Differential activities of the two closely related withanolides, Withaferin A and Withanone: bioinformatics and experimental evidences

Mutagenicity and safety evaluation of Ashwagandha (Withania somnifera) root aqueous extract in different models

Withania somnifera (Ashwagandha) also called as Indian ginseng, a revered herb from Indian traditional system of medicine is a rejuvenator and tonic (Rasayana) used for its varied benefits. The roots of ashwagandha exhibit properties like anti-inflammatory, aphrodisiac, anthelmintic, astringent, diuretic, stimulant and thermogenic. However, data of ashwagandha on its mutagenic effects are lacking. In the present study, in-vitro genotoxicity tests were used to evaluate the mutagenic potential of Ashwagandha Root Extract (ARE). Concentrations of 0.156 to 5.00 mg/plate ARE were used for conducting Bacterial reverse mutation test (BRMT). For chromosome aberration (CA) test ARE was used in concentrations of 0.25 to 2.00 mg/ml, and for micronucleus (MN) tests ARE concentrations of 500/1000/2000 mg/kg were used. Acute oral toxicity was conducted in Wistar rats (n = 25) as per the OECD guideline (#423) with doses of 500/1000/2000 mg/kg body weight in male Swiss albino mice for morbidity and mortality for 3 days. The BRMT and CA tests were conducted with and without metabolic activation (S9). The study was approved by the institutional ethics committee (IEC) and institutional animal ethics committee (IAEC). ARE failed to show any mutagenic effects up to a dose of 5 mg/plate in BRMT. Also, ARE did not show any clastogenic activity in doses up to 2 mg/ml in CA test and in micronucleus test up to 2000 mg/kg body weight. These results were observed with and without metabolic activation (S9) under the stated experimental conditions. No mortality, morbidity, or any clinical signs were observed up to 3 days following ARE administration. Ashwagandha root extract failed to show any mortality in doses up to 2000 mg/kg oral dosage and did not show any mutagenic (genotoxic) effects in high concentrations.

Phyto-therapeutic potential of Withania somnifera: Molecular mechanism and health implications

Withania somnifera, the plant named Indian ginseng, Ashwagandha, or winter cherry, has been used since ancient times to cure various health ailments. Withania somnifera is rich in constituents belonging to chemical classes like alkaloids, saponins, flavonoids, phenolic acids, and withanolides. Several chemotypes were identified based on their phytochemical composition and credited for their multiple bioactivities. Besides, exhibiting neuroprotective, immunomodulatory, adaptogenic, anti-stress, bone health, plant has shown promising anti-cancer properties. Several withanolides have been reported to play a crucial role in cancer; they target cancer cells by different mechanisms such as modulating the expression of tumor suppressor genes, apoptosis, telomerase expression, and regulating cell signaling pathway. Though, many treatments are available for cancer; however, to date, no assured reliable cure for cancer is made available. Additionally, synthetic drugs may lead to development of resistance in time; therefore, focus on new and natural drugs for cancer therapeutics may prove a longtime effective alternative. This current report is a comprehensive combined analysis upto 2023 with articles focused on bio-activities of plant Withania somnifera from various sources, including national and international government sources. This review focuses on understanding of various mechanisms and pathways to inhibit uncontrolled cell growth by W. somnifera bioactives, as reported in literature. This review provides a recent updated status of the W. somnifera on pharmacological properties in general and anti-cancer in particular and may provide a guiding resource for researchers associated with natural product-based cancer research and healthcare management.

Molecular targets and mechanisms of anti-cancer effects of withanolides

Withanolides are a class of natural products with a steroidal lactone structure that exhibit a broad spectrum of anti-cancer effects. To date, several studies have shown that their possible mechanisms in cancer development and progression are associated with the regulation of cell proliferation, apoptosis, metastasis, and angiogenesis. Withanolides can also attenuate inflammatory responses, as well as modulate the genomic instability and energy metabolism of cancer cells. In addition, they may improve the safety and efficacy of cancer treatments as adjuvants to traditional cancer therapeutics. Herein, we summarize the molecular targets and mechanisms of withanolides in different cancers, as well as their current clinical studies on them.

Endophytic Fungi as a Promising Source of Anticancer L-Asparaginase: A Review

L-asparaginase is a tetrameric enzyme from the amidohydrolases family, that catalyzes the breakdown of L-asparagine into L-aspartic acid and ammonia. Since its discovery as an anticancer drug, it is used as one of the prime chemotherapeutic agents to treat acute lymphoblastic leukemia. Apart from its use in the biopharmaceutical industry, it is also used to reduce the formation of a carcinogenic substance called acrylamide in fried, baked, and roasted foods. L-asparaginase is derived from many organisms including plants, bacteria, fungi, and actinomycetes. Currently, L-asparaginase preparations from Escherichia coli and Erwinia chrysanthemi are used in the clinical treatment of acute lymphoblastic leukemia. However, they are associated with low yield and immunogenicity problems. At this juncture, endophytic fungi from medicinal plants have gained much attention as they have several advantages over the available bacterial preparations. Many medicinal plants have been screened for L-asparaginase producing endophytic fungi and several studies have reported potent L-asparaginase producing strains. This review provides insights into fungal endophytes from medicinal plants and their significance as probable alternatives for bacterial L-asparaginase.

Alzheimer's disease: Molecular aspects and treatment opportunities using herbal drugs

Alzheimer's disease (AD), also called senile dementia, is the most common neurological disorder. Around 50 million people, mostly of advanced age, are suffering from dementia worldwide and this is expected to reach 100-130 million between 2040 and 2050. AD is characterized by impaired glutamatergic and cholinergic neurotransmission, which is associated with clinical and pathological symptoms. AD is characterized clinically by loss of cognition and memory impairment and pathologically by senile plaques formed by Amyloid β deposits or neurofibrillary tangles (NFT) consisting of aggregated tau proteins. Amyloid β deposits are responsible for glutamatergic dysfunction that develops NMDA dependent Ca2+ influx into postsynaptic neurons generating slow excitotoxicity process leading to oxidative stress and finally impaired cognition and neuronal loss. Amyloid decreases acetylcholine release, synthesis and neuronal transport. The decreased levels of neurotransmitter acetylcholine, neuronal loss, tau aggregation, amyloid β plaques, increased oxidative stress, neuroinflammation, bio-metal dyshomeostasis, autophagy, cell cycle dysregulation, mitochondrial dysfunction, and endoplasmic reticulum dysfunction are the factors responsible for the pathogenesis of AD. Acetylcholinesterase, NMDA, Glutamate, BACE1, 5HT6, and RAGE (Receptors for Advanced Glycation End products) are receptors targeted in treatment of AD. The FDA approved acetylcholinesterase inhibitors Donepezil, Galantamine and Rivastigmine and N-methyl-D-aspartate antagonist Memantine provide symptomatic relief. Different therapies such as amyloid β therapies, tau-based therapies, neurotransmitter-based therapies, autophagy-based therapies, multi-target therapeutic strategies, and gene therapy modify the natural course of the disease. Herbal and food intake is also important as preventive strategy and recently focus has also been placed on herbal drugs for treatment. This review focuses on the molecular aspects, pathogenesis and recent studies that signifies the potential of medicinal plants and their extracts or chemical constituents for the treatment of degenerative symptoms related to AD.

Liver Dangers of Herbal Products: A Case Report of Ashwagandha-Induced Liver Injury

In recent years, cases of liver damage caused by ashwagandha herbal supplements have been reported from different parts of the world (Japan, Iceland, India, and the USA). Here, we describe the clinical phenotype of suspected ashwagandha-induced liver injury and the potential causative mechanism. The patient was admitted to the hospital because of jaundice. In the interview, it was reported that he had been taking ashwagandha for a year. Laboratory results showed an increase in total bilirubin, alanine transaminase (ALT), aspartate transaminase (AST), (gamma-glutamyl transpherase (GGT), alkaline phosphatase (ALP), total cholesterol, triglycerides, and ferritin. Based on clinical symptoms and additional tests, the patient was diagnosed with acute hepatitis and referred to a facility with a higher reference rate to exclude drug-induced liver injury. An R-value was assessed, indicative of hepatocellular injury. The result of the 24 h urine collection exceeded the upper limit of normal for copper excretion in urine twice. The clinical condition improved after intensive pharmacological treatment and four plasmapheresis treatments. This case is another showing the hepatotoxic potential of ashwagandha to cause cholestatic liver damage mixed with severe jaundice. In view of several documented cases of liver damage caused by ashwagandha and the unknown metabolic molecular mechanisms of substances contained in it, attention should be paid to patients reporting the use of these products in the past and presenting symptoms of liver damage.

