5-Phenyl valeric acid attenuates α-synuclein aggregation and endoplasmic reticulum stress in rotenone-induced Parkinson's disease rats: A molecular mechanistic study.

The abnormal accumulation of fibrillar α-synuclein in the substantia nigra contributes to Parkinson's disease (PD). Chemical chaperones like 4-phenyl butyric acid (4PBA) show neuroprotective potential, but high doses are required. A derivative, 5-phenyl valeric acid (5PVA), has reported therapeutic potential for PD by reducing Pael-R expression. This study assessed 5PVA's efficacy in PD animals and its molecular mechanism. In vitro studies revealed 5PVA's anti-aggregation ability against alpha-synuclein and neuroprotective effects on SHSY5Y neuroblastoma cells exposed to rotenone. PD-like symptoms were induced in SD rats with rotenone, followed by 5PVA treatment at 100 mg/kg and 130 mg/kg. Behavioral analysis showed significant improvement in memory and motor activity with 5PVA administration. Histopathological studies demonstrated normal neuronal histoarchitecture in mid-brain tissue sections of 5PVA-treated animals compared to the PD group. mRNA studies revealed significant suppression in the expression of various protein folding and heat-shock protein markers in the 5PVA-treated group. In conclusion, 5PVA, with its anti-aggregation ability against alpha-synuclein, acts as a chemical chaperone, showing potential as a therapeutic candidate for PD treatment.

Linalool acts as a chemical chaperone by inhibiting amyloid-ß aggregation.

Linalool is a neuroprotective monoterpene found in essential oils from aromatic plants. Linalool's effectiveness in AD animal models has been established previously, but its mechanisms of action remain unclear. Therefore, this study aims to investigate whether linalool binds directly to the amyloid beta (Aß) fibrils to understand it's role in preventing neurodegeneration. The anti-aggregation ability of Linalool was determined using Dithiothreitol (DTT), and thermal aggregation assays followed by Thioflavin T (ThT) binding assay. AD animals were treated with Linalool, and Thioflavin T staining was used to check the binding of linalool to Aß fibrils in rat brain tissue sections. Preliminary studies revealed the anti-aggregation potential of linalool under the thermal and chemical stimulus. Further, in ThT binding assay Linalool inhibited Aß aggregation, binding directly to Aß fibrils. The reduced fluorescence intensity of ThT in AD brain tissues following linalool administration, highlights its neuroprotective potential as a therapeutic agent for AD.

Protective effect of olopatadine hydrochloride against LPS-induced acute lung injury: via targeting NF-κB signaling pathway.

BACKGROUND: Morbidity and mortality rates associated with acute lung injury/acute respiratory distress syndrome (ALI/ARDS) are high (30-40%). Nuclear factor-kappa B (NF-κB) is a transcription factor, associated with transcription of numerous cytokines leading to cytokine storm, and thereby, plays a major role in ALI/ARDS and in advanced COVID-19 syndrome. METHODS: Considering the role of NF-κB in ALI, cost-effective in silico approaches were utilized in the study to identify potential NF-κB inhibitor based on the docking and pharmacokinetic results. The identified compound was then pharmacologically validated in lipopolysaccharide (LPS) rodent model of acute lung injury. LPS induces ALI by altering alveolar membrane permeability, recruiting activated neutrophils and macrophages to the lungs, and compromising the alveolar membrane integrity and ultimately impairs the gaseous exchange. Furthermore, LPS exposure is associated with exaggerated production of various proinflammatory cytokines in lungs. RESULTS: Based on in silico studies Olopatadine Hydrochloride (Olo), an FDA-approved drug was found as a potential NF-κB inhibitor which has been reported for the first time, and considered further for the pharmacological validation. Intraperitoneal LPS administration resulted in ALI/ARDS by fulfilling 3 out of the 4 criteria described by ATS committee (2011) published workshop report. However, treatment with Olo attenuated LPS-induced elevation of proinflammatory markers (IL-6 and NF-κB), oxidative stress, neutrophil infiltration, edema, and damage in lungs. Histopathological studies also revealed that Olo treatment significantly ameliorated LPS-induced lung injury, thus conferring improvement in survival. Especially, the effects produced by Olo medium dose (1 mg/kg) were comparable to dexamethasone standard. CONCLUSION: In nutshell, inhibition of NF-κB pathway by Olo resulted in protection and reduced mortality in LPS- induced ALI and thus has potential to be used clinically to arrest disease progression in ALI/ARDS, since the drug is already in the market. However, the findings warrant further extensive studies, and also future studies can be planned to elucidate its role in COVID-19-associated ARDS or cytokine storm.

