Molecular mechanisms underlying mangiferin-induced apoptosis and cell cycle arrest in A549 human lung carcinoma cells

Role of Mangiferin in Management of Cancers through Modulation of Signal Transduction Pathways

Cancer is a major public health concern worldwide in terms of mortality. The exact reason behind the development of cancer is not understood clearly, but it is evidenced that alcohol consumption, radiation, and exposure to chemicals are main players in this pathogenesis. The current mode of treatments such as surgery, chemotherapy, and radiotherapy are effective, but, still, cancer is a major problem leading to death and other side effects. However, safer and effective treatment modules are needed to overcome the adverse effects of current treatment modules. In this regard, natural compounds have been recognized to ameliorate diseases by exerting anti-inflammatory, anti-oxidative, and anti-tumor potential through several mechanisms. Mangiferin, a xanthone C-glucoside, is found in several plant species including Mangifera indica (mango), and its role in disease prevention has been confirmed through its antioxidant and anti-inflammatory properties. Furthermore, its anti-cancer-potential mechanism has been designated through modulation of cell signaling pathways such as inflammation, angiogenesis, PI3K/AKT, apoptosis, and cell cycle. This article extensively reviews the anticancer potential of mangiferin in different cancers through the modulation of cell signaling pathways. Moreover, the synergistic effects of this compound with some commonly used anti-cancer drugs against different cancer cells are discussed. More clinical trials should be performed to reconnoiter the anti-cancer potential of this compound in human cancer treatment. Further, understanding of mechanisms of action and the safety level of this compound can help to manage diseases, including cancer.

Evaluation of the association of chronic inflammation and cancer: Insights and implications

Among the most extensively researched processes in the development and treatment of cancer is inflammatory condition. Although acute inflammation is essential for the wound healing and reconstruction of tissues that have been damaged, chronic inflammation may contribute to the onset and growth of a number of diseases, including cancer. By disrupting the signaling processes of cells, which result in cancer induction, invasion, and development, a variety of inflammatory molecules are linked to the development of cancer. The microenvironment surrounding the tumor is greatly influenced by inflammatory cells and their subsequent secretions, which also contribute significantly to the tumor's growth, survivability, and potential migration. These inflammatory variables have been mentioned in several publications as prospective diagnostic tools for anticipating the onset of cancer. Targeting inflammation with various therapies can reduce the inflammatory response and potentially limit or block the proliferation of cancer cells. The scientific medical literature from the past three decades has been studied to determine how inflammatory chemicals and cell signaling pathways related to cancer invasion and metastasis are related. The current narrative review updates the relevant literature while highlighting the specifics of inflammatory signaling pathways in cancer and their possible therapeutic possibilities.

A review of the botany, ethnopharmacology, phytochemistry, pharmacology, toxicology and quality of Anemarrhena asphodeloides Bunge

ETHNOPHARMACOLOGICAL RELEVANCE

The rhizomes of Anemarrhena asphodeloides Bunge., belonging to the family Liliaceae, are named 'Zhi-mu' according to traditional Chinese medicine theory. It is a medicinal plant that has long been used as a tonic agent in various ethnomedicinal systems in East Asia, especially in China, and also for treating arthralgia, hematochezia, tidal fever, night sweats, cough, dry mouth and tongue, hemoptysis, etc. THE ARM OF THE REVIEW: The review aims to provide a systematic overview of botany, ethnopharmacology, phytochemistry, pharmacology, toxicology and quality control of Anemarrhena asphodeloides and to explore the future therapeutic potential and scientific potential of this plant.

MATERIALS AND METHODS

A comprehensive literature search was performed on Anemarrhena asphodeloides using scientific databases including Web of Science, PubMed, Google Scholar, CNKI, Elsevier, SpringerLink, ACS publications, ancient books, Doctoral and master's Theses. Collected data from different sources was comprehensively summarised for botany, ethnopharmacology, phytochemistry, pharmacology, toxicology and quality control of Anemarrhena asphodeloides.

RESULTS

A comprehensive analysis of the literature as mentioned above confirmed that the ethnomedical uses of Anemarrhena asphodeloides had a history of thousands of years in eastern Asian countries. Two hundred sixty-nine compounds have been identified from Anemarrhena asphodeloides, including steroidal saponins, flavonoids, phenylpropanoids, alkaloids, steroids, organic acids, polysaccharides, benzophenones and other ingredients. Studies have shown that the extracts and compounds from Anemarrhena asphodeloides have extensive pharmacological activities, such as nervous system activity, antitumour, anti-inflammatory, antidiabetic, antiosteoporotic, antiallergic, antiplatelet aggregation, antimicrobial, antiviral, anti-ageing, hair growth promoting, preventing cell damage, etc. Evaluating the quality and toxicity of Anemarrhena asphodeloides is essential to confirm its safe use in humans.

