Phytoagents for cancer management: regulation of nucleic acid oxidation, ROS, and related mechanisms

Buparvaquone Induces Ultrastructural and Physiological Alterations Leading to Mitochondrial Dysfunction and Caspase-Independent Apoptotic Cell Death in Leishmania donovani

Leishmaniasis is a neglected tropical disease (endemic in 99 countries) caused by parasitic protozoa of the genus Leishmania. As treatment options are limited, there is an unmet need for new drugs. The hydroxynaphthoquinone class of compounds demonstrates broad-spectrum activity against protozoan parasites. Buparvaquone (BPQ), a member of this class, is the only drug licensed for the treatment of theileriosis. BPQ has shown promising antileishmanial activity but its mode of action is largely unknown. The aim of this study was to evaluate the ultrastructural and physiological effects of BPQ for elucidating the mechanisms underlying the in vitro antiproliferative activity in Leishmania donovani. Transmission and scanning electron microscopy analyses of BPQ-treated parasites revealed ultrastructural effects characteristic of apoptosis-like cell death, which include alterations in the nucleus, mitochondrion, kinetoplast, flagella, and the flagellar pocket. Using flow cytometry, laser scanning confocal microscopy, and fluorometry, we found that BPQ induced caspase-independent apoptosis-like cell death by losing plasma membrane phospholipid asymmetry and cell cycle arrest at sub-G0/G1 phase. Depolarization of the mitochondrial membrane leads to the generation of oxidative stress and impaired ATP synthesis followed by disruption of intracellular calcium homeostasis. Collectively, these findings provide valuable mechanistic insights and demonstrate BPQ's potential for development as an antileishmanial agent.

Unwinding Helicase MCM Functionality for Diagnosis and Therapeutics of Replication Abnormalities Associated with Cancer: A Review

The minichromosome maintenance (MCM) protein is a component of an active helicase that is essential for the initiation of DNA replication. Dysregulation of MCM functions contribute to abnormal cell proliferation and genomic instability. The interactions of MCM with cellular factors, including Cdc45 and GINS, determine the formation of active helicase and functioning of helicase. The functioning of MCM determines the fate of DNA replication and, thus, genomic integrity. This complex is upregulated in precancerous cells and can act as an important tool for diagnostic applications. The MCM protein complex can be an important broad-spectrum therapeutic target in various cancers. Investigations have supported the potential and applications of MCM in cancer diagnosis and its therapeutics. In this article, we discuss the physiological roles of MCM and its associated factors in DNA replication and cancer pathogenesis.

Caenorhabditis elegans RAC1/ced-10 mutants as a new animal model to study very early stages of Parkinson's disease

Patients with Parkinson's disease (PD) display non-motor symptoms arising prior to the appearance of motor signs and before a clear diagnosis. Motor and non-motor symptoms correlate with progressive deposition of the protein alpha-synuclein (Asyn) both within and outside of the central nervous system, and its accumulation parallels neurodegeneration. The genome of Caenorhabditis elegans does not encode a homolog of Asyn, thus rendering this nematode an invaluable system with which to investigate PD-related mechanisms in the absence of interference from endogenous Asyn aggregation. CED-10 is the nematode homolog of human RAC1, a small GTPase needed to maintain the function and survival of dopaminergic neurons against human Asyn-induced toxicity in C. elegans. Here, we introduce C. elegans RAC1/ced-10 mutants as a predictive tool to investigate early PD symptoms before neurodegeneration occurs. Deep phenotyping of these animals reveals that, early in development, they displayed altered defecation cycles, GABAergic abnormalities and an increased oxidation index. Moreover, they exhibited altered lipid metabolism evidenced by the accumulation of lipid droplets. Lipidomic fingerprinting indicates that phosphatidylcholine and sphingomyelin, but not phosphatidylethanolamine or phosphatidylserine, were elevated in RAC1/ced-10 mutant nematodes. These collective characteristics reflect the non-motor dysfunction, GABAergic neurotransmission defects, upregulation of stress response mechanisms, and metabolic changes associated with early-onset PD. Thus, we put forward an easy-to-manipulate preclinical animal model to deepen our understanding of early-stage PD and accelerate the translational path for therapeutic target discovery.

Protective effects of macromolecular polyphenols, metals (zinc, selenium, and copper) - Polyphenol complexes, and different organs with an emphasis on arsenic poisoning: A review

For the potential health benefits and nutritional value, polyphenols are one of the secondary metabolites of plants that have received extensive research. It has anti-inflammatory and cytotoxicity-reducing properties in addition to a high antioxidant content. Macromolecular polyphenols and polysaccharides are biologically active natural polymers with antioxidant and anti-inflammatory potential. Arsenic is an ecologically toxic metalloid. Arsenic in drinking water is the most common way people come into contact with this metalloid. While arsenic is known to cause cancer, it is also used to treat acute promyelocytic leukemia (APL). The treatment's effectiveness is hampered by the adverse effects it can cause on the body. Oxidative stress, inflammation, and the inability to regulate cell death cause the most adverse effects. Polyphenols and other macromolecules like polysaccharides act as neuroprotectants by mitigating free radical damage, inhibiting nitric oxide (NO) production, lowering A42 fibril formation, boosting antioxidant levels, and controlling apoptosis and inflammation. To prevent the harmful effects of toxins, polyphenols and pectin lower oxidative stress, boost antioxidant levels, improve mitochondrial function, control apoptosis, and suppress inflammation. Therefore, it prevents damage to the heart, liver, kidneys, and reproductive system. This review aims to identify the effects of the polyphenols in conjugation with polysaccharides as an ameliorative strategy for arsenic-induced toxicity in various organs.

Effects of microfiber and bead microplastic exposure in the goldfish Carassius auratus: Bioaccumulation, antioxidant responses, and cell damage

We confirmed antioxidant-related gene expression, bioaccumulation, and cell damage following exposure to various microplastics in vivo and in vitro in the goldfish Carassius auratus. Exposure of C. auratus to a 500 µm fiber-type microplastic environment (MF; 10 and 100 fibers/L) and two sizes (0.2 and 1.0 µm) of beads (MB; 10 and 100 beads/L) for 120 h increased superoxide dismutase (SOD) mRNA expression in the liver until 24 h followed by a decrease. Whereas, catalase (CAT) mRNA expression increased from 12 h to the end of the in vivo experiment. In vitro experiments were conducted with diluted microfibers (1 and 5 fibers/L) and microbeads (1 and 5 beads/L) using cultured liver cells. The results of SOD and CAT mRNA expression analysis conducted in vitro showed a tendency similar to those of experiments conducted in vivo. The H2O2 level increased in the high-concentration experimental groups compared with that in the low-concentration groups of 0.2-µm beads. In addition, the H2O2 level increased in both MF and MB groups from 12 h of exposure. Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels in plasma were used as indicators of liver damage in fish. The ALT and AST levels increased up to 120 h after exposure. Caspase-3 (casp-3) mRNA expression was higher in the MB group than in the MF group. We visually confirmed liver casp-3 mRNA signals using in situ hybridization. The degree of DNA damage in the MF and MB high-concentration groups increased with the exposure time. The tail length and percent of DNA in the tail of the MB group were significantly higher than those of the MF group, confirming that DNA damage was greater in the MB group. Both fiber- and bead-type microplastics induced oxidative stress in C. auratus, but the bead-type induced greater stress than the fiber-type.

