Effect of Withaferin A on A549 cellular proliferation and apoptosis in non-small cell lung cancer

The Therapeutic Effects of Withaferin A against Cancer: Overview and Updates

Cancer is a rapidly rising health problem among the global population, and this burden causes a significant challenge for public health. Current chemotherapeutic agents have different limitations, including drug resistance and severe side effects, and it demands a robust approach to accessing promising anti-cancer therapeutics. The natural compounds have been extensively studied to identify improved therapeutic agents for cancer therapy. Withaferin A (WA) is a steroidal lactone found in Withania somnifera and possesses anti-inflammatory, antioxidant, anti-angiogenesis, and anticancer properties. Multiple studies have shown that WA treatment attenuated various cancer hallmarks by inducing apoptosis and reducing angiogenesis and metastasis with reduced side effects. WA is a promising agent for the treatment of various cancer, and it targets various signaling pathways. With recent updates, the current review highlights the therapeutic implications of WA and its molecular targets in different cancer.

Withaferin A and Celastrol Overwhelm Proteostasis

Withaferin A (WA) and celastrol (CEL) are major bioactive components of plants that have been widely employed in traditional medicine. The pleiotropic activities of plant preparations and the isolated compounds in vitro and in vivo have been documented in hundreds of studies. Both WA and CEL were shown to have anticancer activity. Although WA and CEL belong to different chemical classes, our synthesis of the available information suggests that the compounds share basic mechanisms of action. Both WA and CEL bind covalently to numerous proteins, causing the partial unfolding of some of these proteins and of many bystander proteins. The resulting proteotoxic stress, when excessive, leads to cell death. Both WA and CEL trigger the activation of the unfolded protein response (UPR) which, if the proteotoxic stress persists, results in apoptosis mediated by the PERK/eIF-2/ATF4/CHOP pathway or another UPR-dependent pathway. Other mechanisms of cell death may play contributory or even dominant roles depending on cell type. As shown in a proteomic study with WA, the compounds appear to function largely as electrophilic reactants, indiscriminately modifying reachable nucleophilic amino acid side chains of proteins. However, a remarkable degree of target specificity is imparted by the cellular context.

Phytochemical characterization and toxicological activity attributed to the acetonic extract of South American Vassobia breviflora

The particular plant species found in southern Brazil, Vassobia breviflora (Solanaceae) has only a few apparent studies examining its biological effect. Thus, the aim of the present study was to determine the activity of the acetone extract fraction derived from V. breviflora. Four compounds were identified by ESI-qTOF-MS: eucalrobusone R, aplanoic acid B, pheophorbide A, and pheophytin A. In addition, 5 compounds were identified by HPLC-PDA-MS/MS: all-trans-lutein, 15-cis-lutein, all-trans-β-carotene, 5,8-epoxy-β-carotene, and cis-β-carotene. Cell lines A549 (lung cancer), A375 (melanoma cancer) and HeLa (cervical cancer) were incubated with different concentrations of each studied extract using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), lactate dehydrogenase (LDH), and 2'-7'dichlorofluorescin diacetate (DCFH-DA) assays. The acetonic extract exhibited cytotoxic activity at a concentration of 0.03 mg/ml in the HeLa strain and 0.1 mg/ml in the others. In addition to increased production of reactive oxygen species (ROS). Antibacterial activity was assessed utilizing minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) in 9 ATCCs strains and 7 clinical isolates, as well as determination of biofilm production. Data demonstrated that MIC and MBC were approximately 256 mg/ml in most of the strains tested and antibiofilm effect at S. aureus, S. epidermidis, A. baumannii, and E. faecalis, concentrations below the MIC. Genotoxic activity on plasmid DNA did not produce significant elevated levels in breaks in the isolated genetic material.

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.

Withaferin A: A Dietary Supplement with Promising Potential as an Anti-Tumor Therapeutic for Cancer Treatment - Pharmacology and Mechanisms