Endoplasmic reticulum stress and its role in various neurodegenerative diseases.

The Endoplasmic reticulum (ER), a critical cellular organelle, maintains cellular homeostasis by regulating calcium levels and orchestrating essential functions such as protein synthesis, folding, and lipid production. A pivotal aspect of ER function is its role in protein quality control. When misfolded proteins accumulate within the ER due to factors like protein folding chaperone dysfunction, toxicity, oxidative stress, or inflammation, it triggers the Unfolded protein response (UPR). The UPR involves the activation of chaperones like calnexin, calreticulin, glucose-regulating protein 78 (GRP78), and Glucose-regulating protein 94 (GRP94), along with oxidoreductases like protein disulphide isomerases (PDIs). Cells employ the Endoplasmic reticulum-associated degradation (ERAD) mechanism to counteract protein misfolding. ERAD disruption causes the detachment of GRP78 from transmembrane proteins, initiating a cascade involving Inositol-requiring kinase/endoribonuclease 1 (IRE1), Activating transcription factor 6 (ATF6), and Protein kinase RNA-like endoplasmic reticulum kinase (PERK) pathways. The accumulation and deposition of misfolded proteins within the cell are hallmarks of numerous neurodegenerative diseases. These aberrant proteins disrupt normal neuronal signalling and contribute to impaired cellular homeostasis, including oxidative stress and compromised protein degradation pathways. In essence, ER stress is defined as the cellular response to the accumulation of misfolded proteins in the endoplasmic reticulum, encompassing a series of signalling pathways and molecular events that aim to restore cellular homeostasis. This comprehensive review explores ER stress and its profound implications for the pathogenesis and progression of neurodegenerative diseases.

Identification of Bile Acid-Derived Chemical Chaperone(s) Targeting E46K-Mutated Alpha-Synuclein Protein to Treat Parkinson's Disease: Molecular Modelling, Docking, ADME, and Simulation Studies.

Aggregated α-synuclein (α-syn) present inside small cytoplasmic inclusions in the substantia nigra region marks the major pathological hallmark of Parkinson's disease (PD) and makes it an attractive target for the drug development process. Certain small-molecule chaperones (such as DCA, UDCA, TUDCA) presented the ability to prevent misfolding and aggregation of α-syn as well as to disentangle mature α-syn amyloid fibrils. However, due to toxicity constraints, these small molecules could not be translated into clinical settings. Computational biology methods and bioinformatics approaches allow virtual screening of a large number of molecules, with reduced side effects and better efficacy. In the present study, a library of 10,928 derivatives was generated using DCA, UDCA, and TUDCA bile acid scaffolds and analysed for their binding affinity, pharmacokinetic properties, and drug likeliness profile, to come up with promising compounds with reduced toxicity and better chaperone ability. Molecular docking revealed that with respect to their free binding energy, C1-C25 have the lowest binding energy and bind significantly to recombinantly assembled E46K α-syn fibrils (PDB ID-6UFR). In silico ADME predictions revealed that all these compounds had minimal toxic effects and had good absorption as well as solubility characteristics. Simulation studies further showed that the imidazole ring-based TUDCA derivatives interacted better with the protein in comparison to the others. The proposed study has identified potent chemical chaperones (C2 and C3) as effective therapeutic agents for Parkinson's disease, and further in vitro and in vivo testing will be undertaken to substantiate their potential as novel drugs.