CONCLUSION

Anemarrhena asphodeloides is widely used in traditional medicine and have diverse chemical constituents with obvious biological activities. Nevertheless, more studies should be carried out in animals and humans to evaluate the cellular and molecular mechanisms involved in its biological activity and confirm its safe use.

Mangiferin: the miraculous xanthone with diverse pharmacological properties

Mangiferin (1,3,6,7-tetrahydroxy-2-[3,4,5-trihydroxy-6-(hydroxymethyl) oxan-2-yl] xanthen-9-one) is a bioactive component derived primarily from the mango tree. Belonging to the Xanthone family, its structure allows it to engage with a variety of pharmacological targets. The symmetric linked core of xanthones has a heterogeneous biogenetic background. The carbon atoms are designated in a biochemical order, which reveals the reason of ring A (C1-C4) being referred to as acetate originated, and ring B (C5-C8) is referred to as shikimate originated. The antibacterial, hypocholesterolemic, antiallergic, cardiotonic, antidiabetic, anti-neoplastic, neuroprotective, antioxidant and immunomodulatory properties have all been demonstrated for the secondary metabolite. This study assessed and explained the important medical properties of mangiferin available in published literature, as well as its natural source, biosynthesis, absorption and bioavailability; multiple administration routes; metabolism; nanotechnology for enhanced efficacy of mangiferin and its toxicity, to aid the anticipated on-going potential of mangiferin as a novel diagnostic treatment.

The therapeutic potential of natural products for treating pancreatic cancer

Pancreatic cancer is one of the most malignant tumors of the digestive tract, with the poor prognosis and low 5-year survival rate less than 10%. Although surgical resection and chemotherapy as gemcitabine (first-line treatment) has been applied to the pancreatic cancer patients, the overall survival rates of pancreatic cancer are quite low due to drug resistance. Therefore, it is of urgent need to develop alternative strategies for its treatment. In this review, we summarized the major herbal drugs and metabolites, including curcumin, triptolide, Panax Notoginseng Saponins and their metabolites etc. These compounds with antioxidant, anti-angiogenic and anti-metastatic activities can inhibit the progression and metastasis of pancreatic cancer. Expecting to provide comprehensive information of potential natural products, our review provides valuable information and strategies for pancreatic cancer treatment.

Mangiferin Alleviates Postpartum Depression-Like Behaviors by Inhibiting MAPK Signaling in Microglia

Postpartum depression (PPD), a severe mental health disorder, is closely associated with decreased gonadal hormone levels during the postpartum period. Mangiferin (MGF) possesses a wide range of pharmacological activities, including anti-inflammation. Growing evidence has suggested that neuroinflammation is involved in the development of depression. However, the role of MGF in the development of PPD is largely unknown. In the present study, by establishing a hormone-simulated pregnancy PPD mouse model, we found that the administration of MGF significantly alleviated PPD-like behaviors. Mechanistically, MGF treatment inhibited microglial activation and neuroinflammation. Moreover, we found that MGF treatment inhibited mitogen-activated protein kinase (MAPK) signaling in vivo and in vitro. Together, these results highlight an important role of MGF in microglial activation and thus give insights into the potential therapeutic strategy for PPD treatment.

Transferrin-Modified Mangiferin-Loaded SLNs: Preparation, Characterization, and Application in A549 Lung Cancer Cell

Introduction

Mangiferin is a plant antitumor compound with poor water solubility and low bioavailability. In this study, transferrin-modified mangiferin-loaded solid lipid nanoparticles (Tf-modified MGF-SLNs) were prepared to overcome the above defects.

Methods

Tf-modified MGF-SLNs were prepared by the emulsification-solvent evaporation method. The physicochemical properties of Tf-MGF-SLNs such as particle size, zeta potential and in vitro drug release were investigated. We also demonstrated the effect of Tf-MGF-SLNs in lung cancer.

