Nonsteroidal anti-inflammatory drug activated gene-1 (NAG-1) modulators from natural products as anti-cancer agents

Diallyl disulfide in oncotherapy: molecular mechanisms and therapeutic potentials

Garlic possesses a broad spectrum of medicinal properties, such as anti-cancer, antioxidant, anti-diabetic effects, and protective effects on the heart, nervous system, and liver. Diallyl disulfide (DADS), an oil-soluble organic sulfur-containing compound in garlic, has garnered attention in recent years for its demonstrated anti-cancer efficacy in various cancer types such as leukemia, breast cancer, hepatocellular carcinoma, stomach cancer, and prostate cancer. The anticancer properties of DADS are attributed to its ability to suppress cancer cell proliferation, impede invasion and metastasis, as well as induce apoptosis, promote differentiation, and facilitate cell cycle arrest. Although many literatures have reviewed the pharmacokinetics, molecular mechanisms of anti-cancer effects and some clinical trials of DADS, the specific mechanisms and clinical-translational therapeutic potentials have not been elucidated. This comprehensive review focuses on delineating the molecular mechanisms underlying the anticancer effects of DADS, with a particular emphasis on its potential utility as a therapeutic intervention in the clinical management of cancer, and analyzes the challenges and coping strategies faced in the application of DADS as an anti-cancer drug, pointing out the directions for scientific research.

The Role of Mitokines in Diabetic Nephropathy

Diabetic nephropathy (DN) has gradually become one of the main causes of end-stage renal disease (ESRD). However, there is still a lack of effective preventive measures to delay its progression. As the energy factory in the cell, mitochondria play an irreplaceable role in maintaining cell homeostasis. Interestingly, recent studies have shown that in addition to maintaining homeostasis in cells in which mitochondria reside, when mitochondrial perturbations occur in one tissue, distal tissues can also sense and act through mitochondrial stress response pathways through a group of proteins or peptides called "mitokines". Here, we reviewed the mitokines that have been found thus far and summarized their research progress in DN. Finally, we explored the possibility of mitokines as potential therapeutic targets for DN.

Quercetin and microRNA Interplay in Apoptosis Regulation: A New Therapeutic Strategy for Cancer?

Cancer is known as a global problem for the health and economy. Following cancer onset, apoptosis is the primary mechanism countering the tumor cells' growth. Most anticancer agents initiate apoptosis to remove tumor cells. Phytochemicals have appeared as a beneficial treatment option according to their less adverse effects. In recent decades, quercetin has been highlighted due to its high pharmacological benefits, and various literature has suggested it as a potential anti-proliferative agent against different kinds of cancers. The microRNAs (miRNAs) play key roles in cancer treatment, progression, and apoptosis. This review reviewed the effect of quercetin on miRNAs contributing to the induction or inhibition of apoptosis in cancers.

Anticancer Potential of Pineapple and its Bioactive Compound Bromelain

Various ailments have been treated with pineapple (Ananas comosus (L.) Merr.) throughout medicinal history. Pineapple and its bioactive compound bromelain possess health-promoting benefits. Detailed information on the chemotherapeutic activities of pineapple and its bioactive compound bromelain is provided in this review, which analyses the current literature regarding their therapeutic potential in cancer. Research on disease models in cell cultures is the focus of much of the existing research. Several studies have demonstrated the benefits of pineapple extract and bromelain for in vitro and in vivo cancer models. Preliminary animal model results show promise, but they must be translated into the clinical setting. Research on these compounds represents a promising future direction and may be well-tolerated.

GDF15/MIC-1: a stress-induced immunosuppressive factor which promotes the aging process

The GDF15 protein, a member of the TGF-β superfamily, is a stress-induced multifunctional protein with many of its functions associated with the regulation of the immune system. GDF15 signaling provides a defence against the excessive inflammation induced by diverse stresses and tissue injuries. Given that the aging process is associated with a low-grade inflammatory state, called inflammaging, it is not surprising that the expression of GDF15 gradually increases with aging. In fact, the GDF15 protein is a core factor secreted by senescent cells, a state called senescence-associated secretory phenotype (SASP). Many age-related stresses, e.g., mitochondrial and endoplasmic reticulum stresses as well as inflammatory, metabolic, and oxidative stresses, induce the expression of GDF15. Although GDF15 signaling is an effective anti-inflammatory modulator, there is robust evidence that it is a pro-aging factor promoting the aging process. GDF15 signaling is not only an anti-inflammatory modulator but it is also a potent immunosuppressive enhancer in chronic inflammatory states. The GDF15 protein can stimulate immune responses either non-specifically via receptors of the TGF-β superfamily or specifically through the GFRAL/HPA/glucocorticoid pathway. GDF15 signaling stimulates the immunosuppressive network activating the functions of MDSCs, Tregs, and M2 macrophages and triggering inhibitory immune checkpoint signaling in senescent cells. Immunosuppressive responses not only suppress chronic inflammatory processes but they evoke many detrimental effects in aged tissues, such as cellular senescence, fibrosis, and tissue atrophy/sarcopenia. It seems that the survival functions of GDF15 go awry in persistent inflammation thus promoting the aging process and age-related diseases.

Recent advancement of novel marine fungi derived secondary metabolite fibrinolytic compound FGFC in biomedical applications: a review

For several decades, products derived from marine natural sources (PMN) have been widely identified for several therapeutic applications due to their rich sources of bioactive sub-stances, unique chemical diversity, biocompatibility and excellent biological activity. For the past 15 years, our research team explored several PMNs, especially fungi fibrinolytic compounds (FGFCs). FGFC is an isoindolone alkaloid derived from marine fungi, also known as staplabin analogs or Stachybotrys microspora triprenyl phenol (SMTP). For instance, our previous studies explored different types of FGFCs such as FGFC 1, 2, 3 and 4 from the marine fungi Stachybotrys longispora FG216 derived metabolites. The derivatives of FGFC are potentially employed in several disease treatments, mainly for stroke, cancer, ischemia, acute kidney injury, inflammation, cerebral infarction, thrombolysis and hemorrhagic activities, etc. Due to the increasing use of FGFCs in pharmaceutical and biomedical applications, it is important to understand the fundamental signaling concept of FGFCs. Hence, for the first time, this review collectively summarizes the background, types, mode of action and biological applications of FGFCs and their current endeavors for future therapies.

E-Stilbenes: General Chemical and Biological Aspects, Potential Pharmacological Activity Based on the Nrf2 Pathway

Stilbenes are phytoalexins, and their biosynthesis can occur through a natural route (shikimate precursor) or an alternative route (in microorganism cultures). The latter is a metabolic engineering strategy to enhance production due to stilbenes recognized pharmacological and medicinal potential. It is believed that in the human body, these potential activities can be modulated by the regulation of the nuclear factor erythroid derived 2 (Nrf2), which increases the expression of antioxidant enzymes. Given this, our review aims to critically analyze evidence regarding E-stilbenes in human metabolism and the Nrf2 activation pathway, with an emphasis on inflammatory and oxidative stress aspects related to the pathophysiology of chronic and metabolic diseases. In this comprehensive literature review, it can be observed that despite the broad number of stilbenes, those most frequently explored in clinical trials and preclinical studies (in vitro and in vivo) were resveratrol, piceatannol, pterostilbene, polydatin, stilbestrol, and pinosylvin. In some cases, depending on the dose/concentration and chemical nature of the stilbene, it was possible to identify activation of the Nrf2 pathway. Furthermore, the use of some experimental models presented a challenge in comparing results. In view of the above, it can be suggested that E-stilbenes have a relationship with the Nrf2 pathway, whether directly or indirectly, through different biological pathways, and in different diseases or conditions that are mainly related to inflammation and oxidative stress.