Protein misfolding, ER stress and chaperones: an approach to develop chaperone-based therapeutics for Alzheimer's disease.

Alzheimer's disease (AD) is a heterogeneous neurodegenerative disorder with complex etiology that eventually leads to dementia. The main culprit of AD is the extracellular deposition of ß-amyloid (Aß) and intracellular neurofibrillary tangles. The protein conformational change and protein misfolding are the key events of AD pathophysiology; therefore, endoplasmic reticulum (ER) stress is an apparent consequence. ER, stress-induced unfolded protein response (UPR) mediators (viz. PERK, IRE1, and ATF6) have been reported widely in the AD brain. Considering these factors, preventing protein misfolding or aggregation of tau or amyloidogenic proteins appears to be the best approach to halt its pathogenesis. Therefore, therapies through chemical and pharmacological chaperones came to light as an alternative for the treatment of AD. Diverse studies have demonstrated 4-phenylbutyric acid (4-PBA) as a potential therapeutic agent in AD. The current review outlined the mechanism of protein misfolding, different etiological features behind the progression of AD, the significance of ER stress in AD, and the potential therapeutic role of different chaperones to counter AD. The study also highlights the gaps in current knowledge of the chaperones-based therapeutic approach and the possibility of developing chaperones as a potential therapeutic agent for AD treatment.

Impact of Calcium Influx on Endoplasmic Reticulum in Excitotoxic Neurons: Role of Chemical Chaperone 4-PBA.

Excessive activation of α-amino-3-hydroxy-5-methyl-4-isoxazole propoinic acid (AMPA) receptors instigates excitotoxicity via enhanced calcium influx in the neurons thus inciting deleterious consequences. Additionally, Endoplasmic Reticulum (ER) is pivotal in maintaining the intracellular calcium balance. Considering this, studying the aftermath of enhanced calcium uptake by neurons and its effect on ER environment can assist in delineating the pathophysiological events incurred by excitotoxicty. The current study was premeditated to decipher the role of ER pertaining to calcium homeostasis in AMPA-induced excitotoxicity. The findings showed, increased intracellular calcium levels (measured by flowcytometry and spectroflourimeter using Fura 2AM) in AMPA excitotoxic animals (male Sprague dawely rats) (intra-hippocampal injection of 10 mM AMPA). Further, ER resident proteins like calnexin, PDI and ERp72 were found to be upregulated, which further modulated the functioning of ER membrane calcium channels viz. IP3R, RyR, and SERCA pump. Altered calcium homeostasis further led to ER stress and deranged the protein folding capacity of ER post AMPA toxicity, which was ascertained by unfolded protein response (UPR) pathway markers such as IRE1α, eIF2α, and ATF6α. Chemical chaperone, 4-phenybutric acid (4-PBA), ameliorated the protein folding capacity and subsequent UPR markers. In addition, modulation of calcium channels and calcium regulating machinery of ER post 4-PBA administration restored the calcium homeostasis. Therefore the study reinforces the significance of ER stress, a debilitating outcome of impaired calcium homeostasis, under AMPA-induced excitotoxicity. Also, employing chaperone-based therapeutic approach to curb ER stress can restore the calcium imbalance in the neuropathological diseases.

4-PBA rescues hyperoxaluria induced nephrolithiasis by modulating urinary glycoproteins: Cross talk between endoplasmic reticulum, calcium homeostasis and mitochondria.