Withaferin A: A Pleiotropic Anticancer Agent from the Indian Medicinal Plant Withania somnifera (L.) Dunal

Cancer represents the second most deadly disease and one of the most important public health concerns worldwide. Surgery, chemotherapy, radiation therapy, and immune therapy are the major types of treatment strategies that have been implemented in cancer treatment. Unfortunately, these treatment options suffer from major limitations, such as drug-resistance and adverse effects, which may eventually result in disease recurrence. Many phytochemicals have been investigated for their antitumor efficacy in preclinical models and clinical studies to discover newer therapeutic agents with fewer adverse effects. Withaferin A, a natural bioactive molecule isolated from the Indian medicinal plant Withania somnifera (L.) Dunal, has been reported to impart anticancer activities against various cancer cell lines and preclinical cancer models by modulating the expression and activity of different oncogenic proteins. In this article, we have comprehensively discussed the biosynthesis of withaferin A as well as its antineoplastic activities and mode-of-action in in vitro and in vivo settings. We have also reviewed the effect of withaferin A on the expression of miRNAs, its combinational effect with other cytotoxic agents, withaferin A-based formulations, safety and toxicity profiles, and its clinical potential.

Potential Therapeutic Agents on Alzheimer's Disease through Molecular Docking and Molecular Dynamics Simulation Study of Plant-Based Compounds

Globally Alzheimer's disease (AD) is a highly complex, heterogeneous, and multifactorial neurological disease. AD is categorized clinically through a steady loss in memory and progressive decline of cognitive function. So far, there is no effective cure is available for the treatment of AD. Here, we identified Plant-based compounds (PBCs) from seven therapeutic plants through pharmacophore and pharmacokinetics approaches. Subsequently, we retrieved 65 AD associated proteins by Text Mining approach .We observed the interactions between 39 PBCs with 65 AD-associated targets by using molecular docking. Further, we carried out Molecular dynamics simulation analysis to predict the steady binding of top drug-target complexes. The entire MD simulation results analysis was evidence that seven drug-target complexes consistently interacted during the in silico experiment. The top complexes were the target CHLE interacted with 2 PBCs (Pseudojujubogenin and Anahygrine), target VDAC1 interacted with Withanolide R, target THOP1 interacted with Withaolide R, target AOFB interacted with 2 PBCs (Nardostachysin and Viscosalactone B), and target ACHE interacted with the drug (12-Deoxywithastramonolide). These PBCs have stably and flexibly interacted at the protein's active site region. Our results suggest that these PBCs and targets are potential therapeutic candidates for molecular development in AD.

Withania somnifera - a magic plant targeting multiple pathways in cancer related inflammation

BACKGROUND

Deregulated inflammatory responses are known to play a pivotal role in cancer initiation and progression. Tumor microenvironment is associated with the presence of a diverse array of inflammatory reactions, which further help tumor growth, metastasis and drug resistance. Withania somnifera is known to curb proliferation of cancer cells and lower inflammatory responses.

PURPOSE

In order to minimize the inflammation, cancer treatments often include immunomodulatory drugs. However, given the side effects of both of the cytotoxic cancer drugs and synthetic immunomodulatory agents, there is a need to develop novel anti-inflammatory agents for improved cancer therapy. A number of reports indicate that bioactive phytochemicals derived from W. somnifera exhibit anti-inflammatory capabilities in cancer. A deeper look into the underlying molecular mechanisms implicated in W. somnifera mediated anti inflammation is lacking, which is essential to fully understand the potential of this magical plant in cancer. Therefore, in the present review we are summarizing various reports, which describe mechanistic understanding of W. somnifera in cancer related inflammation.

STUDY DESIGN AND METHODOLOGY

In order to gather information on the molecular pathways affected by W. somnifera in cancer related inflammation, 'PubMed' and 'Science Direct' databases were searched using keywords Withania, cancer inflammation, and Withaferin A. Selected literature was analyzed to cover the role of inflammation in cancer, usage and side effects of anti-inflammatory drugs, W. somnifera as an immunomodulatory agent in cancer, molecular pathways modulated by W. somnifera in various preclinical models, and clinical trials using W. somnifera as an anti-inflammatory agent.

RESULTS

Upon literature survey we found that both W. somnifera extracts and Withaferin-A, exhibit anti inflammatory activities in various preclinical cancer models. W. somnifera modulates a number of signaling pathways such as NF-kB, JAK-STAT and AP1 to reduce cancer related inflammation. Anti inflammatory properties of W. somnifera might be effective in the treatment of drug resistance in cancers. Based on its promising effects against cancer associated inflammation in preclinical studies, W. somnifera derived products are being tested in clinical trials.

CONCLUSION

Several preclinical studies demonstrated anti-inflammatory potential of W. somnifera in a variety of cancers. While a few clinical trials are investigating the role of W. somnifera in various diseases, focused studies on its role in cancer related inflammation are lacking. Additionally, its anti-inflammatory effects offer targeting of senescence associated secretory phenotype (SASP), which is speculated to play a critical role in chemoresistance. Apart from targeting cancer cell proliferation, anti-inflammatory effects of Withania provide double advantage in cancer management. Therefore, clinical trials to target cancer related inflammation using W. somnifera as a drug, should be performed to validate its advantages in cancer therapy.

Why is Mortalin a Potential Therapeutic Target for Cancer?

Cancer is one of the leading causes of death worldwide, accounting for nearly 10 million deaths in 2020. Therefore, cancer therapy is a priority research field to explore the biology of the disease and identify novel targets for the development of better treatment strategies. Mortalin is a member of the heat shock 70 kDa protein family. It is enriched in several types of cancer and contributes to carcinogenesis in various ways, including inactivation of the tumor suppressor p53, deregulation of apoptosis, induction of epithelial–mesenchymal transition, and enhancement of cancer stemness. It has been studied extensively as a therapeutic target for cancer treatment, and several types of anti-mortalin molecules have been discovered that effectively suppress the tumor cell growth. In this review, we 1) provide a comprehensive sketch of the role of mortalin in tumor biology; 2) discuss various anti-mortalin molecules, including natural compounds, synthetic small molecules, peptides, antibodies, and nucleic acids, that have shown potential for cancer treatment in laboratory studies; and 3) provide future perspectives in cancer treatment.

In-silico validation of novel therapeutic activities of withaferin a using molecular docking and dynamics studies

Withaferin A is a bioactive molecule of W. somnifera. We access its efficacy against various target proteins associated with Cancer, Type-II Diabetes and hypercholesterolemia using molecular docking. Although it's efficacy against some of these targets have been reported earlier, we validate each mechanism in order to report the most appropriate mechanism of action. We explain the anti-cancer activity of Withaferin A by inhibition of Mortalin (mtHsp70) and Nrf2 protein with binding energies -8.85 kcal/mol and -12.59 kcal/mol respectively. Similarly, the anti-diabetic activity could be explained by inhibition of alpha and betα-glucosidase with binding energies -6.44 and -4.43 kcal/mol respectively and the cholesterol reduction could be explained by its ability to inhibition of NPC1 and SRB1 with binding energies -5.73 and -7.16 kcal/mol respectively. The molecular dynamics of the apoprotein and the protein-ligand complex simulated for the best targets of each activity namely Nrf2 protein for anti-cancer, α-glucosidase for anti-diabetic and SR-B1 for anti-hypercholesterolemia activity indicated the formation of stable complexes due to low RMSD deviations, low RMSF fluctuations and low RG values after the docking simulation. Finally, an ADME + T (Adsorption, distribution, metabolism, excretion and toxicity) prediction on Withaferin A showed that it obeyed all the Lipinsky's rules and qualified the drug-like criteria. All these results validate that Withaferin A possess potential anti-cancer, anti-diabetic and cholesterol reducing properties. This is the first report that indicates the possibility of Withaferin A binding and inhibiting SR-B1 as a mechanism of its anti-hypercholesterolemia activity.

