Pathophysiological and therapeutic implications of neuropeptide S system in neurological disorders

Neuropeptide S (NPS) is a 20 amino acids-containing neuroactive molecule discovered by the reverse pharmacology method. NPS is detected in specific brain regions like the brainstem, amygdala, and hypothalamus, while its receptor (NPSR) is ubiquitously expressed in the central nervous system (CNS). Besides CNS, NPS and NPSR are also expressed in the peripheral nervous system. NPSR is a G-protein coupled receptor that primarily uses Gq and Gs signaling pathways to mediate the actions of NPS. In animal models of Parkinsonism and Alzheimer's disease, NPS exerts neuroprotective effects. NPS suppresses oxidative stress, anxiety, food intake, and pain, and promotes arousal. NPSR facilitates reward, reinforcement, and addiction-related behaviors. Genetic variation and single nucleotide polymorphism in NPSR are associated with depression, schizophrenia, rheumatoid arthritis, and asthma. NPS interacts with several neurotransmitters including glutamate, noradrenaline, serotonin, corticotropin-releasing factor, and gamma-aminobutyric acid. It also modulates the immune system via augmenting pro-inflammatory cytokines and plays an important role in the pathogenesis of rheumatoid arthritis and asthma. In the present review, we discussed the distribution profile of NPS and NPSR, signaling pathways, and their importance in the pathophysiology of various neurological disorders. We have also proposed the areas where further investigations on the NPS system are warranted.

Potentially active aspirin derivative to release nitric oxide: In-vitro, in-vivo and in-silico approaches

The series of newer salicylate derivatives incorporating nitroxy functionality were synthesized and evaluated for their potential effect in gastrointestinal (GI) related toxicity produced by aspirin. The synthesized compounds (5a-j) were subjected to %NO (nitric oxide) release study, in-vitro anti-inflammatory potential, % inhibition of carrageenan-induced paw edema and the obtained results were validated by in-silico studies including molecular docking, MD simulations and in-silico ADME (absorption, distribution, metabolism, and elimination) calculations. Compounds 5a (20.86 %) and 5g (18.20 %) displayed the highest percentage of NO release in all the tested compounds. Similarly, 5a and 5h were found to have (77.11 % and 79.53 %) &(78.56 % and 66.10 %) inhibition in carrageenan induced paw edema in animal mode which were relatively higher than ibuprofen (standard used). The obtained results were validated by molecular docking and MD simulations studies. The molecular docking study of 5a and 5h revealed that docking scores were also obtained in very close proximity of -8.35, -9.67 and -8.48 for ibuprofen, 5g and 5h respectively. In MD simulations studies, the calculated lower RMSD (root mean square deviation) values 2.8 Å and 5.6 Å for 5g and 5h, respectively indicated the stability of ligand-protein complexes. Similarly lower RSMF (root mean square fluctuation) values indicated the molecules remained in the active pocket throughout the entire MD simulations run. Further, in-silico ADME calculations were determined and all compounds obey the Lipinski's rule of five and it was predicted that these molecules would be orally active without any serious toxic effect.

CB2 Cannabinoid Receptor as a Potential Target in Myocardial Infarction: Exploration of Molecular Pathogenesis and Therapeutic Strategies

The lipid endocannabinoid system has recently emerged as a novel therapeutic target for several inflammatory and tissue-damaging diseases, including those affecting the cardiovascular system. The primary targets of cannabinoids are cannabinoid type 1 (CB1) and 2 (CB2) receptors. The CB2 receptor is expressed in the cardiomyocytes. While the pathological changes in the myocardium upregulate the CB2 receptor, genetic deletion of the receptor aggravates the changes. The CB2 receptor plays a crucial role in attenuating the advancement of myocardial infarction (MI)-associated pathological changes in the myocardium. Activation of CB2 receptors exerts cardioprotection in MI via numerous molecular pathways. For instance, delta-9-tetrahydrocannabinol attenuated the progression of MI via modulation of the CB2 receptor-dependent anti-inflammatory mechanisms, including suppression of pro-inflammatory cytokines like IL-6, TNF-α, and IL-1β. Through similar mechanisms, natural and synthetic CB2 receptor ligands repair myocardial tissue damage. This review aims to offer an in-depth discussion on the ameliorative potential of CB2 receptors in myocardial injuries induced by a variety of pathogenic mechanisms. Further, the modulation of autophagy, TGF-β/Smad3 signaling, MPTP opening, and ROS production are discussed. The molecular correlation of CB2 receptors with cardiac injury markers, such as troponin I, LDH1, and CK-MB, is explored. Special attention has been paid to novel insights into the potential therapeutic implications of CB2 receptor activation in MI.

Mechanisms of emerging resistance associated with non-antibiotic antimicrobial agents: a state-of-the-art review

Although the development of resistance by microorganisms to antimicrobial drugs has been recognized as a global public health concern, the contribution of various non-antibiotic antimicrobial agents to the development of antimicrobial resistance (AMR) remains largely neglected. The present review discusses various chemical substances and factors other than typical antibiotics, such as preservatives, disinfectants, biocides, heavy metals and improper chemical sterilization that contribute to the development of AMR. Furthermore, it encompasses the mechanisms like co-resistance and co-selection, horizontal gene transfer, changes in the composition and permeability of cell membrane, efflux pumps, transposons, biofilm formation and enzymatic degradation of antimicrobial chemicals which underlie the development of resistance to various non-antibiotic antimicrobial agents. In addition, the review addresses the resistance-associated changes that develops in microorganisms due to these agents, which ultimately contribute to the development of resistance to antibiotics. In order to prevent the indiscriminate use of chemical substances and create novel therapeutic agents to halt resistance development, a more holistic scientific approach might provide diversified views on crucial factors contributing to the persistence and spread of AMR. The review illustrates the common and less explored mechanisms contributing directly or indirectly to the development of AMR by non-antimicrobial agents that are commonly used.

Neuroinflammation in the Central Nervous System: Exploring the Evolving Influence of Endocannabinoid System

Neuroinflammation is a complex biological process that typically originates as a protective response in the brain. This inflammatory process is triggered by the release of pro-inflammatory substances like cytokines, prostaglandins, and reactive oxygen and nitrogen species from stimulated endothelial and glial cells, including those with pro-inflammatory functions, in the outer regions. While neuronal inflammation is common in various central nervous system disorders, the specific inflammatory pathways linked with different immune-mediated cell types and the various factors influencing the blood-brain barrier significantly contribute to disease-specific characteristics. The endocannabinoid system consists of cannabinoid receptors, endogenous cannabinoids, and enzymes responsible for synthesizing and metabolizing endocannabinoids. The primary cannabinoid receptor is CB1, predominantly found in specific brain regions such as the brainstem, cerebellum, hippocampus, and cortex. The presence of CB2 receptors in certain brain components, like cultured cerebellar granular cells, Purkinje fibers, and microglia, as well as in the areas like the cerebral cortex, hippocampus, and cerebellum is also evidenced by immunoblotting assays, radioligand binding, and autoradiography studies. Both CB1 and CB2 cannabinoid receptors exhibit noteworthy physiological responses and possess diverse neuromodulatory capabilities. This review primarily aims to outline the distribution of CB1 and CB2 receptors across different brain regions and explore their potential roles in regulating neuroinflammatory processes.

Recent Advancements in Topical Anti-Psoriatic Nanostructured Lipid Carrier-Based Drug Delivery

Psoriasis is linked with unusual differentiation and hyperproliferation of epidermal keratinocytes that significantly impair the quality of life (QoL) of patients. The present treatment options only provide symptomatic relief and are surrounded by various adverse effects. Recently, nanostructured lipid carriers (NLCs) have emerged as next-generation nanocarriers with better physicochemical characteristics. The current manuscript provides background information on psoriasis, its pathophysiology, existing treatment options, and its limitations. It highlights the advantages, rationale, and mechanism of the permeation of NLCs for the treatment of psoriasis. It further gives a detailed account of various NLC nanoformulations for the treatment of psoriasis. In addition, tabular information is provided on the most relevant patents on NLCs for treating psoriasis. Lastly, light is shed on regulatory considerations related to NLC-like nanoformulations. In the treatment of psoriasis, NLCs display a sustained release drug profile, an ability to incorporate both hydrophobic and hydrophilic drugs, an enhancement in skin hydration, penetrability, retention, and bioavailability of the drug, along with reduced staining potential as compared to conventional ointments, and decreased side effects of drug molecules. This affirms the bright future of NLC nanoformulations in the treatment of psoriasis. However, academic industry collaboration and more sound regulatory controls are required to commercialize the NLC nanoformulations for psoriasis treatment.

Ghrelin alleviates depression-like behaviour in rats subjected to high-fat diet and diurnal rhythm disturbance

OBJECTIVES

In the era of globalization, a sedentary lifestyle is highly linked with obesity and neurobehavioral complications such as depression. While depression is associated with dopamine dysfunction in the ventral tegmental area (VTA), ghrelin enhances the dopaminergic activity in the VTA. Therefore, the present study aimed to assess the effect of ghrelin on depression-like behaviour in rats subjected to a high-fat diet (HFD) and disturbed diurnal rhythm (DDR) for 45 days.