AIM: Urinary glycoproteins such as Tamm Horsfall Protein (THP) and Osteopontin (OPN) are well established key regulators of renal stone formation. Additionally, recent revelations have highlighted the influence of Endoplasmic Reticulum (ER) and mitochondria of crucial importance in nephrolithiasis. However, till date conclusive approach highlighting the influence of ER stress on urinary glycoproteins and chaperone in nephrolithiasis remains elusive. Therefore, the present study was focussed on deciphering the possible effect of 4-PBA mitigating ER stress on urinary glycoproteins and calnexin (chaperone) with emphasis on interlinking calcium homeostasis in hyperoxaluric rats. MATERIAL AND METHODS: Post 9 days of treatment, animals were sacrificed, and renal tissues were investigated for urinary glycoproteins, calnexin, calcium homeostasis, ER environment, redox status, and mitochondrial linkage. KEY FINDINGS: 4-PBA appreciably reversed the altered levels of THP, OPN, and calnexin observed along with curtailing the disrupted calcium homeostasis when assessed for SERCA activity and intra-cellular calcium levels. Additionally, significant improvement in the perturbed ER environment as verified by escalated ER stress markers, disturbed protein folding-aggregation-degradation (congo red assay) pathway, and redox status was found post 4-PBA intervention. Interestingly, linkage of ER stress and mitochondria was established under hyperoxaluric conditions when assessed for protein levels of VDAC1 and GRP75. SIGNIFICANCE: 4-PBA treatment resulted in rectifying the repercussions of ER-mitochondrial caused distress when assessed for protein folding/aggregation/degradation events along with disturbed calcium homeostasis. The present study advocates the necessity to adopt a holistic vision towards hyperoxaluria with emphasis on glycoproteins and ER environment.

Insights into the cytoprotective potential of Bergenia ligulata against oxalate-induced oxidative stress and epithelial-mesenchymal transition (EMT) via TGFß1/p38MAPK pathway in human renal epithelial cells.

Oxalate exposure to human renal epithelial cells triggers a vicious cycle of oxidative stress leading to cellular injury and deposition of calcium oxalate crystals on the injured cells. This results in further oxidative damage causing inflammation and loss of cell-cell adhesion factors, ultimately leading to irreparable kidney damage. However, these events can be attenuated or prevented by plants rich in antioxidants used in the traditional system of medicine for treatment of kidney stones. To delineate the mechanism by which Bergenia ligulata extract exerts its cytoprotective role in oxalate-induced injury we designed this study. Our results revealed that oxalate-injured HK2 cells cotreated with ethanolic extract of Bergenia ligulata displayed increased viability, reduced oxidative stress due to lowered production of intracellular reactive oxygen species (ROS) and decreased apoptosis. We also observed lowered markers of inflammation, along with increased expression of epithelial marker E-cadherin and decreased expression of mesenchymal markers Vimentin, F-actin, Transforming growth factor beta 1 (TGF-ß1) and EMT-related proteins in renal tubular epithelial cells through immunocytochemistry, real-time PCR and western blotting. Our findings collectively suggest that by reducing oxidative stress, modulating crystal structure and preventing crystal-cell adhesion, B. ligulata inhibits the EMT pathway by downregulating the various mediators and thereby exerts its cytoprotective effect.

AMPA induced cognitive impairment in rats: Establishing the role of endoplasmic reticulum stress inhibitor, 4-PBA.

Glutamate excitotoxicity and endoplasmic reticulum (ER) recently have been found to be instrumental in the pathogenesis of various neurodegenerative diseases. However, the paucity of literature deciphering the inter-linkage among glutamate receptors, behavioral alterations, and ER demands thorough exploration. Reckoning the aforesaid concerns, a prospective study was outlined to delineate the influence of ER stress inhibition via 4-phenylbutyric acid (PBA) on α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) excitotoxicity-induced behavioral aspects and possible ER stress-glutamate linkage. Male SD rats were randomly divided into four groups namely sham (surgical control+vehicle, group 1), AMPA-induced excitotoxic group 2 receive a single intra-hippocampal injection of 10 mM AMPA, group 3 received AMPA along with PBA (i.p, 100 mg/kg body weight) for 15 days, and group 4 received PBA alone. Behavioral analyses were performed prior to the sacrifice of animals and hippocampus was extracted thereafter for further analysis. AMPA-induced excitotoxicity exhibited significant impairment of locomotion as well as cognitive functions. The levels of neurotransmitters such as dopamine, homo vanillic acid (HVA), norepinephrine, and serotonin were reduced accompanied by reduced expression of GLUR1 and GLUR4 (glutamate receptor) as well as loss of neurons in different layers of hippocampus. ER stress markers were upregulated upon AMPA excitotoxicity. However, chemical chaperone PBA supplementation remarkably mitigated the behavioral alterations along with expression of glutamate and ER stress intermediates/markers in AMPA excitotoxic animals. Therefore, the present exploration convincingly emphasizes the significance of ER stress and its inhibition via PBA in combating cognitive impairment as well as improving locomotion in excitotoxic animals.