Results

The mean hydrodynamic diameter of the Tf-MGF-SLNs was 121.8±2.9 nm with a polydispersity index of 0.134±0.03. According to TEM micrographs, Tf-MGF-SLNs are spherical and uniform, and the EE% was found to be 72.5±2.4%. In vitro release, we identified an initial burst effect release, followed by controlled release, in SLNs at both pHs and the Tf-MGF-SLNs drug accumulation release percentages reached over 68% at pH 4.0 and 72% at pH 7.4 in 6 hours, respectively. In vivo studies showed that depending on surface modification, Tf-MGF-SLNs, which suggested that cell internalization was changed and more drugs entered the cells successfully.

Discussion

Tf-MGF-SLNs were highly efficient in suppressing the tumor growth in xenograft tumor model. Sustained release of the drug delivery system and Tf-modified MGF-SLNs played a major role. Tf-MGF-SLNs would be a promising formulation for the treatment of lung cancer.

Chemical and Biological Evidence of the Efficacy of Shengxian Decoction for Treating Human Lung Adenocarcinoma

Shengxian Decoction (SXT) is a traditional Chinese medicine prescription comprising several anti-cancer medicinal herbs. However, the anti-cancer effect of SXT has rarely been reported. Herein, we explored the therapeutic potential of SXT for the treatment of lung adenocarcinoma (LUAD). High-performance liquid chromatography analysis of crude SXT extract revealed the abundance of mangiferin, an established anti-cancer compound. The serum pharmacological evaluation revealed that serum SXT suppressed A549 lung cancer cell proliferation in vitro. The tumor-inhibitory activity of SXT was confirmed in vivo via tumor formation assays in nude mice. We applied biochemical, histopathological and imaging approaches to investigate the cellular targets of SXT. The results indicated that the treatment with SXT induced tumor necrosis, and downregulated hypoxia-inducible factor 1 alpha in the serum. In vivo biosafety assessment of SXT revealed low levels of toxicity in mouse models. Our study provides the first scientific evidence that SXT effectively represses cancer cell growth and, thus, may serve as a safe anti-cancer agent for LUAD treatment.

Modulator effect of mangiferin on biochemical characterization in 7,12-dimethylbenz[a]anthracene induced oral cancer in experimental hamsters

BACKGROUND

Newly, chemo-preventive technique might be a hopeful advancement in developing countries for treating cancers with the aid of toxic less natural based constituents. Malignancy urges to augment effectual chemo-preventive agents that are look forward to suppress the tumours which may be stimulated by chewing and smoking of tobacco and over alcohol consumption related with the high prevalence of human oral cancer (OC) patients.

METHODS

In the present research, we examined to assess antioxidants, lipid peroxidation (LPO) and detoxification enzymes levels of anticancer activity of mangiferin on 0.5% 7.12-dimethylbenz[a]anthracene (DMBA) provoked hamster cheek pouch carcinoma (HCPC). OC on hamster buccal pouch (HBP) was incited by DMBA treatment for thrice per week for over 14 weeks.

RESULTS

100% well defined OC establishment with body weight (bw), tumour burden (TB), antioxidant, LPO and liver marker enzymes and also histological changes were observed on DMBA-challenged buccal pouch carcinoma (BPC) in hamsters. Orally treated mangiferin at an effective dosage of 50 mg/kg bw, to DMBA painted hamsters were significantly averted the body weight, succession of tumour, the biochemical as well as histopathological changes.

CONCLUSION

Findings of this work clearly suggest that the anti-carcinoma effect of mangiferin possesses the modulator effects on potent antioxidant, anti-LPO and detoxification agents to expel the metabolites of malignant cells, on DMBA-provoked BPC in hamsters.

Mangiferin Inhibits Human Lung Adenocarcinoma by Suppressing MiR-27b and MiR-92a

Lung adenocarcinoma (LUAD) is one of the most prevalent malignancies. However, its mechanism and therapeutic strategy remain to be clarified. Mangiferin is a flavonoid derived from the leaves of mango trees of the lacquer family that has many pharmacological and physiological effects. This research aimed to elucidate the biological effect of mangiferin in LUAD cell lines and clarify the in vitro mechanism of mangiferin. Mangiferin was shown to significantly restrain the proliferation of LUAD cells (A549, H1299, and H2030 cells) in a dose- and time-dependent manner. Furthermore, mangiferin was capable of stimulating apoptosis, and more cells were blocked in G1 and S phase in the mangiferin-treated cells than in those not treated with mangiferin. Microarrays and micro-RNA sequencing data suggested that there is a higher level of miR-27b and miR-92a in LUAD tissues than in non-LUAD tissues. Additional experiments indicated that mangiferin may be related to the downregulated levels of miR-92a and miR-27b. In conclusion, mangiferin likely regulates proliferation and apoptosis in LUAD cells by reducing the expression levels of miR-92a and miR-27b.