Evidence for Anticancer Effects of Chinese Medicine Monomers on Colorectal Cancer

Colorectal cancer is one of the most commonly occurring cancers worldwide. Although clinical reports have indicated the anticancer effects of Chinese herbal medicine, the multiple underlying molecular and biochemical mechanisms of action remain to be fully characterized. Chinese medicine (CM) monomers, which are the active components of CM, serve as the material basis of the functional mechanisms of CM. The aim of this review is to summarize the current experimental evidence from in vitro, in vivo, and clinical studies for the effects of CM monomers in colorectal cancer prevention and treatment, providing some useful references for future research.

Therapeutic potential of traditional Chinese medicine in atherosclerosis: A review

Atherosclerosis is the onset of endothelial cell damage and is characterized by abnormal accumulation of fibrinogen and lipid in large and middle arteries. Recent researches indicate that traditional Chinese medicine including Notoginseng Radix et Rhizoma, Astragali Radix, Salviae Miltiorrhizae Radix et Rhizoma, Ginseng Radix et Rhizoma, Fructus Crataegi, Glycyrrhizae Radix et Rhizoma, Polygoni Multiflori Radix, Fructus Lycii, and Coptidis Rhizoma have therapeutic effects on atherosclerosis. Furthermore, the pharmacological roles of these kinds of traditional Chinese medicine in atherosclerosis refer to endothelial function influences, cell proliferation and migration, platelet aggregation, thrombus formation, oxidative stress, inflammation, angiogenesis, apoptosis, autophagy, lipid metabolism, and the gut microbiome. Traditional Chinese medicine may serve as potential and effective anti-atherosclerosis drugs. However, a critical study has shown that Notoginseng Radix et Rhizoma may also have toxic effects including pustules, fever, and elevate circulating neutrophil count. Further high-quality studies are still required to determine the clinical safety and efficacy of traditional Chinese medicine and its active ingredients.

Undescribed C-Glycosylflavones from Corn Silk and Potential Anti-inflammatory Activity Evaluation of Isolates

Phytochemical investigation of corn silk resulted in isolation and characterization of four flavone C-glycosides, chrysoeriol 6-C-β-oliopyranosyl-7-O-β-D-glucopyranoside (1: ), 3'-methoxycassiaoccidentalin A (2: ), chrysoeriol 6-C-β-boivinopyranosyl-7-O-β-D-glucopyranoside (3: ), and ax-4″-OH-3'-methoxymaysin (4: ), a triterpenoid, friedelin (5: ), two sterols, (22E)-5α,8α-epidioxyergosta-6,22-dien-3β-ol (6: ) and 6β-hydroxystigmasta-4,22-diene-3-one (7: ), and a mixture of β-sitosterol and stigmasterol. Compounds 1: and 2: were previously undescribed. Structure elucidation of the isolated compounds was attained using spectral data including 1D and 2D NMR and HRESIMS. Compounds1, 2, 5: , and 6: inhibited iNOS activity in LPS-induced macrophages and decreased nitrite levels by 68.64 ± 4.46, 65.67 ± 6.47, 88.50 ± 0.50, and 94.00 ± 4.00%, respectively, at 50 µM. Compound 5: also showed inhibition of NF-κB (51.00 ± 1.50%). Compounds 1: and 2: induced NAG-1 activity in chondrocytes by 1.80 ± 0.05 and 2.00 ± 0.13 fold, respectively. The extract of corn silk, however, did not exhibit inhibition of iNOS or NF-κB but induced NAG-1 by 1.80 ± 0.51 fold.

Astragalus-Scorpion Drug Pair Inhibits the Development of Prostate Cancer by Regulating GDPD4-2/PI3K/AKT/mTOR Pathway and Autophagy

Objective: Prostate cancer (PCa) is an epithelial malignancy of the prostate that currently lacks effective treatment. Traditional Chinese medicine (TCM) can play an anticancer role through regulating the immune system, anti-tumor angiogenesis, regulating tumor cell apoptosis, autophagy dysfunction, and other mechanisms. This study attempted to explore the active ingredients and potential mechanism of action of the Astragalus-Scorpion (A-S) drug pair in PCa, in order to provide new insights into the treatment of PCa. Methods: Network pharmacology was used to analyze the A-S drug pair and PCa targets. Bioinformatics analysis was used to analyze the LncRNAs with significant differences in PCa. The expression of LC3 protein was detected by immunofluorescence. CCK8 was used to detect cell proliferation. The expressions of GDPD4-2, AC144450.1, LINC01513, AC004009.2, AL096869.1, AP005210.1, and BX119924.1 were detected by RT-qPCR. The expression of the PI3K/AKT/mTOR pathway and autophagy-related proteins were detected by western blot. LC-MS/MS was used to identify the active components of Astragalus and Scorpion. Results: A-S drug pair and PCa have a total of 163 targets, which were mainly related to the prostate cancer and PI3K/AKT pathways. A-S drug pair inhibited the formation of PCa, promoted the expression of LC3Ⅱ and Beclin1 proteins, and inhibited the expression of P62 and PI3K-AKT pathway proteins in PCa mice. Astragaloside IV and polypeptide extract from scorpion venom (PESV) were identified as the main active components of the A-S drug pair. GDPD4-2 was involved in the treatment of PCa by Astragaloside IV-PESV. Silencing GDPD4-2 reversed the therapeutic effects of Astragaloside IV-PESV by regulating the PI3K/AKT/mTOR pathway. Conclusion: Astragaloside IV-PESV is the main active components of A-S drug pair treated PCa by regulating the GDPD4-2/PI3K-AKT/mTOR pathway and autophagy.

Myokines: Novel therapeutic targets for diabetic nephropathy

With the increasing incidence of diabetic nephropathy (DN), there is an urgent need to find effective DN preventive and therapeutic modalities. It is widely believed that effective exercise is good for health. However, the beneficial role of exercise in kidney disease, especially in DN, and the underlying molecular mechanisms have rarely been reported. Muscle is not only an important motor organ but also an important endocrine organ, secreting a group of proteins called "myokines" into the blood circulation. Circulating myokines then move to various target organs to play different biological roles. In this review, we summarize the currently known myokines and the progress in research relating them to DN and discuss its potential as a therapeutic target for DN.

Transcriptional Regulation of GDF15 by EGR1 Promotes Head and Neck Cancer Progression through a Positive Feedback Loop

Growth and differentiation factor 15 (GDF15), a divergent member of the transforming growth factor-β (TGF-β) superfamily, has been reported to be overexpressed in different kinds of cancer types. However, the function and mechanism of GDF15 in head and neck cancer (HNC) remains unclear. The Cancer Genome Atlas (TCGA) data show that the expression of GDF15 is significantly associated with tumor AJCC stage, lymph vascular invasion and tumor grade in HNC. In this study, we confirmed that knockdown of GDF15 attenuated: cell proliferation, migration and invasion via regulation of EMT through a canonical pathway; SMAD2/3 and noncanonical pathways; PI3K/AKT and MEK/ERK in HNC cell lines. Furthermore, we found that early growth response 1 (EGR1) was a transcription factor of GDF15. Interestingly, we also demonstrated that GDF15 could regulate the expression of EGR1, which meant a positive feedback loop occurred between these two factors. Moreover, combined inhibition of both GDF15 and EGR1 in a HNC mouse xenograft model showed significantly decreased tumor volume compared to inhibition of EGR1 or GDF15 alone. Our study showed that the GDF15–EGR1 signaling axis may be a good target in HNC patients.