Downregulation of inflammatory mediators by ethanolic extract of Bergenia ligulata (Wall.) in oxalate injured renal epithelial cells.

ETHNOPHARMACOLOGICAL RELEVANCE: In the Indian traditional system of medicine, Bergenia ligulata (Wall.) Engl. has been used for treatment of urolithiasis. Its efficacious nature has led to its incorporation in various commercial herbal formulations such as Cystone and Neeri which are prescribed for kidney related ailments. AIM OF THE STUDY: To assess whether ethanolic extract of B. ligulata can mitigate the cascade of inflammatory responses that cause oxidative stress and ultimately cell death in renal epithelial cells exposed to hyperoxaluric conditions. MATERIAL AND METHODS: Bioactivity guided fractionation using solvents of varying polarities was employed to evaluate the potential of the extracts of B. ligulata to inhibit the crystallization process. Modulation of crystal morphology was visualized through Scanning electron microscopy (SEM) analysis. Cell death was assessed using flow cytometry based assays. Alteration in the inflammatory mediators was evaluated using real time PCR and immunocytochemistry. Phytochemical characterization of the ethanolic extract was carried out using FTIR, LC-MS and GC-MS. RESULTS: Bioactivity guided fractionation for the assessment of antilithiatic activity revealed dose dependent inhibition of nucleation and aggregation process of calcium oxalate crystals in the presence of various extracts, however ethanolic extract showed maximum inhibition and was chosen for further experiments. Studies on renal epithelial NRK-52E cells showed, cytoprotective efficacy of B. ligulata extract against oxalate injury. SEM anaysis further revealed the potential of the extract to modulate the crystal structure and adhesion to renal cell surface. Exposure of the renal cells to the extract led to conversion of the calcium oxalate monohydrate (COM) crystals to the less injurious calcium oxalate dihydrate (COD) form. Expression analysis for oxidative stress and inflammatory biomarkers in NRK-52E cells revealed up-regulation of Mitogen activated protein kinase (MAPK), Osteopontin (OPN) and Nuclear factor- ĸB (NF-ĸB), in response to calcium oxalate insult; which was drastically reduced in the presence of B. ligulata extract. Flow cytometric evaluation pointed to caspase 3 mediated apoptotic cell death in oxalate injured cells, which was attenuated by B. ligulata extract. CONCLUSION: Considering the complex multifactorial etiology of urolithiasis, ethanolic extract from B. ligulata can be a promising option for the management of kidney stones, as it has the potential to limit inflammation and the subsequent cell death.

Genetic comparison among various coronavirus strains for the identification of potential vaccine targets of SARS-CoV2.

On-going pandemic pneumonia outbreak COVID-19 has raised an urgent public health issue worldwide impacting millions of people with a continuous increase in both morbidity and mortality. The causative agent of this disease is identified and named as SARS-CoV2 because of its genetic relatedness to SARS-CoV species that was responsible for the 2003 coronavirus outbreak. The immense spread of the disease in a very small period demands urgent development of therapeutic and prophylactic interventions for the treatment of SARS-CoV2 infected patients. A plethora of research is being conducted globally on this novel coronavirus strain to gain knowledge about its origin, evolutionary history, and phylogeny. This review is an effort to compare genetic similarities and diversifications among coronavirus strains, which can hint towards the susceptible antigen targets of SARS-CoV2 to come up with the potential therapeutic and prophylactic interventions for the prevention of this public threat.

