Withania somnifera: From prevention to treatment of cancer

Bio-modified TiO2 nanoparticles with Withania somnifera, Eclipta prostrata and Glycyrrhiza glabra for anticancer and antibacterial applications

Titanium dioxide nanoparticles exhibit good anticancer and antibacterial activities. They are known to be environmentally friendly and stable, less toxic and excellent biocompatibility nature. In this paper we report the biological properties of pure TiO₂ nanoparticles modified with Withania somnifera (Ashwagandha), Eclipta prostrata (Karisalankanni) and Glycyrrhiza glabra (Athimathuram) for biological applications. X-ray diffraction results revealed the anatase nature of the samples. From the TEM analyses, it is observed that there is an increase in the particle size of the bio modified samples. UV results show the red shift for the bio modified samples when compared with the pure samples. The samples are then subjected to MTT assay to determine the cell viability. KB oral cancer cells are used for the determination of anticancer nature of the pure and bio modified nanoparticles. It is observed that Withania somnifera - Eclipta prostrate modified TiO₂ nanoparticles exhibit excellent anticancer activities among other bio modified and pure samples. The samples are then examined for their antibacterial activities against three Gram-negative bacterial strains namely, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa and two Gram-positive bacterial strains namely, Staphylococcus aureus and Streptococcus mutans. Among the modified and pure samples, Withania somnifera - Eclipta prostrata showed good antibacterial nature against Gram-positive and Gram-negative bacteria.

Withaferin A-mediated apoptosis in breast cancer cells is associated with alterations in mitochondrial dynamics

Withaferin A (WA), a steroidal lactone derived from a medicinal plant (Withania somnifera), inhibits cancer development in transgenic and chemically-induced rodent models of breast cancer but the underlying mechanism is not fully grasped. We have shown previously that WA treatment causes apoptotic cell death in human breast cancer cells that is preceded by inhibition of complex III of the mitochondrial electron transport chain. This study extends these observations to now demonstrate alterations in mitochondrial dynamics in WA-induced apoptosis. Assembly of complex III was decreased in MCF-7 and SUM159 cells but not in MDA-MB-231 as determined by native blue gel electrophoresis. Because WA is a Michael acceptor (electrophile), we explored the possibility of whether it covalently modifies cysteine residue(s) in ubiquinol-cytochrome c reductase, Rieske iron-sulfur polypeptide 1 (UQCRFS1). Covalent modification of cysteine in UQCRFS1 was not observed after WA treatment. Instead, WA treatment inhibited chemically-induced mitochondrial fusion and decreased the mitochondrial volume, and this effect was accompanied by a decrease in the expression of proteins involved in fusion process, including mitofusin1, mitofusin2, and full-length optic atrophy protein 1 (OPA1). A loss of volume in fragmented mitochondria also occurred in WA-exposed cells when compared to vehicle-treated control. WA treatment also caused a decrease in protein level of mitochondrial fission-regulating protein dynamin-related protein 1 (DRP1). Functional studies revealed that DRP1 deficiency and OPA1 knockdown attenuated apoptotic potential of WA. Taken together, these results indicate that WA not only alters Complex III assembly but also inhibits mitochondrial dynamics in breast cancer cells.

An anti-cancerous protein fraction from Withania somnifera induces ROS-dependent mitochondria-mediated apoptosis in human MDA-MB-231 breast cancer cells

Withania somnifera exhibits different pharmacological activities which mainly stem from its broad range of bioactive molecules. Majority of these bioactive molecules, fall into the groupings of alkaloids, steroidal lactones, phenolic compounds and glycoproteins. In this study, we evaluated a novel protein fraction, named here as WSPF, isolated from Withania somnifera roots for its cytotoxic properties against various human cancer cell lines. WSPF exhibited apoptotic activity for each cancer cell line tested, demonstrating significant activity against MDA-MB-231 human breast cancer cells with an IC₅₀ value of 92 μg/mL. WSPF induced mitochondrial-mediated apoptosis of MDA-MB-231 cells via extensive reactive oxygen species generation, dysregulation of Bax/Bcl-2, loss of mitochondrial membrane potential and caspase-3 activation. Additionally, we observed G2/M-phase cell cycle arrest, cleavage of nuclear lamin A/C proteins, and nuclear morphological changes. The present results highlight the anti-cancer properties of WSPF, indicating that the proteins in this fraction can be potential therapeutic agents for triple negative breast cancer treatment.