Preclinical Drug Discovery in Colorectal Cancer: A Focus on Natural Compounds

BACKGROUND

Colorectal cancer (CRC) is considered one of the most predominant and deadly cancer globally. Nowadays, the main clinical management for this cancer includes chemotherapy and surgery; however, these treatments result in the occurrence of drug resistance and severe side effects, and thus it is a crucial requirement to discover an alternative and potential therapy for CRC treatment. Numerous therapeutic cancers were initially recognized from natural metabolites utilized in traditional medicine, and several recent types of research have shown that many natural products own potential effects against CRC and may assist the action of chemotherapy for the treatment of CRC. It has been indicated that most patients are well tolerated by natural compounds without showing any toxicity signs even at high doses. Conventional chemotherapeutics interaction with natural medicinal compounds presents a new feature in cancer exploration and treatment. Most of the natural compounds overwhelm malignant cell propagation by apoptosis initiation of CRC cells and arresting of the cell cycle (especially at G, S, and G2/M phase) that result in inhibition of tumor growth.

OBJECTIVE

This mini-review aimed to focus on natural compounds (alkaloids, flavonoids, polysaccharides, polyphenols, terpenoids, lactones, quinones, etc.) that were identified to have anti- CRC activity in vitro on CRC cell lines and/or in vivo experiments on animal models.

CONCLUSION

Most of the studied active natural compounds possess anti-CRC activity via different mechanisms and pathways in vitro and in vivo that might be used as assistance by clinicians to support chemotherapy therapeutic strategy and treatment doses for cancer patients.

Quercetin Induces Anticancer Activity by Upregulating Pro-NAG-1/GDF15 in Differentiated Thyroid Cancer Cells

Simple Summary

Thyroid cancer is one of the most common cancers worldwide, and its incidence has increased over the last few decades. It is difficult to diagnose different types of thyroid cancer. Tumor tissues from papillary thyroid cancer patient showed higher expression of mature NAG-1, whereas adjacent normal tissues showed higher expression of pro-NAG-1. Several anti-cancer compounds increased pro-NAG-1 expression in thyroid cancer cell line. Quercetin (3,3’,4’,5,7-pentahydroxyflavone) is a flavonoid that is a major component of various plants, including raspberries, grapes, and onions. Quercetin induced apoptosis by inducing only pro-NAG-1 expression, but not mature NAG-1, mediated by the transcription factor C/EBP. This study indicates that pro-NAG-1 could be used as a useful biomarker for thyroid cancer and also provides a potential therapeutic target for the treatment of thyroid cancer with quercetin.

Abstract

Although the treatment of thyroid cancer has improved, unnecessary surgeries are performed due to a lack of specific diagnostic and prognostic markers. Therefore, the identification of novel biomarkers should be considered in the diagnosis and treatment of thyroid cancer. In this study, antibody arrays were performed using tumor and adjacent normal tissues of patients with papillary thyroid cancer, and several potential biomarkers were identified. Among the candidate proteins chosen based on the antibody array data, mature NAG-1 exhibited increased expression in tumor tissues compared to adjacent normal tissues. In contrast, pro-NAG-1 expression increased in normal tissues, as assessed by western blot analysis. Furthermore, pro-NAG-1 expression was increased when the thyroid cancer cells were treated with phytochemicals and nonsteroidal anti-inflammatory drugs in a dose-dependent manner. In particular, quercetin highly induced the expression of pro-NAG-1 but not that of mature NAG-1, with enhanced anticancer activity, including apoptosis induction and cell cycle arrest. Examination of the NAG-1 promoter activity showed that p53, C/EBPα, or C/EBPδ played a role in quercetin-induced NAG-1 expression. Overall, our study indicated that NAG-1 may serve as a novel biomarker for thyroid cancer prognosis and may be used as a therapeutic target for thyroid cancers.

Qizhen capsule inhibits colorectal cancer by inducing NAG-1/GDF15 expression that mediated via MAPK/ERK activation

ETHNOPHARMACOLOGICAL RELEVANCE

Qizhen capsule (QZC) is a traditional Chinese medicine (TCM) preparation that has been widely used in clinical practice and exerts promising therapeutic effects against breast, lung, and gastric cancers. However, studies have not reported whether QZC inhibits colorectal cancer (CRC) development and progression. Meanwhile, the underlying molecular mechanisms of its anticancer activity have not been studied.

AIM OF THE STUDY

To investigate the anticancer effects of QZC on CRC and the possible underlying molecular mechanisms of QZC in vitro and in vivo.

MATERIALS AND METHODS

The MTT assay and flow cytometry were used to determine the viability and apoptosis of HCT116 and HT-29 cancer cells. A xenograft nude mouse model was used to study the antitumor effects of QZC in vivo. Western blotting was performed to determine the expression of key proteins responsible for the molecular mechanisms elicited by QZC. Immunofluorescence staining was performed to detect the expression of nonsteroidal anti-inflammatory drug (NSAID)-activated gene-1 or growth differentiation factor-15 (NAG-1/GDF15). Small interfering RNAs (siRNAs) were used to silence NAG-1/GDF15 in cells.

RESULTS

In this study, QZC significantly reduced the viability of HCT116 and HT-29 cells and induced apoptosis in dose- and time-dependent manners, but displayed much less toxicity toward normal cells. QZC-induced apoptosis in HCT116 cells was accompanied by the deregulation of the expression of the Bcl-2, Bax, PARP, caspase-3, and caspase-9 proteins. Furthermore, QZC induced NAG-1/GDF15 expression in HCT116 cells, while silencing of NAG-1/GDF15 attenuated QZC-induced apoptosis and cell death. Next, QZC increased the phosphorylation of mTOR, AMPK, p38, and MAPK/ERK in HCT116 cells. We then demonstrated that QZC-induced apoptosis and NAG-1/GDF15 upregulation were mediated by MAPK/ERK activation. Moreover, QZC significantly inhibited HCT116 xenograft tumor growth in nude mice, which was accompanied by NAG/GDF15 upregulation and MAPK/ERK activation. QZC also prevented 5-FU-induced weight loss or cachexia in tumor-bearing mice. The expression of Ki67 and PCNA was suppressed, while cleaved caspase-3 level and TUNEL staining were increased in the tumor sections from QZC-treated mice compared to the control.

CONCLUSION

QZC is a novel anticancer agent for CRC that targets NAG-1/GDF15 via the MAPK/ERK signaling pathway.

Berberine Exerts Anti-cancer Activity by Modulating Adenosine Monophosphate- Activated Protein Kinase (AMPK) and the Phosphatidylinositol 3-Kinase/ Protein Kinase B (PI3K/AKT) Signaling Pathways

Background

The antagonistic relationship between adenosine monophosphate-activated protein kinase (AMPK) and phosphatidylinositol 3-kinase/protein kinase B (PI3K/AKT) signaling play a vital role in cancer development. The anti-cancer effects of berberine have been reported as a main component of the traditional Chinese medicine Rhizoma coptidis, although the roles of these signaling pathways in these effects have not been systematically reviewed.