Cancer, as the leading cause of death worldwide, poses a serious threat to human health, making the development of effective tumor treatments a significant challenge. Natural products continue to serve as crucial resources for drug discovery. Among them, Withaferin A (WA), the most active phytocompound extracted from the renowned dietary supplement Withania somnifera (L.) Dunal, exhibits remarkable anti-tumor efficacy. In this manuscript, we aim to comprehensively summarize the pharmacological characteristics of WA as a potential anti-tumor drug candidate, with the objective of contributing to its further development and the discovery of prospective drugs. Through an extensive review of literature from PubMed, Science Direct, and Web of Science, we have gathered substantial evidence showcasing WA's significant anti-tumor effects against a wide range of cancers in both in vitro and in vivo studies. Mechanistically, WA exerts its anti-tumor influence by inducing cell cycle arrest, apoptosis, autophagy, and ferroptosis. Additionally, it inhibits cell proliferation, cancer stem cells, tumor metastasis, and also suppresses epithelial-mesenchymal transition (EMT) and angiogenesis. Several studies have identified direct target proteins of WA, such as vimentin, Hsp90, annexin II and mFAM72A, while BCR-ABL, Mortalin (mtHsp70), Nrf2, and c-MYB are potential targets of WA. Notwithstanding its remarkable anti-tumor efficacy, there are some limitations associated with WA, including potential toxicity and poor oral bioavailability, which need to be addressed when considering it as an anti-tumor candidate agent. Nevertheless, I given its promising anti-tumor attributes, WA remains an encouraging candidate for future drug development. Unveiling the exact target and comprehensive mechanism of WA's action represents a crucial research direction to pursue in the future.

Hairy root culture: a potent method for improved secondary metabolite production of Solanaceous plants

Secondary metabolites synthesized by the Solanaceous plants are of major therapeutic and pharmaceutical importance, many of which are commonly obtained from the roots of these plants. 'Hairy roots', mirroring the same phytochemical pattern of the corresponding root of the parent plant with higher growth rate and productivity, are therefore extensively studied as an effective alternative for the in vitro production of these metabolites. Hairy roots are the transformed roots, generated from the infection site of the wounded plants with Agrobacterium rhizogenes. With their fast growth, being free from pathogen and herbicide contamination, genetic stability, and autotrophic nature for plant hormones, hairy roots are considered as useful bioproduction systems for specialized metabolites. Lately, several elicitation methods have been employed to enhance the accumulation of these compounds in the hairy root cultures for both small and large-scale production. Nevertheless, in the latter case, the cultivation of hairy roots in bioreactors should still be optimized. Hairy roots can also be utilized for metabolic engineering of the regulatory genes in the metabolic pathways leading to enhanced production of metabolites. The present study summarizes the updated and modern biotechnological aspects for enhanced production of secondary metabolites in the hairy root cultures of the plants of Solanaceae and their respective importance.

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.

Withania somnifera (L.) Dunal (Ashwagandha); current understanding and future prospect as a potential drug candidate

Cancer and Neurodegenerative diseases are one of the most dreadful diseases to cure and chemotherapy has found a prime place in cancerous treatments while as different strategies have been tested in neurodegenerative diseases as well. However, due to adverse shortcomings like the resistance of cancerous cells and inefficiency in neurodegenerative disease, plant sources have always found a prime importance in medicinal use for decades, Withania somnifera (L.) Dunal (W. somnifera) is a well-known plant with medicinal use reported for centuries. It is commonly known as winter cherry or ashwagandha and is a prime source of pharmaceutically active compounds withanolides. In recent years research is being carried in understanding the extensive role of W. somnifera in cancer and neurological disorders. W. somnifera has been reported to be beneficial in DNA repair mechanisms; it is known for its cellular repairing properties and helps to prevent the apoptosis of normal cells. This review summarizes the potential properties and medicinal benefits of W. somnifera especially in cancer and neurodegenerative diseases. Available data suggest that W. somnifera is effective in controlling disease progressions and could be a potential therapeutic target benefiting human health status. The current review also discusses the traditional medicinal applications of W. somnifera, the experimental evidence supporting its therapeutical potential as well as obstacles that necessitate being overcome for W. somnifera to be evaluated as a curative agent in humans.

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.

TTK is a potential therapeutic target for cisplatin-resistant ovarian cancer

Background

Drug resistance and recurrence are main contributors to the poor prognosis of ovarian cancer. Cisplatin is a platinum compound which is widely used in the treatment of various solid tumors including ovarian cancer. Up to now, the mechanism of cisplatin resistance in ovarian cancer is unclear. Threonine and tyrosine kinase (TTK), an integral part of the spindle assembly checkpoint, may be a potential new target associated with chemotherapy sensitivity.

Results

TTK was up-regulated in the cisplatin-resistant ovarian cancer cell line. Down-regulation of TTK could recover the sensitivity of cisplatin-resistant ovarian cancer cells to cisplatin treatment. Mechanistically, the PI3K/AKT signaling pathway was activated in cisplatin-resistant cells, and this pathway would be affected by TTK expression. Furthermore, TTK was highly expressed in the tissues of ovarian cancer patients, especially those acquired resistance to cisplatin.