Phytochemical Combination PB125 Activates the Nrf2 Pathway and Induces Cellular Protection against Oxidative Injury

Bioactive phytochemicals in Rosmarinus officinalis, Withania somnifera, and Sophora japonica have a long history of human use to promote health. In this study we examined the cellular effects of a combination of extracts from these plant sources based on specified levels of their carnosol/carnosic acid, withaferin A, and luteolin levels, respectively. Individually, these bioactive compounds have previously been shown to activate the nuclear factor erythroid 2-related factor 2 (Nrf2) transcription factor, which binds to the antioxidant response element (ARE) and regulates the expression of a wide variety of cytoprotective genes. We found that combinations of these three plant extracts act synergistically to activate the Nrf2 pathway, and we identified an optimized combination of the three agents which we named PB125 for use as a dietary supplement. Using microarray, quantitative reverse transcription-PCR, and RNA-seq technologies, we examined the gene expression induced by PB125 in HepG2 (hepatocellular carcinoma) cells, including canonical Nrf2-regulated genes, noncanonical Nrf2-regulated genes, and genes which appear to be regulated by non-Nrf2 mechanisms. Ingenuity Pathway Analysis identified Nrf2 as the primary pathway for gene expression changes by PB125. Pretreatment with PB125 protected cultured HepG2 cells against an oxidative stress challenge caused by cumene hydroperoxide exposure, by both cell viability and cell injury measurements. In summary, PB125 is a phytochemical dietary supplement comprised of extracts of three ingredients, Rosmarinus officinalis, Withania somnifera, and Sophora japonica, with specified levels of carnosol/carnosic acid, withaferin A, and luteolin, respectively. Each ingredient contributes to the activation of the Nrf2 pathway in unique ways, which leads to upregulation of cytoprotective genes and protection of cells against oxidative stress and supports the use of PB125 as a dietary supplement to promote healthy aging.

Expanding the Chemical Space of Withaferin A by Incorporating Silicon To Improve Its Clinical Potential on Human Ovarian Carcinoma Cells

Ovarian cancer represents the seventh most commonly diagnosed cancer worldwide. Herein, we report on the development of a withaferin A (WA)-silyl ether library with 30 analogues reported for the first time. Cytotoxicity assays on human epithelial ovarian carcinoma cisplatin-sensitive and -resistant cell lines identified eight analogues displaying nanomolar potency (IC₅₀ ranging from 1 to 32 nM), higher than that of the lead compound and reference drug. This cytotoxic potency is also coupled with a good selectivity index on a nontumoral cell line. Cell cycle analysis of two potent analogues revealed cell death by apoptosis without indication of cell cycle arrest in G0/G1 phase. The structure-activity relationship and in silico absorption, distribution, metabolism, and excretion studies demonstrated that the incorporation of silicon and a carbonyl group at C-4 in the WA framework enhances potency, selectivity, and drug likeness. These findings reveal analogues 22, 23, and 25 as potential candidates for clinical translation in patients with relapsed ovarian cancer.

Frailty index as a biomarker of lifespan and healthspan: Focus on pharmacological interventions

Although survival has been the focus of aging research for many years, the field is rapidly evolving towards incorporating healthspan and health indices in studies that explore aging-related outcomes. Frailty is one such measure that is tightly correlated with human aging. Several frailty measures have been developed that focus on phenotypes of aging, including physical, cognitive and metabolic health that define healthspan. The extent at which cumulative deficits associated with frailty predict functional characteristics of healthy aging and longevity is currently unknown. A growing consensus for the use of animal models has emerged to evaluate a composite measure of frailty that provides a translational basis to understanding human frailty. In this review, we will focus on the impact of several anti-aging interventions, some of which have been characterized as caloric restriction (CR) mimetics such as metformin, rapamycin, and resveratrol as well as more novel approaches that are emerging in the field - nicotinamide adenine dinucleotide precursors, small molecule activators of sirtuins, and senolytics - on a number of frailty measurements associated with aging-related outcomes in mice and discuss the translatability of such measures to human frailty.

Safety and pharmacokinetics of Withaferin-A in advanced stage high grade osteosarcoma: A phase I trial

Background

Withaferin-A (WA), an active principle obtained from a traditional Indian herb known as Ashwagandha or the Indian ginseng, has been shown to prevent and cure urethane-induced lung tumors in mice, and also inhibit the growth of transplanted sarcoma in mice.

Objectives

In this study, we evaluated the safety and pharmacokinetics of WA in patients with advanced stage high-grade osteosarcoma.

