The Phytochemical Indicaxanthin Synergistically Enhances Cisplatin-Induced Apoptosis in HeLa Cells via Oxidative Stress-Dependent p53/p21waf1 Axis

Acetylated tau exacerbates apoptosis by disturbing mitochondrial dynamics in HEK293 cells

An increase in tau acetylation at K274 and K281 and abnormal mitochondrial dynamics have been observed in the brains of Alzheimer's disease (AD) patients. Here, we constructed three types of tau plasmids, TauKQ (acetylated tau mutant, by mutating its K274/K281 into glutamine to mimic disease-associated lysine acetylation), TauKR (non-acetylated tau mutant, by mutating its K274/K281 into arginine), and TauWT (wild-type human full-length tau). By transfecting these tau plasmids in HEK293 cells, we found that TauWT and TauKR induced mitochondrial fusion by increasing the level of mitochondrial fusion proteins. Conversely, TauKQ induced mitochondrial fission by reducing mitochondrial fusion proteins, exacerbating mitochondrial dysfunction and apoptosis. BGP-15 ameliorated TauKQ-induced mitochondrial dysfunction and apoptosis by improving mitochondrial dynamics. Our findings suggest that acetylation of K274/281 represents an important post-translational modification site regulating mitochondrial dynamics, and that BGP-15 holds potential as a therapeutic agent for mitochondria-associated diseases such as AD.

Seseli tortuosum L. subsp. tortuosum Essential Oils and Their Principal Constituents as Anticancer Agents

Seseli tortuosum L. subsp. tortuosum, belonging to the Apiaceae family, is a species that grows in Europe, mainly in the Mediterranean regions. The history of its application in traditional medicine highlights its various biological properties. Trying to explore the phytochemistry and pharmacological aspects of this species, the essential oils (EOs) extracted from flowers, stems, and roots of a locally wild accession, never previously investigated, growing in Sicily, Italy, were investigated. The chemical composition of all EOs, obtained by the hydrodistillation method, was evaluated by GC-MS. The most abundant class of all investigated samples was that of monoterpene hydrocarbons (79.98-91.21%) with p-cymene, α-pinene, β-pinene, and β-ocimene as major compounds. These EOs, and their main components, were tested for their possible anticancer activity. Obtained data provided evidence that among the different EOs tested, at the dose of 100 μg/mL, those extracted from stems and roots were particularly effective, already at 24 h of treatment, in reducing the cell viability of 42% and 95%, respectively, in HCT116 colon cancer cell line. These EOs also exerted a remarkable cytotoxic effect that was accompanied by morphological changes represented by cell shrinkage as well as a reduction in residual cell population. Differently, modest effects were found when EOs extracted from flowers were tested in the same experimental conditions. The evaluation of the phytocompounds mainly represented in the EOs extracted from different parts of the plant and tested in a range of concentrations between 20 and 200 μg/mL, revealed that α-pinene, β-pinene, and p-cymene exerted only modest effects on cell viability. Differently, a remarkable effect was found when β-ocimene, the most abundant phytocomponent in EOs from roots, was tested on colon cancer cells. This phytocompound, among those identified in EOs from Seseli tortuosum L. subsp. tortuosum, was found to be the most effective in reducing colon cancer cell viability with IC50 = 64.52 μg/mL at 24 h of treatment. All together, these data suggest that β-ocimene could be responsible for the effects observed in colon cancer cells.