Conclusions

Our study revealed that TTK may be a promising therapeutic target for cisplatin-resistant ovarian cancer.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13048-021-00884-z.

Preparation and characterization of withaferin A loaded pegylated nanoliposomal formulation with high loading efficacy: In vitro and in vivo anti-tumour study

Withaferin A (WA) is a natural steroidal lactone with promising therapeutic applications. However, its clinical application is limited due to the low bioavailability and hydrophobic nature. In this study, we had prepared PEGylated nanoliposomal withaferin A (LWA) using thin-film hydration method. Dynamic light scattering, Transmission electron microscopy, and HPLC were used to investigate the impact of prepared formulations on the size, charge, morphology, and encapsulation efficiency of the LWA. The prepared nanoliposomal system had spherical vesicles, with the mean particle size of 125 nm and had an encapsulation efficiency of 83.65% with good stability. The characterization results indicated that nanoliposomal formulation is able to improve biocompatibility and bioavailability of WA. In vitro drug release study showed that LWA had an enhanced sustained drug release effect than the free drug. In vitro studies using ascites cell lines (DLA and EAC) showed that LWA treatment could induce apoptosis in ascites cells evidenced by acridine orange/ethidium bromide, Hoechst, and Giemsa staining. In vivo tumour study revealed that LWA treatment significantly reduced tumour growth and improved survival in DLA tumour bearing mice. In vivo results further demonstrated that LWA mitigated solid tumour development by regulating Ki-67 and cyclin D1 protein expression. The overall study results reveal that nanoliposome encapsulated WA exhibits therapeutic efficacy over WA in regulating tumour development as evidenced from ascites cell apoptosis as well as experimental tumour reduction studies.

Anti-angiogenic, apoptotic and matrix metalloproteinase inhibitory activity of Withania somnifera (ashwagandha) on lung adenocarcinoma cells

INTRODUCTION

Withania somnifera belongs to the family Solanaceae, known as Queen of medicinal plants for its enormous use in the medicinal field. Traditionally ashwagandha is used to treat several neurological disorders. This study evaluates the cytotoxic, apoptotic, antiangiogenic and matrix metalloproteinase (MMP) inhibitory activity of W. somnifera on lung adenocarcinoma.

METHODOLOGY

Aqueous and ethanolic extracts were prepared from the roots of the W. somnifera. Qualitative and quantitative phytochemical analyses were performed using the standard protocols. Cytotoxicity was assessed using MTT assay. Further experiments were carried out with IC₅₀ concentration of the extract. Apoptosis and DNA damage were evaluated using AO-EB dual staining, Hoechst staining and Comet assay. Effect of the extract on cell migration was evaluated using scratch assay. Angiogenesis inhibition was evaluated using in ovo CAM assay and angiogenic pathway alterations were evaluated using qRT-PCR and western blotting. Autophagy induction was studied via western blotting.

RESULTS

In this study, we found antioxidant activity and the presence of certain secondary metabolites in the ethanolic extracts. The extract showed cytotoxic activity on lung adenocarcinoma cells with an IC₅₀ of 99.7 μg/ml. The extract showed significant anti-angiogenic, apoptotic and autophagy induction activity. W. somnifera extract induced significant decrease in the cell migration at lower concentrations indicating the anti-migratory potential.

CONCLUSION

Our investigation revealed ethanolic extract of W. somnifera possess significant anti-angiogenic and MMP inhibitory activity and helps in inhibiting the lung adenocarcinoma cells proliferation. Further, our study revealed that the enhanced autophagy induction and apoptotic effects of W. somnifera are responsible for the potential anticancer activity of the extract.

Perspectives on natural compounds in chemoprevention and treatment of cancer: an update with new promising compounds

Cancer is the second deadliest disease worldwide. Although recent advances applying precision treatments with targeted (molecular and immune) agents are promising, the histological and molecular heterogeneity of cancer cells and huge mutational burdens (intrinsic or acquired after therapy) leading to drug resistance and treatment failure are posing continuous challenges. These recent advances do not negate the need for alternative approaches such as chemoprevention, the pharmacological approach to reverse, suppress or prevent the initial phases of carcinogenesis or the progression of premalignant cells to invasive disease by using non-toxic agents. Although data are limited, the success of several clinical trials in preventing cancer in high-risk populations suggests that chemoprevention is a rational, appealing and viable strategy to prevent carcinogenesis. Particularly among higher-risk groups, the use of safe, non-toxic agents is the utmost consideration because these individuals have not yet developed invasive disease. Natural dietary compounds present in fruits, vegetables and spices are especially attractive for chemoprevention and treatment because of their easy availability, high margin of safety, relatively low cost and widespread human consumption. Hundreds of such compounds have been widely investigated for chemoprevention and treatment in the last few decades. Previously, we reviewed the most widely studied natural compounds and their molecular mechanisms, which were highly exploited by the cancer research community. In the time since our initial review, many promising new compounds have been identified. In this review, we critically review these promising new natural compounds, their molecular targets and mechanisms of anticancer activity that may create novel opportunities for further design and conduct of preclinical and clinical studies.