Methods

A phase I dose escalation study was planned using the classical 3 + 3 design (C33D). Dose escalation cohorts comprised of 72, 108, 144 and 216 mg of WA administered in two to four divided doses per day. Three patients were enrolled in each cohort and the last patient was observed for at least 30 days for any dose-limiting toxicity before progressing to a higher cohort. Pharmacokinetic studies were performed using high performance liquid chromatography (HPLC) technique with sensitivity up to 50 ng/ml. Safety evaluation including clinical examination, detailed history of adverse events, Liver Function Tests , Renal Function Tests and complete blood counts were performed at each visit. WA was administered daily till progression. Common Terminology Criteria for Adverse Events (CTCAE) version 3.0 was used for grading adverse events.

Results

The formulation used was generally well tolerated. Eleven adverse events of grade 1 or grade 2 severity were observed. No grade 3 or grade 4 adverse events were observed. Elevation of liver enzymes (5/11) and skin rash (2/11) was the most common adverse events. Other adverse effects include fatigue, fever, edema, and diarrhea (one each). None of the patients had detectable levels of WA in circulation.

Conclusion

The formulation was well tolerated. However, WA appears to have low oral bioavailability. Further studies with improved formulations are warranted.

Withaferin A induces apoptosis by ROS-dependent mitochondrial dysfunction in human colorectal cancer cells

Withaferin A (WA) is an active steroidal lactone derived from the herbal plant Withania somnifera, which exhibits antitumor activity with reactive oxygen species (ROS) modulating in a variety of cancer models, such as breast cancer, lung cancer and pancreatic cancer. However, to the best of our knowledge, the direct effect and mechanism of WA on CRC cells has not been previously determined. The present study investigated the anti-tumor effects of WA on CRC cells in vitro, and explored the mechanisms of action. The flow cytometry was applied for detecting the accumulation of ROS with the treatment of withaferin A. We performed the flow cytometry and western blot to evaluate the withaferin A induced apoptosis and cell cycle arrest in human colon cancer cells. And to verify the ROS accumulation induced mitochondrial dysfunction after the treatment of withaferin A, fluorescence microscope and western blot were applied. WA exerted a dose-dependent cytotoxic effect on HCT-116 and RKO cells. The effect was associated with ROS-mediated cell cycle arrest and the expression of apoptotic proteins. In addition, WA promoted ROS production and decreased mitochondrial membrane potential accompanying with mitochondrial dysfunction. Taken together, these results strongly indicated that WA directly inhibits cell growth and induces apoptosis in CRC cells through ROS-mediated mitochondrial dysfunction and JNKs pathway, and WA may be a promising potential candidate for therapeutic application of CRC.

Integration of botanicals in contemporary medicine: road blocks, checkpoints and go-ahead signals

The use of botanicals for maintaining good health and preventing diseases is undisputed. The claimed health benefits of natural health products and herbal medicines are based on traditional claims, positive results obtained in preclinical studies and early phase clinical trials that are not backed by safety and efficacy evidences approved by regulatory agencies. Although, the popularity of botanicals is growing, health care practitioners of modern medicine seldom recommend their use because of ill equipped database of their safety and potency. This review discusses problems that preclude botanicals from integrating into the mainstream contemporary therapeutics and cues that provide impetus for their realisation.

Peptidyl-prolyl cis/trans isomerase Pin1 regulates withaferin A-mediated cell cycle arrest in human breast cancer cells

We have reported previously that withaferin A (WA) prevents breast cancer development in mouse mammary tumor virus-neu (MMTV-neu) transgenic mice, but the mechanism is not fully understood. Unbiased proteomics of the mammary tumors from control- and WA-treated MMTV-neu mice revealed downregulation of peptidyl-prolyl cis/trans isomerase (Pin1) protein by WA administration. The present study extends these findings to elucidate the role of Pin1 in cancer chemopreventive mechanisms of WA. The mammary tumor level of Pin1 protein was lower by about 55% in WA-treated rats exposed to N-methyl-N-nitrosourea, compared to control. Exposure of MCF-7 and SK-BR-3 human breast cancer cells to WA resulted in downregulation of Pin1 protein. Ectopic expression of Pin1 attenuated G₂ and/or mitotic arrest resulting from WA treatment in both MCF-7 and SK-BR-3 cells. WA-induced apoptosis was increased by Pin1 overexpression in MCF-7 cells but not in the SK-BR-3 cell line. In addition, molecular docking followed by mass spectrometry indicated covalent interaction of WA with cysteine 113 of Pin1. Overexpression of Pin1^C113A mutant failed to attenuate WA-induced mitotic arrest or apoptosis in the MCF-7 cells. Furthermore, antibody array revealed upregulation of proapoptotic insulin-like growth factor binding proteins (IGFBPs), including IGFBP-3, IGFBP-4, IGFBP-5, and IGFBP-6, in Pin1 overexpressing MCF-7 cells following WA treatment when compared to empty vector transfected control cells. These data support a crucial role of the Pin1 for mitotic arrest and apoptosis signaling by WA at least in the MCF-7 cells.