METHODS

We searched the PubMed database for studies with keywords including ["berberine"] and ["tumor" or "cancer"] and ["AMPK"] or ["AKT"] published between January 2010 and July 2020, to elucidate the roles of the AMPK and PI3K/AKT pathways and their upstream and downstream targets in the anti-cancer effects of berberine.

RESULTS

The anti-cancer effects of berberine include inhibition of cancer cell proliferation, promotion of apoptosis and autophagy in cancer cells, and prevention of metastasis and angiogenesis. The mechanism of these effects involves multiple cell kinases and signaling pathways, including activation of AMPK and forkhead box transcription factor O3a (FOXO3a), accumulation of reactive oxygen species (ROS), and inhibition of the activity of PI3K/AKT, rapamycin (mTOR) and nuclear factor-κB (NF-κB). Most of these mechanisms converge on regulation of the balance of AMPK and PI3K/AKT signaling by berberine.

CONCLUSION

This evidence supports the possibility that berberine is a promising anti-cancer natural product, with pharmaceutical potential in inhibiting cancer growth, metastasis and angiogenesis via multiple pathways, particularly by regulating the balance of AMPK and PI3K/AKT signaling. However, systematic preclinical studies are still required to provide scientific evidence for further clinical studies.

Pt(IV) Prodrugs with NSAIDs as Axial Ligands

A chemo-anti-inflammatory strategy is of interest for the treatment of aggressive cancers. The platinum (IV) prodrug with non-steroidal anti-inflammatory drugs (NSAIDs) as axial ligands is designed to efficiently enter tumor cells due to high lipophilicity and release the cytotoxic metabolite and NSAID intracellularly, thereby reducing side effects and increasing the therapeutic efficacy of platinum chemotherapy. Over the last 7 years, a number of publications have been devoted to the design of such Pt(IV) prodrugs in combination with anti-inflammatory chemotherapy, with high therapeutic efficacy in vitro and In vivo. In this review, we summarize the studies devoted to the development of Pt(IV) prodrugs with NSAIDs as axial ligands, the study of the mechanism of their cytotoxic action and anti-inflammatory activity, the structure-activity ratio, and therapeutic efficacy.

Insights Into Mechanisms of GDF15 and Receptor GFRAL: Therapeutic Targets

Growth and differentiation factor 15 (GDF15) belongs to the transforming growth factor-β (TGF-β) superfamily proteins. GDF15 acts as an inflammatory marker, and it plays a role in pathogenesis of tumors, ischemic diseases, metabolic disorders, and neurodegenerative processes. GDF15 is not normally expressed in the tissue; it is prominently induced following 'injury'. GDF15 functions are critical for the regulation of endothelial adaptations after vascular damage. Recently, four research groups simultaneously identified glial-derived neurotrophic factor (GDNF)-family receptor α-like (GFRAL) in the brain, an orphan receptor as the receptor for GDF15, signaling through the coreceptor RET. In this article, new aspects of the biology of GDF15 and receptor GFRAL, and their relationship with various pathologies, are commented on.

Quercetin as an innovative therapeutic tool for cancer chemoprevention: Molecular mechanisms and implications in human health

Cancer is a life-threatening disease afflicting human health worldwide. Recent advances in drug discovery infrastructure and molecular approaches have helped a lot in identifying the novel drug targets for therapeutic intervention. Nevertheless, the morbidity and mortality rates because of this disease keep on rising at an alarming rate. Recently, the use of natural and synthetic molecules as innovative therapeutic tools for cancer prevention has lead to the development of cancer chemoprevention. Cancer chemoprevention is a prophylactic strategy that involves the chronic administration of one or more natural or synthetic agents to block, to inhibit, or to suppress the process of cancer development before it becomes an invasive disease. Quercetin, a dietary bioflavonoid, can specifically retard the growth of cancer cells and behaves as a potent cancer chemopreventive agent. Quercetin has multiple intracellular targets in a cancer cell. Therefore, many mechanisms have been postulated to explain its chemopreventive action. The chemopreventive effects elicited by this natural molecule in different model systems are believed to include antioxidant/pro-oxidant action, regulation of redox homeostasis, apoptosis, cell cycle arrest, anti-inflammatory action, modulation of drug metabolizing enzymes, alterations in gene expression patterns, inhibition of Ras gene expression, and modulation of signal transduction pathways. However, cell signaling networks have recently garnered attention as common molecular target for various chemopreventive effects of quercetin. In this review, we made an attempt to critically summarize the emerging knowledge on the role of quercetin in cancer chemoprevention and the underlying molecular mechanisms implicated in its chemopreventive and therapeutic effects.

Apigenin as Tumor Suppressor in Cancers: Biotherapeutic Activity, Nanodelivery, and Mechanisms With Emphasis on Pancreatic Cancer

Pancreatic cancer is the most lethal malignancy of the gastrointestinal tract. Due to its propensity for early local and distant spread, affected patients possess extremely poor prognosis. Currently applied treatments are not effective enough to eradicate all cancer cells, and minimize their migration. Besides, these treatments are associated with adverse effects on normal cells and organs. These therapies are not able to increase the overall survival rate of patients; hence, finding novel adjuvants or alternatives is so essential. Up to now, medicinal herbs were utilized for therapeutic goals. Herbal-based medicine, as traditional biotherapeutics, were employed for cancer treatment. Of them, apigenin, as a bioactive flavonoid that possesses numerous biological properties (e.g., anti-inflammatory and anti-oxidant effects), has shown substantial anticancer activity. It seems that apigenin is capable of suppressing the proliferation of cancer cells via the induction of cell cycle arrest and apoptosis. Besides, apigenin inhibits metastasis via down-regulation of matrix metalloproteinases and the Akt signaling pathway. In pancreatic cancer cells, apigenin sensitizes cells in chemotherapy, and affects molecular pathways such as the hypoxia inducible factor (HIF), vascular endothelial growth factor (VEGF), and glucose transporter-1 (GLUT-1). Herein, the biotherapeutic activity of apigenin and its mechanisms toward cancer cells are presented in the current review to shed some light on anti-tumor activity of apigenin in different cancers, with an emphasis on pancreatic cancer.

Isoliquiritigenin Inhibits Atherosclerosis by Blocking TRPC5 Channel Expression

Isoliquiritigenin (ISL) is a flavonoid isolated mainly from the licorice plant, a traditional Chinese herb. ISL has shown anticancer, anti-inflammatory, antioxidant, and antidiabetic activities. However, the pharmaceutical effects of ISL on atherosclerosis are seldom explored. In this study, we used apolipoprotein E (ApoE) knockout mouse model and angiotensin II- (Ang II-) stimulated vascular smooth muscle cells (VSMCs) to elucidate the pharmacological mechanism of ISL to inhibit atherosclerosis. We found that in ApoE^-/- mice ISL could attenuate atherosclerotic lesion, reduce serum lipid levels, and inhibit TRPC5 expression. In vitro, ISL inhibited Ang II-stimulated proliferation of VSMCs and suppressed Ang II-induced TRPC5 and PCNA expressions in a dose-dependent fashion. In conclusion, our findings provide novel insight into the pharmacological effects of ISL on atherosclerosis and suggest that ISL is beneficial for cardiovascular protection.