Venlafaxine's effect on resilience to stress is associated with a shift in the balance between glucose and fatty acid utilization

Brain metabolism is a fundamental process involved in the proper development of the central nervous system and in the maintenance of the main higher functions in humans. As consequence, energy metabolism imbalance has been commonly associated to several mental disorders, including depression. Here, by employing a metabolomic approach, we aimed to establish if differences in energy metabolite concentration may underlie the vulnerability and resilience in an animal model of mood disorder named chronic mild stress (CMS) paradigm. In addition, we have investigated the possibility that modulation of metabolite concentration may represent a pharmacological target for depression by testing whether repeated treatment with the antidepressant venlafaxine may normalize the pathological phenotype by acting at metabolic level. The analyses were conducted in the ventral hippocampus (vHip) for its key role in the modulation of anhedonia, a core symptom of patients affected by depression. Interestingly, we showed that a shift from glycolysis to beta oxidation seems to be responsible for the vulnerability to chronic stress and that vHip metabolism contributes to the ability of the antidepressant venlafaxine to normalize the pathological phenotype, as shown by the reversal of the changes observed in specific metabolites. These findings may provide novel perspectives on metabolic changes that could serve as diagnostic markers and preventive strategies for the early detection and treatment of depression as well as for the identification of potential drug targets.

Heavy metal(loid) effect on multi-biomarker responses in apex predator: Novel assays in the monitoring of white stork nestlings

The goal of the present study was to investigate differences in biomarker responses related to metal(loid)s in white stork (Ciconia ciconia) nestling's blood from continental Croatia. To achieve this, a battery of biomarkers that can be affected by environmental pollutants, including metal(loid)s, was assessed (esterase activity, fluorescence-based oxidative stress biomarkers, metallothionein levels, glutathione-dependent enzyme activity). The research was conducted during the white stork breeding season in diverse areas (a landfill, industrial and agricultural sites, and an unpolluted area). White storks' nestlings near the landfill exhibited reduced carboxylesterase (CES) activity, elevated glutathione (GSH) concentration, as well as high Pb content in the blood. Increased As and Hg concentrations in blood were attributable to environmental contamination in agricultural area and an assumed unpolluted area, respectively. Furthermore, agricultural practices appeared to affect CES activity, as well as elevate Se levels. In addition to the successful implementation of biomarkers, present research showed that agricultural areas and a landfill are areas with increased metal(loid) levels possibly causing adverse effects on the white storks. This first-time heavy metal and metalloid analyses in the white stork nestlings from Croatia point to the necessary monitoring and future assessments of pollution impact to prevent irreversible adverse effects.

Rheumatoid Arthritis and Reactive Oxygen Species: A Review

Rheumatoid arthritis (RA) is a chronic, systemic inflammatory disease that causes progressive joint damage and can lead to lifelong disability. Numerous studies support the hypothesis that reactive oxygen species (ROS) are associated with RA pathogenesis. Recent advances have clarified the anti-inflammatory effect of antioxidants and their roles in RA alleviation. In addition, several important signaling pathway components, such as nuclear factor kappa B, activator-protein-1, nuclear factor (erythroid-derived 2)-like 2/kelch-like associated protein, signal transducer and activator of transcription 3, and mitogen-activated protein kinases, including c-Jun N-terminal kinase, have been identified to be associated with RA. In this paper, we outline the ROS generation process and relevant oxidative markers, thereby providing evidence of the association between oxidative stress and RA pathogenesis. Furthermore, we describe various therapeutic targets in several prominent signaling pathways for improving RA disease activity and its hyper oxidative state. Finally, we reviewed natural foods, phytochemicals, chemical compounds with antioxidant properties and the association of microbiota with RA pathogenesis.

The Double-Edged Sword of Oleuropein in Ovarian Cancer Cells: From Antioxidant Functions to Cytotoxic Effects

Oleuropein plays a key role as a pro-oxidant as well as an antioxidant in cancer. In this study, the activity of oleuropein, in an in vitro model of ovarian (OCCs) and breast cancer cells (BCCs) was investigated. Cell viability and cell death were analyzed. Oxidative stress was measured by CM-H2DCFDA flow cytometry assay. Mitochondrial dysfunction was evaluated based on mitochondrial reactive oxygen species (ROS) and GPX4 protein levels. Further, the effects on iron metabolism were analyzed by measuring the intracellular labile iron pool (LIP). We confirmed that high doses of oleuropein show anti-proliferative and pro-apoptotic activity on HEY and MCF-7 cells. Moreover, our results indicate that low doses of oleuropein impair cell viability without affecting the mortality of cells, and also decrease the LIP and ROS levels, keeping them unchanged in MCF-7 cells. For the first time, our data show that low doses of oleuropein reduce erastin-mediated cell death. Interestingly, oleuropein decreases the levels of intracellular ROS and LIP in OCCs treated with erastin. Noteworthily, we observed an increased amount of ROS scavenging enzyme GPX4 together with a consistent reduction in mitochondrial ROS, confirming a reduction in oxidative stress in this model.

Fighting Carcinogenesis with Plant Metabolites by Weakening Proliferative Signaling and Disabling Replicative Immortality Networks of Rapidly Dividing and Invading Cancerous Cells

BACKGROUND

Cancer, an uncontrolled multistage disease causing swift division of cells, is a leading disease with the highest mortality rate. Cellular heterogeneity, evading growth suppressors, resisting cell death, and replicative immortality drive the tumor progression by resisting the therapeutic action of existing anticancer drugs through a series of intrinsic and extrinsic cellular interactions. The innate cellular mechanisms also regulate the replication process as a fence against proliferative signaling, enabling replicative immortality through telomere dysfunction.

AREA COVERED

The conventional genotoxic drugs have several off-target and collateral side effects associated with them. Thus, the need for the therapies targeting cyclin-dependent kinases or P13K signaling pathway to expose cancer cells to immune destruction, deactivation of invasion and metastasis, and maintaining cellular energetics is imperative. Compounds with anticancer attributes isolated from plants and rich in alkaloids, terpenes, and polyphenols have proven to be less toxic and highly targetspecific, making them biologically significant. This has opened a gateway for the exploration of more novel plant molecules by signifying their role as anticancer agents in synergy and alone, making them more effective than the existing cytotoxic regimens.

EXPERT OPINION

In this context, the current review presented recent data on cancer cases around the globe, along with discussing the fundamentals of proliferative signaling and replicative immortality of cancer cells. Recent findings were also highlighted, including antiproliferative and antireplicative action of plant-derived compounds, besides explaining the need for improving drug delivery systems.

Fluorescent half-sandwich iridium picolinamidate complexes for in-cell visualization

In this work, we report on the development of fluorescent half-sandwich iridium complexes using a fluorophore attachment strategy. These constructs consist of pentamethylcyclopentadienyl (Cp*) iridium units ligated by picolinamidate donors conjugated to green-emitting boron-dipyrromethene (bodipy) dyes. Reaction studies in H₂O/THF mixtures showed that the fluorescent Ir complexes were active as catalysts for transfer hydrogenation, with activities similar to that of their non-fluorescent counterparts. The iridium complexes were taken up by NIH-3T3 mouse fibroblast cells, with 50% inhibition concentrations ranging from ~20-70 μM after exposure for 3 h. Visualization of the bodipy-functionalized Ir complexes in cells using fluorescence microscopy revealed that they were localized in the mitochondria and lysosome but not the nucleus. These results indicate that our fluorescent iridium complexes could be useful for future biological studies requiring intracellular catalyst tracking.