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.

Quantitative Chemical Proteomics Reveals Resveratrol Inhibition of A549 Cell Migration Through Binding Multiple Targets to Regulate Cytoskeletal Remodeling and Suppress EMT

Resveratrol (RSV), a health-promoting natural product, has been shown to affect various cellular processes in tumor cells. However, the specific protein targets of RSV and the mechanism of action (MOA) of its anticancer effect remain elusive. In this study, the pharmacological activity of RSV was first evaluated in A549 cells, and the results showed that RSV significantly inhibited A549 cell migration but did not affect cell viability. To elucidate the underlying mechanism, a quantitative chemical proteomics approach was employed to identify the protein targets of RSV. A total of 38 target proteins were identified, and proteomic analysis showed that the targets were mainly involved in cytoskeletal remodeling and EMT, which were verified by subsequent in vitro and in vivo assays. In conclusion, RSV inhibits A549 cell migration by binding to multiple targets to regulate cytoskeletal remodeling and suppress EMT.

Mangiferin as New Potential Anti-Cancer Agent and Mangiferin-Integrated Polymer Systems-A Novel Research Direction

For a long time, the pharmaceutical industry focused on natural biologically active molecules due to their unique properties, availability and significantly less side-effects. Mangiferin is a naturally occurring C-glucosylxantone that has substantial potential for the treatment of various diseases thanks to its numerous biological activities. Many research studies have proven that mangiferin possesses antioxidant, anti-infection, anti-cancer, anti-diabetic, cardiovascular, neuroprotective properties and it also increases immunity. It is especially important that it has no toxicity. However, mangiferin is not being currently applied to clinical use because its oral bioavailability as well as its absorption in the body are too low. To improve the solubility, enhance the biological action and bioavailability, mangiferin integrated polymer systems have been developed. In this paper, we review molecular mechanisms of anti-cancer action as well as a number of designed polymer-mangiferin systems. Taking together, mangiferin is a very promising anti-cancer molecule with excellent properties and the absence of toxicity.

Mangiferin induces immune responses and evaluates the survival rate in WEHI-3 cell generated mouse leukemia in vivo

Mangiferin is a naturally occurring polyphenol, widely distributed in Thymeraceae families, and presents pharmacological activity, including anti-cancer activities in many human cancer cell lines. Mangiferin has also been reported to affect immune responses; however, no available information concerning the effects of mangiferin on immune reactions in leukemia mice in vivo. In the present study, we investigated the effects of mangiferin on leukemia WEHI-3 cell generated leukemia BLAB/c mice. Overall, the experiments were divided into two parts, one part was immune responses experiment and the other was the survival rate experiment. The immune responses and survival rate study, 40 mice for each part, were randomly separated into five groups (N = 8): Group I was normal animals and groups II-V WEHI-3 cell generated leukemia mice. Group II mice were fed normal diet as a positive control; group III, IV, and V mice received mangiferin at 40, 80, and 120 mg/kg, respectively, by intraperitoneal injection every 2 days for 20 days. Leukocytes cell population, macrophage phagocytosis, and NK cell activities were analyzed by flow cytometry. Isolated splenocytes stimulated with lipopolysaccharide (LPS) and concanavalin A (Con A) were used to determine the proliferation of B and T cells, respectively, and subsequently were analyzed by flow cytometry. Results indicated that mangiferin significantly increased body weight, decreased the liver and spleen weights of leukemia mice. Mangiferin also increased CD3 T-cell and CD19 B cell population but decreased Mac-3 macrophage and CD11b monocyte. Furthermore, mangiferin decreased phagocytosis of macrophages from PBMC and peritoneal cavity at 40, 80, and 120 mg/kg treatment. However, it also increased NK cell activity at 40 and 120 mg/kg treatment. There were no effects on T and B cell proliferation at three examined doses. In survival rate studies, mangiferin significantly elevated survival rate at 40 and 120 mg/kg treatment of leukemia mice in vivo.