METHODS

The neurobehavioral deficits resulting from HFD and DDR in rats, and the behaviour modulation by intra-VTA administration of ghrelin, alone or in combination with ghrelin receptor antagonist were confirmed by evaluation of behavioural parameters in the elevated plus-maze, forced swim test, open field test, and rotarod assessment. Further, the levels of pro-inflammatory cytokines such as tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and IL-6, oxidative stress marker malondialdehyde (MDA), and antioxidants enzymes like superoxide dismutase (SOD), reduced glutathione (GSH), and catalase (CAT) were measured.

RESULTS

The levels of TNF-α, IL-1β, IL-6, and MDA were increased in the brain of HFD and DDR exposed rats, while that of SOD, GSH, and CAT were reduced. Intra-VTA ghrelin administration from day 41-45 to the HFD and DDR exposed rats improved cognitive behaviour and physical activity confirming the antidepressant effect. Moreover, ghrelin restored the levels of SOD, GSH and CAT efficiently, and reduced that of MDA, TNF-α, IL-1β and IL-6, which signifies its protective effect.

CONCLUSION

Overall, this study confirmed the ameliorative effect of ghrelin in HFD- and DDR-induced depression-like behaviour.

Therapeutic Potential and Pharmaceutical Development of a Multitargeted Flavonoid Phloretin

Phloretin is a flavonoid of the dihydrogen chalcone class, present abundantly in apples and strawberries. The beneficial effects of phloretin are mainly associated with its potent antioxidant properties. Phloretin modulates several signaling pathways and molecular mechanisms to exhibit therapeutic benefits against various diseases including cancers, diabetes, liver injury, kidney injury, encephalomyelitis, ulcerative colitis, asthma, arthritis, and cognitive impairment. It ameliorates the complications associated with diabetes such as cardiomyopathy, hypertension, depression, memory impairment, delayed wound healing, and peripheral neuropathy. It is effective against various microbial infections including Salmonella typhimurium, Listeria monocytogenes, Mycobacterium tuberculosis, Escherichia coli, Candida albicans and methicillin-resistant Staphylococcus aureus. Considering the therapeutic benefits, it generated interest for the pharmaceutical development. However, poor oral bioavailability is the major drawback. Therefore, efforts have been undertaken to enhance its bioavailability by modifying physicochemical properties and molecular structure, and developing nanoformulations. In the present review, we discussed the pharmacological actions, underlying mechanisms and molecular targets of phloretin. Moreover, the review provides insights into physicochemical and pharmacokinetic characteristics, and approaches to promote the pharmaceutical development of phloretin for its therapeutic applications in the future. Although convincing experimental data are reported, human studies are not available. In order to ascertain its safety, further preclinical studies are needed to encourage its pharmaceutical and clinical development.

Verapamil hydrochloride loaded solid lipid nanoparticles: Preparation, optimization, characterisation, and assessment of cardioprotective effect in experimental model of myocardial infarcted rats

Verapamil, a calcium channel blocker has poor bioavailability (20-30%) owing to extensive hepatic first-pass metabolism. Hence, the major objective of this research was to improve the oral bioavailability of Verapamil by Solid Lipid Nanoparticles (V-SLNs) using high shear homogenization and ultrasonication technology. A 3² factorial design was employed to statistically optimize the formulation to get minimum particle size with maximum entrapment efficiency. The average particle size was 218 nm and the entrapment efficiency was 80.32%. The V-SLN formulation exhibited biphasic behavior with a rapid release at first, then a steady release (75-80%) up to 24 h following the Korsmeyer Peppas release model. In the Isoproterenol induced myocardial necrosis model, oral administration of V-SLNs positively modulated almost all the studied hemodynamic parameters such as left ventricular end-diastolic pressure, cardiac injury markers, and tissue architecture. The cardioprotective effect was also confirmed with histopathological studies. When compared with free drugs, in-vivo pharmacokinetic studies demonstrated a rise in t_1/2, AUC_0-∞, and Cmax, indicating that bioavailability has improved. These encouraging results demonstrate the promising potential of developed V-SLNs for oral delivery and thereby improve the therapeutic outcome.

Thymoquinone Produces Cardioprotective Effect in β-Receptor Stimulated Myocardial Infarcted Rats via Subsiding Oxidative Stress and Inflammation

Earlier studies reported that long-term treatment with thymoquinone (TQ) at a high dose (20 mg/kg) exerts a cardioprotective effect against isoproterenol (ISO)-triggered myocardial infarction (MI) in rats. In the present study, we tested the hypothesis that TQ, as a potent molecule, can exhibit cardioprotective effects at the lower dose for a short-term regimen. The rats were administered with TQ (5 mg/kg, intraperitoneal) at the 4 h interval for 2 days. ISO (100 mg/kg/day, subcutaneous) was given for 2 days to produce MI. ISO challenge results in deformation in ECG wave front, elevated left ventricular (LV) end-diastolic pressure, and reduced LVdP/dtmax and LVdP/dtmin. The levels of the cardiac biomarker in serum, such as creatine kinase MB, alanine aminotransferase, and aspartate aminotransferase, were increased. In the myocardium, a rise in malonaldehyde and decreased superoxide dismutase, glutathione, and catalase contents were observed. Furthermore, increased levels of tumor necrotic factor-α, interleukin-6, and interleukin-1β were observed in the myocardium. TQ pretreatment significantly normalized alterations in hemodynamic parameters, strengthened the antioxidant defense system, and decreased the contents of pro-inflammatory cytokines and hepatic enzymes as compared to the ISO group. Based on the results, TQ appears to be cardioprotective at low doses, and effective even administered for a shorter duration.

In vitro and in vivo characterization of Entacapone-loaded nanostructured lipid carriers developed by quality-by-design approach

Entacapone, a reversible catechol-o-methyl transferase inhibitor, is used to enhance the action of dopamine agonists by reducing their metabolism and the 'Wearing-off' effects associated with long-term use in the treatment of Parkinson's disease. It is used as an adjunct to levodopa/Carbidopa therapy. Due to limited dissolution and first-pass clearance, it suffers low and variable bioavailability issues. To overcome this problem, the present study aims to explore the potential of nanostructured lipid carriers (NLCs) for the delivery of Entacapone. The Quality by Design (QbD) approach was used for the systematic development of NLCs. The 2³ full factorial designs were investigated using Design-Expert®11 software. The three independent variables namely content of total lipid (X1), surfactant (X2), and sonication time (X3) were optimized against two responses namely particle size and entrapment efficiency. The optimized NLCs were characterized for their size, surface morphology, entrapment efficiency, drug release, thermal and crystallographic studies. In-vivo pharmacokinetic studies in Entacapone-loaded NLCs showed an increase in t_1/2, AUC_0-∞, MRT compared to free drug. The reduction in elimination (Kel) depicts the prolonged action of Entacapone by loading in NLCs. The results displayed Entacapone-loaded NLCs have promising potential for oral delivery and enhanced therapeutic effect which otherwise was a major issue.

Ghrelin mediated regulation of neurosynaptic transmitters in depressive disorders

Ghrelin is a peptide released by the endocrine cells of the stomach and the neurons in the arcuate nucleus of the hypothalamus. It modulates both peripheral and central functions. Although ghrelin has emerged as a potent stimulator of growth hormone release and as an orexigenic neuropeptide, the wealth of literature suggests its involvement in the pathophysiology of affective disorders including depression. Ghrelin exhibits a dual role through the advancement and reduction of depressive behavior with nervousness in the experimental animals. It modulates depression-related signals by forming neuronal networks with various neuropeptides and classical neurotransmitter systems. The present review emphasizes the integration and signaling of ghrelin with other neuromodulatory systems concerning depressive disorders. The role of ghrelin in the regulation of neurosynaptic transmission and depressive illnesses implies that the ghrelin system modulation can yield promising antidepressive therapies.

•

Ghrelin is the orexigenic type of neuropeptide.

•

It binds with the growth hormone secretagogue receptor (GHSR).

•

GHSR is ubiquitously present in the various brain regions.

•

Ghrelin is involved in the regulation of depression-related behavior.

•

The review focuses on the neurotransmission and signaling of ghrelin in neuropsychiatric and depressive disorders.

Pharmacological Properties, Therapeutic Potential and Molecular Mechanisms of JWH133, a CB2 Receptor-Selective Agonist

The endocannabinoid system has attracted attention as a pharmacological target for several pathological conditions. Cannabinoid (CB2)-selective agonists have been the focus of pharmacological studies because modulation of the CB2 receptor (CB2R) can be useful in the treatment of pain, inflammation, arthritis, addiction, and cancer among other possible therapeutic applications while circumventing CNS-related adverse effects. Increasing number of evidences from different independent preclinical studies have suggested new perspectives on the involvement of CB2R signaling in inflammation, infection and immunity, thus play important role in cancer, cardiovascular, renal, hepatic and metabolic diseases. JWH133 is a synthetic agonist with high CB2R selectivity and showed to exert CB2R mediated antioxidant, anti-inflammatory, anticancer, cardioprotective, hepatoprotective, gastroprotective, nephroprotective, and immunomodulatory activities. Cumulative evidences suggest that JWH133 protects against hepatic injury, renal injury, cardiotoxicity, fibrosis, rheumatoid arthritis, and cancer as well as against oxidative damage and inflammation, inhibits fibrosis and apoptosis, and acts as an immunosuppressant. This review provides a comprehensive overview of the polypharmacological properties and therapeutic potential of JWH133. This review also presents molecular mechanism and signaling pathways of JWH133 under various pathological conditions except neurological diseases. Based on the available data, this review proposes the possibilities of developing JWH133 as a promising therapeutic agent; however, further safety and toxicity studies in preclinical studies and clinical trials in humans are warranted.