Quantitative Proteome Analysis Reveals Melissa officinalis Extract Targets Mitochondrial Respiration in Colon Cancer Cells

Melissa officinalis (MO), known as lemon balm, is a popular ingredient blended in herbal tea. In recent decades, the bioactivities of MO have been studied in sub-health and pathological status, highlighting MO possesses multiple pharmacological effects. We previously showed that hot water MO extract exhibited anticancer activity in colorectal cancer (CRC). However, the detailed mechanisms underlying MO-induced cell death remain elusive. To elucidate the anticancer regulation of MO extract in colon cancer, a data-driven analysis by proteomics approaches and bioinformatics analysis was applied. An isobaric tandem mass tags-based quantitative proteome analysis using liquid chromatography–coupled tandem mass spectrometry was performed to acquire proteome-wide expression data. The over-representation analysis and functional class scoring method were implemented to interpret the MO-induced biological regulations. In total, 3465 quantifiable proteoforms were identified from 24,348 peptides, with 67 upregulated and 54 downregulated proteins in the MO-treated group. Mechanistically, MO impeded mitochondrial respiratory electron transport by triggering a reactive oxygen species (ROS)-mediated oxidative stress response. MO hindered the mitochondrial membrane potential by reducing the protein expression in the electron transport chain, specifically the complex I and II, which could be restored by ROS scavenger. The findings comprehensively elucidate how MO hot water extract activates antitumor effects in colorectal cancer (CRC) cells.

Involvement of Phytochemical-Encapsulated Nanoparticles' Interaction with Cellular Signalling in the Amelioration of Benign and Malignant Brain Tumours

Brain tumours have unresolved challenges that include delay prognosis and lower patient survival rate. The increased understanding of the molecular pathways underlying cancer progression has aided in developing various anticancer medications. Brain cancer is the most malignant and invasive type of cancer, with several subtypes. According to the WHO, they are classified as ependymal tumours, chordomas, gangliocytomas, medulloblastomas, oligodendroglial tumours, diffuse astrocytomas, and other astrocytic tumours on the basis of their heterogeneity and molecular mechanisms. The present study is based on the most recent research trends, emphasising glioblastoma cells classified as astrocytoma. Brain cancer treatment is hindered by the failure of drugs to cross the blood–brain barrier (BBB), which is highly impregnableto foreign molecule entry. Moreover, currently available medications frequently fail to cross the BBB, whereas chemotherapy and radiotherapy are too expensive to be afforded by an average incomeperson and have many associated side effects. When compared to our current understanding of molecularly targeted chemotherapeutic agents, it appears that investigating the efficacy of specific phytochemicals in cancer treatment may be beneficial. Plants and their derivatives are game changers because they are efficacious, affordable, environmentally friendly, faster, and less toxic for the treatment of benign and malignant tumours. Over the past few years, nanotechnology has made a steady progress in diagnosing and treating cancers, particularly brain tumours. This article discusses the effects of phytochemicals encapsulated in nanoparticles on molecular targets in brain tumours, along with their limitations and potential challenges.

Blood biomarkers in white stork (Ciconia ciconia) nestlings show different responses in several areas of Croatia

White stork nestlings can provide quantitative data on the quality of the environment, as they are dependent on their parents that provide locally foraged food. Blood was sampled from the brachial vein (n = 109) and the sampling was performed in parallel with ringing during breeding season 2020 from five areas in eastern Croatia: Lonjsko polje, Jelas polje, Slavonski Brod-east, Podunavlje, and Donje Podravlje. In the present study, for the first time in Croatia, the following enzymatic biomarkers were assessed in white stork nestlings: activities of acetylcholinesterase (AChE), carboxylesterase (CES), glutathione S-transferase (GST), and glutathione reductase (GR), as well as nonenzymatic biomarkers: levels of glutathione (GSH) and reactive oxygen species (ROS). All endpoints were measured in two blood fractions: plasma and a postmitochondrial fraction (S9). Nestlings from Podunavlje and Donje Podravlje, areas known for intensive agriculture, showed lower AChE and CES activity when compared to the other investigated areas, indicating the presence of inhibitory xenobiotics. Higher oxidative stress was observed in Slavonski Brod-east, an area surrounded by metal and engineering industry, and Podunavlje compared to the other sampling areas. Hence, this study shows the impact of pollutants from the surrounding metal, petroleum, and agricultural industry might have on the biomarkers in white stork nestlings, which are often seen as early-warning signals.

Nutraceutic Potential of Bioactive Compounds of Eugenia dysenterica DC in Metabolic Alterations

The fruit and leaves of Eugenia dysenterica DC., locally known as cagaita, are rich in antioxidant glycosylated quercetin derivatives and phenolic compounds that have beneficial effects on diabetes mellitus, hypertension and general inflammation. We conducted a literature search to investigate the nutraceutical potentials of these phenolic compounds for treating obesity, diabetes mellitus and intestinal inflammatory disease. The phenolic compounds in E. dysenterica have demonstrated effects on carbohydrate metabolism, which can prevent the development of these chronic diseases and reduce LDL (low-density lipoprotein) cholesterol and hypertension. E. dysenterica also improves intestinal motility and microbiota and protects gastric mucosa, thereby preventing inflammation. However, studies are necessary to identify the mechanism by which E. dysenterica nutraceutical compounds act on such pathological processes to support future research.

Bax/Bcl-2 Cascade Is Regulated by the EGFR Pathway: Therapeutic Targeting of Non-Small Cell Lung Cancer

Non-small cell lung carcinoma (NSCLC) comprises 80%-85% of lung cancer cases. EGFR is involved in several cancer developments, including NSCLC. The EGFR pathway regulates the Bax/Bcl-2 cascade in NSCLC. Increasing understanding of the molecular mechanisms of fundamental tumor progression has guided the development of numerous antitumor drugs. The development and improvement of rationally planned inhibitors and agents targeting particular cellular and biological pathways in cancer have been signified as a most important paradigm shift in the strategy to treat and manage lung cancer. Newer approaches and novel chemotherapeutic agents are required to accompany present cancer therapies for improving efficiency. Using natural products as a drug with an effective delivery system may benefit therapeutics. Naturally originated compounds such as phytochemicals provide crucial sources for novel agents/drugs and resources for tumor therapy. Applying the small-molecule inhibitors (SMIs)/phytochemicals has led to potent preclinical discoveries in various human tumor preclinical models, including lung cancer. In this review, we summarize recent information on the molecular mechanisms of the Bax/Bcl-2 cascade and EGFR pathway in NSCLC and target them for therapeutic implications. We further described the therapeutic potential of Bax/Bcl-2/EGFR SMIs, mainly those with more potent and selectivity, including gefitinib, EGCG, ABT-737, thymoquinone, quercetin, and venetoclax. In addition, we explained the targeting EGFR pathway and ongoing in vitro and in vivo and clinical investigations in NSCLC. Exploration of such inhibitors facilitates the future treatment and management of NSCLC.