Nrf2 signaling pathway: current status and potential therapeutic targetable role in human cancers

Cancer is a borderless global health challenge that continues to threaten human health. Studies have found that oxidative stress (OS) is often associated with the etiology of many diseases, especially the aging process and cancer. Involved in the OS reaction as a key transcription factor, Nrf2 is a pivotal regulator of cellular redox state and detoxification. Nrf2 can prevent oxidative damage by regulating gene expression with antioxidant response elements (ARE) to promote the antioxidant response process. OS is generated with an imbalance in the redox state and promotes the accumulation of mutations and genome instability, thus associated with the establishment and development of different cancers. Nrf2 activation regulates a plethora of processes inducing cellular proliferation, differentiation and death, and is strongly associated with OS-mediated cancer. What's more, Nrf2 activation is also involved in anti-inflammatory effects and metabolic disorders, neurodegenerative diseases, and multidrug resistance. Nrf2 is highly expressed in multiple human body parts of digestive system, respiratory system, reproductive system and nervous system. In oncology research, Nrf2 has emerged as a promising therapeutic target. Therefore, certain natural compounds and drugs can exert anti-cancer effects through the Nrf2 signaling pathway, and blocking the Nrf2 signaling pathway can reduce some types of tumor recurrence rates and increase sensitivity to chemotherapy. However, Nrf2's dual role and controversial impact in cancer are inevitable consideration factors when treating Nrf2 as a therapeutic target. In this review, we summarized the current state of biological characteristics of Nrf2 and its dual role and development mechanism in different tumor cells, discussed Keap1/Nrf2/ARE signaling pathway and its downstream genes, elaborated the expression of related signaling pathways such as AMPK/mTOR and NF-κB. Besides, the main mechanism of Nrf2 as a cancer therapeutic target and the therapeutic strategies using Nrf2 inhibitors or activators, as well as the possible positive and negative effects of Nrf2 activation were also reviewed. It can be concluded that Nrf2 is related to OS and serves as an important factor in cancer formation and development, thus provides a basis for targeted therapy in human cancers.

Prickly pear fruits from Opuntia ficus-indica varieties as a source of potential bioactive compounds in the Mediterranean diet

Cactus has been used in traditional folk medicine because of its role in treating a number of diseases and conditions. Prickly pear fruit is an excellent source of secondary metabolites (i.e., betalains, flavonoids, and ascorbic acid) with health-promoting properties against many common human diseases, including diabetes, hypertension, hypercholesterolemia, rheumatic pain, gastric mucosa diseases and asthma. In addition, prickly pears are potential candidates for the development of low-cost functional foods because they grow with low water requirements in arid regions of the world. This review describes the main bioactive compounds found in this fruit and shows the in vitro and some clinical studies about the fruit of most important cactus (Opuntia ficus-indica) and its relationship with some chronic diseases. Even though a lot of effort have been done to study the relationship between this fruit and the human health, more studies on Opuntia ficus-indica could help better understand its pharmacological mechanism of action to provide clear scientific evidence to explain its traditional uses, and to identify its therapeutic potential in other diseases.

Redox Properties, Bioactivity and Health Effects of Indicaxanthin, a Bioavailable Phytochemical from Opuntia ficus indica, L.: A Critical Review of Accumulated Evidence and Perspectives

Phytochemicals from plant foods are considered essential to human health. Known for their role in the adaptation of plants to their environment, these compounds can induce adaptive responses in cells, many of which are directed at maintaining the redox tone. Indicaxanthin is a long-known betalain pigment found in the genus Opuntia of cactus pear and highly concentrated in the edible fruits of O. ficus indica, L. whose bioactivity has been overlooked until recently. This review summarizes studies conducted so far in vitro and in vivo, most of which have been performed in our laboratory. The chemical and physicochemical characteristics of Indicaxanthin are reflected in the molecule's reducing properties and antioxidant effects and help explain its ability to interact with membranes, modulate redox-regulated cellular pathways, and possibly bind to protein molecules. Measurement of bioavailability in volunteers has been key to exploring its bioactivity; amounts consistent with dietary intake, or plasma concentration after dietary consumption of cactus pear fruit, have been used in experimental setups mimicking physiological or pathophysiological conditions, in cells and in animals, finally suggesting pharmacological potential and relevance of Indicaxanthin as a nutraceutical. In reporting experimental results, this review also aimed to raise questions and seek insights for further basic research and health promotion applications.

