted in a significant loss of nigral TH-positive neurons. The results highlighted the involvement of mitochondrial complex-I dysfunction with subsequent generation of hydroxyl radicals for the observed loss of midbrain dopamine neurons in animals receiving the combined treatment. Thus, the findings of the present study pointed out the combined effect of homocysteine and cholesterol toward dopamine neuronal dysfunctions, which has substantial relevance to Parkinson's disease.

Disturbed purine nucleotide metabolism in chronic kidney disease is a risk factor for cognitive impairment.

Chronic kidney disease (CKD) is an increasing global health burden. Disturbance in purine metabolism pathway and a higher level of serum uric acid, called hyperuricemia, is a risk factor of CKD, and it has been linked to increased prevalence and progression of the disease. In a recent study, it has been demonstrated that purine nucleotides and uric acid alter the activity of acetylcholinesterase (AChE). Thus, we hypothesize that adenine, hypoxanthine, xanthine, 2,8-dihydroxyadenine and uric acid may potentially interfere with the activity of AChE. The hypothesis has been tested using computational tools. Uric acid has been found to be the most potent inhibitor of AChE, with a binding affinity higher than the known inhibitors of the enzyme. Further, since depleted AChE activity is associated with dementia and cognitive impairment, the present study suggest that disturbed purine nucleotide metabolism in CKD is a risk factor for cognitive impairment.

Melatonin protects against behavioral deficits, dopamine loss and oxidative stress in homocysteine model of Parkinson's disease.

AIM: Hyperhomocysteinemia and homocysteine (Hcy) mediated dopaminergic neurotoxicity is a matter of concern in the pathophysiology of Parkinson's disease (PD). Our previous study established the involvement of oxidative stress in the substantia nigra (SN) of Hcy rat model of PD; however, the role of antioxidants, such as melatonin, was not tested in this model. MAIN METHODS: Melatonin (10, 20 and 30mg/kg, i.p.) was administered to rats injected with Hcy in right SN (1.0µmol in 2µl saline) to investigate its potency in attenuating the behavioral abnormalities, dopamine depletion and oxidative stress prompted by Hcy. KEY FINDINGS: Treatment of melatonin protected against nigral dopamine loss and replenished the striatal dopamine loss that resulted in amelioration of rotational behavioral bias in Hcy denervated animals. Melatonin administration significantly improved mitochondrial complex-I activity and protected the SN neurons from the toxic insults of oxidative stress induced by Hcy. Amelioration of oxidative stress by melatonin in Hcy-infused SN was bought by dose-dependently scavenging of hydroxyl radicals, restoration of glutathione level and elevation in the activity of antioxidant enzymes. SIGNIFICANCE: The observations bring into light the significant neuroprotective potentials of melatonin in Hcy model of PD which is attributed to the attenuation of oxidative stress in SN.