Co-abuse of alprazolam augments the hepato-renal toxic effects of methylphenidate.

OBJECTIVE: Methylphenidate (MPH) is a first-line treatment option for attention-deficit hyperactive disorder and narcolepsy. MPH is one of the most abused psychostimulants by the adults and young population to stay awake, perform better, or improve concentration. The scanty reports say that the medical users or abusers mostly consider the administration of benzodiazepines to overcome the adverse effects, i.e., mood- and anxiety-related problems associated with MPH chronic abuse. This work aims to study the effect of alprazolam (ALZ) on MPH-associated adverse effects on liver and kidney. MATERIALS AND METHODS: Female Wistar rats (n = 58) were administered with MPH (10, 20, and 40 mg/kg) and ALZ (5, 10, and 20 mg/kg) alone and in combination for 28 days. Bodyweight, feed intake, and water intake were monitored weekly. Parameters related to liver and renal function, oxidative stress, and histopathology were performed to evaluate the toxic impacts on the liver and kidneys. RESULTS: ALZ, along with MPH, increased the serum alkaline phosphatase, alanine aminotransferase, aspartate aminotransferase, creatinine, and urea levels. The co-abuse also led to elevated oxidative stress and structural abnormalities in the liver and kidney tissues. CONCLUSION: The co-abuse of ALZ has amplified the hepato-renal toxic effects of MPH. Therefore, it is a significant concern for public safety, and their co-abuse must be restricted and discouraged.

Differential effects of alprazolam against methylphenidate-induced neurobehavioral alterations.

BACKGROUND: In the previous decade, abuse of several types of prescription drugs, particularly anxiolytics, opioid analgesics, and stimulants has increased significantly worldwide. Methylphenidate (MPH) and Alprazolam (ALZ) are extensively used drugs for the treatment of attention deficit hyperactivity disorder (ADHD) and anxiety disorders, respectively. However, these drugs have a high risk of being misused or abused alone, and their combination in some peculiar cases has shown their deleterious effects. In this study, we evaluated the extent of damage both these drugs (MPH and ALZ) may cause in the brain at different dosages. METHODS: Female Wistar rats were administered with MPH (10, 20, 40mg/kg) and ALZ (5, 10, 20mg/kg) alone and in combination. Following the treatment, neurobehavioral studies were conducted, and later brain tissue was removed for studying the extent of oxidative stress and inflammation in the hippocampus and cortex region of the brain. Further histopathological parameters, along with neurotransmitter levels, were also assessed. RESULTS: Both MPH and ALZ, in combination, enhanced oxidative stress, inflammation, and neurobehavioral alterations in a dose-dependent manner. These toxic effects were associated with histopathological alterations and neurotransmitters levels CONCLUSIONS: In this study, it is found that the combination of psychostimulant (MPH) and depressant (ALZ) tends to enhance toxicity in the brain, and their long-term usage is a significant public health concern. Therefore, their co-administration should be strictly monitored by medical practitioners, and under compulsive circumstances, their use must be restricted to lower doses.

Delving into the Antiurolithiatic Potential of Tribulus terrestris Extract Through -In Vivo Efficacy and Preclinical Safety Investigations in Wistar Rats.