Withanolides from Withania somnifera Ameliorate Neutrophil Infiltration in Endotoxin-Induced Peritonitis by Regulating Oxidative Stress and Inflammatory Cytokines

Identification of novel anti-inflammatory strategies are needed to avoid the side effects associated with the currently available therapies. Use of anti-inflammatory herbal remedies is gaining attention. The purpose of the present investigation was to evaluate the pharmacological potential of the withanolide-rich root extracts of the medical plant Withania somnifera (L.) Dunal using in vivo and in vitro models of endotoxin-induced inflammation and oxidative stress. The pharmacological effects of W. somnifera root extracts were evaluated using a mouse model of endotoxin (lipopolysaccharide)-induced peritonitis and various relevant human cell lines. HPLC analysis of the W. somnifera root extracts identified the presence of various bioactive withanolides. In vivo challenge of mice with endotoxin resulted in the infiltration of various leukocytes, specifically neutrophils, along with monocytes and lymphocytes into the peritoneal cavity. Importantly, prophylactic treatment with W. somnifera inhibited the migration of neutrophils, lymphocytes, and monocytes and decreased the release of interleukin-1β, TNF-α, and interleukin-6 cytokines into the peritoneal cavity as identified by ELISA. Liver (glutathione peroxidase, glutathione, glutathione disulfide, superoxide dismutase, malondialdehyde, myeloperoxidase) and peritoneal fluid (nitrite) biochemical analysis revealed the antioxidant profile of W. somnifera. Similarly, in human HepG2 cells, W. somnifera significantly modulated the antioxidant levels. In THP-1 cells, W. somnifera decreased the secretion of interleukin-6 and TNF-α. In HEK-Blue reporter cells, W. somnifera inhibited TNF-α-induced nuclear factor-κB/activator protein 1 transcriptional activity. Our findings suggest the pharmacological effects of root extracts of W. somnifera rich in withanolides inhibit neutrophil infiltration, oxidative hepatic damage, and cytokine secretion via modulating the nuclear factor-κB/activator protein 1 pathway.

Withania somnifera (L.) Dunal: Phytochemistry, structure-activity relationship, and anticancer potential

BACKGROUND

Ayurveda is a highly recognized, well-documented, and well-accepted traditional medicine system. This system utilizes many natural products in various forms for therapeutic purposes. Thousands of plants mentioned in the Ayurvedic system are useful in disease mitigation and health preservation. One potential plant of the Ayurvedic system is "Ashwagandha" [Withania somnifera (L.) Dunal], commonly regarded as Indian Ginseng. It possesses various therapeutic activities, such as neuroprotective, hypoglycemic, hepatoprotective, antiarthritic, and anticancer effects.

PURPOSE

Here we present a comprehensive insight on the anticancer effects of W. somnifera and mechanistic attributes of its bioactive phytocompounds. This review also provides updated information on the clinical studies pertaining to cancer, safety evaluation and opportunities for chemical modifications of withanolides, a group of specialized phytochemicals of W. somnifera.

METHODS

The present study was performed in accordance with the guidelines of the Preferred Reporting Items for Systemic Reviews and Meta-Analysis. Various scientific databases, such as PubMed, Science Direct, Scopus, Google Scholar, were explored for related studies published up to May 2021.

RESULTS

An updated review on the anticancer potential and mechanisms of action of the major bioactive components of W. somnifera, including withanolides, withaferin A and withanone, is presented. Comprehensive information on clinical attributes of W. somnifera and its active components are presented with the structure-activity relationship (SAR) and toxicity evaluation.

CONCLUSION

The outcome of the work clearly indicates that W. somnifera has a significant potential for cancer therapy. The SAR revealed that various withanolides in general and withaferin A in particular have binding energies against various proteins and tremendous potential to serve as the lead for new chemical entities. Nevertheless, additional studies, particularly well-designed clinical trials are required before therapeutic application of withanolides for cancer treatment.

Withania somnifera: Progress towards a Pharmaceutical Agent for Immunomodulation and Cancer Therapeutics

Chemotherapy is one of the prime treatment options for cancer. However, the key issues with traditional chemotherapy are recurrence of cancer, development of resistance to chemotherapeutic agents, affordability, late-stage detection, serious health consequences, and inaccessibility. Hence, there is an urgent need to find innovative and cost-effective therapies that can target multiple gene products with minimal adverse reactions. Natural phytochemicals originating from plants constitute a significant proportion of the possible therapeutic agents. In this article, we reviewed the advances and the potential of Withania somnifera (WS) as an anticancer and immunomodulatory molecule. Several preclinical studies have shown the potential of WS to prevent or slow the progression of cancer originating from various organs such as the liver, cervix, breast, brain, colon, skin, lung, and prostate. WS extracts act via various pathways and provide optimum effectiveness against drug resistance in cancer. However, stability, bioavailability, and target specificity are major obstacles in combination therapy and have limited their application. The novel nanotechnology approaches enable solubility, stability, absorption, protection from premature degradation in the body, and increased circulation time and invariably results in a high differential uptake efficiency in the phytochemical’s target cells. The present review primarily emphasizes the insights of WS source, chemistry, and the molecular pathways involved in tumor regression, as well as developments achieved in the delivery of WS for cancer therapy using nanotechnology. This review substantiates WS as a potential immunomodulatory, anticancer, and chemopreventive agent and highlights its potential use in cancer treatment.

Computational Identification of BCR-ABL Oncogenic Signaling as a Candidate Target of Withaferin A and Withanone

Withaferin-A (Wi-A), a secondary metabolite extracted from Ashwagandha (Withania somnifera), has been shown to possess anticancer activity. However, the molecular mechanism of its action and the signaling pathways have not yet been fully explored. We performed an inverse virtual screening to investigate its binding potential to the catalytic site of protein kinases and identified ABL as a strong candidate. Molecular docking and molecular dynamics simulations were undertaken to investigate the effects on BCR-ABL oncogenic signaling that is constitutively activated yielding uncontrolled proliferation and inhibition of apoptosis in Chronic Myeloid Leukemia (CML). We found that Wi-A and its closely related withanolide, Withanone (Wi-N), interact at both catalytic and allosteric sites of the ABL. The calculated binding energies were higher in the case of Wi-A at catalytic site (−82.19 ± 5.48) and allosteric site (−67.00 ± 4.96) as compared to the clinically used drugs Imatinib (−78.11 ± 5.21) and Asciminib (−54.00 ± 6.45) respectively. Wi-N had a lesser binding energy (−42.11 ± 10.57) compared to Asciminib at the allosteric site. The interaction and conformational changes, subjected to ligand interaction, were found to be similar to the drugs Imatinib and Asciminib. The data suggested that Ashwagandha extracts containing withanolides, Wi-A and Wi-N may serve as natural drugs for the treatment of CML. Inhibition of ABL is suggested as one of the contributing factors of anti-cancer activity of Wi-A and Wi-N, warranting further in vitro and in vivo experiments.

Phosphatidylserine Exposed Lipid Bilayer Models for Understanding Cancer Cell Selectivity of Natural Compounds: A Molecular Dynamics Simulation Study

Development of drugs that are selectively toxic to cancer cells and safe to normal cells is crucial in cancer treatment. Evaluation of membrane permeability is a key metric for successful drug development. In this study, we have used in silico molecular models of lipid bilayers to explore the effect of phosphatidylserine (PS) exposure in cancer cells on membrane permeation of natural compounds Withaferin A (Wi-A), Withanone (Wi-N), Caffeic Acid Phenethyl Ester (CAPE) and Artepillin C (ARC). Molecular dynamics simulations were performed to compute permeability coefficients. The results indicated that the exposure of PS in cancer cell membranes facilitated the permeation of Wi-A, Wi-N and CAPE through a cancer cell membrane when compared to a normal cell membrane. In the case of ARC, PS exposure did not have a notable influence on its permeability coefficient. The presented data demonstrated the potential of PS exposure-based models for studying cancer cell selectivity of drugs.