Re-establishing the comprehension of phytomedicine and nanomedicine in inflammation-mediated cancer signaling

Recent mounting evidence has revealed extensive genetic heterogeneity within tumors that drive phenotypic variation affecting key cancer pathways, making cancer treatment extremely challenging. Diverse cancer types display resistance to treatment and show patterns of relapse following therapy. Therefore, efforts are required to address tumor heterogeneity by developing a broad-spectrum therapeutic approach that combines targeted therapies. Inflammation has been progressively documented as a vital factor in tumor advancement and has consequences in epigenetic variations that support tumor instigation, encouraging all the tumorigenesis phases. Increased DNA damage, disrupted DNA repair mechanisms, cellular proliferation, apoptosis, angiogenesis, and its incursion are a few pro-cancerous outcomes of chronic inflammation. A clear understanding of the cellular and molecular signaling mechanisms of tumor-endorsing inflammation is necessary for further expansion of anti-cancer therapeutics targeting the crosstalk between tumor development and inflammatory processes. Multiple inflammatory signaling pathways, such as the NF-κB signaling pathway, JAK-STAT signaling pathway, MAPK signaling, PI3K/AKT/mTOR signaling, Wnt signaling cascade, and TGF-β/Smad signaling, have been found to regulate inflammation, which can be modulated using various factors such as small molecule inhibitors, phytochemicals, recombinant cytokines, and nanoparticles in conjugation to phytochemicals to treat cancer. Researchers have identified multiple targets to specifically alter inflammation in cancer therapy to restrict malignant progression and improve the efficacy of cancer therapy. siRNA-and shRNA-loaded nanoparticles have been observed to downregulate STAT3 signaling pathways and have been employed in studies to target tumor malignancies. This review highlights the pathways involved in the interaction between tumor advancement and inflammatory progression, along with the novel approaches of nanotechnology-based drug delivery systems currently used to target inflammatory signaling pathways to combat cancer.

Promoting a pro-oxidant state in skeletal muscle: Potential dietary, environmental, and exercise interventions for enhancing endurance-training adaptations

Accumulating evidence now shows that supplemental antioxidants including vitamin C, vitamin E and N-Acetylcysteine consumption can suppress adaptations to endurance-type exercise by attenuating reactive oxygen and nitrogen species (RONS) formation within skeletal muscle. This emerging evidence points to the importance of pro-oxidation as an important stimulus for endurance-training adaptations, including mitochondrial biogenesis, endogenous antioxidant production, insulin signalling, angiogenesis and growth factor signaling. Although sustained oxidative distress is associated with many chronic diseases, athletes have, on average, elevated levels of certain endogenous antioxidants to maintain redox homeostasis. As a result, trained athletes may have a better capacity to buffer oxidants during and after exercise, resulting in a reduced oxidative eustress stimulus for adaptations. Thus, higher levels of RONS input and exercise-induced oxidative stress may benefit athletes in the pursuit of continuous endurance training redox adaptations. This review addresses why athletes should be looking to enhance exercise-induced oxidative stress and how it can be accomplished. Methods covered include high-intensity interval training, hyperthermia and heat stress, dietary antioxidant restriction and modified antioxidant timing, dietary antioxidants and polyphenols as adjuncts to exercise, and vitamin C as a pro-oxidant.

Pomegranate Polyphenols Attenuate Inflammation and Hepatic Damage in Tumor-Bearing Mice: Crucial Role of NF-κB and the Nrf2/GSH Axis

It has been widely reported that cancer, along with its treatment regimens, cause severe toxicity in the host. A suitable agent having chemopreventive properties as well as capabilities of ameliorating tumor- and drug-induced toxicities is of imminent need. Pomegranate has been projected as an excellent anti-tumor, anti-inflammatory and anti-oxidant agent. In this study, for the first time, we delineated the exact signaling cascade by which dietary supplementation of pomegranate fruit extract (PFE) protects tumor-bearing mice from tumor-induced hepatotoxicity. Increased activities of serum Alanine transaminase, Aspartate transaminase, Lactate dehydrogenase and Alkaline phosphatase, as well as histological studies confirmed the establishment of a state of hepatic dysfunction in tumor-bearers. Further investigations revealed that increased hepatic reactive oxygen species content and glutathione depletion-initiated apoptosis in these hepatocytes as we observed an alteration in the apoptotic proteins. PFE supplementation in tumor-bearing mice, on the other hand, differentially modulated redox-sensitive transcription factors Nrf2 and NF-κB, ultimately decreasing tumor-induced hepatic oxidative damage and cell death. siRNA-mediated inhibition of Nrf2 and NF-κB completely abolished the hepato-protective activities of PFE while pre-treatment of tumor-conditioned hepatocytes with N-acetyl cysteine augmented the cyto-protective properties of PFE. The present study clearly identified Nrf2/NF-κB/glutathione axis as the key factor behind the hepatoprotective potential of PFE. These findings would add to the existing knowledge about cancer chemoprevention by dietary polyphenols and might lead to the application of pomegranate polyphenols as supplement to escalate the effectiveness of cancer therapy by protecting normal cells from cancer related toxicities.

The role of natural antioxidants in cisplatin-induced hepatotoxicity

Cisplatin is a potent platinum-based anticancer drug approved by the Food Drug Administration (FDA) in 1978. Despite its advantages against solid tumors, cisplatin confers toxicity to various tissues that limit its clinical uses. In cisplatin-induced hepatotoxicity, few mechanisms have been identified, which started as excess generation of reactive oxygen species that leads to oxidative stress, inflammation, DNA damage and apoptosis in the liver. Various natural products, plant extracts and oil rich in flavonoids, terpenoids, polyphenols, and phenolic acids were able to minimize oxidative stress by restoring the level of antioxidant enzymes and acting as an anti-inflammatory agent. Likewise, treatment with honey and royal jelly was demonstrated to decrease serum transaminases and scavenge free radicals in the liver after cisplatin administration. Medicinal properties of these natural products have a promising potential as a complementary therapy to counteract cisplatin-induced hepatotoxicity. This review concentrated on the protective role of several natural products, which has been proven in the laboratory findings to combat cisplatin-induced hepatotoxicity.

Pro-Oxidant Effect of Resveratrol on Human Breast Cancer MCF-7 Cells is Associated with CK2 Inhibition

Casein kinase 2 (CK2) plays a critical role in the proliferation and apoptosis of cancer cells. Resveratrol is a bioactive compound with anticancer and anti-inflammatory effects. This study investigated the pro-oxidant cytotoxic effects of resveratrol in association with the inhibition of CK2 activity on human breast carcinoma cells MCF-7. We showed that resveratrol and TBB, an inhibitor of CK2, decreased cell viability in a concentration dependent manner with an IC₅₀ value of 238 µM and 106 µM after 24 h, of treatment, respectively. Resveratrol and TBB decreased CK2 activity by 1.6 and 1.4-fold, respectively, and both significantly decreased mitochondrial membrane potential. However, only resveratrol increased reactive oxygen species (ROS) levels by 1.7-fold as opposed to TBB, which did not affect ROS levels. Indeed, incubating MCF-7 cells with the antioxidant polyethylene glycol-catalase (PEG-CAT) preserved cell viability from the cytotoxic effects of resveratrol, but not from TBB toxicity. This effect seemed to be related to PEG-CAT ability to prevent CK2 inhibition induced by resveratrol incubation. In conclusion, this study demonstrated that the cytotoxic effect of resveratrol on MCF-7 cells might be associated with its pro-oxidant action, which inhibited CK2 activity, affecting cell viability and mitochondrial function.