Modern treatment interventions for kidney stones are wrought with side-effects, hence the need for alternative therapies such as plant-based medicines. We have previously documented through in vitro studies that statistically optimized aqueous extract of Tribulus terrestris (Zygophyllaceae family) possesses antiurolithic and antioxidant potential. This provides strong scientific foundation to conduct in vivo efficacy and preclinical safety studies to corroborate and lend further proof to its ability to prevent and cure kidney stones. The preventive and curative urolithiatic efficacy in experimentally induced nephrolithiatic Wistar rats, along with preclinical toxicity was evaluated following oral administration of statistically optimized aqueous extract of T. terrestris. Treatment showed augmented renal function, restoration of normal renal architecture and increase in body weight. Microscopic analysis of urine revealed excretion of small sized urinary crystals, demonstrating that treatment potentially modulated the morphology of renal stones. Tissue enzymatic estimation affirmed the antioxidant efficacy of treatment with reduced free radical generation. Significant upregulation of p38MAPK at both the gene and protein level was noted in hyperoxaluric group and interestingly treatment reversed it. Acute oral toxicity study established the Median Lethal Dose (LD50) to be greater than 2000 mg/kg body weight (b.wt.) No observed adverse effect level (NOAEL) by repeated oral toxicity for 28 days at 750 mg/kg b.wt. was noted. This study lends scientific evidence to the safe, preventive and curative potential of statistically optimized aqueous extract of T. terrestris at a dose of 750 mg/kg b.wt. and suggests that the extract shows promise as a therapeutic antiurolithic agent.

Exploring the Effect of Endoplasmic Reticulum Stress Inhibition by 4-Phenylbutyric Acid on AMPA-Induced Hippocampal Excitotoxicity in Rat Brain.

Excessive stimulation of ionotropic glutamate receptor is associated with glutamate-mediated excitotoxicity, thereby causing oxidative imbalance and mitochondrial dysfunction, resulting in the excitotoxic death of neurons. Eminent role of endoplasmic reticulum under glutamate-induced excitotoxicity has been highlighted in numerous literatures which have been observed to trigger endoplasmic reticulum stress (ER stress) as well as regulating oxidative stress. However, combating ER stress in excitotoxic neurons can provide a novel approach to alleviate the mitochondrial dysfunctioning and ROS generation. Therefore, we propose to investigate the cross-communication of α-amino-3-hydroxy-5-methyl-4-isoxzole-propionate (AMPA) excitotoxicity-induced oxidative injury with ER stress by employing ER stress inhibitor-4-phenlybutyric acid (4-PBA). Male SD rats were divided into four groups viz sham group (group 1), AMPA (10 mM)-induced excitotoxic group (group 2), curative group of AMPA-induced excitotoxic animals given 4-PBA at a dose of 100 mg/kg body weight (group 3), and alone 4-PBA treatment group (100 mg/kg body weight) (group 4). Animals were sacrificed after 15 days of treatment, and hippocampi were analyzed for histopathological examination, ROS, inflammatory markers, mitochondrial dysfunction, and ER stress markers. AMPA-induced excitotoxicity exhibited a significant increase in the levels of ROS, upregulated ER stress markers, inflammation markers, and compromised mitochondrial functioning in the hippocampus. However, 4-PBA administration significantly curtailed the AMPA-induced excitotoxic insult. This study suggests that targeting ER stress with a chemical chaperone can provide a better therapeutic intervention for neurological disorders involving excitotoxicity, and thus, it opens a new avenue to screen chemical chaperones for the therapeutic modalities.

Amelioration of hyperoxaluria-induced kidney dysfunction by chemical chaperone 4-phenylbutyric acid.

Hyperoxaluria is characterized by an increased excretion of urinary oxalate which is caused by inherited disorders or high oxalate intake leading to renal stone ailment. Until date, reactive oxygen species and inflammation has been convicted for the progression of kidney stones for which antioxidant therapy has been employed. However, recent studies have linked the association of endoplasmic reticulum stress and oxidative imbalance in the progression of renal diseases. Considering oxidative stress being at forefront in causing hyperoxaluric consequences, current study was designed to correlate the impact of hyperoxaluria and regulation of oxidative imbalance via inhibition of endoplasmic reticulum stress by 4-phenylbutyric acid (4-PBA). Male wistar rats were subdivided into three groups, i.e., normal control (C), hyperoxaluric rats given ethylene glycol (EG), and hyperoxaluric rats treated with 4-PBA (EG + PBA). After 28 days of treatment, assessment of antioxidant defence system, inflammation, ER stress, and subsequent unfolded protein response was studied in renal tissue. It was found that the hyperoxaluric insult led to a marked damage to the renal tissue resulting in compromised antioxidant levels, upregulation of ER stress markers along with a steep surge in the extent of inflammation. However, 4-PBA treatment significantly curtailed the deleterious effects of hyperoxaluria by lowering down the level of stress markers as well as normalizing the antioxidant defence enzymes. Therefore, chemical chaperones can be deemed as a new class of drugs for the treatment of hyperoxaluric induced renal damage.