Pharmacological potential of JWH133, a cannabinoid type 2 receptor agonist in neurodegenerative, neurodevelopmental and neuropsychiatric diseases

The pharmacological activation of cannabinoid type 2 receptors (CB2R) gained attention due to its ability to mitigate neuroinflammatory events without eliciting psychotropic actions, a limiting factor for the drugs targeting cannabinoid type 1 receptors (CB1R). Therefore, ligands activating CB2R are receiving enormous importance for therapeutic targeting in numerous neurological diseases including neurodegenerative, neuropsychiatric and neurodevelopmental disorders as well as traumatic injuries and neuropathic pain where neuroinflammation is a common accompaniment. Since the characterization of CB2R, many CB2R selective synthetic ligands have been developed with high selectivity and functional activity. Among numerous ligands, JWH133 has been found one of the compounds with high selectivity for CB2R. JWH133 has been reported to exhibit numerous pharmacological activities including antioxidant, anti-inflammatory, anticancer, cardioprotective, hepatoprotective, gastroprotective, nephroprotective, and immunomodulatory. Recent studies have shown that JWH133 possesses potent neuroprotective properties in several neurological disorders, including neuropathic pain, anxiety, epilepsy, depression, alcoholism, psychosis, stroke, and neurodegeneration. Additionally, JWH133 showed to protect neurons from oxidative damage and inflammation, promote neuronal survival and neurogenesis, and serve as an immunomodulatory agent. The present review comprehensively examined neuropharmacological activities of JWH133 in neurological disorders including neurodegenerative, neurodevelopmental and neuropsychiatric using synoptic tables and elucidated pharmacological mechanisms based on reported observations. Considering the cumulative data, JWH133 appears to be a promising CB2R agonist molecule for further evaluation and it can be a prototype agent in drug discovery and development for a unique class of agents in neurotherapeutics. Further, regulatory toxicology and pharmacokinetic studies are required to determine safety and proceed for clinical evaluation.

Nerolidol, a Sesquiterpene from the Essential Oils of Aromatic Plants, Attenuates Doxorubicin-Induced Chronic Cardiotoxicity in Rats

The clinical usage of doxorubicin (DOX), a potent anthracycline antineoplastic drug, is limited due to its cardiotoxicity. The aim of this study was to assess the possible cardioprotective effects of nerolidol (NERO) in a rat model of DOX-induced chronic cardiotoxicity and the underlying molecular mechanisms. DOX (2.5 mg/kg) was injected intraperitoneally once in a week for 5 weeks to induce chronic cardiotoxicity in male albino Wistar rats. The rats were treated with NERO (50 mg/kg, orally) 6 days a week for a duration of 5 weeks. DOX-injected rats showed a significant decline in cardiac function, elevated levels of serum cardiac marker enzymes, and enhanced oxidative stress markers along with altered PI3K/Akt and Nrf2/Keap1/HO-1 signaling pathways. DOX also triggered the activation of NF-κB/MAPK signaling and increased the levels/expression of proinflammatory cytokines (TNF-α, IL-6, and IL-1β) and expression of inflammatory mediators (iNOS and COX-2) in the heart. DOX activated NLRP3 inflammasome-mediated pyroptotic cell death along with fibrosis, mitochondrial dysfunction, DNA damage, and apoptosis in the myocardium. Additionally, histological studies, TUNEL staining, and myocardial lesions revealed structural alterations of the myocardium. NERO treatment showed considerable protective effects on the biochemical and molecular parameters studied. The findings demonstrate that NERO protects against DOX-induced chronic cardiotoxicity and the observed cardioprotective effects are attributed to its potent antioxidant and free radical scavenging properties.

Nerolidol Attenuates Oxidative Stress, Inflammation, and Apoptosis by Modulating Nrf2/MAPK Signaling Pathways in Doxorubicin-Induced Acute Cardiotoxicity in Rats

The clinical usage of doxorubicin (DOX), a potent anthracycline antineoplastic drug, is often limited by its cardiotoxic effects. Thus, for improving usage of DOX, the aim of this study was to assess the cardioprotective effects of nerolidol (NERO) in a rat model of DOX-induced acute cardiotoxicity and examine underlying molecular mechanisms that contribute to these effects. To induce acute cardiotoxicity male albino Wistar rats were injected with single dose intraperitoneal DOX (12.5 mg/kg). The rats were treated with NERO (50 mg/kg, orally) for five days. DOX-injected rats showed elevated levels of cardiac marker enzymes and enhanced oxidative stress markers along with altered Nrf2/Keap1/HO-1 signaling pathways. DOX administration also induced the activation of NF-κB/MAPK signaling and increased the levels and expression of pro-inflammatory cytokines (TNF-α, IL-6, and IL-1β) as well as expression of inflammatory mediators (iNOS and COX-2) in the heart. DOX also triggered DNA damage and apoptotic cell death in the myocardium. Additionally, histological studies revealed structural alterations of the myocardium. NERO treatment exhibited protection against the deleterious results of DOX on myocardium, as evidenced by the restoration of altered biochemical parameters, mitigated oxidative stress, inflammation, and apoptosis. The findings of the present study demonstrate that NERO provides cardioprotective effects against DOX-induced acute cardiotoxicity attributed to its potent antioxidant, anti-inflammatory, and antiapoptotic activities through modulating cellular signaling pathways.

A focused review on CB2 receptor-selective pharmacological properties and therapeutic potential of β-caryophyllene, a dietary cannabinoid

The endocannabinoid system (ECS), a conserved physiological system emerged as a novel pharmacological target for its significant role and potential therapeutic benefits ranging from neurological diseases to cancer. Among both, CB1 and CB2R types, CB2R have received attention for its pharmacological effects as antioxidant, anti-inflammatory, immunomodulatory and antiapoptotic that can be achieved without causing psychotropic adverse effects through CB1R. The ligands activate CB2R are of endogenous, synthetic and plant origin. In recent years, β-caryophyllene (BCP), a natural bicyclic sesquiterpene in cannabis as well as non-cannabis plants, has received attention due to its selective agonist property on CB2R. BCP has been well studied in a variety of pathological conditions mediating CB2R selective agonist property. The focus of the present manuscript is to represent the CB2R selective agonist mediated pharmacological mechanisms and therapeutic potential of BCP. The present narrative review summarizes insights into the CB2R-selective pharmacological properties and therapeutic potential of BCP such as cardioprotective, hepatoprotective, neuroprotective, nephroprotective, gastroprotective, chemopreventive, antioxidant, anti-inflammatory, and immunomodulator. The available evidences suggest that BCP, can be an important candidate of plant origin endowed with CB2R selective properties that may provide a pharmacological rationale for its pharmacotherapeutic application and pharmaceutical development like a drug. Additionally, given the wide availability in edible plants and dietary use, with safety, and no toxicity, BCP can be promoted as a nutraceutical and functional food for general health and well-being. Further, studies are needed to explore pharmacological and pharmaceutical opportunities for therapeutic and preventive applications of use of BCP in human diseases.

β-Caryophyllene, A Natural Dietary CB2 Receptor Selective Cannabinoid can be a Candidate to Target the Trinity of Infection, Immunity, and Inflammation in COVID-19

Coronavirus disease (COVID-19), caused by novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is an ongoing pandemic and presents a public health emergency. It has affected millions of people and continues to affect more, despite tremendous social preventive measures. Identifying candidate drugs for the prevention and treatment of COVID-19 is crucial. The pathogenesis and the complications with advanced infection mainly involve an immune-inflammatory cascade. Therefore, therapeutic strategy relies on suppressing infectivity and inflammation, along with immune modulation. One of the most promising therapeutic targets for the modulation of immune-inflammatory responses is the endocannabinoid system, particularly the activation of cannabinoid type 2 receptors (CB2R), a G-protein coupled receptor which mediates the anti-inflammatory properties by modulating numerous signaling pathways. To pharmacologically activate the CB2 receptors, a naturally occurring cannabinoid ligand, beta-caryophyllene (BCP), received attention due to its potent anti-inflammatory, antiviral, and immunomodulatory properties. BCP is recognized as a full selective functional agonist on CB2 receptors and produces therapeutic effects by activating CB2 and the nuclear receptors, peroxisome proliferator-activated receptors (PPARs). BCP is regarded as the first dietary cannabinoid with abundant presence across cannabis and non-cannabis plants, including spices and other edible plants. BCP showed tissue protective properties and favorably modulates numerous signaling pathways and inhibits inflammatory mediators, including cytokines, chemokines, adhesion molecules, prostanoids, and eicosanoids. Based on its pharmacological properties, molecular mechanisms, and the therapeutic potential of BCP as an immunomodulator, anti-inflammatory, organ-protective, and antiviral, we hypothesize that BCP could be a promising therapeutic and/or preventive candidate to target the triad of infection, immunity, and inflammation in COVID-19. In line with numerous studies that proposed the potential of cannabinoids in COVID-19, BCP may be a novel candidate compound for pharmaceutical and nutraceutical development due to its unique functional receptor selectivity, wide availability and accessibility, dietary bioavailability, nonpsychoactivity, and negligible toxicity along with druggable properties, including favorable pharmacokinetic and physicochemical properties. Based on reasonable pharmacological mechanisms and therapeutic properties, we speculate that BCP has potential to be investigated against COVID-19 and will inspire further preclinical and clinical studies.

