Pharmacologic overview of Withania somnifera, the Indian Ginseng

Covalent Ligand Discovery against Druggable Hotspots Targeted by Anti-cancer Natural Products

Many natural products that show therapeutic activities are often difficult to synthesize or isolate and have unknown targets, hindering their development as drugs. Identifying druggable hotspots targeted by covalently acting anti-cancer natural products can enable pharmacological interrogation of these sites with more synthetically tractable compounds. Here, we used chemoproteomic platforms to discover that the anti-cancer natural product withaferin A targets C377 on the regulatory subunit PPP2R1A of the tumor-suppressor protein phosphatase 2A (PP2A) complex leading to activation of PP2A activity, inactivation of AKT, and impaired breast cancer cell proliferation. We developed a more synthetically tractable cysteine-reactive covalent ligand, JNS 1-40, that selectively targets C377 of PPP2R1A to impair breast cancer signaling, proliferation, and in vivo tumor growth. Our study highlights the utility of using chemoproteomics to map druggable hotspots targeted by complex natural products and subsequently interrogating these sites with more synthetically tractable covalent ligands for cancer therapy.

Natural Withanolides in the Treatment of Chronic Diseases

Withanolides, and in particular extracts from Withania somnifera, have been used for over 3,000 years in traditional Ayurvedic and Unani Indian medical systems as well as within several other Asian countries. Traditionally, the extracts were ascribed a wide range of pharmacologic properties with corresponding medical uses, including adaptogenic, diuretic, anti-inflammatory, sedative/anxiolytic, cytotoxic, antitussive, and immunomodulatory. Since the discovery of the archetype withaferin A in 1965, approximately 900 of these naturally occurring, polyoxygenated steroidal lactones with 28-carbon ergostane skeletons have been discovered across 24 diverse structural types. Subsequently, extensive pharmacologic research has identified multiple mechanisms of action across key inflammatory pathways. In this chapter we identify and describe the major withanolides with anti-inflammatory properties, illustrate their role within essential and supportive inflammatory pathways (including NF-κB, JAK/STAT, AP-1, PPARγ, Hsp90 Nrf2, and HIF-1), and then discuss the clinical application of these withanolides in inflammation-mediated chronic diseases (including arthritis, autoimmune, cancer, neurodegenerative, and neurobehavioral). These naturally derived compounds exhibit remarkable biologic activity across these complex disease processes, while showing minimal adverse effects. As novel compounds and analogs continue to be discovered, characterized, and clinically evaluated, the interest in withanolides as a novel therapeutic only continues to grow.

Mystic Acetaldehyde: The Never-Ending Story on Alcoholism

After decades of uncertainties and drawbacks, the study on the role and significance of acetaldehyde in the effects of ethanol seemed to have found its main paths. Accordingly, the effects of acetaldehyde, after its systemic or central administration and as obtained following ethanol metabolism, looked as they were extensively characterized. However, almost 5 years after this research appeared at its highest momentum, the investigations on this topic have been revitalized on at least three main directions: (1) the role and the behavioral significance of acetaldehyde in different phases of ethanol self-administration and in voluntary ethanol consumption; (2) the distinction, in the central effects of ethanol, between those arising from its non-metabolized fraction and those attributable to ethanol-derived acetaldehyde; and (3) the role of the acetaldehyde-dopamine condensation product, salsolinol. The present review article aims at presenting and discussing prospectively the most recent data accumulated following these three research pathways on this never-ending story in order to offer the most up-to-date synoptic critical view on such still unresolved and exciting topic.

Metabolite Profiling in Withania somnifera Roots Hydroalcoholic Extract Using LC/MS, GC/MS and NMR Spectroscopy

Ashwagandha (Withania somnifera) is a very well-known herbal medicine and it was well studied for its active metabolites throughout the World. Although, nearly 40 withanolides were isolated from W. somnifera root extract, still there is remaining unidentified metabolites due to very low abundance and geographical variation. Advanced separation technology with online identification by mass and nuclear magnetic resonance (NMR) are nowadays used to find out the new compounds in the crude herbal extract. This article described the metabolite profiling of ashwagandha root hydroalcoholic extract using ultra-performance liquid chromatography coupled with a positive ion electrospray ionization tandem mass spectrometry through gas chromatography mass spectrometry (GC/MS) and NMR spectroscopy. A total of 43 possible withanolides was identified and proposed their structures based on the mass of molecular and fragment ions. GC/MS and NMR analysis indicated the presence of several known withanolides including withaferin A, withanolide D, withanoside IV or VI, withanolide sulfoxide, etc. To the best of our knowledge, dihydrowithanolide D at m/z 473 (t_R 7.86 min) and ixocarpalactone A at m/z 505 (t_R 8.43 min) were first time identified in the ashwagandha root hydroalcoholic extract. The current study that described the identification of withanolides with summarized literature review might be helpful for designing the experiment to identify of the new chemical constituents in Withania species.