Application of Non-Destructive Methods: Biomarker Assays in Blood of White Stork (Ciconia ciconia) Nestlings

White stork (Ciconia ciconia) nestlings can provide quantitative information on the quality of the surrounding environment by indicating the presence of pollutants, as they depend on locally foraged food. This study represents the first comparison of biomarkers in two fractions of white stork nestling blood: plasma and S9 (the post-mitochondrial fraction). The aim of this study was to evaluate acetylcholinesterase (AChE), carboxylesterase (CES), glutathione S-transferase (GST), and glutathione reductase (GR), as well as to establish a novel fluorescence-based method for glutathione (GSH) and reactive oxygen species (ROS) detection in plasma and S9. Considering the enzymatic biomarkers, lower variability in plasma was detected only for AChE, as CES, GST, and GR had lower variability in S9. Enzyme activity was higher in plasma for AChE, CES, and GST, while GR had higher activity in S9. Regarding the fluorescence-based method, lower variability was detected in plasma for GSH and ROS, although higher GSH detection was reported in S9, and higher ROS was detected in plasma. The present study indicated valuable differences by successfully establishing protocols for biomarker measurement in plasma and S9 based on variability, enzyme activity, and fluorescence. For a better understanding of the environmental effects on nestlings' physiological condition, biomarkers can be measured in plasma and S9.

Assessment of Dietary Bioactive Phenolic Compounds and Agricultural Sustainability of an African Leafy Vegetable Corchorus olitorius L

Corchorus olitorius L. is an African leafy vegetable of high nutritional interest. To assess its agricultural suitability to sustainable cultivation conditions and its potential benefits for human nutrition, its phytochemical content in response to conservation agriculture practices [i.e., no-tillage (NT) and cover crop maintenance] and low water regime were evaluated and compared with response under conventional agriculture management. Hydric stress and NT did not affect the content of antioxidant metabolites, compared to conventional agricultural practices. In both conditions, leaves were found to be a great source of phenolic compounds. The effect of these phenolic fractions was assessed on two colon cell phenotypes to evaluate putative nutraceutical properties. Polyphenol-enriched extracts (PEEs) displayed selective cytotoxic activities against tumor Caco-2 cells but not on the healthy CCD841 line. PEEs were able to trigger oxidative stress and to inhibit the activity of glutathione-independent antioxidant enzymes on Caco-2 cells. C. olitorius showed to be a promising crop for improving both agricultural sustainability and health benefits due to the great amount of antioxidant compounds in leaves, whose occurrence is not altered by stressful farming conditions. Given its high adaptability, the cultivation of this crop is therefore recommendable also in the Mediterranean Basin.

Antiproliferative potential of Andean Berry (Vaccinium meridionale Swartz) juice in combination with Aspirin in human SW480 colon adenocarcinoma cells

Andean Berry (Vaccinium meridionale Sw.) is a South American fruit rich in phytochemicals with promising anti-cancer properties as co-adjuvants to nonsteroidal anti-inflammatory drugs such as Aspirin. This study aimed to evaluate the antiproliferative potential of Andean Berry Juice (ABJ) in combination with Aspirin in human SW480 colon adenocarcinoma cells. ABJ primarily contained 3,4-dihydroxybenzoic and chlorogenic acids. The combined treatment of ABJ (IC₅₀ : 30.0 ± 0.11%) and Aspirin (IC₅₀ : 20.0 ± 0.57) exhibited a higher (p < .01) antiproliferative effect than each counterpart. Moreover the same mixture displayed a lower reduced glutathione/oxidized glutathione ratio (GSH/GSSG) than the untreated cells. ABJ-Aspirin combination induced late apoptosis stage without stimulating mitochondrial depolarization and prompted phosphatidylserine relocalization. These results emphasize the antiproliferative potential of bioactive compounds from ABJ and Aspirin combinations. PRACTICAL APPLICATIONS: Natural products such as Andean Berry (V. meridionale Sw.) juice (ABJ) contains antioxidant polyphenols that could reduce the need to use non-steroidal anti-inflammatory drugs, currently employed in cancer treatment, to prevent its side effects. The high abundance of polyphenols from this underutilized berry could stimulate the standardization of its production and industrial exploitation to be transformed into suitable food products delivering natural bioactive compounds with potential anti-cancer effects in vitro.

Ligustrazine Suppresses Platelet-Derived Growth Factor-BB-Induced Pulmonary Artery Smooth Muscle Cell Proliferation and Inflammation by Regulating the PI3K/AKT Signaling Pathway

Pulmonary arterial hypertension (PAH) is a serious pulmonary vascular disease. Excessive proliferation of pulmonary artery smooth muscle cells (PASMCs) plays an important role in the course of this disease. Ligustrazine is an alkaloid monomer extracted from the rhizome of the herb Ligusticum chuanxiong. It is often used to treat cardiovascular diseases, but its effect on PAH has rarely been reported. This study aims to explore the protective effect and mechanism of ligustrazine on PAH. In the in vivo experiment, monocrotaline (MCT) was used to induce PAH in rats, and then ligustrazine (40, 80, 160 mg/kg/day) or sildenafil (25 mg/kg/day) was administered. Four weeks later, hemodynamic changes, right ventricular hypertrophy index, lung morphological characteristics, inflammatory factors, phosphoinositide 3-kinase (PI3K), and AKT expression were evaluated. In addition, primary rat PASMCs were extracted by the tissue adhesion method, a proliferation model was established with platelet-derived growth factor-BB (PDGF-BB), and the cells were treated with ligustrazine to investigate its effects on cell proliferation, inflammation, and cell cycle distribution. The results indicate that ligustrazine can markedly alleviate right ventricular systolic pressure, right ventricular hypertrophy, pulmonary vascular remodeling, and inflammation caused by MCT, and that it decreased PI3K and AKT phosphorylation expression. Moreover, ligustrazine can inhibit the proliferation and inflammation of PASMCs and arrest the progression of G0/G1 to S phase through the PI3K/AKT signaling pathway. Therefore, we conclude that ligustrazine may inhibit the proliferation and inflammation of PASMCs by regulating the activation of the PI3K/AKT signaling pathway, thereby attenuating MCT-induced PAH in rats. Collectively, these findings suggest that ligustrazine may be a promising therapeutic for PAH.

Jab1 Inhibition by Methanolic Extract of Moringa Oleifera Leaves in Cervical Cancer Cells: A Potent Targeted Therapeutic Approach

Modern research propounded that alteration in signaling pathways have shown strong connection with the progression of cervical cancer and modulation of these pathways by natural compounds could be a better treatment approach for the management of cervical cancer. Additionally, inhibitory role of methanolic extract of Moringa oleifera leaves against Jab1 has not been elucidated yet. Therefore, we have elucidated the inhibitory potential of MMLE against Jab1 in cervical cancer by analyzing several In Vitro assays. The MMLE treatment in cervical cancer cells showed decreased cell growth in a dose and time dependent manner. Furthermore, MMLE treated cervical cells have also depicted enhanced nuclear condensation (apoptotic induction potential) confirmed by Hoechst analysis. RT-PCR results clearly illustrated the inhibitory potential of MMLE against Jab1 via down regulating its expression. Conversely, a significant increase in p27 expression was also reported which could explain the cells growth arrest at G0/G1 phase. Additionally, enhanced ROS production and caspase-3 activation explains one of the possible mechanisms behind the inhibitory potential of MMLE against Jab1 in cervical cancer cells (HeLa). Thus our experimental findings may pave a potent phyto compound for targeting a crucial signalosome (Jab1) in cervical cancer.