β-Caryophyllene, a natural bicyclic sesquiterpene attenuates β-adrenergic agonist-induced myocardial injury in a cannabinoid receptor-2 dependent and independent manner

The downregulation of cannabinoid type-2 receptors (CB2R) have been reported in numerous diseases including cardiovascular diseases (CVDs). The activation of CB2R has recently emerged as an important therapeutic target to mitigate myocardial injury. We examined whether CB2R activation can protect against isoproterenol (ISO)-induced myocardial injury (MI) in rats. In the present study, we investigated the cardioprotective effect of β-caryophyllene (BCP), a naturally occurring dietary cannabinoid in rat model of MI. Rats were pre- and co-treated with BCP (50 mg/kg, orally) twice daily for 10 days along with subcutaneous injection of ISO (85 mg/kg) at an interval of 24 h for two days (9th and 10th days). AM630 (1 mg/kg), a CB2 receptor antagonist, was injected intraperitoneal as a pharmacological challenge prior to BCP treatment to reveal CB2R-mediated cardioprotective mechanisms of BCP. Desensitization of beta-adrenergic receptor (β-AR) signaling, receptor phosphorylation and recruitment of adapter β-arrestins were observed in ISO-induced MI in rats. ISO injections caused impaired cardiac function, elevated the levels of serum cardiac marker enzymes, and enhanced oxidative stress markers along with altered PI3K/Akt and NrF2/Keap1/HO-1 signaling pathways. ISO also promoted lysosomal dysfunction along with activation of NLRP3 inflammasomes and TLR4-NFκB/MAPK signaling and triggered rise in proinflammatory cytokines. There was a concomitant mitochondrial dysfunction followed by the activation of endoplasmic reticulum (ER) stress-mediated Hippo signaling and intrinsic pathway of apoptosis as well as altered autophagic flux/mTOR signaling in ISO-induced MI. Furthermore, ISO also triggered dyslipidemia evidenced by altered lipids, lipoproteins and lipid marker enzymes along with ionic homeostasis malfunction. However, treatment with BCP resulted in significant protective effects on all biochemical and molecular parameters analyzed. The cardioprotective effects were further strengthened by preservation of cardiomyocytes and cell organelles as observed in histopathological and ultrastructural studies. Interestingly, treatment with AM630, a CB2R antagonist was observed to abrogate the protective effects of BCP on the biochemical and molecular parameters except hyperlipidemia and ionic homeostasis in ISO-induced MI in rats. The present study findings demonstrate that BCP possess the potential to protect myocardium against ISO-induced MI in a CB2-dependent and independent manner.

Can Echinacea be a potential candidate to target immunity, inflammation, and infection - The trinity of coronavirus disease 2019

Coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is an ongoing public health emergency. The pathogenesis and complications advanced with infection mainly involve immune-inflammatory cascade. Therefore, the therapeutic strategy relies on immune modulation, reducing infectivity and inflammation. Given the interplay of infection and immune-inflammatory axis, the natural products received attention for preventive and therapeutic usage in COVID-19 due to their potent antiviral and anti-immunomodulatory activities. Recently, Echinacea preparations, particularly E. purpurea, have been suggested to be an important antiviral agent to be useful in COVID-19 by modulating virus entry, internalization and replication. In principle, the immune response and the resultant inflammatory process are important for the elimination of the infection, but may have a significant impact on SARS-CoV-2 pathogenesis and may play a role in the clinical spectrum of COVID-19. Considering the pharmacological effects, therapeutic potential, and molecular mechanisms of Echinacea, we hypothesize that it could be a reasonably possible candidate for targeting infection, immunity, and inflammation in COVID-19 with recent recognition of cannabinoid-2 (CB2) receptors and peroxisome proliferator-activated receptor gamma (PPARγ) mediated mechanisms of bioactive components that make them notable immunomodulatory, anti-inflammatory and antiviral agent. The plausible reason for our hypothesis is that the presence of numerous bioactive agents in different parts of plants that may synergistically exert polypharmacological actions in regulating immune-inflammatory axis in COVID-19. Our proposition is to scientifically contemplate the therapeutic perspective and prospect of Echinacea on infection, immunity, and inflammation with a potential in COVID-19 to limit the severity and progression of the disease. Based on the clinical usage for respiratory infections, and relative safety in humans, further studies for the evidence-based approach to COVID-19 are needed. We do hope that Echinacea could be a candidate agent for immunomodulation in the prevention and treatment of COVID-19.

Can limonene be a possible candidate for evaluation as an agent or adjuvant against infection, immunity, and inflammation in COVID-19?

Coronavirus disease (COVID-19) caused by novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is an ongoing pandemic and presents a public health emergency. It has affected millions of people and continues to affect more, despite the tremendous social preventive measures. The therapeutic strategy relies on suppressing infectivity and inflammation, along with immune modulation. The identification of candidate drugs effective for COVID-19 is crucial, thus many natural products including phytochemicals are also being proposed for repurposing and evaluated for their potential in COVID-19. Among numerous phytochemicals, limonene (LMN), a dietary terpene of natural origin has been recently showed to target viral proteins in the in-silico studies. LMN is one of the main compounds identified in many citrus plants, available and accessible in diets and well-studied for its therapeutic benefits. Due to dietary nature, relative safety and efficacy along with favorable physicochemical properties, LMN has been suggested to be a fascinating candidate for further investigation in COVID-19. LMN showed to modulate numerous signaling pathways and inhibits inflammatory mediators, including cytokines, chemokines, adhesion molecules, prostanoids, and eicosanoids. We hypothesized that given the pathogenesis of COVID-19 involving infection, inflammation, and immunity, LMN may have potential to limit the severity and progression of the disease owing to its immunomodulatory, anti-inflammatory, and antiviral properties. The present article discusses the possibilities of LMN in SARS-CoV-2 infections based on its immunomodulatory, anti-inflammatory, and antiviral properties. Though, the suggestion on the possible use of LMN in COVID-19 remains inconclusive until the in-silico effects confirmed in the experimental studies and further proof of the concept studies. The candidature of LMN in COVID-19 treatment somewhat appear speculative but cannot be overlooked provided favorable physiochemical and druggable properties. The safety and efficacy of LMN are necessary to be established in preclinical and clinical studies before making suggestions for use in humans.

Solid self-microemulsifying nutraceutical delivery system for hesperidin using quality by design: assessment of biopharmaceutical attributes and shelf-life

AIM

The present study endeavours to develop a solid self-microemulsifying nutraceutical drug delivery system for hesperidin (HES) using quality by design (QbD) to improve its biopharmaceutical attributes.

METHODS

A 3² full factorial design was employed to study the influence of factors on selected responses. Risk assessment was performed by portraying Ishikawa fishbone diagram and failure mode effect analysis (FMEA). The in vivo antidiabetic study was carried on induced diabetic rats.

RESULTS

The optimised liquid SMEDDS-HES (OF) formulation showed emulsification time (Y ₁) = 102.5 ± 2.52 s, globule size (Y ₂) = 225.2 ± 3.40 nm, polydispersity index (Y ₃) = 0.294 ± 0.62, and zeta potential (Y ₄) = -25.4 ± 1.74 mV, respectively. The solid SMEDDS-HES (SOF-7) formulation was characterised by FTIR, PXRD, DSC, and SEM. The shelf life of SOF-7 was found to be 32.88 months. The heamatological and histopathological data of diabetic rats showed prominent antidiabetic activity.

CONCLUSIONS

The optimised formulation showed improved dissolution, desired stability, and promising antidiabetic activity.

CB2 receptor-selective agonists as candidates for targeting infection, inflammation, and immunity in SARS-CoV-2 infections

The COVID-19 pandemic caused by SARS-CoV-2 is a deadly disease afflicting millions. The pandemic continues affecting population due to nonavailability of drugs and vaccines. The pathogenesis and complications of infection mainly involve hyperimmune-inflammatory responses. Thus, therapeutic strategies rely on repurposing of drugs aimed at reducing infectivity and inflammation and modulate immunity favourably. Among, numerous therapeutic targets, the endocannabinoid system, particularly activation of cannabinoid type-2 receptors (CB2R) emerged as an important one to suppress the hyperimmune-inflammatory responses. Recently, potent antiinflammatory, antiviral and immunomodulatory properties of CB2R selective ligands of endogenous, plant, and synthetic origin were showed mediating CB2R selective functional agonism. CB2R activation appears to regulate numerous signaling pathways to control immune-inflammatory mediators including cytokines, chemokines, adhesion molecules, prostanoids, and eicosanoids. Many CB2R ligands also exhibit off-target effects mediating activation of PPARs, opioids, and TRPV, suggestive of adjuvant use with existing drugs that may maximize efficacy synergistically and minimize therapeutic doses to limit adverse/ side effects. We hypothesize that CB2R agonists, due to immunomodulatory, antiinflammatory, and antiviral properties may show activity against COVID-19. Based on the organoprotective potential, relative safety, lack of psychotropic effects, and druggable properties, CB2R selective ligands might make available promising candidates for further investigation.