Network ethnopharmacological evaluation of the immunomodulatory activity of Withania somnifera

ETHNOPHARMACOLOGICAL RELEVANCE

Withania somnifera (L.) Dunal (Ashwagandha, WS) is one of the extensively explored Ayurvedic botanicals. Several properties including immunomodulation, anti-cancer and neuro-protection of the botanical have been reported. Even though, in indigenous medicine, WS is well known for its immunomodulatory activity, the molecular mechanism of immunomodulation has not been elucidated.

AIM OF THE STUDY

This study aimed the evaluation of the immunomodulatory effect of WS using network ethnopharmacology technique to elucidate the in silico molecular mechanism.

MATERIALS AND METHODS

Databases- DPED, UNPD, PubChem, Binding DB, ChEMBL, KEGG and STRING were used to gather information to develop the networks. The networks were constructed using Cytoscape 3.2.1. Data analysis was performed with the help of Excel pivot table and Cytoscape network analyzer tool.

RESULTS

Investigation for WS immune modulation mechanism identified five bioactives that are capable of regulating 15 immune system pathways through 16 target proteins by bioactive-target and protein-protein interactions. The study also unveils the potential of withanolide-phytosterol combination to achieve effective immunomodulation and seven novel bioactive-immune target combinations.

CONCLUSION

The study elucidated an in silico molecular mechanism of immunomodulation of WS. It unveils the potential of withanolide-phytosterol combination to achieve a better immunomodulation. Experimental validation of the network findings would aid in understanding the rationale behind WS immunomodulation as well as aid in bioactive formulation based drug discovery.

Withania somnifera: Advances and Implementation of Molecular and Tissue Culture Techniques to Enhance Its Application

Withania somnifera, commonly known as Ashwagandha an important medicinal plant largely used in Ayurvedic and indigenous medicine for over 3,000 years. Being a medicinal plant, dried powder, crude extract as well as purified metabolies of the plant has shown promising therapeutic properties. Withanolides are the principal metabolites, responsible for the medicinal properties of the plant. Availability and amount of particular withanolides differ with tissue type and chemotype and its importance leads to identification characterization of several genes/ enzymes related to withanolide biosynthetic pathway. The modulation in withanolides can be achieved by controlling the environmental conditions like, different tissue culture techniques, altered media compositions, use of elicitors, etc. Among all the in vitro techniques, hairy root culture proved its importance at industrial scale, which also gets benefits due to more accumulation (amount and number) of withanolides in roots tissues of W. somnifera. Use of media compostion and elicitors further enhances the amount of withanolides in hairy roots. Another important modern day technique used for accumulation of desired secondary metabolites is modulating the gene expression by altering environmental conditions (use of different media composition, elicitors, etc.) or through genetic enginnering. Knowing the significance of the gene and the key enzymatic step of the pathway, modulation in withanolide contents can be achieved upto required amount in therapeutic industry. To accomplish maximum productivity through genetic enginnering different means of Withania transformation methods have been developed to obtain maximum transformation efficiency. These standardized transformation procedues have been used to overexpress/silence desired gene in W. somnifera to understand the outcome and succeed with enhanced metabolic production for the ultimate benefit of human race.

Natural products against Alzheimer's disease: Pharmaco-therapeutics and biotechnological interventions

Alzheimer's disease (AD) is a severe, chronic and progressive neurodegenerative disease associated with memory and cognition impairment ultimately leading to death. It is the commonest reason of dementia in elderly populations mostly affecting beyond the age of 65. The pathogenesis is indicated by accumulation of the amyloid-beta (Aβ) plaques and neurofibrillary tangles (NFT) in brain tissues and hyperphosphorylation of tau protein in neurons. The main cause is considered to be the formation of reactive oxygen species (ROS) due to oxidative stress. The current treatment provides only symptomatic relief by offering temporary palliative therapy which declines the rate of cognitive impairment associated with AD. Inhibition of the enzyme acetylcholinesterase (AChE) is considered as one of the major therapeutic strategies offering only symptomatic relief and moderate disease-modifying effect. Other non-cholinergic therapeutic approaches include antioxidant and vitamin therapy, stem cell therapy, hormonal therapy, use of antihypertensive or lipid-lowering medications and selective phosphodiesterase (PDE) inhibitors, inhibition of β-secretase and γ-secretase and Aβ aggregation, inhibition of tau hyperphosphorylation and intracellular NFT, use of nonsteroidal anti-inflammatory drugs (NSAIDs), transition metal chelators, insulin resistance drugs, etanercept, brain-derived neurotrophic factor (BDNF) etc. Medicinal plants have been reported for possible anti-AD activity in a number of preclinical and clinical trials. Ethnobotany, being popular in China and in the Far East and possibly less emphasized in Europe, plays a substantial role in the discovery of anti-AD agents from botanicals. Chinese Material Medica (CMM) involving Chinese medicinal plants has been used traditionally in China in the treatment of AD. Ayurveda has already provided numerous lead compounds in drug discovery and many of these are also undergoing clinical investigations. A number of medicinal plants either in their crude forms or as isolated compounds have exhibited to reduce the pathological features associated with AD. In this present review, an attempt has been made to elucidate the molecular mode of action of various plant extracts, phytochemicals and traditional herbal formulations investigated against AD as reported in various preclinical and clinical tests. Herbal synergism often found in polyherbal formulations were found effective to combat disease heterogeneity as found in complex pathogenesis of AD. Finally a note has been added to describe biotechnological improvement, genetic and genomic resources and mathematical and statistical techniques for empirical model building associated with anti-AD plant secondary metabolites and their source botanicals.