Friend or foe, the role of EGR-1 in cancer

Early growth response-1 (EGR-1), also termed NEFI-A and Krox-24, as a multi-domain protein is implicated in several vital physiological processes, including development, metabolism, cell growth and proliferation. Previous studies have implied that EGR-1 was producing in response to the tissue injury, immune response and fibrosis. Meanwhile, emerging studies stressed the pronounced correlation of EGR-1 and human cancers. Nevertheless, the intricate mechanisms of cancer-reduce EGR-1 alteration still poorly characterized. In the review, we evaluated the effects of EGR-1 in tumor cell proliferation, apoptosis, migration, invasion and tumor microenvironment, and then, we dwell on the intricate signaling pathways that EGR-1 involved in. The aberrantly expressed of EGR-1 in cancers are expected to provide a new cancer therapy strategy or a new marker for assessing treatment efficacy.

Competitive inhibition by NAG-1/GDF-15 NLS peptide enhances its anti-cancer activity

Non-steroidal anti-inflammatory drug activated gene-1 (NAG-1), also known as growth differentiation factor 15 (GDF15), is a TGF-β (transforming growth factor beta) superfamily protein with a distinctive secretion pathway. NAG-1 is associated with multiple diseases including cancer, wherein it plays a role in both pro- and anti-cancer activities. We previously reported that NAG-1 is translocated to different subcellular compartments and its activity depends on its localization. In this paper, we report that the transfection of a novel peptide corresponding to the nuclear localization signal (NLS) of NAG-1 blocks its translocation to the nucleus. Further, accumulation of NAG-1 in the cytoplasm decreased mitochondrial membrane potential, thus implying apoptosis induction as a consequence. Overall, our results indicate that the novel peptide derived from NAG-1 NLS sequence is a promising tool for enhancing the anti-tumorigenic activity of NAG-1.

Epigallocatechin gallate (EGCG) suppresses epithelial-Mesenchymal transition (EMT) and invasion in anaplastic thyroid carcinoma cells through blocking of TGF-β1/Smad signaling pathways

Transforming growth factor (TGF)-β1 plays a crucial role in the epithelial-to-mesenchymal transition (EMT) in many cancer types and in thyroid cancers. Epigallocatechin-3-gallate (EGCG), the most important ingredient in the green tea, has been reported to possess antioxidant and anticancer activities. However, the cellular and molecular mechanisms explaining its action have not been completely understood. In this study, we found that EGCG significantly suppresses EMT, invasion and migration in anaplastic thyroid carcinoma (ATC) 8505C cells in vitro by regulating the TGF-β/Smad signaling pathways. EGCG significantly inhibited TGF-β1-induced expression of EMT markers (E-cadherin reduction and vimentin induction) in 8505C cells in vitro. Treatment with EGCG completely blocked the phosphorylation of Smad2/3, translocation of Smad4. Taken together, these results suggest that EGCG suppresses EMT and invasion and migration by blocking TGFβ/Smad signaling pathways.

Apoptosis and metastasis inhibitory potential of pineapple vinegar against mouse mammary gland cells in vitro and in vivo

BACKGROUND

Plant-based food medicine and functional foods have been consumed extensively due to their bioactive substances and health-beneficial effects. Vinegar is one of them due to its bioactivities, which confers benefits on human body. Our previous study has produced pineapple vinegar that is rich in gallic acid and caffeic acid via 2 steps fermentation. There are many evidences that show the effectiveness of these resources in inhibiting the proliferation and metastasis of the cancer cells through several mechanisms.

METHODS

Freeze-dried pineapple vinegar was evaluated for its in vitro apoptosis and metastasis inhibitory potential using MTT, cell cycle, Annexin V and scratch assays. The in vivo test using BALB/c mice challenged with 4 T1 cells was further investigated by pre-treating the mice with 0.08 or 2 ml/kg body weight of freshly-prepared pineapple vinegar for 28 days. The tumor weight, apoptotic state of cells in tumor, metastasis and immune response of the untreated and pineapple vinegar treatment group were evaluated and compared.

RESULTS

From the in vitro study, an IC50 value of 0.25 mg/mL after 48 h of treatment was established. Annexin V/PI and scratch closure assays showed that pineapple vinegar induced 70% of cell population to undergo apoptosis and inhibited 30% of wound closure of 4 T1 cells. High concentration of pineapple vinegar (2 ml/kg body weight) led to the reduction of tumor weight and volume by 45%as compared to the untreated 4 T1-challenged mice. This effect might have been contributed by the increase of T cell and NK cells population associated with the overexpression of IL-2 andIFN-γ cytokines and splenocyte cytotoxicity. Furthermore, fewer instances of metastasis events were recorded in the pineapple vinegar treatment group and this could be explained by the downregulation of inflammation related genes (iNOS, NF-kB and COX2), metastasis related genes (iCAM, VEGF and MMP9) and angeogenesis related genes (CD26, TIMP1, HGF, MMP3, IGFBP-1 and IGFBP-2).

CONCLUSION

The ability of pineapple vinegar to delay cancer progression portrayed its potential as chemopreventive dietry intervention for cancer therapy.

Pinosylvin reduced migration and invasion of oral cancer carcinoma by regulating matrix metalloproteinase-2 expression and extracellular signal-regulated kinase pathway

BACKGROUND

Pinosylvin possesses several biological properties, including anti-inflammatory, antitumor, and antioxidant characteristics. However, the effects of pinosylvin on the migration and invasion of human oral cancer cells and the underlying mechanisms remain unclear.

HYPOTHESIS/PURPOSE

In this research, we investigated the outcome of different concentrations of pinosylvin (0-80 μM) on the metastatic and invasive abilities of SAS, SCC-9, and HSC-3 cells.

METHODS AND RESULTS

Western blotting assay and Gelatin zymography assay indicated that pinosylvin inhibited the enzymatic activity of matrix metalloproteinase-2 (MMP-2) and reduced its protein level but increased the expression of tissue inhibitor of metalloproteinase-2 (TIMP-2). Additionally, the wound healing assay and Transwell method showed that pinosylvin reduced the migration of SAS, SCC-9 and HSC-3 oral cancer cells. Besides, pinosylvin decreased the phosphorylation of ERK1/2 protein experssion in both SAS and SCC-9 cells.

CONCLUSION

These results indicate that pinosylvin is a potential anticancer agent for preventing oral cancer metastasis.

Anti-Aging Implications of Astragalus Membranaceus (Huangqi): A Well-Known Chinese Tonic

Owing to a dramatic increase in average life expectancy and the Family Planning program of the 1970s - 1990s, China is rapidly becoming an aging society. Therefore, the investigation of healthspan-extending drugs becomes more urgent. Astragalus membranaceus (Huangqi) is a major medicinal herb that has been commonly used in many herbal formulations in the practice of traditional Chinese medicine (TCM) to treat a wide variety of diseases and body disorders, or marketed as life-prolonging extracts for human use in China, for more than 2000 years. The major components of Astragalus membranaceus are polysaccharides, flavonoids, and saponins. Pharmacological research indicates that the extract component of Astragalus membranaceus can increase telomerase activity, and has antioxidant, anti-inflammatory, immunoregulatory, anticancer, hypolipidemic, antihyperglycemic, hepatoprotective, expectorant, and diuretic effects. A proprietary extract of the dried root of Astragalus membranaceus, called TA-65, was associated with a significant age-reversal effect in the immune system. Our review focuses on the function and the underlying mechanisms of Astragalus membranaceus in lifespan extension, anti-vascular aging, anti-brain aging, and anti-cancer effects, based on experimental and clinical studies.