Structural Effects on the Antioxidant Properties of Amino Acid Betaxanthins

Betaxanthins are natural products with high antioxidant and anti-inflammatory properties. Here, we describe the semisynthesis of twenty-one betaxanthins derived from proteinogenic amino acids, including the elusive betaxanthin of l-cysteine and two betaxanthins derived from l-lysine, and rationalize their antioxidant properties in mechanistic terms. The antioxidant capacity and redox potential of these betaxanthins were compared to those of model betaxanthins derived from dopamine, l-DOPA (L-3,4-dihydroxyphenylalanine), and pyrrolidine and structure-property relationships were established by using matched molecular pair analysis and a model developed using a genetic algorithm. Either a phenol or indole moiety enhance the antioxidant capacity of betaxanthins, which is overall much higher than that of their amino acid precursors and standard antioxidants, except for the cysteine-betaxanthin. The one-electron oxidation of amino acid betaxanthins produces radicals stabilized in multiple centers, as demonstrated by quantum chemical calculations.

An overview and update on the chemical composition and potential health benefits of Opuntia ficus-indica (L.) Miller

Opuntia ficus-indica (OFI), widely recognized as prickly pear, is native to Mexico and it is distributed in many areas of the world because of its socioeconomic, agronomic, and ecological benefits, besides its large amounts of functional, nutraceutical, and biological activities. Various parts of this plant including the fruit pulp and peel, cladode, and seeds are scientifically proven to have therapeutic potentials and are safe for human use. The contents of phytochemical compounds in each part of the OFI are different. Each pharmacological activity depends on the phytochemical compounds, the components used, and the extraction type. In this review, we summarize the active constituents from different parts of OFI and their pharmacological effects including the antioxidant, wound healing, skin protective, hepatoprotective, anticancer, antidiabetic, antihypercholesterolemic, and anti-obesity activities. Besides its effects on the bone health, cardiovascular system, kidneys, and gastrointestinal tract, its gastroprotective, anti-ulcer, anti-inflammatory, antiviral, neuroprotective, sedative, analgesic, anxiolytic and antimicrobial effects and effects on cognitive and memory function are also mentioned. PRACTICAL APPLICATIONS: Over the past few decades, the health benefits of Opuntia ficus-indica (OFI) have received much attention. All parts of the plant, including the fruit pulp and peel, cladode, and seeds have found use in the treatment of many diseases. The chemical composition of OFI provides both a high nutritional value and various health benefits. Therefore, the aim of this review is to present the up-to-date research carried out on OFI phytochemicals, showing the most important biological activities reported.

Essential oil of Foeniculum vulgare subsp. piperitum fruits exerts an anti‑tumor effect in triple‑negative breast cancer cells

At present, the growing spread of tumor cases worldwide renders the research of new promising and selective anticancer drugs urgent. The biological action of extracts of medicinal plants or their essential oils (EOs) is an emerging field of interest, since they could comprise a rich source of phytochemicals that can prove promising. In the present study, the biological activity and mechanism of action of the EO of Foeniculum vulgare subsp. piperitum fruits (FVPEO) were investigated using MTT assays, morphological analyses and western blotting in MDA‑MB231 cells, a triple‑negative breast cancer cell line. The findings revealed that FVPEO could exert strong anticancer effects, causing a dose‑dependent inhibition of breast cancer MDA‑MB231 cell growth, accompanied with DNA condensation and fragmentation. The cytotoxic effect of FVPEO was counteracted by the addition of the antioxidant N‑acetylcysteine and was associated with a marked increase in reactive oxygen species and stress‑related proteins; such as manganese superoxide dismutase, c‑Jun, phospho‑c‑Jun N‑terminal kinase and nuclear factor E2‑related factor 2, and the latter's transcriptional targets, Heme oxygenase‑1 and NAD(P)H quinone oxidoreductase 1 (NQO1). As evidenced by the activation of caspase‑3 and fragmentation of poly(ADP‑ribose) polymerase‑1, which are typical apoptosis markers, FVPEO promoted apoptotic cell death accompanied with an increase in phosphorylated H2A histone family member X and the activation of the NQO1/p53 axis. In combination, the present experiments provided evidence that FVPEO could represent a reservoir of biologically active compounds suitable for both cancer prevention and treatment.