Multidrug resistance protein 4 (MRP4/ABCC4) is overexpressed in clear cell renal cell carcinoma (ccRCC) and is essential to regulate cell proliferation

Kidney cancer accounts for 2.5% of all cancers, with an annual global incidence of almost 300,000 cases leading to 111,000 deaths. Approximately 85% of kidney tumors are renal cell carcinoma (RCC) and their major histologic subtype is clear cell renal cell carcinoma (ccRCC). Although new therapeutic treatments are being designed and applied based on the combination of tyrosine kinase inhibitors and immunotherapy, no major impact on the mortality has been reported so far. MRP4 is a pump efflux that transporters multiple endogenous and exogenous substances. Recently it has been associated with tumoral persistence and cell proliferation in several types of cancer including pancreas, lung, ovary, colon, ostesarcoma, etc. Herein, we demonstrate for the first time, that MRP4 is overexpressed in ccRCC tumors, compared to control renal tissues. In addition, using cell culture models, we observed that MRP4 pharmacological inhibition produces an imbalance in cAMP metabolism, induces cell arrest, changes in lipid composition, increase in cytoplasmic lipid droplets and finally apoptosis. These data provide solid evidence for the future evaluation of MRP4 as a possible new therapeutic target in ccRCC.

Hypolipidemic and anti-atherogenic activities of crude polysaccharides from abalone viscera

This study was performed to evaluate the hypolipidemic and anti-atherogenic activities of the crude polysaccharides extracted from abalone viscera (AVCP). The major functional groups of purified polysaccharides were analyzed by infrared spectroscopy (IR). Male Kunming mice (SPF) were divided into six groups and were treated with normal diet or high-fat diet with AVCP or Xuezhikang (hypotensive drug) for 5 weeks. Physicochemnical analysis of AVCP showed the presence of 60.4% polysaccharides, 17.9% protein, 6.0% fat and 10.9% moisture. The IR analysis of AVP showed the presence of functional groups of sugar moiety and sulfate groups. The results demonstrated that AVCP not only led to significant reduction of total cholesterol (TC), triglycerides (TG), low-density lipoprotein cholesterol (LDL-C), and increase of high-density lipoprotein cholesterol (HDL-C) in plasma, but also to significant increments of malondialdehyde (MDA) and superoxide dismutase (SOD) activities. However, AVCP played no role in mice weight. Furthermore, the results of the photomicrograph of liver tissue showed that AVCP reduced lipid droplets and prevented the disordered structure of the liver. The results suggested that AVCP exhibited significantly hypolipidemic and anti-atherogenic activities.

Dietary polyphenol impact on gut health and microbiota

Polyphenols are naturally occurring compounds in plants and they are the most abundant antioxidants in the human diet. Due to their considerable structural diversity, this largely influences their bioavailability. Since a large proportion of polyphenols remains unabsorbed along the gastrointestinal tract, they may accumulate in the large intestine, where most of them are extensively metabolized by the intestinal microbiota. The formation of bioactive polyphenol-derived metabolites may also benefit the health status of the subjects, although the mechanisms have not been delineated. This review aims to highlight the impact of polyphenols on gut health and the modes of action could be through modulation of intestinal barrier function, innate and adaptive immune response, signaling pathways, as well as the ability to modify gut microbiota composition. The review will conclude by presenting future perspective and challenges of polyphenols application in food products to be used for preventing or treating diseases.

Phytochemicals in Cancer Treatment: From Preclinical Studies to Clinical Practice

Cancer is a severe health problem that continues to be a leading cause of death worldwide. Increasing knowledge of the molecular mechanisms underlying cancer progression has led to the development of a vast number of anticancer drugs. However, the use of chemically synthesized drugs has not significantly improved the overall survival rate over the past few decades. As a result, new strategies and novel chemoprevention agents are needed to complement current cancer therapies to improve efficiency. Naturally occurring compounds from plants known as phytochemicals, serve as vital resources for novel drugs and are also sources for cancer therapy. Some typical examples include taxol analogs, vinca alkaloids such as vincristine, vinblastine, and podophyllotoxin analogs. These phytochemicals often act via regulating molecular pathways which are implicated in growth and progression of cancer. The specific mechanisms include increasing antioxidant status, carcinogen inactivation, inhibiting proliferation, induction of cell cycle arrest and apoptosis; and regulation of the immune system. The primary objective of this review is to describe what we know to date of the active compounds in the natural products, along with their pharmacologic action and molecular or specific targets. Recent trends and gaps in phytochemical based anticancer drug discovery are also explored. The authors wish to expand the phytochemical research area not only for their scientific soundness but also for their potential druggability. Hence, the emphasis is given to information about anticancer phytochemicals which are evaluated at preclinical and clinical level.

Velvet antler methanol extracts (MEs) protects against oxidative stress in Caenorhabditis elegans by SKN-1

Velvet antler is one of the most important animal medicines or functional foods widely used in East Asia for many centuries, which has several biological activities including anti-ageing and health promotion. To date, the mechanism underlying these effects of velvet antler is widely studied by its protein or polypeptide components. Few studies have been reported for the function of the other components in velvet antler. Herein, C. elegans is used as the model animal to dissect how none protein components of velvet antler affect in vivo oxidative stress. Methanol extracts (MEs) from velvet antler which has few protein components extends the maximum lifespan of C. elegans compared to the control under oxidative stress, while water extracts (WEs) which is protein-rich component has no apparent function. The activity of MEs is mediated by clk-1 signaling pathway, but not via daf-2, eat-2 or glp-1 pathway. Further investigations show MEs decrease endogenous ROS by promoting SKN-1 nuclei translocation, subsequently up-regulating the expression of its target genes gst-4, gst-7 and gst-10 in C. elegans. In all, MEs, the none protein components of velvet antler, protects against oxidative stress in C. elegans, which indicates it might be a product with potential of being a curative medicine.

Iron deficiency impairs contractility of human cardiomyocytes through decreased mitochondrial function

AIMS

Iron deficiency is common in patients with heart failure and associated with a poor cardiac function and higher mortality. How iron deficiency impairs cardiac function on a cellular level in the human setting is unknown. This study aims to determine the direct effects of iron deficiency and iron repletion on human cardiomyocytes.

METHODS AND RESULTS

Human embryonic stem cell-derived cardiomyocytes were depleted of iron by incubation with the iron chelator deferoxamine (DFO). Mitochondrial respiration was determined by Seahorse Mito Stress test, and contractility was directly quantified using video analyses according to the BASiC method. The activity of the mitochondrial respiratory chain complexes was examined using spectrophotometric enzyme assays. Four days of iron depletion resulted in an 84% decrease in ferritin (P < 0.0001) and significantly increased gene expression of transferrin receptor 1 and divalent metal transporter 1 (both P < 0.001). Mitochondrial function was reduced in iron-deficient cardiomyocytes, in particular ATP-linked respiration and respiratory reserve were impaired (both P < 0.0001). Iron depletion affected mitochondrial function through reduced activity of the iron-sulfur cluster containing complexes I, II and III, but not complexes IV and V. Iron deficiency reduced cellular ATP levels by 74% (P < 0.0001) and reduced contractile force by 43% (P < 0.05). The maximum velocities during both systole and diastole were reduced by 64% and 85%, respectively (both P < 0.001). Supplementation of transferrin-bound iron recovered functional and morphological abnormalities within 3 days.

CONCLUSION

Iron deficiency directly affects human cardiomyocyte function, impairing mitochondrial respiration, and reducing contractility and relaxation. Restoration of intracellular iron levels can reverse these effects.

Oxidative stress, consequences and ROS mediated cellular signaling in rheumatoid arthritis

There are numerous extra- and intra-cellular processes involved in the production of reactive oxygen species (ROS). Augmented ROS generation can cause the damage of biomolecules such as proteins, nucleic acid and lipids. ROS act as an intracellular signaling component and is associated with various inflammatory responses, chronic arthropathies, including rheumatoid arthritis (RA). It is well documented that ROS can activate different signaling pathways having a vital importance in the patho-physiology of RA. Hence, understanding of the molecular pathways and their interaction might be advantageous in the development of novel therapeutic approaches for RA.