Anti-neoplastic effect of mangiferin on human ovarian adenocarcinoma OVCAR8 cells via the regulation of YAP

Ovarian cancer is the most malignant gynecologic neoplasm in women and has the worst prognosis of all cancer types in women based on the 5-year survival rates. A previous study indicated that mangiferin exerts an anti-neoplastic effect on human ovarian cancer cells by targeting Notch3. Additionally, it has been demonstrated that Notch signaling is a functionally important downstream effector of Yes-associated protein (YAP), therefore it was hypothesized that YAP may be involved in the antitumor effect of mangiferin. The present study aimed to further reveal the mangiferin-mediated inhibitory effect on ovarian cancer and investigate the molecular anticancer mechanism of mangiferin. Based on the in vitro data, accompanied with the significantly reduced cell proliferation of mangiferin-treated cells compared with mangiferin-treated YAP-overexpressed cells (P<0.05), YAP expression was identified to be substantially downregulated by mangiferin. In contrast, observations of the cell morphology and apoptotic percentages revealed that the antitumor effect of mangiferin may be reversed by YAP overexpression. Furthermore, decreased levels of migration and invasion were observed in mangiferin-treated cells, which may also be abrogated by YAP overexpression. Thus, these data further demonstrated that mangiferin inhibits metastasis by regulating YAP. Additionally, due to the frequent chemoresistance observed in cisplatin-based chemotherapy, the present study evaluated the cisplatin resistance in OVCAR8 cells and elucidated that mangiferin may sensitize the tumor cells to cisplatin; and this improved sensitization was also abolished by YAP overexpression. These results collectively indicated that YAP was not only closely associated with the anticancer effect of mangiferin, but also mediated drug resistance in tumor. Furthermore, the downregulation of downstream TEA domain transcription factor 4 expression was observed in the mangiferin-treated cells, further validating the inhibitory effect of mangiferin on YAP. In addition, OVCAR8 cell xenograft models revealed that through increasing the sensitivity of a tumor to cisplatin, mangiferin inhibited the growth of a tumor and increased the survival time of tumor xenograft mice. Based on these results, it was concluded that mangiferin may inhibit tumor cell growth and enhance cisplatin-sensitivity in OVCAR8 cells via the regulation of the YAP pathway. Altogether, by targeting YAP and enhancing the response to cisplatin treatment, mangiferin potentially functioned as a novel therapeutic agent in the treatment of ovarian cancer.

Rhaponticum carthamoides Transformed Root Extract Has Potent Anticancer Activity in Human Leukemia and Lung Adenocarcinoma Cell Lines

Rhaponticum carthamoides (Willd.) Iljin. is an endemic plant species, which is important in Siberian medicine. It possesses adaptogenic properties and has been used for treatment of overstrain and weakness after illness, physical weakness, and mental weariness. The roots of this species obtained after Agrobacterium rhizogenes transformation are rich in caffeoylquinic acid derivatives known as strong antioxidant compounds. The study makes the first evaluation of the cytotoxic and genotoxic activity of transformed root extract (Rc TR extract) in various human cancer cell lines: leukemia cells (K-562 and CCRF-CEM) and lung adenocarcinoma cells (A549). It was found that Rc TR extract inhibited the cell viability of all tested cell lines in a concentration-dependent manner, and leukemia cell lines were more sensitive to plant extract than A549 lung cancer cell line. Additionally, the Rc TR extract reduced the mitochondrial membrane potential and demonstrated genotoxicity against tested cell lines by increasing mitochondrial DNA lesions in ND1 and ND5 genes and causing nuclear DNA damage in TP53 gene. Our results show that Rc TR extract may effectively treat cancer cells by inducing dysfunction of mitochondria. Additionally, the role of mtDNA may be a promising factor in chemotherapy, and it needs further studies.

Mangiferin: An effective therapeutic agent against several disorders (Review)

Mangiferin (1,3,6,7‑tetrahydroxyxanthone‑C2‑β‑D‑glucoside) is a bioactive ingredient predominantly isolated from the mango tree, with potent antioxidant activity and multifactorial pharmacological effects, including antidiabetic, antitumor, lipometabolism regulating, cardioprotective, anti‑hyperuricemic, neuroprotective, antioxidant, anti‑inflammatory, antipyretic, analgesic, antibacterial, antiviral and immunomodulatory effects. Therefore, it possesses several health‑endorsing properties and is a promising candidate for further research and development. However, low solubility, mucosal permeability and bioavailability restrict the development of mangiferin as a clinical therapeutic, and chemical and physical modification is required to expand its application. This review comprehensively analyzed and collectively summarized the primary pharmacological actions of mangiferin that have been demonstrated in the literature, to support the potential future development of mangiferin as a novel therapeutic drug.