Withanone, an Active Constituent from Withania somnifera, Affords Protection Against NMDA-Induced Excitotoxicity in Neuron-Like Cells

Withania somnifera has immense pharmacologic and clinical uses. Owing to its similar pharmacologic activity as that of Korean Ginseng tea, it is popularly called as Indian ginseng. In most cases, extracts of this plant have been evaluated against various diseases or models of disease. However, little efforts have been made to evaluate individual constituents of this plant for neurodegenerative disorders. Present study was carried out to evaluate Withanone, one of the active constituents of Withania somnifera against NMDA-induced excitotoxicity in retinoic acid, differentiated Neuro2a cells. Cells were pre-treated with 5, 10 and 20 μM doses of Withanone and then exposed to 3-mM NMDA for 1 h. MK801, a specific NMDA receptor antagonist, was used as positive control. The results indicated that NMDA induces significant death of cells by accumulation of intracellular Ca²⁺, generation of reactive oxygen species (ROS), loss of mitochondrial membrane potential, crashing of Bax/Bcl-2 ratio, release of cytochrome c, increased caspase expression, induction of lipid peroxidation as measured by malondialdehyde levels and cleavage of poly(ADP-ribose) polymerase-1 (Parp-1), which is indicative of DNA damage. All these parameters were attenuated with various doses of Withanone pre-treatment. These results suggest that Withanone may serve as potential neuroprotective agent.

Withania somnifera and Its Withanolides Attenuate Oxidative and Inflammatory Responses and Up-Regulate Antioxidant Responses in BV-2 Microglial Cells

Withania somnifera (L.) Dunal, commonly known as Ashwagandha, has been used in Ayurvedic medicine for promoting health and quality of life. Recent clinical trials together with experimental studies indicated significant neuroprotective effects of Ashwagandha and its constituents. This study is aimed to investigate anti-inflammatory and anti-oxidative properties of this botanical and its two withanolide constituents, namely, Withaferin A and Withanolide A, using the murine immortalized BV-2 microglial cells. Ashwagandha extracts not only effectively inhibited lipopolysaccharide (LPS)-induced nitric oxide (NO) and reactive oxygen species (ROS) production in BV-2 cells, but also stimulates the Nuclear factor (erythroid-derived 2)-like 2 (Nrf2) pathway, leading to induction of heme oxygenase-1 (HO-1), both in the presence and absence of LPS. Although the withanolides were also capable of inhibiting LPS-induced NO production and stimulating Nrf2/HO-1 pathway, Withaferin A was tenfold more effective than Withanolide A. In serum-free culture, LPS can also induce production of long thin processes (filopodia) between 4 and 8 h in BV-2 cells. This morphological change was significantly suppressed by Ashwagandha and both withanolides at concentrations for suppressing LPS-induced NO production. Taken together, these results suggest an immunomodulatory role for Ashwagandha and its withanolides, and their ability to suppress oxidative and inflammatory responses in microglial cells by simultaneously down-regulating the NF-kB and upregulating the Nrf2 pathways.

Low dose effects of a Withania somnifera extract on altered marble burying behavior in stressed mice

Aim:

Withania somnifera root (WSR) extracts are often used in traditionally known Indian systems of medicine for prevention and cure of psychosomatic disorders. The reported experiment was designed to test whether low daily oral doses of such extracts are also effective in suppressing marble burying behavior in stressed mice or not.

Materials and Methods:

Groups of mice treated with 10, 20, or 40 mg/kg daily oral doses of WSR were subjected to a foot shock stress-induced hyperthermia test on the 1^st, 5^th, 7^th, and 10^th day of the experiment. On the 11^th and 12^th treatment days, they were subjected to marble burying tests. Stress response suppressing effects of low dose WSR were estimated by its effects on body weight and basal core temperature of animals during the course of the experiment.

Results:

Alterations in bodyweight and basal core temperature triggered by repeated exposures to foot shock stress were absent even in the 10 mg/kg/day WSR treated group, whereas the effectiveness of the extract in foot shock stress-induced hyperthermia and marble burying tests increased with its increasing daily dose.

Conclusion:

Marble burying test in stressed mice is well suited for identifying bioactive constituents of W. somnifera like medicinal plants with adaptogenic, anxiolytic and antidepressant activities, or for quantifying pharmacological interactions between them.