Antioxidant Potential of Selected Korean Edible Plant Extracts

This study aimed to evaluate the antioxidant activity of various plant extracts. A total of 94 kinds of edible plant extracts obtained from the Korea Plant Extract Bank were screened for cytotoxicity, following which the total phenolic content of 24 shortlisted extracts was determined. Of these, extracts from three plants, namely, Castanea crenata (CC) leaf, Camellia japonica (CJ) fruit, and Viburnum dilatatum (VD) leaf, were examined for antioxidant capabilities by measuring radical scavenging activity, ferric reducing/antioxidant power, and lipid peroxidation inhibitory activity. In addition, cellular antioxidant activities of the three extracts were assessed by a cell-based dichlorofluorescein assay and antioxidant response element (ARE) reporter activity assay. The results demonstrated that all three extracts concentration-dependently scavenged free radicals, inhibited lipid peroxidation, reduced the cellular level of reactive oxygen species, and increased ARE-luciferase activity, indicating antioxidant enzyme-inducing potential. In particular, CJ extract showed significantly greater antioxidative activity and antimigratory effect in a breast cancer cell line compared to CC and VD extracts. Hence, CJ extract deserves further study for its in vivo functionality or biologically active constituents.

Oxidative stress in women with insomnia in different stages of menopause

Aim. To investigate of a lipid peroxidation (LPO) process and the antioxidant defense system (ADS) in peri- and postmenopausal women with insomnia. Subjects and methods. 47 perimenopausal women and 71 postmenopausal ones were examined. Each group was divided into 2 subgroups: 1) individuals with insomnia and 2) controls. LPO-ADS spectrophotometric studies were used in the investigation. Results. There was an increase in the serum levels of ketodienes and conjugated trienes and a decrease in those of α-tocopherol and retinol in postmenopause versus in perimenopause. In insomnia, there was a rise in the level of ketodienes and conjugated trienes in perimenopause; LPO substrates with conjugated double bonds, diene conjugates, and thiobarbituric acid-active products in postmenopause. The indicators of ADS do not differ from those in the controls. The integral indicator of oxidative stress assessment suggests that there is a LPO-ADS imbalance in the menopausal women with insomnia, which is most pronounced in postmenopause. Conclusion. The findings suggest that the patients with insomnia develop oxidative stress that is more marked in postmenopause.

The photodynamic action of pheophorbide a induces cell death through oxidative stress in Leishmania amazonensis

Leishmaniasis is a disease caused by hemoflagellate protozoa, affecting millions of people worldwide. The difficulties of treating patients with this parasitosis include the limited efficacy and many side effects of the currently available drugs. Therefore, the search for new compounds with leishmanicidal action is necessary. Photodynamic therapy has been studied in the medical field because of its selectivity, utilizing a combination of visible light, a photosensitizer compound, and singlet oxygen to reach the area of treatment. The continued search for selective alternative treatments and effective targets that impact the parasite and not the host are fundamentally important for the development of new drugs. Pheophorbide a is a photosensitizer that may be promising for the treatment of leishmaniasis. The present study evaluated the in vitro biological effects of pheophorbide a and its possible mechanisms of action in causing cell death in L. amazonensis. Pheophorbide a was active against promastigote and amastigote forms of the parasite. After treatment, we observed ultrastructural alterations in this protozoan. We also observed changes in promastigote macromolecules and organelles, such as loss of mitochondrial membrane potential [∆Ψ_m], lipid peroxidation, an increase in lipid droplets, DNA fragmentation, phosphatidylserine exposure, an increase in caspase-like activity, oxidative imbalance, and a decrease in antioxidant defense systems. These findings suggest that cell death occurred through apoptosis. The mechanism of cell death in intracellular amastigotes appeared to involve autophagy, in which we clearly observed an increase in reactive oxygen species, a compromised ∆Ψ_m, and an increase in the number of autophagic vacuoles. The present study contributes to the development of new photosensitizers against L. amazonensis. We also elucidated the mechanism of action of pheophorbide a, mainly in intracellular amastigotes, which is the most clinically relevant form of this parasite.

Dietary Phytochemicals Promote Health by Enhancing Antioxidant Defence in a Pig Model

Phytochemical-rich diets are protective against chronic diseases and mediate their protective effect by regulation of oxidative stress (OS). However, it is proposed that under some circumstances, phytochemicals can promote production of reactive oxygen species (ROS) in vitro, which might drive OS-mediated signalling. Here, we investigated the effects of administering single doses of extracts of red cabbage and grape skin to pigs. Blood samples taken at baseline and 30 min intervals for 4 hours following intake were analyzed by measures of antioxidant status in plasma, including Trolox equivalent antioxidant capacity (TEAC) and glutathione peroxidase (GPx) activity. In addition, dose-dependent production of hydrogen peroxide (H₂O₂) by the same extracts was measured in untreated commercial pig plasma in vitro. Plasma from treated pigs showed extract dose-dependent increases in non-enzymatic (plasma TEAC) and enzymatic (GPx) antioxidant capacities. Similarly, extract dose-dependent increases in H₂O₂ were observed in commercial pig plasma in vitro. The antioxidant responses to extracts by treated pigs were highly correlated with their respective yields of H₂O₂ production in vitro. These results support that dietary phytochemicals regulate OS via direct and indirect antioxidant mechanisms. The latter may be attributed to the ability to produce H₂O₂ and to thereby stimulate cellular antioxidant defence systems.

The roles of reactive oxygen species (ROS) and autophagy in the survival and death of leukemia cells

As a clonal disease of hematopoietic stem cells (HSCs), the etiology and pathogenesis of leukemia is not fully understood. Recent studies suggest that cellular homeostasis plays an essential role in maintaining the function of HSCs because dysregulation of cellular homeostasis is one of the major factors underlying the malignant transformation of HSCs. Reactive oxygen species (ROS) and autophagy, key factors regulating cellular homeostasis, are commonly observed in the human body. Autophagy can be induced by ROS through a variety of signaling pathways, and conversely inhibits ROS-induced damage to cells and tissues. ROS and autophagy coordinate to maintain cellular homeostasis. Previous studies have demonstrated that both of ROS and autophagy play important roles in the development of leukemia and are closely involved in drug resistance in leukemia. Interference with cellular homeostasis by promoting programmed leukemia cell death via ROS and autophagy has been verified to be an efficient technique in the treatment of leukemia. However, the critical roles of ROS and autophagy in the development of leukemia are largely unknown. In this review, we summarize the roles of ROS and autophagy in the pathogenesis of leukemia, which may allow the identification of novel targets and drugs for the treatment of leukemia based on the regulation of HSCs homeostasis through ROS and autophagy.