Comparative computational and experimental analyses of some natural small molecules to restore transcriptional activation function of p53 in cancer cells harbouring wild type and p53Ser46 mutant

Genetic mutations in p53 are frequently associated with many types of cancers that affect its stability and activity through multiple ways. The Ser46 residue present in the transactivation domain2 (TAD2) domain of p53 undergoes phosphorylation that blocks its degradation by MDM2 and leads to cell cycle arrest/apoptosis/necrosis upon intrinsic or extrinsic stresses. On the other hand, unphosphorylated p53 mutants escape cell arrest or death triggered by these molecular signaling axes and lead to carcinogenesis. Phosphorylation of Ser in the TAD2 domain of p53 mediates its interactions with transcription factor p62, yielding transcriptional activation of downstream pro-apoptotic genes. The p53 phosphorylation causes string-like elongated conformation that increases its binding affinity with the PH domain of p62. On the other hand, lack of phosphorylation causes helix-like motifs and low binding affinity to p62. We undertook molecular simulation analyses to investigate the potential of some natural small molecules (Withanone (Wi-N) & Withaferin-A (Wi-A) from Ashwagandha; Cucurbitacin-B (Cuc-B) from bitter Cucumber; and Caffeic acid phenethyl ester (CAPE) and Artepillin C (ARC) from honeybee propolis) to interact with p62-binding region of p53 and restore its wild-type activity. We found that Wi-N, Wi-A, and Cuc-B have the potential to restore p53-p62 interaction for phosphorylation-deficient p53 mutants. Wi-N, in particular, caused a reversal of the α-helical structure into an elongated string-like conformation similar to the wild-type p53. These data suggested the use of these natural compounds for the treatment of p53^Ser46 mutant harbouring cancers. We also compared the efficiency of Wi-N, Wi-A, Cuc-B, CAPE, and ARC to abrogate Mortalin-p53 binding resulting in nuclear translocation and reactivation of p53 function and provide experimental evidence to the computational analysis. Taken together, the use of these small molecules for reactivation of p53 in cancer cells is suggested.

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Wild type p53 (p53^WT) and its mutant form (p53^S46PΔ) are associated with multiple cancers.

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Natural compounds serve as a potential mediator to restore the function of p53 in wild type and Ser46 phosphor mutant.

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In-silico analysis suggested that Wi-A, Wi-N, and Cuc-B are stronger inhibitors of p53 -mortalin interaction.

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These entities could also bind to p53^S46PΔ and mimic the phosphorylated conformation, suggesting reactivation of p53^WT.

In Silico Assessment and Molecular Docking Studies of Some Phyto-Triterpenoid for Potential Disruption of Mortalin-p53 Interaction

Human hepatocellular carcinoma (HCC), the most common type of liver cancer, represents the second most common cause of death from cancer worldwide. The high toxicity and side effects of some cancer chemotherapy drugs increase the demand for new anti-cancer drugs from natural products. Mortalin/mtHsp70, a stress response protein, has been reported to contribute to the process of carcinogenesis in several ways, including the inhibition of the transcriptional activation of p53. This study conducted a molecular docking study of 41 phyto triterpenes originated from Vietnamese plants for potential Mortalin inhibition activity. Nine compounds were considered as promising inhibitors based on the analysis of binding affinity and drug-like and pharmacokinetic properties.

Dual inhibition of COVID-19 spike glycoprotein and main protease 3CLpro by Withanone from Withania somnifera

Objective

To identify the safe and effective natural inhibitors of spike glycoprotein and main protease 3CLpro using potential natural antiviral compounds which are studied under various animal models and viral cell lines.

Methods

First, compounds were retrieved from the PubChem database and predicted for their druggability using the MolSoft web server, and compounds having drug-like property were predicted for major adverse drug reactions like cardiotoxicity, hepatotoxicity, arrhythmia, myocardial infarction, and nephrotoxicity using ADVERpred. Docking of nontoxic antiviral compounds with spike glycoprotein and main protease 3CLpro was performed using AutoDock vina by PyRx 0.8 version. The stability of compound-protein interactions was checked by molecular dynamic (MD) simulation using Schrodinger Desmond software.

Results

Based on the druggable and nontoxic profile, nine compounds were selected. Among them, Withanone from Withania somnifera showed the highest binding affinity and best fit at active sites 1 of spike glycoprotein (glycosylation site) and main protease 3CLpro via interacting with active site amino acid residues before and after MD simulation at 50 ns. Withanone, which may reduce the glycosylation of SARS-CoV-2 via interacting with Asn343 and inhibit viral replication.

Conclusion

The current study reports Withanone as a non-toxic antiviral against SARS-CoV-2 and serve as a potential lead hit for further experimental validation.

Review on anticancerous therapeutic potential of Withania somnifera (L.) Dunal

ETHNOPHARMACOLOGICAL RELEVANCE

Withania somnifera, commonly known as Ashwagandha, is an important medicinal herb belonging to family Solanaceae. It is widely used in folkloric and Ayurvedic medicines since antiquity. Traditionally, the plant is highly practiced throughout the globe as immunomodulator, anti-inflammatory, anti-stress, anti-parkinson, anti-alzheimer, cardio protective, neural and physical health enhancer, neurodefensive, anti-diabetic, aphrodisiac, memory boosting etc. The plant is also effective in combating various types of cancer and other related problems of colon, mammary, lung, prostate, skin, blood, liver and kidney.

AIM OF THIS REVIEW

The present review represents the critical assessment of the literature available on the anticancerous role of W. somnifera. The present study throws light on its diverse chemical compounds and the possible mechanisms of action involved. This review also suggests further research strategies to harness the therapeutic potential of this plant.

MATERIALS AND METHODS

The present review is the outcome of a systematic search of scientific literature about 'Withania somnifera and its role in cancer prevention'. The scientific databases viz. Google Scholar, Science Direct, Pubmed and Web of Science were searched from 2001 to 2019. Textbooks, magazines and newspapers were also consulted. This review summarizes all the published literature about its therapeutic potential for the treatment of different types of cancers.

RESULTS

W. somnifera has been widely used in traditional and ayurvedic medicines for treatment of numerous problems related to health and vitality. The plant is a reservoir of diverse phytoconstituents like alkaloids, steroids, flavonoids, phenolics, nitrogen containing compounds and trace elements. Withanolides are the major alkaloids which renders its anticancer potential due to its highly oxygenated nature. The plant is highly effective in combating various types of cancers viz. colon, mammary, lung, prostate, skin, blood, liver and kidney. Previous studies depict that this plant is more effective against breast cancer followed by colon, lung, prostate and blood cancer. Furthermore, from different clinical studies it has been observed that the active constituents of the plant like withaferin-A, withanolide-D have least toxic effects.

CONCLUSION

The present review confirms the various medicinal values of W. somnifera without any significant side effects. Withaferin-A (WA) and Withanolides are its most promising anticancer compounds that play a major role in apoptosis induction. Keeping in mind the anticancerous potential of this plant, it is suggested that this plant may further be investigated and more clinical studies can be performed.

DNA damage by Withanone as a potential cause of liver toxicity observed for herbal products of Withania somnifera (Ashwagandha)

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The widely used medicinal herb Withania somnifera (Ashwagandha) has been recently reported to cause liver damage.

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Withanone is a major metabolite of Ashwagandha.

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Withanone was found to cause DNA damage.

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Withanone forms adducts with amines and thiols.

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Withanone-mediated DNA damage has serious biological consequences.

Withania somnifera, commonly known as Ashwagandha, is a medicinal plant used for thousands of years for various remedies. Extracts of Ashwagandha contain more than 200 metabolites, with withanone (win) being one of the major ones responsible for many of its medicinal properties. Recently, several cases of liver toxicity resulting from commercially available Ashwagandha products have been reported. The first report of Ashwagandha-related liver damage was from Japan, which was quickly resolved after drug-withdrawal. Later, similar cases of liver toxicity due to Ashwagandha consumption were reported from the USA and Iceland. Towards understanding the liver toxicity of Ashwagandha extracts, we studied win, a representative withanolide having toxicophores or structural alerts that are commonly associated with adverse drug reactions. We found that win can form non-labile adducts with the nucleosides dG, dA, and dC. Using various biochemical assays, we showed that win forms adducts in DNA and interfere with its biological property. Win also forms adducts with amines and this process is reversible. Based on the data presented here we concluded that win is detoxified by GSH but under limiting GSH levels it can cause DNA damage. The work presented here provides a potential mechanism for the reported Ashwagandha-mediated liver damage.