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.

Attenuating role of withaferin A in the proliferation and migration of lung cancer cells via a p53-miR-27a/miR-10b pathway

MicroRNAs (miRNAs/miRs) are known to play a key role in tumorigenesis and usually serve as therapeutic targets in cancer treatment. In the present study, the inhibitory effects and the targeting miRNAs of withaferin A (WA) were investigated in human lung cancer cells. Different lung cancer cell lines were administrated with different concentrations of WA for different time interval followed by western blot or reverse transcription-quantitative PCR analyses to determine the underlying signaling pathway. The results demonstrated that WA decreased the viability of lung cancer cells in a caspase-dependent manner. Further investigations indicated that treatment with WA induced the expression of proapoptotic molecules, p53 and Bax, and decreased Bcl-2 expression in A549 cells. Notably, the results demonstrated that WA also decreased the motility of lung cancer cells in a dose-dependent manner, at a relatively lower concentration. Western blot analysis revealed increased E-cadherin and decreased vimentin expression levels in lung cancer cells treated with WA. In addition, two oncomiRs, including miR-10b and miR-27a, which regulate the expression of E-cadherin and Bax, respectively, were downregulated in the presence of WA. The ectopic expression of miR-10b mimics was able to recover the WA-decreased motility of lung cancer cells, which was accompanied by a reduction in E-cadherin expression. Conversely, the ectopic expression of miR-27a mimics decreased the expression of Bax and recovered the viability of lung cancer cells attenuated by WA. In addition, the ectopic expression of p53-wild type decreased the expression levels of both miR-10b and miR-27a, whereas p53 knockdown induced their expression. Transient knockdown of p53 decreased the inhibitory effects of WA in the motility and viability of lung cancer cells, suggesting an association between WA-p53-miR-10b/27a and motility/viability. Further investigations demonstrated that p53 knockdown in lung cancer stable cell lines exhibited higher levels of both miR-10b and miR-27a, and higher motility and viability following treatment with WA. However, suppression of miR-10b and miR-27a effectively decreased motility and viability, respectively, following treatment with WA. Taken together, the results of the present study suggest that WA inhibits the functionality of lung cancer cells by decreasing the expression levels of both miR-10b and miR-27a in a p53-dependent manner.

Novel diphenyl urea derivative serves as an inhibitor on human lung cancer cell migration by disrupting EMT via Wnt/β-catenin and PI3K/Akt signaling

Targeted anti-tumor small molecules are considered to be promising candidates for cancer treatment. The novel diphenyl urea derivative (DUD) was synthesized by the molecular docking based on the structure optimization of Taspine (a natural product). In this study, we explored the anti-metastatic potential of DUD for NSCLC in vitro. DUD significantly suppressed A549 cell migration by reversing EMT. The inhibition was reflected on upregulation of E-cadherin and downregulation of N-cadherin, vimentin, Snail and HIF-1α. Meanwhile, DUD inhibited the β-catenin nuclear translocation by upregulating Axin and downregulating the expression of APC, CK1 and phosphorylation of GSK3β, and simultaneously decreasing MMP9 and MMP13 expression. Moreover, it was associated with the downregulation of the PI3K/Akt/mTOR signaling. Furthermore, we used XAV939, an β-catenin inhibitor, to verify the mechanism of DUD. These results suggested that DUD inhibited A549 cells migration by reversing EMT via Wnt/β-catenin and PI3K/Akt signaling. DUD might be a potential therapeutic drug candidate for NSCLC treatment.