Plant-derived natural therapeutics targeting cannabinoid receptors in metabolic syndrome and its complications: A review

The endocannabinoid system (ECS) is natural physiological system in the humans. The presence of the ECS system involves different roles in body. The endocannabinoid system involves regulation of most of the centers, which regulates the hunger and leads to changes in the weight. In the present article, we reviewed the role of natural cannabinoid compounds in metabolic disorders and related complications. We studied variety of a plant-derived cannabinoids in treating the metabolic syndrome including stoutness, fatty acid liver diseases, insulin obstruction, dementia, hypertension, lipid abnormalities, non-alcoholic steatohepatitis, endothelial damage, and polycystic ovarian syndrome and so on. The activation of cannabinoid receptors demonstrates a significant number of beneficial approaches concerning metabolic syndrome and reduces the pro-inflammatory cytokines on account of aggravation, decreased oxidative stress and uneasiness, diminishes liver fibrosis, with reduces adiponectin. Pre-clinical investigations of plant-derived cannabinoids resulted in promising outcomes. The different distinctive plant-derived cannabinoids were discovered like cannabidiol (CBD), cannabinol (CBN), cannabichromene (CBC), and cannabidiol (CBG). It has been observed that endogenous cannabinoids and plant-derived cannabinoids have an advantageous impact on limiting the metabolic disorder arising due to lifestyle changes.

Aloin alleviates doxorubicin-induced cardiotoxicity in rats by abrogating oxidative stress and pro-inflammatory cytokines

PURPOSE

Aloin, an anthraquinone present in the aloe species, possesses antiangiogenic, chemopreventive and antioxidant properties. It exerts cytotoxicity against breast cancer and ovarian cancer cell lines. These properties of aloin project it as a chemopreventive adjuvant to anticancer chemotherapy.

METHODS

We evaluated the effect of concurrent oral administration of aloin against doxorubicin (DOX)-induced cardiotoxicity in rats. The protective effects of aloin against DOX-induced toxicity were evident as a statistically significant inhibition of a rise in the biochemical markers of myocardial damage including lactate dehydrogenase (LDH), creatinine kinase-myocardial band (CK-MB), alanine aminotransferase (ALT), and aspartate aminotransferase (AST).

RESULTS

Aloin dose dependently inhibited the DOX-induced changes in ECG like increased ST-height and prolonged QT interval. It protected heart against the lipid peroxidation and restored the levels of antioxidative defenses: reduced glutathione, catalase and superoxide dismutase. Aloin prominently reduced the levels of proinflammatory cytokines- TNF-α, IL-1β and IL-6. Notably, the significant protective effects of aloin were evident even at the strikingly lower doses of 1 and 5 mg/kg per day.

CONCLUSION

Our results highlight the necessity to further investigate the chemopreventive effects of aloin against other chemotherapeutic agents.

Aloin protects against arsenic trioxide-induced myocardial membrane damage and release of inflammatory cytokines

Aloin exerts concentration-dependent pro-oxidant and antioxidant effects when tested in vitro. Such duality of effects has not been investigated through in vivo studies on aloin. We evaluated the effects of aloin at doses ranging between 1 and 125 mg/kg against the arsenic trioxide (As₂O₃)-induced cardiotoxicity in mice. As₂O₃ (5 mg/kg/day) was intraperitoneally administrated for 10 days. Aloin was administered through oral gavage at 1, 5, 25, and 125 mg/kg/day. As₂O₃ induced rise in ST height and QT interval in ECG, increased oxidative stress, and depleted the antioxidative defense. As₂O₃ increased inflammatory cytokine concentrations in the heart. Aloin dose dependently inhibited the As₂O₃-induced cardiotoxicity. There was no evidence of increased oxidative stress in the low-dose aloin-treated mice receiving As₂O_3. Our results indicate that aloin possesses cardioprotective potentials and its pro-oxidant effect is not evident in vivo at tested doses.

Disulfiram and Its Copper Chelate Attenuate Cisplatin-Induced Acute Nephrotoxicity in Rats Via Reduction of Oxidative Stress and Inflammation

The use of cisplatin (CP) in chemotherapy of resistant cancers is limited due to its dose-dependent nephrotoxicity. Disulfiram (DSF), the aversion therapy for alcoholism, has recently emerged as an anticancer and chemopreventive agent. Its anticancer activity is potentiated in the presence of copper. However, such use of copper leads to several adverse effects. In the present study, the protective effect of DSF and its copper chelate (Cu-DEDC) against CP-induced nephrotoxicity in rats was evaluated. Nephrotoxicity was induced by a single intraperitoneal injection of CP (5 mg/kg). The treatment groups included control (vehicle treated), CP (CP-treated), CP + DSF (CP followed by DSF), CP + DSF + Cu (CP followed by DSF and CuCl₂), CP + Cu-DEDC (CP followed by Cu-DEDC), and CP + AMF (amifostine pre-treated and CP-treated). The DSF, Cu-DEDC, and CuCl₂ were administered orally at 50 mM/kg/day dose for 5 days post CP injection. AMF served as a standard chemo protectant, administered intravenously 30 min prior to CP. The markers of oxidative stress, inflammation, and kidney function estimated on the 6th day revealed that both DSF and Cu-DEDC significantly attenuated the CP-induced rise in the serum/urine creatinine and blood urea nitrogen (BUN). The CP-induced rise in serum alkaline phosphatase (ALPase) was reversed by these drugs. Both drugs reduced the levels of malondialdehyde and nitric oxide (NO) in kidney tissues. These drugs reversed CP-induced depletion of SOD, catalase, and GSH in the kidneys. There was a significant reduction in the CP-induced TNF-α and IL-1β production along with prevention of histological alterations. Above observations indicate that DSF and Cu-DEDC may have significance as adjuvants to protect against CP-induced nephrotoxicity.

α-Bisabolol protects against β-adrenergic agonist-induced myocardial infarction in rats by attenuating inflammation, lysosomal dysfunction, NLRP3 inflammasome activation and modulating autophagic flux

Emerging evidence demonstrates that NLRP3 inflammasome activation, lysosomal dysfunction, and impaired autophagic flux play a crucial role in the pathophysiology of myocardial infarction (MI).

Recurrence rate of odontogenic myxoma after different treatments: a systematic review

Our aim was to establish the recurrence rate of odontogenic myxoma after different treatments. Our search covered papers from 1972-2017 from different sources. The papers were evaluated and critically appraised by two independent investigators. The recurrence rate and 95% CI were calculated in relation to each specific treatment, and the chi squared test was calculated to find out if there was any significant difference in the recurrence rate between conservative treatment and resection. The overall recurrence rate was 5 of 39 patients (13%) during a mean follow up period of 10 years. With conservative treatment the recurrence rate was 4/22 (19%) (mean follow up 11 years) and after resection it was 1/17 (6%) (mean follow up nine years). Maxillary lesions were more likely to recur than mandibular ones. Quality of life variables such as disfigurement and neural deficit were more common after resection than with conservative treatment. The frequency of recurrence was relatively low over 10 years' follow up, irrespective of whether resection or a more conservative approach was used, despite being slightly lower (as might be expected) after resection. Conservative treatment should be considered first to avoid resection-associated morbidity and the effect on the quality of life. Maxillary lesions have more room to spread before they are clinically evident, making them difficult to treat optimally and contributing to the recurrence rate.

Animal Models of Inflammation for Screening of Anti-inflammatory Drugs: Implications for the Discovery and Development of Phytopharmaceuticals

Inflammation is one of the common events in the majority of acute as well as chronic debilitating diseases and represent a chief cause of morbidity in today's era of modern lifestyle. If unchecked, inflammation leads to development of rheumatoid arthritis, diabetes, cancer, Alzheimer's disease, and atherosclerosis along with pulmonary, autoimmune and cardiovascular diseases. Inflammation involves a complex network of many mediators, a variety of cells, and execution of multiple pathways. Current therapy for inflammatory diseases is limited to the steroidal and non-steroidal anti-inflammatory agents. The chronic use of these drugs is reported to cause severe adverse effects like gastrointestinal, cardiovascular, and renal abnormalities. There is a massive need to explore new anti-inflammatory agents with selective action and lesser toxicity. Plants and isolated phytoconstituents are promising and interesting sources of new anti-inflammatories. However, drug development from natural sources has been linked with hurdles like the complex nature of extracts, difficulties in isolation of pure phytoconstituents, and the yield of isolated compounds in minute quantities that is insufficient for subsequent lead development. Although various in-vivo and in-vitro models for anti-inflammatory drug development are available, judicious selection of appropriate animal models is a vital step in the early phase of drug development. Systematic evaluation of phytoconstituents can facilitate the identification and development of potential anti-inflammatory leads from natural sources. The present review describes various techniques of anti-inflammatory drug screening with its advantages and limitations, elaboration on biological targets of phytoconstituents in inflammation and biomarkers for the prediction of adverse effects of anti-inflammatory drugs. The systematic approach proposed through present article for anti-inflammatory drug screening can rationalize the identification of novel phytoconstituents at the initial stage of drug screening programs.