Linarin sensitizes tumor necrosis factor-related apoptosis (TRAIL)-induced ligand-triggered apoptosis in human glioma cells and in xenograft nude mice

Tumor necrosis factor-related apoptosis-induced ligand (TRAIL) is reported as a promising anti-cancer therapeutic agent. Nevertheless, a variety of cancer cells, including human malignant glioma cells, are resistant to TRAIL treatment, indicating that it is necessary to find effective strategies to overcome the TRAIL resistance. Linarin (LIN), a natural flavonoid compound in Flos Chrysanthemi Indici (FCI), has been exhibited to exert various pharmacological activities, including anti-cancer. Here in our study, we found that non-cytotoxic doses of LIN (5μM) dramatically potentiated TRAIL (80ng/ml)-induced cytotoxicity (52.36±1.58%) and apoptosis (68.50±1.23%) using 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) and flow cytometry assays, respectively, in human glioma cells of U87MG. Apoptosis was evidenced by enhanced cleavage of Caspase-8/-9/-3 and poly (ADP-ribose) polymerase (PARP), and reduced anti-apoptotic proteins, including B-cell leukemia/lymphoma 2 (Bcl-2), mantle cell lymphoma (Mcl)-1, and Survivin. Moreover, both intrinsic and extrinsic apoptosis pathways were included in apoptosis induced by LIN and TRAIL co-treatment, along with high release of Cyto-c into cytoplasm and enhancement of fas-associated protein with death domain (FADD), death-inducing signaling complex (DISC), death receptor 4 (DR) 4 and DR5, respectively. Reactive oxygen species (ROS) generation, up to 39.86±2.32%, was also highly triggered by TRAIL and LIN combinational treatment, which was accompanied with high phosphorylation of c-Jun-N-terminal kinase (JNK). In vivo, TRAIL and LIN double treatment significantly reduced the tumor growth using xenograft tumor model through inducing apoptosis. We demonstrated that combining LIN with TRAIL treatments might be effective against TRAIL-resistant glioma cells through inducing apoptosis regulated by ROS generation.

New Insights toward Colorectal Cancer Chemotherapy Using Natural Bioactive Compounds

Combination therapy consists in the simultaneous administration of a conventional chemotherapy drug (or sometimes, a radiotherapy protocol) together with one or more natural bioactives (usually from plant or fungal origin) of small molecular weight. This combination of anticancer drugs may be applied to cell cultures of tumor cells, or to an animal model for a cancer type (or its xenograft), or to a clinical trial in patients. In this review, we summarize current knowledge describing diverse synergistic effects on colorectal cancer cell cultures, animal models, and clinical trials of various natural bioactives (stilbenes, flavonoids, terpenes, curcumin, and other structural families), which may be important with respect to diminish final doses of the chemotherapy drug, although maintaining its biological effect. This is important as these approaches may help reduce side effects in patients under conventional chemotherapy. Also, these molecules may exerts their synergistic effects via different cell cycle pathways, including different ones to those responsible of resistance phenotypes: transcription factors, membrane receptors, adhesion and structural molecules, cell cycle regulatory components, and apoptosis pathways.

Inhibition of Epstein-Barr virus reactivation by the flavonoid apigenin

Background

Lytic reactivation of EBV has been reported to play an important role in human diseases, including NPC carcinogenesis. Inhibition of EBV reactivation is considered to be of great benefit in the treatment of virus-associated diseases. For this purpose, we screened for inhibitory compounds and found that apigenin, a flavonoid, seemed to have the ability to inhibit EBV reactivation.

Methods

We performed western blotting, immunofluorescence and luciferase analyses to determine whether apigenin has anti-EBV activity.

Results

Apigenin inhibited expression of the EBV lytic proteins, Zta, Rta, EAD and DNase in epithelial and B cells. It also reduced the number of EBV-reactivating cells detectable by immunofluorescence analysis. In addition, apigenin has been found to reduce dramatically the production of EBV virions. Luciferase reporter analysis was performed to determine the mechanism by which apigenin inhibits EBV reactivation: apigenin suppressed the activity of the immediate-early (IE) gene Zta and Rta promoters, suggesting it can block initiation of the EBV lytic cycle.

Conclusion

Taken together, apigenin inhibits EBV reactivation by suppressing the promoter activities of two viral IE genes, suggesting apigenin is a potential dietary compound for prevention of EBV reactivation.

Electronic supplementary material

The online version of this article (doi:10.1186/s12929-016-0313-9) contains supplementary material, which is available to authorized users.

Dementia, Preclinical Studies in Neurodegeneration and its Potential for Translational Medicine in South America

Latin-American people with dementia will increase to an astounding 368% in 2050, higher than USA and Europe. In addition, to sporadic dementia type like Alzheimer, and vascular dementia (VaD) progression after Cerebrovascular disease is also found. These incidences are increased in Colombia by specific populations affected with pure Neurodegenerative and VaDs like Autosomical Dominant familial Alzheimer’s disease (AD) and Cerebral Autosomal-Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy (CADASIL). In spite of the enormous human effort with and economical effort and investment costs, neither sporadic nor genetic kinds of dementia progression have been prevented or blocked yet. Currently, there exist several animal models that partially solve the understanding of the neurodegenerative etiopathogenesis and its treatment. However, when the potential therapies are translated to humans, those do not work or present a limited action. Main difficulties are the diverse comorbility associated to the cause and/or several affected brain regions, reducing the efficacy of some therapies which are limited to a tissue-specific action or modulating a kind of neurotransmission. Global investigation suggests that a general prevention could be achieved with the improvement in the quality of lifestyle, including healthy diet, physical and mental activity, and avoiding mechanical or chemical pro-inflammatory events in an early stage in the most of non-communicable diseases. In this review article, we present some molecular targets and preclinical studies in animal models to propose strategies that could be useful in a future translation to prevent or block neurodegeneration: one is gene therapy; silencing pathogenic genes in critical brain areas where excitotoxicity arise and spread. Another is to take advantage of the natural source and its wide biodiversity of natural products that are capable of identifying, by the blocking and prevention of neurodegeneration. On the other side, the casuistic of pure dementias in the Latin-American region gives an exceptional opportunity to understand the pathogenesis in these human populations. Further, this is in support of the basic and clinical researchers working on an interaction for a better understanding and medical care of mixed dementias, which have more complex factors than pure ones. However, to promote the translation of any therapeutical alternative is necessary to clarify the normative and the protocols for developing clinical trials with original candidates or work upon strategies proposed from South-American countries.

GDF15 promotes EMT and metastasis in colorectal cancer

Metastasis is the major cause of cancer deaths, and the epithelial–mesenchymal transition (EMT) has been considered to be a fundamental event in cancer metastasis. However, the role of growth differentiation factor 15 (GDF15) in colorectal cancer (CRC) metastasis and EMT remains poorly understood. Here, we showed that GDF15 promoted CRC cell metastasis both in vitro and in vivo. In addition, the EMT process was enhanced by GDF15 through binding to TGF-β receptor to activate Smad2 and Smad3 pathways. Clinical data showed GDF15 level in tumor tissues, and the serum was significantly increased, in which high GDF15 level correlated with a reduced overall survival in CRC. Thus, GDF15 may promote colorectal cancer metastasis through activating EMT. Promisingly, GDF15 could be considered as a novel prognostic marker for CRC in the clinic.