Efficacy of linalool to ameliorate uremia induced vascular calcification in wistar rats.

BACKGROUND: Uremia is the condition generally associated with the last stage of chronic kidney disease (CKD) due to highly reduced glomerular filtration rate. Mortality of the patients diagnosed with Uremia generally occurs due to cardiovascular involvement. This occurs due to the transdifferentiation of vascular smooth muscle cells (VSMCs) into osteogenic cells in hyperphosphatemic condition that is associated with kidney failure promoting extra-osseous calcification. PURPOSE: Linalool is an essential oil that has been recently studied for its procardiovascular effects, thus the aim of the study involved to identify its potential role on vascular calcification (VC). METHODS: Uremia was induced in male wistar rats, weighing 250-350 gm by giving adenine diet for 4 weeks followed by phosphate diet for next 4 weeks. Linalool was given orally at two different doses (100 mg/kg bodyweight and 150 mg/kg bodyweight) daily for 4 weeks with phosphate diet. RESULTS: Linalool being a moderate antioxidant probably scavenged superoxide radicals (in vitro analysis). Deposition of calcium was observed by alizarin and von-kossa stains in aorta of uremic rats whereas linalool co-administration prevents calcium deposition in aorta of uremic rats. Elevated mRNA expression of calcification markers, increased lipid peroxidation levels and increased levels of catalase and superoxide dismutase (SOD) was found in aorta of uremic animals. However, with supplementation of linalool reduction in the mRNA expression of calcification markers, lipid peroxidation and antioxidant enzymes were observed. CONCLUSION: Therefore it can be concluded that linalool could be a promising therapeutic candidate for exploring its clinical application in VC.

Design and Characterization of Apocynin Loaded PLGA Nanoparticles and their In vivo Efficacy in Hyperoxaluric Rats.

BACKGROUND: Apocynin has become a drug of choice in NADPH oxidase induced pathological conditions. Hyperoxaluria is one such pathological condition where NADPH oxidase is involved in eliciting renal injury. OBJECTIVE: Recently apocynin has shown to reverse the transcriptome profile of the NADPH oxidaseassociated genes and reduced oxidative burden in hyperoxaluric animals. The poor solubility of this drug creates certain apprehensions about its bioavailability. PLGA (Poly Lactic co-Glycolic Acid) encapsulation of drug nanoparticles have showed to induce sustain release and henceforth enhance the efficiency and bioavailability of drugs. Therefore, the present study is aimed to envisage a novel approach of synthesizing apocynin doped PLGA nanoparticles. METHODS: The PLGA nanoparticles (both unloaded and loaded) were prepared using solvent extraction method and analyzed for size and stability by Dynamic Light Scattering (DLS), TEM (transmission electron microscopy) and zeta potential. Furthermore, the drug release and encapsulation efficiency of the drug was calculated in vitro. RESULTS: The nanoencapsulation formed was stable with desired size (217-259 nm) and posses a controlled drug release of 20%. Further this nanoencapsulation was explored for its potential to reduce hyperoxaluric manifestations in rats given ethylene glycol with ammonium chloride for 9 days. CONCLUSION: In comparison to free apocynin, it was found that nanoparticles containing apocynin showed moderately better results in vivo by maintaining serum urea and createnine levels. These nanoparticles can be used in diseases where a sustained release of apocynin is required.