A novel small-molecule PI3K/Akt signaling inhibitor, W934, exhibits potent antitumor efficacy in A549 non-small-cell lung cancer

Small-molecule targeted antitumor drugs are considered to be a promising treatment that can improve the efficacy and reduce side effects. PI3K/Akt signaling pathway is constantly activated in various cancers. We recently synthesized a series of novel compounds of PI3K/Akt pathway inhibitors and found the most effective analog to be W934. In this study, we explored the in-vitro and in-vivo antitumor effects of W934 on A549 non-small-cell lung cancer cells and HCT116 colorectal cancer cells. In-vitro assays showed that W934 caused an inhibition of PI3Kα kinase. W934 can significantly suppress the viability of A549 and HCT116 cells with IC50 values of 0.25 and 0.23 μmol/l, respectively. Besides, the inhibitory effects on cell migration, invasion and apoptosis were also observed after treatment of W934 for the indicated hours. According to the cell cycle analysis, W934 caused an inhibition of G0-G1 phase progression and correspondingly decreased the percentage of cells in S and G2-M phases. Results of western blotting indicated that W934 concentration dependently suppressed the activation of the PI3K/Akt pathway. Meanwhile, the in-vivo effect was studied in an A549 xenograft mouse model. Oral administration of W934 inhibited the tumor growth in a dose-dependent manner. Hereby, W934 might be considered as a potential therapeutic drug candidate for non-small-cell lung cancer treatment.

A Comprehensive Review and Perspective on Anticancer Mechanisms of Withaferin A in Breast Cancer

Withaferin A (hereafter abbreviated as WA) is a promising anticancer steroidal lactone abundant in a medicinal plant (Withania somnifera) native to Asia. The root/leaf extract of Withania somnifera, which belongs to the Solanaceae family, continues to be included in the Ayurvedic medicine formulations of alternative medicine practice. Numerous chemicals are detectable in the root/leaf extract of Withania somnifera [e.g., withanolides (WA, withanone, withanolide A, etc.), alkaloids, sitoindosides, etc.], but the anticancer effect of this medicinal plant is largely attributed to WA. Anticancer effect of WA was initially reported in the early 70s in the Ehrlich ascites tumor cell model in vitro Since then, numerous preclinical studies have been performed using cellular and animal models of different cancers including breast cancer to determine cancer therapeutic and chemopreventive effects of WA. Chemoprevention, a word first introduced by Dr. Michael B. Sporn, was intended to impede, arrest, or reverse carcinogenesis at its earliest stages with pharmacologic agents. This review succinctly summarizes the published findings on anticancer pharmacology of WA in breast cancer focusing on pharmacokinetic behavior, in vivo efficacy data in preclinical models in a therapeutic and chemoprevention settings, and its known effects on cancer-relevant cellular processes (e.g., growth arrest, apoptosis induction, autophagy, metabolic adaptation, immune function, etc.) and molecular targets (e.g., suppression of oncogenes such as estrogen receptor-α, STAT3, etc.). Potential gaps in knowledge as well as future research directions essential for clinical development of WA for chemoprevention and/or treatment of breast cancer are also discussed.

RNA-seq reveals novel mechanistic targets of withaferin A in prostate cancer cells

Withaferin A (WA) is a promising phytochemical exhibiting in vitro and in vivo anticancer activities against prostate and other cancers, but the mechanism of its action is not fully understood. In this study, we performed RNA-seq analysis using 22Rv1 human prostate cancer cell line to identify mechanistic targets of WA. Kyoto Encyclopedia of Genes and Genomes pathway analysis of the differentially expressed genes showed most significant enrichment of genes associated with metabolism. These results were validated using LNCaP and 22Rv1 human prostate cancer cells and Hi-Myc transgenic mice as models. The intracellular levels of acetyl-CoA, total free fatty acids and neutral lipids were decreased significantly following WA treatment in both cells, which was accompanied by downregulation of mRNA (confirmed by quantitative reverse transcription-polymerase chain reaction) and protein levels of key fatty acid synthesis enzymes, including ATP citrate lyase, acetyl-CoA carboxylase 1, fatty acid synthase and carnitine palmitoyltransferase 1A. Ectopic expression of c-Myc, but not constitutively active Akt, conferred a marked protection against WA-mediated suppression of acetyl-CoA carboxylase 1 and fatty acid synthase protein expression, and clonogenic cell survival. WA was a superior inhibitor of cell proliferation and fatty acid synthesis in comparison with known modulators of fatty acid metabolism including cerulenin and etomoxir. Intraperitoneal WA administration to Hi-Myc transgenic mice (0.1 mg/mouse, three times/week for 5 weeks) also resulted in a significant decrease in circulating levels of total free fatty acids and phospholipids, and expression of ATP citrate lyase, acetyl-CoA carboxylase 1, fatty acid synthase and carnitine palmitoyltransferase 1A proteins in the prostate in vivo.