A plant alkaloid, veratridine, potentiates cancer chemosensitivity by UBXN2A-dependent inhibition of an oncoprotein, mortalin-2

Veratridine (VTD), an alkaloid derived from the Liliaceae plant shows anti-tumor effects; however, its molecular targets have not been thoroughly studied. Using a high-throughput drug screen, we found that VTD enhances transactivation of UBXN2A, resulting in upregulation of UBXN2A in the cytoplasm, where UBXN2A binds and inhibits the oncoprotein mortalin-2 (mot-2). VTD-treated cancer cells undergo cell death in UBXN2A- and mot-2-dependent manners. The cytotoxic function of VTD is grade-dependent, and the combined treatment with a sub-optimal dose of the standard chemotherapy, 5-Fluorouracil (5-FU) and etoposide, demonstrated a synergistic effect, resulting in higher therapeutic efficacy. VTD influences the CD44+ stem cells, possibly through UBXN2A-dependent inhibition of mot-2. The VTD-dependent expression of UBXN2A is a potential candidate for designing novel strategies for colon cancer treatment because: 1) In 50% of colon cancer patients, UBXN2A protein levels in tumor tissues are significantly lower than those in the adjacent normal tissues. 2) Cytoplasmic expression of the mot-2 protein is very low in non-cancerous cells; thus, VTD can produce tumor-specific toxicity while normal cells remain intact. 3) Finally, VTD or its modified analogs offer a valuable adjuvant chemotherapy strategy to improve the efficacy of 5-FU-based chemotherapy for colon cancer patients harboring WT-p53.

The Protective Effects of 18β-Glycyrrhetinic Acid on Helicobacter pylori-Infected Gastric Mucosa in Mongolian Gerbils

18β-Glycyrrhetinic acid (GRA), a major component of Glycyrrhiza glabra, is widely used therapeutically in clinic. In this study, the effect of GRA on Helicobacter pylori- (H. pylori-) infected gastritis was investigated in Mongolian gerbils in vivo. The gerbils were randomly divided into groups: uninfected; H. pylori-infected; H. pylori + antibiotics (clarithromycin, amoxicillin, and esomeprazole); and H. pylori + GRA. The gastric intraluminal pH value, histopathological changes, and the expression levels of inflammation-related cytokines (IL-1β, TNF-α, COX-2, and iNOS) were investigated. The results showed that, in the H. pylori + GRA group, the intraluminal gastric pH value was lower (2.14 ± 0.08 versus 3.17 ± 0.23, P < 0.05), erosion and hyperplasia were alleviated, the infiltration of neutrophils and mononuclear cells was attenuated (P < 0.05), and the expression levels of TNF-α, IL-1β, COX-2, and iNOS were decreased (P < 0.05) compared with the H. pylori-infected group. There was no significant difference in results between the H. pylori + GRA group and the H. pylori + antibiotics group. This study indicated that GRA significantly attenuated H. pylori-infected gastritis in gerbils and has the potential to be developed as a new therapeutic drug.

Epigenetic and miRNAs Dysregulation in Prostate Cancer: The role of Nutraceuticals

The control of cancer onset and progression is recognized to benefit from specific molecular targeting. MiRNAs are increasingly being implicated in prostate cancer, and the evidence suggests they are possible targets for molecular therapy and diagnosis. In cancer cells, growing attention has been dedicated to novel molecular mechanisms linking the epigenetic scenario to miRNA dysregulation. Currently, the rising evidence shows that nutritional and natural agents, the so-called nutraceuticals, could modulate miRNAs expression, and, as a consequence, might influence cellular responses in health or diseases conditions, including cancer. Among dietary components, plant-derived polyphenols are receiving wide interest, either for their anti-aging and anti-oxidant properties, or for their more general "cell-protective" effects. Above all, their role in preventing the occurrence/recurrence of cancer and, in particular, their potentiality in nutritional intervention for modulating the functions of miRNAs and the epigenetic mechanisms, is still under active debate. This review is focused on the more recent highlights of the impact of miRNAs dysregulation on the onset and progression of prostate cancer, their interplay with epigenetic control and their modulation by natural agents.

Pretreatment serum xanthophyll concentrations as predictors of head and neck cancer recurrence and survival

BACKGROUND

The purpose of this study was to examine associations of pretreatment serum carotenoids, tocopherols, and quercetin with prognosis in 154 patients newly diagnosed with head and neck cancer.

METHODS

Pretreatment blood and health surveys were collected. Serum micronutrients were measured by high performance liquid chromatography. Data on recurrence and death were collected annually. Cox proportional hazards models measured associations of serum nutrient concentrations with recurrence and overall survival.

RESULTS

During a median follow-up time of 37 months, there were 32 recurrences and 27 deaths. After controlling for covariates, subjects with high versus low serum xanthophyll and total carotenoid concentrations had significantly longer recurrence-free time (p = .002 and p = .02, respectively). Overall survival time was significantly longer in patients with high versus low serum xanthophyll concentrations (p = .02).

CONCLUSION

Future research should evaluate the possible benefits of interventions to increase intakes of rich food sources of xanthophylls in this patient population. © 2015 Wiley Periodicals, Inc. Head Neck 38: E1591-E1597, 2016.

Network pharmacology applications to map the unexplored target space and therapeutic potential of natural products

It is widely accepted that drug discovery often requires a systems-level polypharmacology approach to tackle problems such as lack of efficacy and emerging resistance of single-targeted compounds. Network pharmacology approaches are increasingly being developed and applied to find new therapeutic opportunities and to re-purpose approved drugs. However, these recent advances have been relatively slow to be translated into the field of natural products. Here, we argue that a network pharmacology approach would enable an effective mapping of the yet unexplored target space of natural products, hence providing a systematic means to extend the druggable space of proteins implicated in various complex diseases. We give an overview of the key network pharmacology concepts and recent experimental-computational approaches that have been successfully applied to natural product research, including unbiased elucidation of mechanisms of action as well as systematic prediction of effective therapeutic combinations. We focus specifically on anticancer applications that use in vivo and in vitro functional phenotypic measurements, such as genome-wide transcriptomic response profiles, which enable a global modelling of the multi-target activity at the level of the biological pathways and interaction networks. We also provide representative examples of other disease applications, databases and tools as well as existing and emerging resources, which may prove useful for future natural product research. Finally, we offer our personal view of the current limitations, prospective developments and open questions in this exciting field.

Potential of Horse Apple Isoflavones in Targeting Inflammation and Tau Protein Fibrillization

In our ongoing search for anti-inflammatory and neuroprotective agents of natural origin, the total methanolic extract (MPE) of horse apple (Maclura pomifera) and its two major prenylated isoflavones, osajin (OSA) and pomiferin (POM), were evaluated in vitro for their ability to affect four mediators of inflammation and to inhibit tau protein fibrillization. The two isoflavones were effective in enhancing the activity of NSAID activated gene (NAG-1) at 2.5 μg/mL (1.5 – 1.8 fold increase) and inhibiting iNOS and NF-κB activity with IC50 values in the range of 6 – 13 μg/mL. Pomiferin also inhibited intracellular oxidative stress with IC50 of 3.3 μg/mL, while osajin did not show any effect. The extract activated NAG-1 and inhibited iNOS and oxidative stress without affecting NF-κB. As observed by transmission electron microscopy (TEM), MPE, OSA and POM also inhibited arachidonic acid-induced tau fibrillization in a concentration-dependent manner.