Mangiferin induces islet regeneration in aged mice through regulating p16INK4a

Previous studies by our group on mangiferin demonstrated that it exerts an antihyperglycemic effect through the regulation of cell cycle proteins in 3-month-old, partially pancreatectomized (PPx) mice. However, β-cell proliferation is known to become severely restricted with advanced age. Therefore, it is unknown whether mangiferin is able to reverse the diabetic condition and retain β-cell regeneration capability in aged mice. In the present study, 12-month-old C57BL/6J mice that had undergone PPx were subjected to mangiferin treatment (90 mg/kg) for 28 days. Mangiferin-treated aged mice exhibited decreased blood glucose levels and increased glucose tolerance, which was accompanied with higher serum insulin levels when compared with those in untreated PPx control mice. In addition, islet hyperplasia, elevated β-cell proliferation and reduced β-cell apoptosis were also identified in the mice that received mangiferin treatment. Further studies on the mRNA transcript and protein expression levels indicated comparatively increased levels of cyclins D1 and D2 and cyclin-dependent kinase 4 in mangiferin-treated mice, while the levels of p27^Kip1 and p16^INK4a were decreased relative to those in the untreated PPx controls. Of note, mangiferin treatment improved the proliferation rate of islet β-cells in adult mice overexpressing p16^INK4a, suggesting that mangiferin induced β-cell proliferation via the regulation of p16^INK4a. In addition, the mRNA transcription levels of critical genes associated with insulin secretion, including pancreatic and duodenal homeobox 1, glucose transporter 2 and glucokinase, were observed to be upregulated after mangiferin treatment. Taken together, it was indicated that mangiferin treatment significantly induced β-cell proliferation and inhibited β-cell apoptosis by regulating cell cycle checkpoint proteins. Furthermore, mangiferin was also demonstrated to regulate genes associated with insulin secretion. Collectively these, results suggest the therapeutic potential of mangiferin in the treatment of diabetes in aged individuals.

Mangiferin prevents the growth of gastric carcinoma by blocking the PI3K-Akt signalling pathway

The aim of the present study was to investigate the effects of mangiferin on gastric carcinoma cells and to determine the possible mechanisms underlying such effects. The MTT assay was performed to evaluate the antiproliferative effect of mangiferin. Following treatment, apoptosis rates of SGC-7901 were established by flow cytometry and laser confocal microscopy, and western blot analysis was used to detect the expression of apoptosis-related proteins. The MTT assay showed that mangiferin inhibited the proliferation of SGC-7901 and BCG-823 cells in a dose-dependent and time-dependent manner. After SGC-7901 cells were exposed to mangiferin for 24, 48 and 72 h, the half-maximal inhibitory concentration values were 16.00, 8.63 and 4.79 µmol/l, respectively. SGC-7901 cell apoptosis induced by mangiferin was observed by Annexin V/PI doubling staining and terminal deoxynucleotidyl transferase dUTP nick end labeling-positive staining. We found a significant decrease in Bcl-2, Bcl-xL and Mcl-1 expression and a significant increase in Bax, Bad and cleaved caspase-3 and caspase-9 expression in SGC-7901 cells by mangiferin treatment. Moreover, mangiferin significantly decreased the levels of p-PI3K, p-Akt and p-mTOR, but had no effects on those of PI3K, Akt and mTOR in epidermal growth factor-treated SGC-7901 cells. Interestingly, the proapoptotic effect of mangiferin on SGC-7901 cells was partially blocked by the Akt activator SC79, whereas LY294002 significantly increased mangiferin-induced apoptosis and growth inhibition. Taken together, our findings indicate that mangiferin effectively inhibits cell growth and induces apoptosis of gastric cancer cells through inhibiting the PI3K/Akt pathways with relative safety, and may be used as a novel chemotherapeutic agent against gastric cancer.

Targeting oncogenic transcription factors by polyphenols: A novel approach for cancer therapy

Inflammation is one of the major causative factor of cancer and chronic inflammation is involved in all the major steps of cancer initiation, progression metastasis and drug resistance. The molecular mechanism of inflammation driven cancer is the complex interplay between oncogenic and tumor suppressive transcription factors which include FOXM1, NF-kB, STAT3, Wnt/β- Catenin, HIF-1α, NRF2, androgen and estrogen receptors. Several products derived from natural sources modulate the expression and activity of multiple transcription factors in various tumor models as evident from studies conducted in cell lines, pre-clinical models and clinical samples. Further combination of these natural products along with currently approved cancer therapies added an additional advantage and they considered as promising targets for prevention and treatment of inflammation and cancer. In this review we discuss the application of multi-targeting natural products by analyzing the literature and future directions for their plausible applications in drug discovery.