Mechanisms of Anti-Tumor Activity of Withania somnifera (Ashwagandha)

Increasing herbal formulations have been used to treat several diseases including cancer. W. somnifera (Ashwagandha) is one such plant the extracts of which have been tested against a number of ailments including cancer, which remains as one of the most dreadful diseases on the globe. The ever-increasing number of cancer related mortality demands the development of novel chemopreventive agents with minimum side effects. Different compounds isolated from various parts of the plant like root, stem, and leaves have been reported to display significant anti-cancerous and immunomodulating properties and thus can be used alone or in combination with other chemotherapeutic drugs for cancer treatment. Through this review, we highlight the importance of W. somnifera in countering the potential oncogenic signaling mediators that are modulated by active constituents of W. somnifera in a variety of cancer types. Further, we hope that active constituents of W. somnifera will be tested in clinical trials so that they can be used as an important adjuvant in the near future for the effective treatment of cancer.

Synergistic combinations of paclitaxel and withaferin A against human non-small cell lung cancer cells

Platinum-taxane combination chemotherapy still represents the standard of care for advanced non-small cell lung cancer (NSCLC) with no targetable driver mutations. However, the efficacy of these drugs has plateaued at 10–14 months primarily due to dose-limiting toxicity, chemoresistance, and metastasis. Here, we explored the effects of withaferin A (WFA) alone and in combination with paclitaxel (PAC) on the growth, proliferation, migration, and invasion of human NSCLC cells. We show that the sensitivity of H1299 and A549 cells to concomitant treatment with PAC and WFA was greater than that of either PAC or WFA alone. Using the combination index and dose-reduction index, we demonstrated that various combinations (1:40, 1:20, 1:10) of PAC to WFA, respectively, were highly synergistic. In addition, PAC+WFA co-treatment synergistically inhibited colony formation, migration, invasion and increased the induction of apoptosis in H1299 and A549 cells. Interestingly, the synergism of PAC and WFA was not schedule-dependent but was enhanced when cells were pretreated with WFA indicating a chemo-sensitizing effect. Importantly, WFA was active against both PAC-sensitive (TS-A549) and PAC-resistant (TR-A549) cells both in vitro and in vivo. Mechanistically, WFA inhibits the proliferation of NSCLC cells via thiol oxidation. The effects of WFA were inhibited in the presence of N-acetyl cysteine and other thiol donors. Taken together, our results demonstrate the efficacy of WFA alone or alongside PAC on NSCLC cells and provide a strong rationale for further detailed testing in clinically relevant models for the development of PAC+WFA combination as an alternative therapeutic strategy for advanced NSCLC.

Withania Somnifera (Ashwagandha) and Withaferin A: Potential in Integrative Oncology

Ashwagandha (Withania Somnifera, WS), belonging to the family Solanaceae, is an Ayurvedic herb known worldwide for its numerous beneficial health activities since ancient times. This medicinal plant provides benefits against many human illnesses such as epilepsy, depression, arthritis, diabetes, and palliative effects such as analgesic, rejuvenating, regenerating, and growth-promoting effects. Several clinical trials of the different parts of the herb have demonstrated safety in patients suffering from these diseases. In the last two decades, an active component of Withaferin A (WFA) has shown tremendous cytotoxic activity suggesting its potential as an anti-carcinogenic agent in treatment of several cancers. In spite of enormous progress, a thorough elaboration of the proposed mechanism and mode of action is absent. Herein, we provide a comprehensive review of the properties of WS extracts (WSE) containing complex mixtures of diverse components including WFA, which have shown inhibitory properties against many cancers, (breast, colon, prostate, colon, ovarian, lung, brain), along with their mechanism of actions and pathways involved.

Withaferin A inhibits Epithelial to Mesenchymal Transition in Non-Small Cell Lung Cancer Cells

Lung cancer is the leading cause of cancer-related deaths worldwide and in the United States. Despite recent advancements in treatment approaches, metastasis remains a major therapeutic challenge in lung cancer and explains the extremely poor prognosis. Epithelial to mesenchymal transition (EMT), a complex process of cellular reprogramming has become an attractive drug target because it plays a crucial role in the metastasis of non-small cell lung cancer (NSCLC). In the present study, we examined the effects of withaferin A (WFA), a plant-derived steroidal lactone on EMT in human NSCLC cell lines. First, we demonstrated that WFA displayed time- and concentration-dependent cytotoxicity on A549 and H1299 NSCLC cells. Then, cells were exposed to ≤ 0.5 µM WFA for ≤ 4 h to minimize cytotoxicity and determined its effects on EMT, cell adhesion, motility, migration, and invasion. EMT induction was performed by culturing cells in serum-free media containing TGFβ1 (5 ng/mL) and TNFα (25 ng/mL) for 48 h. We observed that pretreatment of cells with WFA inhibited cell adhesion, migration, and invasion of A549 and H1299 cells. Using western blot, immunofluorescence, and qRT-PCR analysis, we demonstrated that WFA suppressed TGFβ1 and TNFα-induced EMT in both cell lines. Mechanistically, WFA suppressed the phosphorylation and nuclear translocation of Smad2/3 and NF-κB in A549 and H1299 cells. Together, our study provides additional evidence demonstrating the inhibitory effects of WFA on EMT induction in NSCLC cells and further demonstrates the therapeutic potential of WFA against the metastasis in NSCLC.