Therapeutic Potential of Plants and Plant Derived Phytochemicals against Acetaminophen-Induced Liver Injury

Acetaminophen (APAP), which is also known as paracetamol or N-acetyl-p-aminophenol is a safe and potent drug for fever, pain and inflammation when used at its normal therapeutic doses. It is available as over-the-counter drug and used by all the age groups. The overdose results in acute liver failure that often requires liver transplantation. Current clinical therapy for APAP-induced liver toxicity is the administration of N-acetyl-cysteine (NAC), a sulphydryl compound an approved drug which acts by replenishing cellular glutathione (GSH) stores in the liver. Over the past five decades, several studies indicate that the safety and efficacy of herbal extracts or plant derived compounds that are used either as monotherapy or as an adjunct therapy along with conventional medicines for hepatotoxicity have shown favorable responses. Phytochemicals mitigate necrotic cell death and protect against APAP-induced liver toxicityby restoring cellular antioxidant defense system, limiting oxidative stress and subsequently protecting mitochondrial dysfunction and inflammation. Recent experimental evidences indicat that these phytochemicals also regulate differential gene expression to modulate various cellular pathways that are implicated in cellular protection. Therefore, in this review, we highlight the role of the phytochemicals, which are shown to be efficacious in clinically relevant APAP-induced hepatotoxicity experimental models. In this review, we have made comprehensive attempt to delineate the molecular mechanism and the cellular targets that are modulated by the phytochemicals to mediate the cytoprotective effect against APAP-induced hepatotoxicity. In this review, we have also defined the challenges and scope of phytochemicals to be developed as drugs to target APAP-induced hepatotoxicity.

Eplerenone attenuates myocardial infarction in diabetic rats via modulation of the PI3K-Akt pathway and phosphorylation of GSK-3β

We investigated the effect of eplerenone on myocardial infarcted diabetic rats via modulation of the PI3K/Akt pathway and its downstream target GSK-3β. Diabetes was induced by administration of a single dose of streptozotocin (55 mg/kg IP). Diabetic rats received either eplerenone or PI3k/Akt antagonist (wortmannin) or in combination for 14 days with concurrent administration of isoproterenol (100 mg/kg s.c) on 13^th and 14^th day. Isoproterenol prompted cardiotoxicity and was demonstrated by a decrease in the maximal positive rate of developed left ventricular pressure, the maximal negative rate of developed left ventricular pressure and an increase in left ventricular end-diastolic pressure along with oxidative stress. Myocardial infarcted diabetic rats exhibited increased myonecrosis, edema, and apoptotic cell death. Treatment with eplerenone significantly improved the redox status of the myocardium. Eplerenone markedly inhibited Bax expression, TUNEL-positive cells, and myonecrosis. On the other hand, the administration of eplerenone and wortmanin did not draw out the same effects, when administered concomitantly or individually. Moreover, the rats treated with eplerenone showed increased expression of PI3K/Akt and decreased its downstream target GSK-3β. The present study confirms the protective effects of eplerenone on myocardial infarction in diabetic rats via modulation of PI3K/Akt pathway and its downstream regulator GSK-3β.

Ultra-diluted Toxicodendron pubescens attenuates pro-inflammatory cytokines and ROS- mediated neuropathic pain in rats

Despite the availability of multiple therapeutic agents, the search for novel pain management of neuropathic pain is still a challenge. Oxidative stress and inflammatory signaling are prominently involved in clinical manifestation of neuropathic pain. Toxicodendron pubescens, popularly known as Rhus Tox (RT) is recommended in alternative medicines as an anti-inflammatory and analgesic remedy. Earlier, we reported anti-inflammatory, anti-arthritic and immunomodulatory activities of Rhus Tox. In continuation, we evaluated antinociceptive efficacy of Rhus Tox in the neuropathic pain and delineated its underlying mechanism. Initially, in-vitro assay using LPS-mediated ROS-induced U-87 glioblastoma cells was performed to study the effect of Rhus Tox on reactive oxygen species (ROS), anti-oxidant status and cytokine profile. Rhus Tox decreased oxidative stress and cytokine release with restoration of anti-oxidant systems. Chronic treatment with Rhus Tox ultra dilutions for 14 days ameliorated neuropathic pain revealed as inhibition of cold, warm and mechanical allodynia along with improved motor nerve conduction velocity (MNCV) in constricted nerve. Rhus Tox decreased the oxidative and nitrosative stress by reducing malondialdehyde (MDA) and nitric oxide (NO) content, respectively along with up regulated glutathione (GSH), superoxide dismutase (SOD) and catalase activity in sciatic nerve of rats. Notably, Rhus Tox treatment caused significant reductions in the levels of tumor necrosis factor (TNF-α), interleukin-6 (IL-6) and interleukin-1β (IL-1β) as compared with CCI-control group. Protective effect of Rhus Tox against CCI-induced sciatic nerve injury in histopathology study was exhibited through maintenance of normal nerve architecture and inhibition of inflammatory changes. Overall, neuroprotective effect of Rhus Tox in CCI-induced neuropathic pain suggests the involvement of anti-oxidative and anti-inflammatory mechanisms.

Pharmacological Properties, Molecular Mechanisms, and Pharmaceutical Development of Asiatic Acid: A Pentacyclic Triterpenoid of Therapeutic Promise

Asiatic acid (AA) is a naturally occurring aglycone of ursane type pentacyclic triterpenoids. It is abundantly present in many edible and medicinal plants including Centella asiatica that is a reputed herb in many traditional medicine formulations for wound healing and neuropsychiatric diseases. AA possesses numerous pharmacological activities such as antioxidant and anti-inflammatory and regulates apoptosis that attributes its therapeutic effects in numerous diseases. AA showed potent antihypertensive, nootropic, neuroprotective, cardioprotective, antimicrobial, and antitumor activities in preclinical studies. In various in vitro and in vivo studies, AA found to affect many enzymes, receptors, growth factors, transcription factors, apoptotic proteins, and cell signaling cascades. This review aims to represent the available reports on therapeutic potential and the underlying pharmacological and molecular mechanisms of AA. The review also also discusses the challenges and prospects on the pharmaceutical development of AA such as pharmacokinetics, physicochemical properties, analysis and structural modifications, and drug delivery. AA showed favorable pharmacokinetics and found bioavailable following oral or interaperitoneal administration. The studies demonstrate the polypharmacological properties, therapeutic potential and molecular mechanisms of AA in numerous diseases. Taken together the evidences from available studies, AA appears one of the important multitargeted polypharmacological agents of natural origin for further pharmaceutical development and clinical application. Provided the favorable pharmacokinetics, safety, and efficacy, AA can be a promising agent or adjuvant along with currently used modern medicines with a pharmacological basis of its use in therapeutics.

D-pinitol attenuates cisplatin-induced nephrotoxicity in rats: Impact on pro-inflammatory cytokines

Cisplatin has been widely used as a first-line agent against various forms of solid cancers. However, nephrotoxicity is the major limiting factor for its clinical use. Several clinical and pre-clinical studies have suggested different strategies for the reduction of cisplatin-induced nephrotoxicity. The present study was conducted to investigate the efficacy of D-Pinitol, against cisplatin-induced nephrotoxicity in Swiss albino mice. A single intraperitoneal injection of cisplatin (20 mg/kg) was used to induce nephrotoxicity in mice. Administration of cisplatin in mice is linked with elevated oxidative stress, imbalanced biochemical parameters, apoptosis and stimulation of mitogen-activated protein kinase (MAPK) pathway. D-Pinitol is a member of the flavonoid family and a chief constituent of Sutherlandia fruitesecnce. It was administered with saline water (10, 20, 40 mg/kg, p.o.) for seven consecutive days after a single dose of cisplatin. At the end of experiment, animals were sacrificed and biochemical parameters in serum and urine were recorded. Kidneys were isolated for the estimation of tumor necrosis factor-alpha, interleukin-1β, interlukin-6 levels and histopathological evaluations. It was noted that D-Pinitol significantly ameliorated biochemical levels of serum and urinary creatinine and blood urea nitrogen. Tissue homogenate levels of TNF-α, IL-6, IL-1β and the renal expression of tissue nitrites were also significantly decreased in D-Pinitol treated mice. These results were supplemented by histopathological findings. This study highlights the potential role of D-Pinitol against cisplatin-induced toxicity, exhibited through favorable alterations in biochemical and histological changes as well as reduction in oxidative stress and cytokine levels.

Eplerenone pretreatment protects the myocardium against ischaemia/reperfusion injury through the phosphatidylinositol 3-kinase/Akt-dependent pathway in diabetic rats

We investigated the eplerenone-induced, PI3K/Akt- and GSK-3β-mediated cardioprotection against ischemia/reperfusion (I/R) injury in diabetic rats. The study groups comprising diabetic rats were treated for 14 days with 150 mg/kg/day eplerenone orally and 1 mg/kg wortmannin (PI3K/Akt antagonist) intraperitoneally with eplerenone. On the 15th day, the rats were exposed to I/R injury by 20-min occlusion of the left anterior descending coronary artery followed by 30 min of reperfusion. The hearts were processed for biochemical, molecular, and histological investigations. The I/R injury in diabetic rats inflicted a significant rise in the oxidative stress and apoptosis along with a decrease in the arterial and ventricular function and the expressions of PI3K/Akt and GSK-3β proteins. Eplerenone pretreatment reduced the arterial pressure, cardiac inotropy, and lusitropy. It significantly reduced apoptosis and cardiac injury markers. The histology revealed cardioprotection in eplerenone-treated rats. Eplerenone up-regulated the PI3K/Akt and reduced the GSK-3β expression. The group receiving wortmannin with eplerenone was deprived eplerenone-induced cardioprotection. Our results reveal the eplerenone-induced cardioprotection against I/R injury in diabetic rats and substantiate the involvement of PI3K/Akt and GSK-3β pathways in its efficacy.

