Modulation by Withania somnifera of stress-induced anxiogenesis and airway inflammation in rats.

OBJECTIVES: Stress is an aversive stimulus which disrupts the biological milieu of the organism and a variety of emotional and environmental stressors are known to influence allergic and immunological disorders like bronchial asthma but the pharmacological basis of such interactions is not clearly defined. Withania somnifera (ashwagandha) is a potent anti-stress agent used widely in Indian traditional medicine and the present experimental study evaluated the effects of W. somnifera extract (WSE) on chronic stress-induced neurobehavioral and immunological responses in an experimental model of allergic asthma in rats. METHODS: Wistar rats (200-250 g) were immunized and challenged with ovalbumin (OVA) and exposed to restraint stress (RS) and WSE treatments for 15 days. Following this, anxiety behavior was assessed by the elevated plus maze (EPM) test, and blood and BAL fluid samples were collected for measuring of inflammatory/immune markers by ELISA and biochemical assay. The data of the various treatment groups were analyzed by ANOVA and Tukey's test. RESULTS: Restraint stress (RS) induced anxiogenic behavior in the (EPM) test in OVA immunized rats, and this was attenuated by WSE (200 and 400 mg/kg), in a dose related manner. Examination of blood and BAL fluid in these RS exposed rats also resulted in elevations in IgE, TNF-α and IL-4 levels, which were also attenuated by WSE pretreatments. Further, WSE pretreatment neutralized the such RS induced changes in oxidative stress markers viz. elevated MDA and reduced GSH levels. CONCLUSIONS: The data pharmacologically validates role of stress in asthma and suggests that adaptogens like WSE could be a potential complementary agent for reducing anxiety as well as airway inflammation by a multi-targeted and holistic approach. The study also highlights the significance of integration of traditional and modern medical concepts in such chronic disorders.

Modulation of Immunological, Biochemical, and Histopathological Changes of Airway Remodeling by Withania somnifera in an Experimental Model of Allergic Asthma in Rats.

Objectives: Airway remodeling in asthma involves chronic inflammation associated with structural changes, which result in severe airflow limitation and very few therapeutic options. Thus, the present study was designed to experimentally evaluate the ameliorative effects of Withania somnifera (WS) root extract against Ovalbumin (OVA)-induced airway remodeling in a rat model of asthma. Methods: Wistar rats were immunized (i.p) and challenged (aerosol) with ovalbumin (OVA), and the effects of WS extract were investigated on the development and progress of airway remodeling by assessing immunological, biochemical, and histological changes in these rats. Results: OVA-immunization and challenge in rats resulted in significant increases in the levels of IL-13, 8-OhdG, TGF-ß, hydroxyproline, and periostin in bronchoalveolar lavage fluid (BALF) and serum/lung homogenate compared to normal control (saline only) rats, and these changes were attenuated after WS extract (200 and 400 mg/kg), as well as dexamethasone (DEX, 1 mg/kg) pretreatments. Further, WS extract attenuated histopathological changes and maintained lung integrity. In herb-drug interactions, sub-threshold doses of WS extract and DEX showed synergistic effects on all parameters studied as compared to either form of monotherapy. Conclusion: These results indicated that WS exerted significant protective effects against airway remodeling in the experimental model by modulating inflammatory and fibrotic cytokines, and could have the potential for developing a therapeutic alternative/adjunct for the treatment of airway remodeling of bronchial asthma.

Postulating the possible cellular signalling mechanisms of antibody drug conjugates in Alzheimer's disease.

Alzheimer's disease (AD) is one of the most common neurodegenerative disorders in the world. Although the basic pathology of the disease is elucidated, it is difficult to restore or prevent the worsening of neurodegeneration and its symptoms. Antibody and small molecule-based approaches have been studied and are in study individually, but a combined approach like conjugation has not been performed to date. The conjugation between antibodies and drugs which are already used for Alzheimer's treatment or developed specifically for this purpose may have better efficacy and dual action in mitigating Alzheimer's disease. A probable mechanism for antibody-drug conjugates in Alzheimer's disease is discussed in the present review.

Periostin: A Potential Biomarker and Therapeutic Target in Pulmonary Diseases.

Periostin is a matricellular, nonstructural protein belonging to the fasciclin family and is encoded by the POSTN gene in humans. Periostin plays an important role in maintaining a normal tissue matrix in the lungs. Despite the vital role as a structural mediator in tissue growth and repair, periostin is involved in the pathogenic mechanism during tissue remodeling and fibrosis. Periostin is a chemoattractant mediator, promotes eosinophil recruitment and adhesion on the airways sub-epithelial membrane of asthmatic patients. POSTN gene was identified as one of the highly expressed genes induced by interleukins IL-13, IL-5 and IL-4 - the key cytokines of Th2 immune responses in the bronchial tissues of asthmatic patients. This review highlights the potential role of periostin as a validated biomarker in respiratory disease progression and its candidacy to predict the response to treatments targeting Th-2 cytokines in bronchial asthma. In addition, its potential role in COPD, IPF, lung cancer and lung infection, is also speculated.   Keywords Periostin, Asthma, Pneumonia, COPD, Idiopathic pulmonary fibrosis, Biomarker.

Polyphenols inhibiting MAPK signalling pathway mediated oxidative stress and inflammation in depression.

Depression is one of the most debilitating psychiatric disorders affecting people of all ages worldwide. Despite significant heterogeneity between studies, increased inflammation and oxidative stress have been found in depression. Oxidative stress and inflammation are involved in the pathogenesis of depression. In the current review, we discussed the markers of oxidative stress and inflammation in depressive disorder and the association between these markers and the antidepressant treatment. The role of natural polyphenols in regulating various cell signaling pathways related to oxidative stress and inflammation has also been reviewed. The inhibitory effect of polyphenols on several cell signaling pathways reveals the vital role of polyphenols in the prevention and treatment of depressive disorder. Understanding the mechanism of polyphenols implicated in the regulation of cell signaling pathways is essential for the identification of lead compounds and the development of novel effective compounds for the prevention and treatment of depressive disorder.

Bioactive Compounds and Traditional Herbal Medicine: Promising Approaches for the Treatment of Dementia.

Dementia is a term that encompasses a group of clinical symptoms affecting memory, thinking and social abilities, characterized by progressive impairment of memory performance and cognitive functions. There are several factors involved in the pathogenesis and progression of dementia, such as old age, brain ischemia, toxin exposure, and oxidative stress. There are extensive similarities between dementia and Alzheimer's disease (AD) either in clinical manifestations or experimental animal models. AD is the most dominant form of dementia, characterized by the accumulation of beta-amyloid protein and cholinergic neurotransmission deficits in the brain. Currently available medications for the treatment of dementia, such as choline esterase inhibitors, N-methyl-D-aspartate (NMDA) antagonists (memantine), have short-term efficacy and only relieve symptoms rather than targeting the main underlying pathogenesis. Several animal studies and clinical trials are being conducted to provide a rational approach to these medicinal plants in the prevention or treatment of memory deficits. This review highlights the potential effects of medicinal plants and their derived lead molecules, and explains the related mechanisms and effects reviewed from published literature as major thrust aspects and hopeful strategies in the prevention or treatment of dementia.