Withaferin A inhibits the proliferation of gastric cancer cells by inducing G2/M cell cycle arrest and apoptosis

Human gastric adenocarcinoma (AGS) is one of the most common types of malignant tumor and the third-leading cause of tumor-associated mortality worldwide. Withaferin A (WA), a steroidal lactone derived from Withania somnifera, exhibits antitumor activity in a variety of cancer models. However, to the best of our knowledge, the direct effect of WA on AGS cells has not previously been determined. The present study investigated the effects of WA on the proliferation and metastatic activity of AGS cells. WA exerted a dose-dependent cytotoxic effect on AGS cells. The effect was associated with cell cycle arrest at the G2/M phase and the expression of apoptotic proteins. Additionally, WA treatment resulted in a decrease in the migration and invasion ability of the AGS cells, as demonstrated using a wound healing assay and a Boyden chamber assay. These results indicate that WA directly inhibits the proliferation and metastatic activity of gastric cancer cells, and suggest that WA may be developed as a drug for the treatment of gastric cancer.

Croton Tiglium Extract Induces Apoptosis via Bax/Bcl-2 Pathways in Human Lung Cancer A549 Cells

Objective: To investigate the impact of a Croton tiglium extract on cellular proliferation and apoptosis in a nonsmall cell lung cancer cell line (A549) in vitro. Methods: A Croton tiglium seed methanol extract was prepare and assessed for effects on A549 cells regarding cellular proliferation, apoptotic rates, and expression of apoptosis related genes and proteins using real-time PCR and immunofluorescence. Results: The tested Croton tiglium extract inhibited A549 cell proliferation in a dose- and time-dependent manner, with significant elevation of apoptotic indexes at various concentrations after 24 h. In addition, rates in both early and late stages were higher in treated than untreated groups, the 100 μg/ml dose causing the highest levels of apoptosis. RT-PCR showed that A549 cells treated with 100 μg/ml Croton tiglium extract for 24 h has markedly higher Bax mRNA expression levels and obviously lower Bcl-2 expression levels than controls, equivalent results being observed for proteins by immunofluorescence. However, the mRNA expression levels of Fas and caspase-8 were not significantly altered. Conclusion: A Croton tiglium extract can inhibit proliferation of A549 cells and promote apoptosis though Bax/Bcl-2 pathways.

Glucocorticoid receptor-mediated delivery of nano gold-withaferin conjugates for reversal of epithelial-to-mesenchymal transition and tumor regression

AIM

To explore the potential of glucocorticoid receptor-targeted nano-gold formulation as antitumor drug sensitizing agent.

MATERIALS & METHODS

Simultaneous conjugation of gold nanoparticle with thiol-modified dexamethasone, a synthetic glucocorticoid and anticancer drug withaferin A afforded stable gold nanoparticle-modifed dexamethasone-withaferin A nanoconjugate.

RESULTS

This metallic nanoparticle formulation showed glucocorticoid receptor-dependent cancer cell selective cytotoxicity, inhibited growth of aggressive mouse melanoma tumor, reduced mice mortality, while reversing epithelial-to-mesenchymal transition in tumor cells. Same treatment also leads to near-complete downregulation of ABCG2 drug transporter in tumor-associated cells thus attributing it to its drug sensitizing ability.

CONCLUSION

The presently synthesized nanoconjugate holds a great promise to sensitize cancer cells to chemotherapeutics and induce epithelial-to-mesenchymal transition reversal in tumor cells preventing metastasis.