Polypharmacological Properties and Therapeutic Potential of β-Caryophyllene: A Dietary Phytocannabinoid of Pharmaceutical Promise

BACKGROUND

β-Caryophyllene (BCP) is a natural bicyclic sesquiterpene abundantly found in essential oils from various spices, fruits and medicinal as well as ornamental plants. It is approved by United States Food and Drug Administration and European agencies as food additive, taste enhancer and flavoring agent and termed as a phytocannabinoid.

METHODS

All the available literature on BCP and its synonyms were collected through different literature databases.

RESULTS

BCP was found to elicit a full agonist action on cannabinoid type 2 (CB2) receptors, a G-protein coupled receptor representing important therapeutic target in several diseases. Activation of CB2 receptors notably appeared devoid of psychotropic adverse effect of cannabinoids contrary to the CB1 receptors. In addition, it activates peroxisome proliferated activator receptors (PPARs) isoforms; PPAR-α &-γ and inhibits pathways triggered by the activation of toll like receptor complex; CD14/TLR4/MD2, reduce immuneinflammatory processes and exhibit synergy with µ-opioid receptor dependent pathways. Additionally, it found as potent antagonist of homomeric nicotinic acetylcholine receptors (α7-nAChRs) and devoid of effects mediated by serotonergic and GABAergic receptors. It also modulates numerous molecular targets by altering their gene expression, signaling pathways or through direct interaction. Various pharmacological activities such as cardioprotective, hepatoprotective, gastroprotective, neuroprotective, nephroprotective, antioxidant, anti-inflammatory, antimicrobial and immune-modulator have been reported in experimental studies. It has shown potent therapeutic promise in neuropathic pain, neurodegenerative and metabolic diseases.

CONCLUSION

The present review provides a comprehensive insight of pharmacological and therapeutic potential of BCP, its molecular mechanism and signaling pathways in different pathological conditions. The review also examines the possibility of its further development as a novel candidate for various pathologies considering the polypharmacological and multifaceted therapeutic properties potential along with favorable oral bioavailability, lipophilicity and physicochemical properties.

Therapeutic Potential and Pharmaceutical Development of Thymoquinone: A Multitargeted Molecule of Natural Origin

Thymoquinone, a monoterpene molecule is chemically known as 2-methyl-5-isopropyl-1, 4-benzoquinone. It is abundantly present in seeds of Nigella sativa L. that is popularly known as black cumin or black seed and belongs to the family Ranunculaceae. A large number of studies have revealed that thymoquinone is the major active constituent in N. sativa oil this constituent is responsible for the majority of the pharmacological properties. The beneficial organoprotective activities of thymoquinone in experimental animal models of different human diseases are attributed to the potent anti-oxidant and anti-inflammatory properties. Thymoquinone has also been shown to alter numerous molecular and signaling pathways in many inflammatory and degenerative diseases including cancer. Thymoquinone has been reported to possess potent lipophilicity and limited bioavailability and exhibits light and heat sensitivity. Altogether, these physiochemical properties encumber the successful formulation for the delivery of drug in oral dosages form and restrict the pharmaceutical development. In recent past, many efforts were undertaken to improve the bioavailability for clinical usage by manipulating the physiochemical parameters. The present review aimed to provide insights regarding the physicochemical characteristics, pharmacokinetics and the methods to promote pharmaceutical development and endorse the clinical usage of TQ in future by overcoming the associated physiochemical obstacles. It also enumerates briefly the pharmacological and molecular targets of thymoquinone as well as the pharmacological properties in various diseases and the underlying molecular mechanism. Though, a convincing number of experimental studies are available but human studies are not available with thymoquinone despite of the long history of use of black cumin in different diseases. Thus, the clinical studies including pharmacokinetic studies and regulatory toxicity studies are required to encourage the clinical development of thymoquinone.

Therapeutic Targeting of NLRP3 Inflammasomes by Natural Products and Pharmaceuticals: A Novel Mechanistic Approach for Inflammatory Diseases

Inflammasomes are multiprotein complexes having nucleotide-binding domain and leucine-rich repeat consisting members along with pyrin and HIN domain family. An inflammasome mainly consists of cytoplasmic sensor molecule, such as NLRP3, the adaptor apoptosisassociated speck-like protein containing caspase recruitment domain) protein along with effector procaspase-1. The inflammasome regulates caspase-1 activation, resulting in secretion of interleukin- 1β and interleukin-18. The inflammasome activation is linked with infection, stress, or other immunological signals involved in inflammation. The pathophysiological role of NLRP3 inflammasome in immune regulation, inflammatory receptor-ligand interactions, microbial-associated molecular patterns, danger as well as pathogen associated molecular patterns has been demonstrated in last few years. Furthermore, the role of the inflammasome in peripheral and central nervous system involved with cytokine and chemokine inflammatory responses has been demonstrated in preclinical and clinical studies. The understanding of molecular regulation of inflammasome associated pathways is crucial for drug design and delivery. The use of natural product as an alternate therapy is gaining focus because of easy access and cost effectiveness. A number of herbal extracts and its bioactive constituents known as phytochemicals have shown to be effective in inflammatory response mediated by NLRP3 inflammasomes pathways. To understand the interaction of phytochemicals and inflammasome at the molecular level, it is vital to develop effective drugs that can be evaluated further in the clinical settings. Therefore, this review renders an extensive account of all the phytochemicals which are evaluated either in inflammatory experimental animal models or in immortalized human/animal cell lines that modulate NLRP3 inflammasome mediated pathways to mitigate inflammatory responses with the hope that this pathway modulation by phytochemicals may provide a another class of drugs in the armamentarium as well as novel molecular mechanism of natural products targeting NLRP3 inflammasome.

In silico Evidence for Binding of Pentacyclic Triterpenoids to Keap1-Nrf2 Protein-Protein Binding Site

AIM AND OBJECTIVE

Kelch like ECH-associated protein 1 (Keap1) and Nuclear factor-E2 related factor 2 (Nrf2) binding is a key step in the ubiquitination and degradation of Nrf2. The compounds inhibiting this binding exert antioxidant actions. Naturally occurring pentacyclic triterpenoids (PTs) and their synthetic derivatives are projected as activators of Nrf2 signalling. The 16-mer Nrf2 peptide binding site on Keap-1 (PDB: 2 FLU) is proposed to be the prospective target where pentacyclic triterpenoid may exert protein-protein interaction.

MATERIAL AND METHOD

In the present study, seventy seven PTs of natural and synthetic origin are screened for Nrf2 stimulatory activity using online PASS (Prediction of Activity Spectrum of Substances) software followed by in silico molecular docking against 16-mer Nrf2 peptide binding site on Keap-1. This virtual screening reveals that Nrf2 stimulatory PTs dock on the 16-mer peptide binding site on Keap-1 and may exert their biological activities by interfering with the Keap-1 and Nrf2 binding.

RESULTS

In the present study shows that the small molecules like PT's bind to keap 1 pocket where the 16 mer peptide of Neh2 domain of Nrf2. High docking score of -10.53, -9.08, -8.36, -7.94, -7.49 and -7.18 is shown by glycyrrhizin, asiatic acid, medecassic acid, barrigenic acid, rotundic acid, ursolic acid, respectively.

CONCLUSION

The identified hits such as asiatic acid and medecassic acid represent a very promising starting point for the development of potent Nrf2 stimulator. The natural PTs are more promising than the most potent synthetic derivatives of oleanolic acid like CDDO, CDDO-methyl and CDDOimidazol.

Past and current perspective on new therapeutic targets for Type-II diabetes

Loss of pancreatic β-cell function is a hallmark of Type-II diabetes mellitus (DM). It is a chronic metabolic disorder that results from defects in both insulin secretion and insulin action. Recently, United Kingdom Prospective Diabetes Study reported that Type-II DM is a progressive disorder. Although, DM can be treated initially by monotherapy with oral agent; eventually, it may require multiple drugs. Additionally, insulin therapy is needed in many patients to achieve glycemic control. Pharmacological approaches are unsatisfactory in improving the consequences of insulin resistance. Single therapeutic approach in the treatment of Type-II DM is unsuccessful and usually a combination therapy is adopted. Increased understanding of biochemical, cellular and pathological alterations in Type-II DM has provided new insight in the management of Type-II DM. Knowledge of underlying mechanisms of Type-II DM development is essential for the exploration of novel therapeutic targets. Present review provides an insight into therapeutic targets of Type-II DM and their role in the development of insulin resistance. An overview of important signaling pathways and mechanisms in Type-II DM is provided for the better understanding of disease pathology. This review includes case studies of drugs that are withdrawn from the market. The experience gathered from previous studies and knowledge of Type-II DM pathways can guide the anti-diabetic drug development toward the discovery of clinically viable drugs that are useful in Type-II DM.