Quinalizarin exerts an anti-tumour effect on lung cancer A549 cells by modulating the Akt, MAPK, STAT3 and p53 signalling pathways

Quinalizarin may be a potential chemical agent for cancer therapy, as it exerts anti‑tumour effects against a variety of different types of cancer. However, the underlying regulatory mechanism and signalling pathways of quinalizarin in lung cancer cells remains unknown. The present study sought to investigate the effects of quinalizarin on proliferation, apoptosis and reactive oxygen species (ROS) generation in lung cancer. MTT assays were used to evaluate the effects of quinalizarin on the viability of lung cancer A549, NCI‑H460 and NCI‑H23 cells. Flow cytometry was employed to evaluate the effects of quinalizarin on the cell cycle, apoptosis and ROS generation in A549 cells. Western blotting was performed to detect cell cycle and apoptosis‑associated protein expression levels in A549 cells. Quinalizarin inhibited A549, NCI‑H460 and NCI‑H23 cell proliferation and induced A549 cell cycle arrest at the G0/G1 phase. Quinalizarin induced apoptosis by upregulating the expression of B‑cell lymphoma 2 (Bcl‑2)‑associated agonist of cell death, cleaved‑caspase‑3 and cleaved‑poly (adenosine diphosphate‑ribose) polymerase, and downregulating the expression of Bcl‑2. Furthermore, quinalizarin activated mitogen‑activated protein kinase (MAPK) and p53, and inhibited the protein kinase B and signal transducer and activator of transcription‑3 (STAT3) signalling pathways. In addition, quinalizarin increased ROS generation. The ROS scavenger N‑acetyl‑L‑cysteine restored quinalizarin‑induced cell apoptosis, and inactivated the MAPK and STAT3 signalling pathways. The results of the present study demonstrated that quinalizarin induces G0/G1 phase cell cycle arrest and apoptosis via ROS mediated‑MAPK and STAT3 signalling pathways.

Mangiferin induces apoptosis in human ovarian adenocarcinoma OVCAR3 cells via the regulation of Notch3

Ovarian cancer is the most lethal gynecological malignancy in the world. Our previous studies showed that mangiferin, purified from plant source, possessed anti-neoplasm effect on human lung adenocarcinoma A549 cells. This study aimed to determine the apoptosis-inducing effect of mangiferin on human ovarian carcinoma OVCAR3 cells. By in vitro studies, we found mangiferin significantly inhibited viability of OVCAR3 cells, and remarkably increased the sensitivity of OVCAR3 cells to cisplatin. In addition, the activation of caspase-dependent apoptosis was observed in mangiferin treated ovarian cancer cells. Importantly, we observed an obviously downregulated Notch expression after mangiferin treatment, indicating the crucial role of Notch in mangiferin mediated apoptosis. In contrast, overexpression of Notch3 abrogated the apoptosis-inducing efficacy of mangiferin, further demonstrating that mangiferin induced apoptosis via Notch pathway. Furthermore, OVCAR3 cell xenograft models revealed that mangiferin treatment inhibited tumor growth and expanded survival of tumor xenograft mice. Based on these results, we concluded that mangiferin could significantly inhibit the proliferation and induce apoptosis in OVCAR3 cells. Our study also suggested the anti-neoplasm effect of mangiferin might be via the regulation of Notch3. Taken together, by targeting cell apoptosis pathways and enhancing the response to cisplatin treatment, mangiferin may represent a potential new drug for the treatment of human ovarian cancer.