Anti-cancer activity of withaferin A in B-cell lymphoma

Withaferin A (WA), a withanolide from the plant, Ashwagandha (Withania somnifera) used in Ayurvedic medicine, has been found to be valuable in the treatment of several medical ailments. WA has been found to have anticancer activity against various solid tumors, but its effects on hematological malignancies have not been studied in detail. WA strongly inhibited the survival of several human and murine B cell lymphoma cell lines. Additionally, in vivo studies with syngeneic-graft lymphoma cells suggest that WA inhibits the growth of tumor but does not affect other proliferative tissues. We demonstrate that WA inhibits the efficiency of NF-κB nuclear translocation in diffuse large B cell lymphomas and found that WA treatment resulted in a significant decrease in protein levels involved in B cell receptor signaling and cell cycle regulation. WA inhibited the activity of heat shock protein (Hsp) 90 as reflected by a sharp increase in Hsp70 expression levels. Hence, we propose that the anti-cancer effects of WA in lymphomas are likely due to its ability to inhibit Hsp90 function and subsequent reduction of critical kinases and cell cycle regulators that are clients of Hsp90.

Withaferin-A--A Natural Anticancer Agent with Pleitropic Mechanisms of Action

Cancer, being the second leading cause of mortality, exists as a formidable health challenge. In spite of our enormous efforts, the emerging complexities in the molecular nature of disease progression limit the real success in finding an effective cancer cure. It is now conceivable that cancer is, in fact, a progressive illness, and the morbidity and mortality from cancer can be reduced by interfering with various oncogenic signaling pathways. A wide variety of structurally diverse classes of bioactive phytochemicals have been shown to exert anticancer effects in a large number of preclinical studies. Multiple lines of evidence suggest that withaferin-A can prevent the development of cancers of various histotypes. Accumulating data from different rodent models and cell culture experiments have revealed that withaferin-A suppresses experimentally induced carcinogenesis, largely by virtue of its potent anti-oxidative, anti-inflammatory, anti-proliferative and apoptosis-inducing properties. Moreover, withaferin-A sensitizes resistant cancer cells to existing chemotherapeutic agents. The purpose of this review is to highlight the mechanistic aspects underlying anticancer effects of withaferin-A.

Inhibitory effect of withaferin A on Helicobacter pylori‑induced IL‑8 production and NF‑κB activation in gastric epithelial cells

Withaferin A (WA), a withanolide purified from Withania somnifera, has been known to exert anti-inflammatory effects. The present study sought to determine the effects of WA on Helicobacter (H.) pylori-mediated inflammation in the AGS gastric epithelial cell line. Cellular production of interleukin (IL)-8 and vascular endothelial growth factor (VEGF) was measured by ELISA. Western blot analysis was performed to determine the activation of nuclear factor (NF)-κB and mitogen-activated protein kinases (MAPKs) as well as hypoxia-inducible factor 1α stabilization. Bacterial growth was also examined by measuring the optical density. Pre-treatment or co-treatment with WA efficiently reduced IL-8 production by AGS cells in response to H. pylori infection. H. pylori-induced activation of NF-κB, but not MAPKs, was also inhibited by pre-treatment of WA in the cells. However, WA did not affect VEGF production and HIF-1α stabilization induced by H. pylori in AGS cells. In addition, WA did not influence the growth of H. pylori, suggesting that the anti-inflammatory effect of WA was not due to any bactericidal effect. These findings indicate that WA is a potential preventive or therapeutic agent for H. pylori-mediated gastric inflammation.

Withaferin A induces apoptosis through the generation of thiol oxidation in human head and neck cancer cells

Withaferin A is a steroidal lactone purified from the Indian medicinal plant, Withania somnifera. Withaferin A has been shown to inhibit the proliferation, metastasis, invasion and angiogenesis of cancer cells. In the present study, we investigated whether withaferin A induces apoptosis in the human head and neck cancer cells, AMC-HN4. Withaferin A markedly increased the sub-G1 cell population and the cleavage of poly(ADP-ribose) polymerase (PARP), which are markers of apoptosis. Pan-caspase inhibitor, z-VAD-fmk (z-VAD), markedly inhibited the withaferin A-induced apoptosis. However, the withaferin A-induced increase in the expression of COX-2 was not affected by treatment with z-VAD. Furthermore, withaferin A upregulated cyclooxygenase-2 (COX-2) expression. The COX-2 inhibitor, NS-398, reduced the withaferin A-induced production of prostaglandin E2. However, treatment with NS-398 did not affect the sub-G1 population and the cleavage of PARP. In addition, the withaferin A-induced apoptosis was independent of reactive oxygen species production. Thiol donors [N-acetylcysteine (NAC) and dithiothreitol (DTT)] reversed withaferin A-induced apoptosis. Therefore, our data suggest that withaferin A induces apoptosis through the mechanism of thiol oxidation in head and neck carcinoma cells.