Cholesterol-Lowering Phytochemicals: Targeting the Mevalonate Pathway for Anticancer Interventions

There are a plethora of cancer causes and the road to fully understanding the carcinogenesis process remains a dream that keeps changing. However, a list of role players that are implicated in the carcinogens process is getting lengthier. Cholesterol is known as bad sterol that is heavily linked with cardiovascular diseases; however, it is also comprehensively associated with carcinogenesis. There is an extensive list of strategies that have been used to lower cholesterol; nevertheless, the need to find better and effective strategies remains vastly important. The role played by cholesterol in the induction of the carcinogenesis process has attracted huge interest in recent years. Phytochemicals can be dubbed as magic tramp cards that humans could exploit for lowering cancer-causing cholesterol. Additionally, the mechanisms that are regulated by phytochemicals can be targeted for anticancer drug development. One of the key role players in cancer development and suppression, Tumour Protein 53 (TP53), is crucial in regulating the biogenesis of cholesterol and is targeted by several phytochemicals. This minireview covers the role of p53 in the mevalonate pathway and how bioactive phytochemicals target the mevalonate pathway and promote p53-dependent anticancer activities.

Phytocompounds from the medicinal and dietary plants: Multi-target agents for cancer prevention and therapy

Cervical cancer is the fourth leading cause of cancer death among women worldwide. Due to cervical cancer's high incidence and mortality, there is an unmet demand for effective diagnostic, therapeutic, and preventive agents. At present, the preferred treatment strategies for advanced metastatic cervical cancer include surgery, radiotherapy, and chemotherapy. However, cervical cancer is gradually developing resistance to chemotherapy, thereby reducing its efficacy. Over the last several decades, phytochemicals, a general term for compounds produced from plants, have gained attention for their role in preventing cervical cancer. This role in cervical cancer prevention has garnered attention on the medicinal properties of fruits and vegetables. Phytochemicals are currently being evaluated for their ability to block proteins involved in carcinogenesis and chemoresistance against cervical cancer. Chemoresistance to cancer drugs like cisplatin, doxorubicin, and 5-fluorouracil has become a significant limitation of drug-based chemotherapy. However, the combination of cisplatin with other phytochemicals has been identified as a promising alternative to subjugate cisplatin resistance. Phytochemicals are promising chemo-preventive and chemotherapeutic agents as they possess antioxidant, anti-inflammatory, and anti-proliferative potential against many cancers, including cervical cancer. Furthermore, the ability of the phytochemicals to modulate cellular signaling pathways through up and down regulation of various proteins has been claimed for their therapeutic potential. Phytochemicals also display a wide range of biological functions, including cell cycle arrest, apoptosis induction, inhibition of invasion, and migration in cervical cancer cells. Numerous studies have revealed the critical role of different signaling proteins and their signaling pathways in the pathogenesis of cervical cancer. Here, we review the ability of several dietary phytochemicals to alter carcinogenesis by modulating various molecular targets.

Synergistic anti-cancer action of salicylic acid and cisplatin on HeLa cells elucidated by network pharmacology and in vitro analysis

AIM

To investigate the anti-cancer potential of salicylic acid and cisplatin combination in HeLa cells and the underlying mechanism.

MAIN METHODS

Drugs and disease targets were extracted from DrugBank, BATMAN-TCM, STITCH, PharmMapper and Comparative Toxigenomics Database. Cytoscape 3.8.2 was used to merge the protein-protein interaction networks and select core targets. GO and KEGG analysis was done using Metascape and WebGestalt. Effect of salicylic acid and cisplatin alone and in combination on cells viability was studied by MTT assay. The type of interaction between salicylic acid and cisplatin was determined by CompuSyn. Apoptosis was evaluated by molecular docking, Rhodamine-123, DAPI, AO/EtBr staining, flow cytometry, qRT-PCR and western blotting. Metastasis was studied using scratch assay and western blotting. UHRF1 transient silencing was performed by siRNA.