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.

Withaferin A Inhibits Prostate Carcinogenesis in a PTEN-deficient Mouse Model of Prostate Cancer

We recently demonstrated that AKT activation plays a role in prostate cancer progression and inhibits the pro-apoptotic function of FOXO3a and Par-4. AKT inhibition and Par-4 induction suppressed prostate cancer progression in preclinical models. Here, we investigate the chemopreventive effect of the phytonutrient Withaferin A (WA) on AKT-driven prostate tumorigenesis in a Pten conditional knockout (Pten-KO) mouse model of prostate cancer. Oral WA treatment was carried out at two different doses (3 and 5 mg/kg) and compared to vehicle over 45 weeks. Oral administration of WA for 45 weeks effectively inhibited primary tumor growth in comparison to vehicle controls. Pathological analysis showed the complete absence of metastatic lesions in organs from WA-treated mice, whereas discrete metastasis to the lungs was observed in control tumors. Immunohistochemical analysis revealed the down-regulation of pAKT expression and epithelial-to-mesenchymal transition markers, such as β-catenin and N-cadherin, in WA-treated tumors in comparison to controls. This result corroborates our previous findings from both cell culture and xenograft models of prostate cancer. Our findings demonstrate that the daily administration of a phytonutrient that targets AKT activation provides a safe and effective treatment for prostate cancer in a mouse model with strong potential for translation to human disease.

Withaferin A induces Nrf2-dependent protection against liver injury: Role of Keap1-independent mechanisms

Small molecules of plant origin offer presumptively safe opportunities to prevent carcinogenesis, mutagenesis and other forms of toxicity in humans. However, the mechanisms of action of such plant-based agents remain largely unknown. In recent years the stress responsive transcription factor Nrf2 has been validated as a target for disease chemoprevention. Withania somnifera (WS) is a herb used in Ayurveda (an ancient form of medicine in South Asia). In the recent past, withanolides isolated from WS, such as Withaferin A (WA) have been demonstrated to be preventive and therapeutic against multiple diseases in experimental models. The goals of this study are to evaluate withanolides such as WA as well as Withania somnifera root extract as inducers of Nrf2 signaling, to probe the underlying signaling mechanism of WA and to determine whether prevention of acetaminophen (APAP)-induced hepatic toxicity in mice by WA occurs in an Nrf2-dependent manner. We observed that WA profoundly protects wild-type mice but not Nrf2-disrupted mice against APAP hepatotoxicity. WA is a potent inducer of Nrf2-dependent cytoprotective enzyme expression both in vivo and in vitro. Unexpectedly, WA induces Nrf2 signaling at least in part, in a Keap1-independent, Pten/Pi3k/Akt-dependent manner in comparison to prototypical Nrf2 inducers, sulforaphane and CDDO-Im. The identification of WA as an Nrf2 inducer that can signal through a non-canonical, Keap1-independent pathway provides an opportunity to evaluate the role of other regulatory partners of Nrf2 in the dietary and pharmacological induction of Nrf2-mediated cytoprotection.

Antifungal and Anticancer Potential of Argemone mexicana L

Background: Medicinal plants are widely used to treat infectious diseases, metabolic disorders and cancer. Argemone mexicana L. (A. mexicana), commonly found on desolate land of Marathwada (Maharashtra, India) has been used to treat oral cavity infections. Methods: In this study, cold aqueous and methanolic extracts were prepared from A. mexicana stem and leaves. These extracts were tested for their antifungal and anticancer activities. The antifungal activity was tested using the agar well diffusion method, while the anticancer activity against immortalized cell lines was assessed by trypan blue assay. Results: It was observed that both cold aqueous and methanolic extracts of A. mexicana stem and leaves inhibited the growth of Mucor indicus, Aspergillus flavus, Aspergillus niger and Penicillum notatum. Antifungal activity of the extract was comparable to that of Amphoterecin-B. A. mexicana extracts had a cytotoxic effect on A549, SiHa and KB immortalized cell lines that were similar to that of berberine. Conclusion: The A. mexicana leaf and stems exhibit strong antifungal and anticancer potential.