Dietary selenium protects adiponectin knockout mice against chronic inflammation induced colon cancer

Selenium (Se) is an essential dietary micronutrient that has been examined for protection against different types of cancers including colon cancer. Despite an established inverse association between Se and chronic inflammation induced colon cancer (CICC), the mechanistic understanding of Se's protective effects requires additional in-vivo studies using preclinical animal models of CICC. Adiponectin (APN) is an adipocytokine that is protective against CICC as well. However, its role in the anti-mutagenic effects of the Se-diet remains unknown. To address this knowledge gap, here we examine the ability of dietary Se in reducing CICC in APN knockout mice (KO) and its wild-type C57BL/6. CICC was induced with the colon cancer agent 1,2 dimethyl hydrazine (DMH) along with dextran sodium sulfate (DSS). Se-enhanced diet increased selenoproteins, Gpx-1 and Gpx-2, in the colon tissues, thereby reducing oxidative stress. Se-mediated reduction of CICC was evident from the histopathological studies in both mouse models. In both mice, reduction in inflammation and tumorigenesis associated well with reduced p65 phosphorylation and elevated 53 phosphorylation. Finally, we show that in both models Se-administration promotes goblet cell differentiation with a concomitant increase in the levels of associated proteins, Muc-2 and Math-1. Our findings suggest that Se's protection against CICC involves both colonic epithelial protection and anti-tumor effects that are independent of APN.

Copper supplementation amplifies the anti-tumor effect of curcumin in oral cancer cells

BACKGROUND

Oral cancer is the sixth most common cancer worldwide and 90% of oral malignancies are caused by oral squamous cell carcinoma (OSCC). Curcumin, a phytocompound derived from turmeric (Curcuma longa) was observed to have anti-cancer activity which can be developed as an alternative treatment option for OSCC. However, OSCC cells with various clinical-pathological features respond differentially to curcumin treatment.

HYPOTHESIS

Intracellular copper levels have been reported to correlate with tumor pathogenesis and affect the sensitivity of cancer cells to cytotoxic chemotherapy. We hypothesized that intracellular copper levels may affect the sensitivity of oral cancer cells to curcumin.

METHODS

We analysed the correlation between intracellular copper levels and response to curcumin treatment in a panel of OSCC cell lines derived from oral cancer patients. Exogenous copper was supplemented in curcumin insensitive cell lines to observe the effect of copper on curcumin-mediated inhibition of cell viability and migration, as well as induction of oxidative stress and apoptosis. Protein markers of cell migration and oxidative stress were also analysed using Western blotting.

RESULTS

Concentrations of curcumin which inhibited 50% OSCC cell viability (IC₅₀) was reduced up to 5 times in the presence of 250 µM copper. Increased copper level in curcumin-treated OSCC cells was accompanied by the induction of intracellular ROS and increased level of Nrf2 which regulates oxidative stress responses in cells. Supplemental copper also inhibited migration of curcumin-treated cells with enhanced level of E-cadherin and decreased vimentin, indications of suppressed epithelial-mesenchymal transition. Early apoptosis was observed in combined treatment but not in treatment with curcumin or copper alone.

CONCLUSION

Supplement of copper significantly enhanced the inhibitory effect of curcumin treatment on migration and viability of oral cancer cells. Together, these findings provide molecular insight into the role of copper in overcoming insensitivity of oral cancer cells to curcumin treatment, suggesting a new strategy for cancer therapy.

Phytomedicine-Modulating oxidative stress and the tumor microenvironment for cancer therapy

In spite of the current advances and achievements in systems biology and translational medicinal research, the current strategies for cancer therapy, such as radiotherapy, targeted therapy, immunotherapy and chemotherapy remain palliative or unsatisfactory due to tumor metastasis or recurrence after surgery/therapy, drug resistance, adverse side effects, and so on. Oxidative stress (OS) plays a critical role in chronic/acute inflammation, carcinogenesis, tumor progression, and tumor invasion/metastasis which is also attributed to the dynamic and complex properties and activities in the tumor microenvironment (TME). Re-educating or reprogramming tumor-associated stromal or immune cells in the TME provides an approach for restoring immune surveillance impaired by disease in cancer patients to increase overall survival and reduce drug resistance. Herbal medicines or plant-derived natural products have historically been a major source of anti-cancer drugs. Delving into the lore of herbal medicine may uncover new leads for anti-cancer drugs. Phytomedicines have been widely documented to directly or indirectly target multiple signaling pathways and networks in cancer cells. A combination of anti-cancer drugs and polypharmacological plant-derived extracts or compounds may offer a significant advantage in sensitizing the efficacy of monotherapy and overcoming drug-induced resistance in cancer patients. This review introduces several phytochemicals and phytoextracts derived from medicinal plants or dietary vegetables that have been studied for their efficacy in preclinical cancer models. We address the underlying modes of action of induction of OS and deregulation of TME-associated stromal cells, mediators and signaling pathways, and reference the related clinical investigations that look at the single or combination use of phytochemicals and phytoextracts to sensitize anti-cancer drug effects and/or overcome drug resistance.

Antiproliferative and apoptotic effect of Morus nigra extract on human prostate cancer cells

Background: Morus nigra L. belongs to the family Moraceae and is frequently used in traditional medicine. Numerous studies have investigated the antiproliferative effects of various extracts of different Morus species, but studies involving the in vitro cytotoxic effect of M. nigra extract are very limited. The purpose of this study was to evaluate the phenolic composition and antioxidant activity of dimethyl sulfoxide extract of M. nigra (DEM) and to investigate, for the first time, the probable cytotoxic effect in human prostate adenocarcinoma (PC-3) cells together with the mechanism involved. Methods: Total polyphenolic contents (TPC), ferric reducing antioxidant power (FRAP) and phenolic compounds of DEM were evaluated using spectrophotometric procedures and HPLC. The cytotoxic effect of DEM on PC-3 cells was revealed using the MTT assay. Mechanisms involved in the cytotoxic effect of DEM on PC-3 cells were then investigated in terms of apoptosis, mitochondrial membrane potential and cell cycle using flow cytometry, while caspase activity was investigated using luminometric analysis. Results: TPC and FRAP values were 20.7 ± 0.3 mg gallic acid equivalents and 48.8 ± 1.6 mg trolox equivalents per g sample, respectively. Ascorbic acid and chlorogenic acid were the major phenolic compounds detected at HPLC analysis. DEM arrested the cell cycle of PC-3 cells at the G₁ phase, induced apoptosis via increased caspase activity and reduced mitochondrial membrane potential. Conclusions: Our results indicate that M. nigra may be a novel candidate for the development of new natural product based therapeutic agents against prostate cancer.

Antioxidant Properties and Gastroprotective Effects of 2-(Ethylthio)Benzohydrazones on Ethanol-Induced Acute Gastric Mucosal Lesions in Rats

A series of new 2-(ethylthio)benzohydrazone derivatives (1-6) were prepared and characterised by IR, 1H NMR, and 13C NMR spectroscopy and mass spectrometry. The newly prepared compounds were screened for their in vitro antioxidant activities using free radical scavenging 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) assays. Among them, most powerful antioxidant, compound 1 has been selected in order to illustrate anti-ulcer effect on ethanol-induced gastric mucosal lesions in rats. Four groups of Sprague Dawley rats were respectively treated with 10% Tween 20 as ulcer control group, 20 mg/kg omeprazole as reference group, 50 mg/kg and 100 mg/kg compound 1 as experimental animals. Macroscopically, ulcer control group showed extensive hemorrhagic lesions of gastric mucosa compared with omeprazole or compound 1. Rats pre-treated with compound 1 showed increased in gastric pH and gastric mucus. Histologically, ulcer control group showed severe damage to gastric mucosa with edema and leucocytes infiltration of submucosal layer. In immunohistochemical analysis, rats which were pre-treated with compound 1 showed up-regulation of HSP70 and down-regulation of Bax proteins. In conclusion, the gastroprotective effect of compound 1 may be due to its antioxidant activity, and/or due to up-regulation of HSP70 and down-regulation of Bax protein in stained tissue section.