Induction of Senescence in Cancer Cells by a Novel Combination of Cucurbitacin B and Withanone: Molecular Mechanism and Therapeutic Potential

Cancer, an uncontrolled proliferation syndrome, is treated with synthetic chemotherapeutic drugs that are associated with severe adverse effects. Development and application of new natural compounds is warranted to deal with the exponentially increasing incidence of cancer worldwide. Keeping selective toxicity to cancer cells as a priority criterion, we developed a combination of Cucurbitacin B and Withanone, and analyzed its anticancer potential using non-small cell lung cancer cells. We demonstrate that the selective cytotoxicity of the combination, called CucWi-N, to cancer cells is mediated by induction of cellular senescence that was characterized by decrease in Lamin A/C, CDK2, CDK4, Cyclin D, Cyclin E, phosphorylated RB, mortalin and increase in p53 and CARF proteins. It compromised cancer cell migration that was mediated by decrease in mortalin, hnRNP-K, vascular endothelial growth factor, matrix metalloproteinase 2, and fibronectin. We provide in silico, molecular dynamics and experimental data to support that CucWi-N (i) possesses high capability to target mortalin-p53 interaction and hnRNP-K proteins, (ii) triggers replicative senescence and inhibits metastatic potential of the cancer cells, and (iii) inhibits tumor progression and metastasis in vivo. We propose that CucWi-N is a potential natural anticancer drug that warrants further mechanistic and clinical studies.

Molecular dynamics simulations and experimental studies reveal differential permeability of withaferin-A and withanone across the model cell membrane

Poor bioavailability due to the inability to cross the cell membrane is one of the major reasons for the failure of a drug in clinical trials. We have used molecular dynamics simulations to predict the membrane permeability of natural drugs-withanolides (withaferin-A and withanone) that have similar structures but remarkably differ in their cytotoxicity. We found that whereas withaferin-A, could proficiently transverse through the model membrane, withanone showed weak permeability. The free energy profiles for the interaction of withanolides with the model bilayer membrane revealed that whereas the polar head group of the membrane caused high resistance for the passage of withanone, the interior of the membrane behaves similarly for both withanolides. The solvation analysis further revealed that the high solvation of terminal O5 oxygen of withaferin-A was the major driving force for its high permeability; it interacted with the phosphate group of the membrane that led to its smooth passage across the bilayer. The computational predictions were tested by raising and recruiting unique antibodies that react to withaferin-A and withanone. The time-lapsed analyses of control and treated cells demonstrated higher permeation of withaferin-A as compared to withanone. The concurrence between the computation and experimental results thus re-emphasised the use of computational methods for predicting permeability and hence bioavailability of natural drug compounds in the drug development process.

Computational Insights into the Potential of Withaferin-A, Withanone and Caffeic Acid Phenethyl Ester for Treatment of Aberrant-EGFR Driven Lung Cancers

The anticancer activities of Withaferin-A (Wi-A) and Withanone (Wi-N) from Ashwagandha and Caffeic Acid Phenethyl Ester (CAPE) from honeybee propolis have been well documented. Here, we examined the binding potential of these natural compounds to inhibit the constitutive phosphorylation of epidermal growth factor receptors (EGFRs). Exon 20 insertion mutants of EGFR, which show resistance to various FDA approved drugs and are linked to poor prognosis of lung cancer patients, were the primary focus of this study. Apart from exon 20 insertion mutants, the potential of natural compounds to serve as ATP competitive inhibitors of wildtype protein and other common mutants of EGFR, namely L858R and exon19del, were also examined. The potential of natural compounds was compared to the positive controls such as erlotinib, TAS6417 and poziotinib. Similar to known inhibitors, Wi-A and Wi-N could displace and binds at the ATP orthosteric site of exon19del, L858R and exon20, while CAPE was limited to wildtype EGFR and exon 20 insertion mutants only. Moreover, the binding free energy of the natural drugs against EGFRs was also comparable to the positive controls. This computational study suggests that Wi-A and Wi-N have potential against multiple mutated EGFRs, warranting further in vitro and in vivo experiments.

Natural Products as Inducers of Non-Canonical Cell Death: A Weapon against Cancer

Simple Summary

Anticancer therapeutic approaches based solely on apoptosis induction are often unsuccessful due to the activation of resistance mechanisms. The identification and characterization of compounds capable of triggering non-apoptotic, also called non-canonical cell death pathways, could represent an important strategy that may integrate or offer alternative approaches to the current anticancer therapies. In this review, we critically discuss the promotion of ferroptosis, necroptosis, and pyroptosis by natural compounds as a new anticancer strategy.

Abstract

Apoptosis has been considered the main mechanism induced by cancer chemotherapeutic drugs for a long time. This paradigm is currently evolving and changing, as increasing evidence pointed out that antitumor agents could trigger various non-canonical or non-apoptotic cell death types. A considerable number of antitumor drugs derive from natural sources, both in their naturally occurring form or as synthetic derivatives. Therefore, it is not surprising that several natural compounds have been explored for their ability to induce non-canonical cell death. The aim of this review is to highlight the potential antitumor effects of natural products as ferroptosis, necroptosis, or pyroptosis inducers. Natural products have proven to be promising non-canonical cell death inducers, capable of overcoming cancer cells resistance to apoptosis. However, as discussed in this review, they often lack a full characterization of their antitumor activity together with an in-depth investigation of their toxicological profile.

Induction of autophagy mitigates TDP-43 pathology and translational repression of neurofilament mRNAs in mouse models of ALS/FTD

Background

TDP-43 proteinopathy is a pathological hallmark of many neurodegenerative diseases including amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). So far, there is no therapy available for these neurodegenerative diseases. In addition, the impact of TDP-43 proteinopathy on neuronal translational profile also remains unknown.

Methods

Biochemical, immunohistology and assay-based studies were done with cell cultures and transgenic mice models. We also used Ribotag with microarray and proteomic analysis to determine the neuronal translational profile in the mice model of ALS/FTD.

Results

Here, we report that oral administration of a novel analog (IMS-088) of withaferin-A, an antagonist of nuclear factor kappa-B (NF-ĸB) essential modulator (NEMO), induced autophagy and reduced TDP-43 proteinopathy in the brain and spinal cord of transgenic mice expressing human TDP-43 mutants, models of ALS/FTD. Treatment with IMS-088 ameliorated cognitive impairment, reduced gliosis in the brain of ALS/FTD mouse models. With the Ribotrap method, we investigated the impact of TDP-43 proteinopathy and IMS-088 treatment on the translation profile of neurons of one-year old hTDP-43^A315T mice. TDP-43 proteinopathy caused translational dysregulation of specific mRNAs including translational suppression of neurofilament mRNAs resulting in 3 to 4-fold decrease in levels type IV neurofilament proteins. Oral administration of IMS-088 rescued the translational defects associated with TDP-43 proteinopathy and restored the synthesis of neurofilament proteins, which are essential for axon integrity and synaptic function.

Conclusions

Our study revealed that induction of autophagy reduces TDP-43 pathology and ameliorates the translational defect seen in mice models of ALS/FTD. Based on these results, we suggest IMS-088 and perhaps other inducers of autophagy should be considered as potential therapeutics for neurodegenerative disorders with TDP-43 proteinopathies.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13024-020-00420-5.

Critical review of the Withania somnifera (L.) Dunal: ethnobotany, pharmacological efficacy, and commercialization significance in Africa

BACKGROUND

Withania somnifera (L.) Dunal (W. somnifera) is a herb commonly known by its English name as Winter Cherry. Africa is indigenous to many medicinal plants and natural products. However, there is inadequate documentation of medicinal plants, including W. somnifera, in Africa. There is, therefore, a need for a comprehensive compilation of research outcomes of this reviewed plant as used in traditional medicine in different regions of Africa.

METHODOLOGY

Scientific articles and publications were scooped and sourced from high-impact factor journals and filtered with relevant keywords on W. somnifera. Scientific databases, including GBIF, PubMed, NCBI, Google Scholar, Research Gate, Science Direct, SciFinder, and Web of Science, were accessed to identify the most influential articles and recent breakthroughs published on the contexts of ethnography, ethnomedicinal uses, phytochemistry, pharmacology, and commercialization of W. somnifera.