Mangiferin from Pueraria tuberosa reduces inflammation via inactivation of NLRP3 inflammasome

Recent reports have demonstrated the role of phyto-constituents in modulating inflammatory responses. Mangiferin isolated from Mangifera indica is known to induce potent anti-oxidative, anti-diabetic and anti-inflammatory activity. However, the molecular mechanism of its anti-inflammatory activity is not properly understood. In this study we have isolated Mangiferin from the tubers of Pueraria tuberosa (PT-Mangiferin) and analysed the mechanism of its potent anti-inflammatory effects in LPS stimulated RAW 264.7 mouse macrophage cell line and in a carrageenan induced air pouch model. PT-Mangiferin was non-toxic to primary cells but showed significant toxicity and apoptotic effect on cancerous cells. It significantly reduced the production of pro-inflammatory mediators (COX-2, iNOS and TNF-α) in LPS stimulated RAW 264.7 cells. Further, it has also reduced the generation of ROS and inhibited LPS induced NF-kB translocation in these cells. Additionally, PT-Mangiferin significantly reduced inflammation in a mouse air pouch model by inhibiting the infiltration of monocytes and neutrophils and reducing the production of cytokines. These effects were mediated via inactivation of NLRP3 inflammasome complex and its downstream signalling molecules. Taken together these results suggest that PT-Mangiferin is potent anti-inflammatory compound that reduces inflammation and holds promise in development of herbal based anti-inflammatory therapeutics in future.

Repositioning of amprenavir as a novel extracellular signal-regulated kinase-2 inhibitor and apoptosis inducer in MCF-7 human breast cancer

Computational drug repositioning by virtually screening existing drugs for additional therapeutic usage could efficiently accelerate anticancer drug discovery. Herein, a library of 1447 Food and Drug Administration (FDA)-approved small molecule drugs was screened in silico for inhibitors of extracellular signal-regulated kinase 2 (ERK2). Then, in vitro kinase assay demonstrated amprenavir, a HIV-1 protease inhibitor, as a potential kinase inhibitor of ERK2. The in vivo kinase assay indicated that amprenavir could inhibit ERK2-mediated phosphorylation of BimEL at Ser69. Amprenavir could suppress this phosphorylation in MCF-7 cells, which may further facilitate the association of BimEL with several pro-survival molecules. Additionally, inhibition of ERK2-BimEL signaling pathway by amprenavir could contribute to its anti-proliferative and apoptosis-inducing activity in MCF-7 cells. Finally, in vivo tumor growth and immunohistochemical studies confirmed that amprenavir remarkably suppressed tumor proliferation and induce apoptosis in MCF-7 xenografts. Taken together, amprenavir can effectively inhibit the kinase activity of ERK2, and thus induces apoptosis and inhibits tumor growth in human MCF-7 cancer cells both in vitro and in vivo, making amprenavir a promising candidate for future anticancer therapeutics.

Anti-Proliferative and Apoptosis-Inducing Effect of Theabrownin against Non-small Cell Lung Adenocarcinoma A549 Cells

With the highest cancer incidence rate, lung cancer, especially non-small cell lung cancer (NSCLC), is the leading cause of cancer death in the world. Tea (leaves of Camellia sinensis) has been widely used as a traditional beverage beneficial to human health, including anti-NSCLC activity. Theabrownin (TB) is one major kind of tea pigment responsible for the beneficial effects of tea liquor. However, its effect on NSCLC is unknown. The aim of the present study was to evaluate anti-proliferative and apoptosis-inducing effect of TB on NSCLC (A549) cells, using MTT assay, morphological observation (DAPI staining), in situ terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay, and annexin-V/PI flow cytometry. Subsequently, the expression of several genes associated with cell proliferation and apoptosis were detected by real time PCR assay to explore its potential underlying mechanism. TB was revealed to inhibit cell proliferation of A549 cells in a concentration-dependent and time-dependent manner. Morphological observation, TUNEL assay and flow cytometric analysis evidenced an apoptosis-inducing effect of TB on A549 cells in a concentration-dependent manner. The real time PCR assay demonstrated that TB down-regulated the expression of TOPO I, TOPO II, and BCL-2, and up-regulated the expression of E2F1, P53, GADD45, BAX, BIM, and CASP 3,7,8,9, which suggests an activation of P53-mediated apoptotic (caspase-dependent) pathway in response to TB treatment. The western blot analysis showed a similar trend for the corresponding protein expression (P53, Bax, Bcl-2, caspase 3,9, and PARP) and further revealed DNA damage as a trigger of the apoptosis (phosphorylation of histone H2A.X). Accordingly, TB can be speculated as a DNA damage inducer and topoisomerase (Topo I and Topo II) inhibitor that can up-regulate P53 expression and subsequently modulate the expression of the downstream genes to induce cell proliferation inhibition and apoptosis of A549 cells. Our results indicate that TB exhibits its anti-NSCLC activity via a P53-dependent mechanism, which may be a promising candidate of natural product for anti-cancer drug development in the treatment of NSCLC.