KEY FINDINGS

Out of 420, 1863 and 1362 respective targets of salicylic acid, cisplatin and cervical cancer, 18 core proteins were enriched in apoptosis and cell migration related pathways. IC50 value of cisplatin was reduced by 14 fold in combination with salicylic acid at IC20 (4 μM). There was loss of mitochondrial membrane potential and downregulation of UHRF1, pAkt, full length PARP and pro-caspase 3 expression. Transient silencing of UHRF1 also induced mitochondrial depolarization and apoptosis. The combination also exhibited anti-metastasis effect as it suppressed migration, upregulated PAX1 and downregulated MMP-2.

SIGNIFICANCE

Reduction in cisplatin concentration, enhanced anti-cancer effects and UHRF1 downregulation due to synergistic interaction between salicylic acid and cisplatin underscores the therapeutic importance of the combination to overcome chemo-resistance and side effects of cisplatin.

Elucidating Role of Reactive Oxygen Species (ROS) in Cisplatin Chemotherapy: A Focus on Molecular Pathways and Possible Therapeutic Strategies

The failure of chemotherapy is a major challenge nowadays, and in order to ensure effective treatment of cancer patients, it is of great importance to reveal the molecular pathways and mechanisms involved in chemoresistance. Cisplatin (CP) is a platinum-containing drug with anti-tumor activity against different cancers in both pre-clinical and clinical studies. However, drug resistance has restricted its potential in the treatment of cancer patients. CP can promote levels of free radicals, particularly reactive oxygen species (ROS) to induce cell death. Due to the double-edged sword role of ROS in cancer as a pro-survival or pro-death mechanism, ROS can result in CP resistance. In the present review, association of ROS with CP sensitivity/resistance is discussed, and in particular, how molecular pathways, both upstream and downstream targets, can affect the response of cancer cells to CP chemotherapy. Furthermore, anti-tumor compounds, such as curcumin, emodin, chloroquine that regulate ROS and related molecular pathways in increasing CP sensitivity are described. Nanoparticles can provide co-delivery of CP with anti-tumor agents and by mediating photodynamic therapy, and induce ROS overgeneration to trigger CP sensitivity. Genetic tools, such as small interfering RNA (siRNA) can down-regulate molecular pathways such as HIF-1α and Nrf2 to promote ROS levels, leading to CP sensitivity. Considering the relationship between ROS and CP chemotherapy, and translating these findings to clinic can pave the way for effective treatment of cancer patients.

Underutilized Mexican Plants: Screening of Antioxidant and Antiproliferative Properties of Mexican Cactus Fruit Juices

Cacti fruits are known to possess antioxidant and antiproliferative activities among other health benefits. The following paper evaluated the antioxidant capacity and bioactivity of five clarified juices from different cacti fruits (Stenocereus spp., Opuntia spp. and M. geomettizans) on four cancer cell lines as well as one normal cell line. Their antioxidant compositions were measured by three different protocols. Their phenolic compositions were quantified through high performance liquid chromatography and the percentages of cell proliferation of fibroblasts as well as breast, prostate, colorectal, and liver cancer cell lines were evaluated though in vitro assays. The results were further processed by principal component analysis. The clarified juice from M. geomettizans fruit showed the highest concentration of total phenolic compounds and induced cell death in liver and colorectal cancer cells lines as well as fibroblasts. The clarified juice extracted from yellow Opuntia ficus-indica fruit displayed antioxidant activity as well as a selective cytotoxic effect on a liver cancer cell line with no toxic effect on fibroblasts. In conclusion, the work supplies evidence on the antioxidant and antiproliferative activities that cacti juices possess, presenting potential as cancer cell proliferation preventing agents.