RESULTS

This critical review covers the W. somnifera ethnography, phytochemistry, and ethnomedicinal usage to demonstrate the use of the plant in Africa and elsewhere to prevent or alleviate several pathophysiological conditions, including cardiovascular, neurodegenerative, reproductive impotence, as well as other chronic diseases.

CONCLUSION

W. somnifera is reportedly safe for administration in ethnomedicine as several research outcomes confirmed its safety status. The significance of commercializing this plant in Africa for drug development is herein thoroughly covered to provide the much-needed highlights towards its cultivations economic benefit to Africa.

Orthobiologics with phytobioactive cues: A paradigm in bone regeneration

Bone injuries occur due to various traumatic and disease conditions. Healing of bone injury occurs via a multi-stage intricate process. Body has the potential to rectify most of the bone injuries but some severe traumatic cases with critical size defects may require interventions. Autografts are still considered the "gold standard" for fracture healing but due to limitations associated with it, new alternatives are warranted. The field of orthobiologics has provided novel approaches using scaffolds, bioactive molecules, stem cells for the treatment of bone defects. Phyto-bioactives have been widely used in alternative medicine and folklore practices for curing bone ailments. It is believed that different bioactive constituents in plants work synergistically to give the therapeutic efficacy. Bioactives in plants extracts act upon different signal transduction pathways aiding in bone healing. The present review focuses on the use, chemical composition, mode of delivery, mechanism of action, and possible future strategies of three medicinal plants popularly used in traditional medicine for bone healing: Cissus quadrangularis, Withania somnifera and Tinospora cordifolia. Plants extracts seem to be a natural and non-toxic therapeutic alternative in treating bone injuries. Most of the studies on bone healing for these plants have reported oral administration of the extracts and presented them as a safe alternative without any side effects despite giving higher doses. Forthcoming studies could be directed towards the local delivery of extracts at the defect site. Unification of herbal extracts and orthobiologics could be an interesting direction in the field of bone healing in future. The present review intends to provide a bird's eye view of different strategies used in bone healing, mechanisms involved and future direction of advancements using phytobioactives and orthobiologics.

Fractionation of Biomolecules in Withania coagulans Extract for Bioreductive Nanoparticle Synthesis, Antifungal and Biofilm Activity

Withania coagulans contains a complex mixture of various bioactive compounds. In order to reduce the complexity of the plant extract to purify its phytochemical biomolecules, a novel fractionation strategy using different solvent combination ratios was applied to isolate twelve bioactive fractions. These fractions were tested for activity in the biogenic synthesis of cobalt oxide nanoparticles, biofilm and antifungal activities. The results revealed that plant extract with bioactive fractions in 30% ratio for all solvent combinations showed more potent bioreducing power, according to the observed color changes and the appearance of representative absorption peaks at 500-510 nm in the UV-visible spectra which confirm the synthesis of cobalt oxide nanoparticles (Co3O4 NPs). XRD diffraction was used to define the crystal structure, size and phase composition of the products. The fractions obtained using 90% methanol/hexane and 30% methanol/hexane showed more effectiveness against biofilm formation by Pseudomonas aeruginosa and Staphylococcus aureus so these fractions could potentially be used to treat bacterial infections. The 90% hexane/H2O fraction showed excellent antifungal activity against Aspergillus niger and Candida albicans, while the 70% methanol/hexane fraction showed good antifungal activity for C. albicans, so these fractions are potentially useful for the treatment of various fungal infections. On the whole it was concluded that fractionation based on effective combinations of methanol/hexane was useful to investigate and study bioactive compounds, and the active compounds from these fractions may be further purified and tested in various clinical trials.

Screening and druggability analysis of some plant metabolites against SARS-CoV-2: An integrative computational approach

The sudden outbreak of novel coronavirus has caused a global concern due to its infection rate and mortality. Despite extensive research, there are still no specific drugs or vaccines to combat SARS-CoV-2 infection. Hence, this study was designed to evaluate some plant-based active compounds for drug candidacy against SARS-CoV-2 by using virtual screening methods and various computational analyses. A total of 27 plant metabolites were screened against SARS-CoV-2 main protease proteins (MPP), Nsp9 RNA binding protein, spike receptor binding domain, spike ecto-domain and HR2 domain using a molecular docking approach. Four metabolites, i.e., asiatic acid, avicularin, guajaverin, and withaferin showed maximum binding affinity with all key proteins in terms of lowest global binding energy. The crucial binding sites and drug surface hotspots were unravelled for each viral protein. The top candidates were further employed for ADME (absorption, distribution, metabolism, and excretion) analysis to investigate their drug profiles. Results suggest that none of the compounds render any undesirable consequences that could reduce their drug likeness properties. The analysis of toxicity pattern revealed no significant tumorigenic, mutagenic, irritating, or reproductive effects by the compounds. However, withaferin was comparatively toxic among the top four candidates with considerable cytotoxicity and immunotoxicity. Most of the target class by top drug candidates belonged to enzyme groups (e.g. oxidoreductases hydrolases, phosphatases). Moreover, results of drug similarity prediction revealed two approved structural analogs of Asiatic acid i.e. Hydrocortisone (DB00741) (previously used for SARS-CoV-1 and MERS) and Dinoprost-tromethamine (DB01160) from DrugBank. In addition, two other biologically active compounds, Mupirocin (DB00410) and Simvastatin (DB00641) could be an option for the treatment of viral infections. The study may pave the way to develop effective medications and preventive measure against SARS-CoV-2. Due to the encouraging results, we highly recommend further in vivo trials for the experimental validation of our findings.

The role of natural products in revealing NRF2 function

Covering: up to 2020The transcription factor NRF2 is one of the body's major defense mechanisms, driving transcription of >300 antioxidant response element (ARE)-regulated genes that are involved in many critical cellular processes including redox regulation, proteostasis, xenobiotic detoxification, and primary metabolism. The transcription factor NRF2 and natural products have an intimately entwined history, as the discovery of NRF2 and much of its rich biology were revealed using natural products both intentionally and unintentionally. In addition, in the last decade a more sinister aspect of NRF2 biology has been revealed. NRF2 is normally present at very low cellular levels and only activated when needed, however, it has been recently revealed that chronic, high levels of NRF2 can lead to diseases such as diabetes and cancer, and may play a role in other diseases. Again, this "dark side" of NRF2 was revealed and studied largely using a natural product, the quassinoid, brusatol. In the present review, we provide an overview of NRF2 structure and function to orient the general reader, we will discuss the history of NRF2 and NRF2-activating compounds and the biology these have revealed, and we will delve into the dark side of NRF2 and contemporary issues related to the dark side biology and the role of natural products in dissecting this biology.

Plant natural products with anti-thyroid cancer activity

Thyroid cancer is the most frequent endocrine malignancy, with more than 500,000 cases per year worldwide. Differentiated thyroid cancers are the most common forms with best prognosis, while poorly/undifferentiated ones are rare (2% of all thyroid cancer), aggressive, frequently metastasize and have a worse prognosis. For aggressive, metastatic and advanced thyroid cancer novel antitumor molecules are urgently needed and phytochemical products can be a rational and extensive source, since secondary plant metabolites can guarantee the necessary biochemical variability for therapeutic purpose. Among bioactive molecules that present biological activity on thyroid cancer, resveratrol, curcumin, isoflavones, glucosinolates are the most common and used in experimental model. Most of them have been studied both in vitro and in vivo on this cancer, but rarely in clinical trial. This review summarizes phytochemicals, phytotherapeutics and plant derived compounds used in thyroid cancer.