NAG-1/GDF15 accumulates in the nucleus and modulates transcriptional regulation of the Smad pathway

Protein dynamics, modifications, and trafficking are all processes that can modulate protein activity. Accumulating evidence strongly suggests that many proteins play distinctive roles dependent on cellular location. Nonsteroidal anti-inflammatory drug activated gene-1 (NAG-1) is a TGF-β superfamily protein that plays a role in cancer, obesity, and inflammation. NAG-1 is synthesized and cleaved into a mature peptide, which is ultimately secreted into the extracellular matrix (ECM). In this study, we have found that full-length NAG-1 is expressed in not only the cytoplasm and ECM, but also in the nucleus. NAG-1 is dynamically moved to the nucleus, exported into cytoplasm, and further transported into the ECM. We have also found that nuclear NAG-1 contributes to inhibition of the Smad pathway by interrupting the Smad complex. Overall, our study indicates that NAG-1 is localized in the nucleus and provides new evidence that NAG-1 controls transcriptional regulation in the Smad pathway.

Macrophage inhibitory cytokine 1 biomarker serum immunoassay in combination with PSA is a more specific diagnostic tool for detection of prostate cancer

Background

Prostate cancer (PCa) is the most common malignancy among men in the United States. Though highly sensitive, the often-used prostate-specific antigen (PSA) test has low specificity which leads to overdiagnosis and overtreatment of PCa. This paper presents results of a retrospective study that indicates that testing for macrophage inhibitory cytokine 1 (MIC-1) concentration along with the PSA assay could provide much improved specificity to the assay.

Methods

The MIC-1 serum level was determined by a novel p-Chip-based immunoassay run on 70 retrospective samples. The assay was configured on p-Chips, small integrated circuits (IC) capable of storing in their electronic memories a serial number to identify the molecular probe immobilized on its surface. The distribution of MIC-1 and pre-determined PSA concentrations were displayed in a 2D plot and the predictive power of the dual MIC-1/PSA assay was analyzed.

Results

MIC-1 concentration in serum was elevated in PCa patients (1.44 ng/ml) compared to normal and biopsy-negative individuals (0.93 ng/ml and 0.88 ng/ml, respectively). In addition, the MIC-1 level was correlated with the progression of PCa. The area under the receiver operator curve (AUC-ROC) was 0.81 providing an assay sensitivity of 83.3% and specificity of 60.7% by using a cutoff of 0.494 for the logistic regression value of MIC-1 and PSA. Another approach, by defining high-frequency PCa zones in a two-dimensional plot, resulted in assay sensitivity of 78.6% and specificity of 89.3%.

Conclusions

The analysis based on correlation of MIC-1 and PSA concentrations in serum with the patient PCa status improved the specificity of PCa diagnosis without compromising the high sensitivity of the PSA test alone and has potential for PCa prognosis for patient therapy strategies.

Antioxidant, α-glucosidase inhibitory and anti-inflammatory effects of aerial parts extract from Korean crowberry (Empetrum nigrum var. japonicum)

Crowberry (Empetrum nigrum L.) is a wild berry commonly found in the northern hemisphere. Crowberry fruits have been suggested as good resources for functional applications in the cosmetic and pharmaceutical industries, but the high polyphenolic content in crowberry leaves also indicates crowberry aerial parts as potential dietary health supplements. In this study, therefore, the biological activities of the aerial parts of Korean crowberry (E. nigrum var. japonicum) were investigated. Antioxidant activity was measured by three different assays on DPPH free radical scavenging, reducing power, and total antioxidant capacities. Dose-dependent antioxidant activities were exhibited by crude methanol extract and its fractions, suggesting that the crude methanol extract and EtOAc fraction possessed strong antioxidant activities and capacities. In addition, the crude methanol extract and EtOAc strongly inhibited α-glucosidase activity and suppressed the secretion of pro-inflammatory mediator and nitrite oxide from LPS-stimulated RAW 264.7 cells. These findings provide valuable evidence for the potential of such parts as good dietary sources of natural antioxidant, α-glucosidase inhibitory, and anti-inflammatory components, suggesting that using the non-edible parts (e.g., leaves and stems) of crowberry can be a potential natural avenue for improving human health.

Hitting the Bull's-Eye in Metastatic Cancers-NSAIDs Elevate ROS in Mitochondria, Inducing Malignant Cell Death

Tumor metastases that impede the function of vital organs are a major cause of cancer related mortality. Mitochondrial oxidative stress induced by hypoxia, low nutrient levels, or other stresses, such as genotoxic events, act as key drivers of the malignant changes in primary tumors to enhance their progression to metastasis. Emerging evidence now indicates that mitochondrial modifications and mutations resulting from oxidative stress, and leading to OxPhos stimulation and/or enhanced reactive oxygen species (ROS) production, are essential for promoting and sustaining the highly metastatic phenotype. Moreover, the modified mitochondria in emerging or existing metastatic cancer cells, by their irreversible differences, provide opportunities for selectively targeting their mitochondrial functions with a one-two punch. The first blow would block their anti-oxidative defense, followed by the knockout blow—promoting production of excess ROS, capitulating the terminal stage—activation of the mitochondrial permeability transition pore (mPTP), specifically killing metastatic cancer cells or their precursors. This review links a wide area of research relevant to cellular mechanisms that affect mitochondria activity as a major source of ROS production driving the pro-oxidative state in metastatic cancer cells. Each of the important aspects affecting mitochondrial function are discussed including: hypoxia, HIFs and PGC1 induced metabolic changes, increased ROS production to induce a more pro-oxidative state with reduced antioxidant defenses. It then focuses on how the mitochondria, as a major source of ROS in metastatic cancer cells driving the pro-oxidative state of malignancy enables targeting drugs affecting many of these altered processes and why the NSAIDs are an excellent example of mitochondria-targeted agents that provide a one-two knockout activating the mPTP and their efficacy as selective anticancer metastasis drugs.

Taiwanin A targets non-steroidal anti-inflammatory drug-activated gene-1 in human lung carcinoma

Taiwanin A (α,β-bis(piperonylidene)-γ-butyrolactone) is extracted from Taiwania cryptomerioides. Taiwanin A is extracted from tree bark and exhibits antitumor activity in breast, liver, and lung cancer cell lines. The objective of this study was to demonstrate the cytotoxicity of Taiwanin A against tumor cells by increasing the expression of non-steroidal anti-inflammatory drug-activated gene-1 (NAG-1). NAG-1 has been reported to exhibit antitumor and proapoptotic activities, suggesting potential use in cancer therapy. Inhibiting NAG-1 mRNA expression in A549 reduced the cytotoxicity caused by Taiwanin A. Furthermore, the c-Jun-N-terminal kinase/Ste20-related protein proline/alanine-rich kinase (JNK/SPAK) pathway played a key role in the influence of NAG-1 on cell viability, whereas the addition of the JNK pathway inhibitor SP600125 resulted in an inhibitory effect on NAG-1 and recovery of Taiwanin-A-treated cells. A xenograft tumor model demonstrated that Taiwanin A dose-dependently significantly decreases tumor-mediated growth in nude mice by increasing the NAG-1 expression accompanying tumor apoptosis. These data supported the hypothesis that Taiwanin A inhibits lung carcinoma growth by increasing NAG-1 expression through the JNK pathway both in vivo and in vitro. This result can contribute to a compound design for increasing cytotoxicity activity in the future.