Molecular Pathways Involved in the Amelioration of Myocardial Injury in Diabetic Rats by Kaempferol

There is growing evidence that chronic hyperglycemia leads to the formation of advanced glycation end products (AGEs) which exerts its effect via interaction with the receptor for advanced glycation end products (RAGE). AGE-RAGE activation results in oxidative stress and inflammation. It is well known that this mechanism is involved in the pathogenesis of cardiovascular disease in diabetes. Kaempferol, a dietary flavonoid, is known to possess antioxidant, anti-apoptotic, and anti-inflammatory activities. However, little is known about the effect of kaempferol on myocardial ischemia-reperfusion (IR) injury in diabetic rats. Diabetes was induced in male albino Wistar rats using streptozotocin (70 mg/kg; i.p.), and rats with glucose level >250 mg/dL were considered as diabetic. Diabetic rats were treated with vehicle (2 mL/kg; i.p.) and kaempferol (20 mg/kg; i.p.) daily for a period of 28 days and on the 28th day, ischemia was produced by one-stage ligation of the left anterior descending coronary artery for 45 min followed by reperfusion for 60 min. After completion of surgery, rats were sacrificed and the heart tissue was processed for biochemical, morphological, and molecular studies. Kaempferol pretreatment significantly reduced hyperglycemia, maintained hemodynamic function, suppressed AGE-RAGE axis activation, normalized oxidative stress, and preserved morphological alterations. In addition, there was decreased level of inflammatory markers (tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and NF-κB), inhibition of active c-Jun N-terminal kinase (JNK) and p38 proteins, and activation of Extracellular signal regulated kinase 1/2 (ERK1/2) a prosurvival kinase. Furthermore, it also attenuated apoptosis by reducing the expression of pro-apoptotic proteins (Bax and Caspase-3), Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) positive cells, and increasing the level of anti-apoptotic protein (Bcl-2). In conclusion, kaempferol attenuated myocardial ischemia-reperfusion injury in diabetic rats by reducing AGE-RAGE/ mitogen activated protein kinase (MAPK) induced oxidative stress and inflammation.

Protective effect of Lagerstroemia speciosa against dextran sulfate sodium induced ulcerative colitis in C57BL/6 mice

The protective effect of methanolic extract of Lagerstroemia speciosaleaves (LS) was evaluated against dextran sulfate sodium (DSS) induced ulcerative colitis in C57BL/6 mice. The administration of DSS (2.5% in drinking water ad libitum) in C57BL/6 mice induced ulcerative colitis in 7 days. The LS was orally administered for 7 days at daily doses of 100 and 200 mg/kg. At the end of 7 days of treatment the animals were sacrificed, colonic tissues were removed and processed for further analysis of oxidative stress, and histopathology. In DSS treated mice the oxidative stress markers were elevated compared to controls. There was also significant reduction in the anti-oxidant defense levels marked by reduced cellular glutathione, catalase, and superoxide dismutase. The DSS-induced damage to the colon epithelium was evident from a significant increase in the lipid peroxidation. The histology of colon sections revealed inflammatory changes and marked impairment in the integrity of the mucosal lining with inflammatory changes. Both the doses of LS significantly prevented DSS-induced inflammatory and ulcerative damages of the colon, reduced lipid peroxidation and also restored the levels of innate antioxidants in the colon tissue. These findings indicate the protective effects of LS against the DSS-induced inflammatory and oxidative damage in the mouse colon. Further investigation involving bioactivity guided fractionation of the LS can yield potent constituent which may have a significant role in the treatment of inflammatory bowel disease and ulcerative colitis.

Protective effect of mangiferin on myocardial ischemia-reperfusion injury in streptozotocin-induced diabetic rats: role of AGE-RAGE/MAPK pathways

Hyperglycemia induced advanced glycation end products-receptor for advanced glycation end products (AGE-RAGE) activation is thought to involve in the development of cardiovascular disease in diabetics. Activation of AGE-RAGE axis results in the oxidative stress and inflammation. Mangiferin is found in the bark of mango tree and is known to treat diseases owing to its various biological activities. Thus, this study was designed to evaluate the effect of mangiferin in ischemia-reperfusion (IR) induced myocardial injury in diabetic rats. A single injection of STZ (70 mg/kg; i.p.) was injected to male albino Wistar rats to induce diabetes. After confirmation of diabetes, rats were administered vehicle (2 ml/kg; i.p.) and mangiferin (40 mg/kg; i.p.) for 28 days. On 28^th day, left anterior descending coronary artery was ligated for 45 min and then reperfused for 60 min. Mangiferin treatment significantly improved cardiac function, restored antioxidant status, reduced inflammation, apoptosis and maintained myocardial architecture. Furthermore, mangiferin significantly inhibited the activation of AGE-RAGE axis, c-Jun N-terminal kinase (JNK) and p38 and increased the expression of extracellular regulated kinase 1/2 (ERK1/2) in the myocardium. Thus, mangiferin attenuated IR injury in diabetic rats by modulation of AGE-RAGE/MAPK pathways which further prevented oxidative stress, inflammation and apoptosis in the myocardium.

Kampeferol protects against oxidative stress and apoptotic damage in experimental model of isoproterenol-induced cardiac toxicity in rats

BACKGROUND

Myocardial infarction (MI) continues to be associated with high morbidity and mortality worldwide despite the availability of current therapeutic modalities. Kaempferol (KMP), a dietary flavonoid, possesses good antioxidant, immunomodulatory and anti-apoptotic properties and has been evaluated in the present study for its role in mitigating myocardial injury following MI.

PURPOSE

In this study, the ability of KMP to protect heart against isoproterenol (ISO) induced oxidative stress and myocardial infarction was evaluated.

MATERIAL AND METHODS

Male Wistar rats (n=48) were administered KMP (5, 10 & 20mg/kg/day, i.p.) or vehicle for 15 days with ISO, 85mg/kg, subcutaneously, for 2 consecutive days was also administered at 24h interval on the 13th and 14th days. On the 15th day, rats were anaesthetized and right coronary artery was cannulated to record hemodynamic parameters. Later on blood sample was collected and heart was removed to estimate biochemical, histopathological, ultrastructural and immuohistochemical studies respectively.

RESULTS

ISO-treated rats showed a significant reduction in arterial pressure, maximum rate of development of left ventricular pressure and increase in left ventricular end-diastolic pressure. Also, there was a significant decrease in antioxidant enzyme levels such as superoxide dismutase, catalase and glutathione and increase in the level of malondialdehyde and serum TNF-α and IL-6 levels. In addition, the cardiac injury markers such as creatine kinase-MB and lactate dehydrogenase were increased in the serum. Furthermore, immunohistochemistry revealed an increased Bax/Bcl-2 ratio in the myocardium. KMP (5, 10 and 20mg/kg) dose dependently restored hemodynamic, left ventricular functions, decreased cardiac injury marker enzymes in serum, increased antioxidant levels, reduced lipid peroxidation and TNF-α level and apoptosis. Histopathological and ultrastructural studies support the protective effect of KMP in ISO-induced myocardial infarcted rats.

CONCLUSION

Thus, the present study revealed that KMP mitigates myocardial damage in ISO-induced cardiac injury by maintaining hemodynamic and biochemical parameters and reducing inflammation owing to its anti-apoptotic, anti-inflammatory and antioxidant activities. It may be concluded that a diet containing KMP may be beneficial in those who are at the risk of myocardial injury.

Chemomodulatory Potential of Bartogenic Acid Against DMBA/Croton Oil Induced Two-Step Skin Carcinogenesis in Mice

Barringtonia racemosa fruits are believed to be useful in cancer treatment in Ayurveda, the Indian system of medicine. In present study, bartogenic acid (BA), a triterpenoid constituent of Barringtonia fruits was evaluated for its cytotoxicity property using the human skin carcinoma cell line (SCC-13) and human peripheral blood mononuclear cells (PBMC). The chemopreventive efficacy of BA was evaluated against the DMBA/Croton oil-induced skin carcinogenesis in mice.BA was orally administered at the doses of 1, 2 or 4 mg/kg/day or applied topically every day for 12 weeks following DMBA application. The in vitro data from cell lines revealed that BA induces cytotoxicity against the SCC-13 cells (IC₅₀=7.5 µM). It was found 4.05 times more selective to exert cytotoxicity against SCC-13 as compared to the PBMC (IC₅₀=30.4 µM). The in vivo datacollected from mice model of DMBA/Croton oil-induced skin carcinogenesis revealed that BA administered orally or applied topically, both reduced the precancerous skin lesions andthe incidence of tumor bearing. The oral doses of BA (2 and 4 mg/kg) and topical treatment significantly reduced the incidence and number of skin papillomas. At these doses, BA also increased the activities of catalase and superoxide dismutase and induced an increase in glutathionecontent and inhibited lipid peroxidation in the skin. These findings reveal the chemopreventive efficacy of BA and also demonstrate that it contributes to the cytotoxic and antioxidative effects of Barringtonia racemosa fruits. The study also validates the traditional claims of Barringtonia fruits and provides a scientific basis of its chemopreventive property.