Combination of Withaferin-A and CAPE Provides Superior Anticancer Potency: Bioinformatics and Experimental Evidence to Their Molecular Targets and Mechanism of Action

We have earlier reported anticancer activity in Withaferin A (Wi-A), a withanolide derived from Ashwagandha (Withania somnifera) and caffeic acid phenethyl ester (CAPE), an active compound from New Zealand honeybee propolis. Whereas Wi-A was cytotoxic to both cancer and normal cells, CAPE has been shown to cause selective death of cancer cells. In the present study, we investigated the efficacy of Wi-A, CAPE, and their combination to ovarian and cervical cancer cells. Both Wi-A and CAPE were seen to activate tumor suppressor protein p53 by downregulation of mortalin and abrogation of its interactions with p53. Downregulation of mortalin translated to compromised mitochondria integrity and function that affected poly ADP-ribose polymerase1 (PARP1); a key regulator of DNA repair and protein-target for Olaparib, drugs clinically used for treatment of breast, ovarian and cervical cancers)-mediated DNA repair yielding growth arrest or apoptosis. Furthermore, we also compared the docking capability of Wi-A and CAPE to PARP1 and found that both of these could bind to the catalytic domain of PARP1, similar to Olaparib. We provide experimental evidences that (i) Wi-A and CAPE cause inactivation of PARP1-mediated DNA repair leading to accumulation of DNA damage and activation of apoptosis signaling by multiple ways, and (ii) a combination of Wi-A and CAPE offers selective toxicity and better potency to cancer cells.

Pharmacological evaluation of Ashwagandha highlighting its healthcare claims, safety, and toxicity aspects

Withania somnifera, commonly known as "Ashwagandha" or "Indian ginseng" is an essential therapeutic plant of Indian subcontinent regions. It is regularly used, alone or in combination with other plants for the treatment of various illnesses in Indian Systems of Medicine over the period of 3,000 years. Ashwagandha (W. somnifera) belongs to the genus Withania and family Solanaceae. It comprises a broad spectrum of phytochemicals having wide range of biological effects. W. somnifera has demonstrated various biological actions such as anti-cancer, anti-inflammatory, anti-diabetic, anti-microbial, anti-arthritic, anti-stress/adaptogenic, neuro-protective, cardio-protective, hepato-protective, immunomodulatory properties. Furthermore, W. somnifera has revealed the capability to decrease reactive oxygen species and inflammation, modulation of mitochondrial function, apoptosis regulation and improve endothelial function. Withaferin-A is an important phytoconstituents of W. somnifera belonging to the category of withanolides been used in the traditional system of medicine for the treatment of various disorders. In this review, we have summarized the active phytoconstituents, pharmacologic activities (preclinical and clinical), mechanisms of action, potential beneficial applications, marketed formulations and safety and toxicity profile of W. somnifera.

2, 3-Dihydro-3β-methoxy Withaferin-A Lacks Anti-Metastasis Potency: Bioinformatics and Experimental Evidences

Withaferin-A is a withanolide, predominantly present in Ashwagandha (Withania somnifera). It has been shown to possess anticancer activity in a variety of human cancer cells in vitro and in vivo. Molecular mechanism of such cytotoxicity has not yet been completely understood. Withaferin-A and Withanone were earlier shown to activate p53 tumor suppressor and oxidative stress pathways in cancer cells. 2,3-dihydro-3β-methoxy analogue of Withaferin-A (3βmWi-A) was shown to lack cytotoxicity and well tolerated at higher concentrations. It, on the other hand, protected normal cells against oxidative, chemical and UV stresses through induction of anti-stress and pro-survival signaling. We, in the present study, investigated the effect of Wi-A and 3βmWi-A on cell migration and metastasis signaling. Whereas Wi-A binds to vimentin and heterogeneous nuclear ribonucleoprotein K (hnRNP-K) with high efficacy and downregulates its effector proteins, MMPs and VEGF, involved in cancer cell metastasis, 3βmWi-A was ineffective. Consistently, Wi-A, and not 3βmWi-A, caused reduction in cytoskeleton proteins (Vimentin, N-Cadherin) and active protease (u-PA) that are essential for three key steps of cancer cell metastasis (EMT, increase in cell migration and invasion).

Folic Acid Receptor-Mediated Targeting Enhances the Cytotoxicity, Efficacy, and Selectivity of Withania somnifera Leaf Extract: In vitro and in vivo Evidence

Nanomedicine holds great potential for drug delivery to achieve more effective and safer cancer treatment. Earlier, we reported that the alcoholic extract of Withania somnifera leaves (i-Extract) has selective cancer cell killing activity. Herein, we developed a folate receptor-targeting i-Extract nanocomplex (FRi-ExNC) that suspends well in water and possesses enhanced selective anticancer activity in both in vitro and in vivo assays. Comparative analyses of folate receptor (FR)-positive and -negative cells revealed that FRi-ExNC caused a stronger decrease in Cyclin D/Cdk4 and anti-apoptotic protein Bcl-2, as well as a higher increase in the growth arrest regulating protein p21^WAF1 and pro-apoptotic protein PARP-1, in FR-enriched cancer cells. Our results demonstrate that FRi-ExNC could be a natural source-based nanomedicine for targeted cancer therapy.

Leishmanicidal Activity of Withanolides from Aureliana Fasciculata var. Fasciculata

Leishmaniasis is the generic denomination to the neglected diseases caused by more than 20 species of protozoa belonging to the genus Leishmania. The toxic and parenteral-delivered pentavalent antimonials remain to be the first-line treatment. However, all the current used drugs have restrictions. The species Aureliana fasciculata (Vell.) Sendtner var. fasciculata is a native Brazilian species parsimoniously studied on a chemical point of view. In this study, the antileishmanial activity of A. fasciculata was evaluated. Among the evaluated samples of the leaves, the dichloromethane partition (AFfDi) showed the more pronounced activity, with IC₅₀ 1.85 µg/ml against promastigotes of L. amazonensis. From AFfDi, two active withanolides were isolated, the Aurelianolides A and B, with IC₅₀ 7.61 μM and 7.94 μM, respectively. The withanolides also proved to be active against the clinically important form, the intracellular amastigote, with IC₅₀ 2.25 μM and 6.43 μM for Aurelianolides A and B, respectively. Furthermore, withanolides showed results for in silico parameters of absorption, distribution, metabolism, excretion, and toxicity (ADMET) similar to miltefosine, the reference drug, and were predicted as good oral drugs, with the advantage of not being hepatotoxic. These results suggest that these compounds can be useful as scaffolds for planning drug design.

Protective effects of Withania somnifera extract in SOD1G93A mouse model of amyotrophic lateral sclerosis

Withania somnifera (WS; commonly known as Ashwagandha or Indian ginseng) is a medicinal plant whose extracts have been in use for centuries in various regions of the world as a rejuvenator. There is now a growing body of evidence documenting neuroprotective functions of the plant extracts or its purified compounds in several models of neurodegenerative diseases including amyotrophic lateral sclerosis (ALS). Based on the extract's beneficial effect in a mouse model of ALS with TDP-43 proteinopathy, the current study was designed to test its efficacy in another model of familial ALS. Our results show that administration of WS extracts by gavage to mice expressing G93A mutant form of superoxide dismutase (SOD1) resulted in increased longevity, improved motor performance and increased number of motor neurons in lumbar spinal cord. The WS treatment caused substantial reduction in levels of misfolded SOD1whereas it enhanced expression of cellular chaperons in spinal cord of SOD1^G93A mice. WS markedly reduced glial activation and prevented phosphorylation of nuclear factor kappaB (NF-κB). The overall immunomodulatory effect of WS was further evidenced by changes in expression of multiple cytokines/chemokines. WS also served as an autophagy inducer which may be beneficial at early stages of the disease. These results suggest that WS extracts might constitute promising therapeutics for treatment of ALS with involvement of misfolded SOD1.

Nano-targeted induction of dual ferroptotic mechanisms eradicates high-risk neuroblastoma

High-risk neuroblastoma is a devastating malignancy with very limited therapeutic options. Here, we identify withaferin A (WA) as a natural ferroptosis-inducing agent in neuroblastoma, which acts through a novel double-edged mechanism. WA dose-dependently either activates the nuclear factor-like 2 pathway through targeting of Kelch-like ECH-associated protein 1 (noncanonical ferroptosis induction) or inactivates glutathione peroxidase 4 (canonical ferroptosis induction). Noncanonical ferroptosis induction is characterized by an increase in intracellular labile Fe(II) upon excessive activation of heme oxygenase-1, which is sufficient to induce ferroptosis. This double-edged mechanism might explain the superior efficacy of WA as compared with etoposide or cisplatin in killing a heterogeneous panel of high-risk neuroblastoma cells, and in suppressing the growth and relapse rate of neuroblastoma xenografts. Nano-targeting of WA allows systemic application and suppressed tumor growth due to an enhanced accumulation at the tumor site. Collectively, our data propose a novel therapeutic strategy to efficiently kill cancer cells by ferroptosis.

Anti-Stress and Glial Differentiation Effects of a Novel Combination of Cucurbitacin B and Withanone (CucWi-N): Experimental Evidence

Background

Natural extracts and compounds used in traditional home medicine are known for their safety and a variety of health promoting and therapeutic potentials. In contrast to the single molecule mediated targets, the combinational therapies are preferred for their multi-functional and limited toxic regimens and may be useful for disease therapeutics as well as to increase the quality of life during a variety of environmental stresses.

Purpose

We aimed to combine the active ingredients of Chinese (Helicteres angustifolia) and Indian (Withania somnifera) ginsengs to develop a natural, efficient, and welfare combinatorial mixture with high anti-stress and glial differentiation potentials.

Methods

Using cultured cells as a model system, we developed a combination of active ingredients of Chinese (Cucurbitacin B [Cuc]) and Indian (Withanone [Wi-N]) ginsengs. Eleven chemical models of environmental stresses were used. Cytotoxicity studies were performed using human skin fibroblast for anti-stress and rat glioma cells for glial differentiation effects.

Results

We demonstrate that the novel combination of Cuc and Wi-N, CucWi-N, was non-toxic to normal cells. It caused stress protection in assays using normal human fibroblasts subjected to a variety of stresses. Of note, cells showed remarkable protection against oxidative and UV stresses and marked by decrease in DNA damage and reactive oxygen species. We examined and found the glial differentiation potential of CucWi-N in rat glioblastoma cells. CucWi-N clearly induced differentiation phenotype, well-marked with upregulation of GAP43, MAP2, and GFAP, which have been shown to play a key role in glial differentiation.

Conclusion

These data demonstrate anti-stress and glial differentiation potential of CucWi-N (a novel combination of Cuc and Wi-N) that could be recruited in nutraceutical and pharmaceutical avenues and hence warrant further evaluation and mechanistic studies.

Modulations in primary and secondary metabolic pathways and adjustment in physiological behaviour of Withania somnifera under drought stress

In general medicinal plants grown under water limiting conditions show much higher concentrations of secondary metabolites in comparison to control plants. In the present study, Withania somnifera plants were subjected to water stress and data related to drought tolerance phenomenon was collected and a putative mechanistic concept considering growth responses, physiological behaviour, and metabolite content and gene expression aspects is presented. Drought induced metabolic and physiological responses as well as drastic decrease in CO₂ uptake due to stomatal limitations. As a result, the consumption of reduction equivalents (NADPH²⁺) for CO₂ assimilation via the calvin cycle declines significantly resulting in the generation of a large oxidative stress and an oversupply of antioxidant enzymes. Drought also results in the shifting of metabolic processes towards biosynthetic activities that consume reduction equivalents. Thus, biosynthesis of reduced compounds (isoprenoids, phenols and alkaloids) is enhanced. The dynamics of various metabolites have been discussed in the light of gene expression analysis of control and drought treated leaves. Gene encoding enzymes of pathways leading to glucose, fructose and fructan production, conversion of triose phosphates to hexoses and hexose phosphorylation were up-regulated in the drought stressed leaves. The down-regulated Calvin cycle genes were co-ordinately regulated with the down-regulation of chloroplast triosephosphate/phosphate translocator, cytoplasmic fructose-1,6-bisphosphate aldolase and fructose bisphosphatase. Expression of gene encoding Squalene Synthase (SQS) was highly upregulated under drought stress which is responsible for the diversion of carbon flux towards withanolides biosynthesis from isoprenoid pathway.

4β-Hydroxywithanolide E selectively induces oxidative DNA damage for selective killing of oral cancer cells

Reactive oxygen species (ROS) induction had been previously reported in 4β-hydroxywithanolide (4βHWE)-induced selective killing of oral cancer cells, but the mechanism involving ROS and the DNA damage effect remain unclear. This study explores the role of ROS and oxidative DNA damage of 4βHWE in the selective killing of oral cancer cells. Changes in cell viability, morphology, ROS, DNA double strand break (DSB) signaling (γH2AX foci in immunofluorescence and DSB signaling in western blotting), and oxidative DNA damage (8-oxo-2'deoxyguanosine [8-oxodG]) were detected in 4βHWE-treated oral cancer (Ca9-22) and/or normal (HGF-1) cells. 4βHWE decreased cell viability, changed cell morphology and induced ROS generation in oral cancer cells rather than oral normal cells, which were recovered by a free radical scavenger N-acetylcysteine (NAC). For immunofluorescence, 4βHWE also accumulated more of the DSB marker, γH2AX foci, in oral cancer cells than in oral normal cells. For western blotting, DSB signaling proteins such as γH2AX and MRN complex (MRE11, RAD50, and NBS1) were overexpressed in 4βHWE-treated oral cancer cells in different concentrations and treatment time. In the formamidopyrimidine-DNA glycolyase (Fpg)-based comet assay and 8-oxodG-based flow cytometry, the 8-oxodG expressions were higher in 4βHWE-treated oral cancer cells than in oral normal cells. All the 4βHWE-induced DSB and oxidative DNA damage to oral cancer cells were recovered by NAC pretreatment. Taken together, the 4βHWE selectively induced DSB and oxidative DNA damage for the ROS-mediated selective killing of oral cancer cells.

2,3-Dihydro-3β-methoxy Withaferin-A Protects Normal Cells against Stress: Molecular Evidence of Its Potent Cytoprotective Activity

2,3-Dihydro-3β-methoxy withaferin-A (3βmWi-A) is a natural withanolide that is structurally close to withaferin-A (Wi-A), is cytotoxic to human cancer cells, and is a candidate anticancer natural compound. Using cell-based biochemical, molecular, and imaging assays, we report that Wi-A and 3βmWi-A possess contrasting activities. Whereas Wi-A caused oxidative stress to normal cells, 3βmWi-A was well tolerated at even 10-fold higher concentrations. Furthermore, it promoted survival and protected normal cells against oxidative, UV radiation, and chemical stresses. We provide molecular evidence that 3βmWi-A induces antistress and pro-survival signaling through activation of the pAkt/MAPK pathway. We demonstrate that 3βmWi-A (i) contrary to Wi-A is safe and possesses stress-relieving activity, (ii) when given subsequent to a variety of stress factors including Wi-A, protects normal cells against their toxicity, and (iii) is a vital compound that may guard normal cells against the toxicity associated with various targeted therapeutic regimes in clinical practice.

Changes in the leaf proteome profile of Withania somnifera (L.) Dunal in response to Alternaria alternata infection

Withania somnifera is a high value medicinal plant which is used against large number of ailments. The medicinal properties of the plant attributes to a wide array of important secondary metabolites. The plant is predominantly infected with leaf spot pathogen Alternaria alternata, which leads to substantial biodeterioration of pharmaceutically important metabolites. To develop an effective strategy to combat this disease, proteomics based approach could be useful. Hence, in the present study, three different protein extraction methods tris-buffer based, phenol based and trichloroacetic acid-acetone (TCA-acetone) based method were comparatively evaluated for two-dimensional electrophoresis (2-DE) analysis of W. somnifera. TCA-acetone method was found to be most effective and was further used to identify differentially expressed proteins in response to fungal infection. Thirty-eight differentially expressed proteins were identified by matrix assisted laser desorption/ionization time of flight-mass spectrometry (MALDI TOF/TOF MS/MS). The known proteins were categorized into eight different groups based on their function and maximum proteins belonged to energy and metabolism, cell structure, stress and defense and RNA/DNA categories. Differential expression of some key proteins were also crosschecked at transcriptomic level by using qRT-PCR and were found to be consistent with the 2-DE data. These outcomes enable us to evaluate modifications that take place at the proteomic level during a compatible host pathogen interaction. The comparative proteome analysis conducted in this paper revealed the involvement of many key proteins in the process of pathogenesis and further investigation of these identified proteins could assist in the discovery of new strategies for the development of pathogen resistance in the plant.

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.