Curcumin induces crosstalk between autophagy and apoptosis mediated by calcium release from the endoplasmic reticulum, lysosomal destabilization and mitochondrial events

Evaluation of hydrogel loading with curcumin and silver nanoparticles: biocompatibilities and anti-biofilm activities

Chronic wound healing is associated with prolonged elevated inflammation and high levels of oxidative stress leading to cell death. The majority of wounds are colonized with antibiotic-resistant bacterial biofilms such as Pseudomonas aeruginosa and Staphylococcus aureus. An ideal wound treatment should include agents with antioxidant, anti-inflammatory, and antibiofilm behavior. Therefore, in this study, a combination of curcumin nanoparticle (Cur-NP) and silver nanoparticle (AgNP) (Cur-NP/AgNP) loaded PVA hydrogel was used to inhibit the bacterial attachment and subsequent biofilm formation of P. aeruginosa and S. aureus. Cur was known for its antioxidant and anti-inflammatory effect while being non-toxic to cells. Meanwhile, AgNP demonstrated superior anti-bacterial and antibiofilm activities against both P. aeruginosa and S. aureus. Cur-NP/AgNP loaded PVA hydrogels completely inhibited the bacterial attachment and biofilm formation, possibly due to synergistic effect of Cur-NPs and AgNPs in killing the bacterial cells. It should be highlighted that no surviving bacterial cells were noted for Cur-NP/AgNP loaded hydrogels. On the other hand, AgNPs or Cur-NPs alone loaded hydrogels were unable to achieve complete inhibition of biofilm formation, even though significant reduction in the biofilm mass was noted compared with control samples. Cur-NP and AgNP exerted oxidative-stress induced cell death in HaCaT cells via mitochondrial dysfunction, mitochondrial membrane potential (MMP) reduction, adenosine triphosphate inhibition, and increased cytochrome C release. The toxicity of formulation followed the decreasing trend: Cur-NP/AgNP < AgNPs alone < Cur-NPs alone. Taken together, the combination of Cur-NP/AgNP completely inhibited bacterial biofilm formation through bactericidal effect on the planktonic cells while exerted the least toxic effects towards skin cells.

Curcumin-Loaded Maltodextrin-Based Proniosomes Potentially Effective against Gemcitabine-Resistant Cholangiocarcinoma

Cholangiocarcinoma (CCA) or bile-duct cancer is most prevalent in Southeast Asian counties including Thailand. Patients present at an advanced stage when the cancer is often drug resistant, leading to chemotherapy failure. Curcumin has therapeutic potential with various anticancer properties. However, its effectiveness is limited by its low bioavailability, poor solubility, and instability. This study aimed to synthesize, characterize and evaluate the efficacy of curcumin-loaded maltodextrin-based proniosomes (CMPNs) to overcome the limitations of curcumin for treating gemcitabine-resistant CCA cells (KKU-213BGemR) in vitro and in vivo. Various proniosome formulations were developed and tested for their efficacy against KKU-213BGemR cells using cytotoxicity, clonogenic, migration, and invasion assays. The potential mechanism involving in cell cycle arrest, apoptosis, expression of C/EBP homologous protein (CHOP), a pro-apoptotic transcription factor, and other apoptotic markers were investigated. The results showed that nanoscale CMPNs exhibited a good curcumin loading capacity and an entrapment efficiency of over 97%, as well as good stability and permeability through porcine esophageal mucosa. CMPNs inhibited proliferation, colony formation, migration/invasion and induced apoptosis in KKU-213BGemR cells. Western blot analysis revealed CMPNs significantly increased CHOP, the cleavage products of poly(ADP-ribose) polymerase-1 (PARP-1), apoptosis-inducing factor, and caspase-3 expression in KKU-213BGemR cells. A xenograft model revealed that 62.5 mg/kg BW CMPNs significantly suppressed proliferating cell nuclear antigen and increased CHOP-mediated apoptosis, leading to significantly reduced tumor volume. In conclusion, CMPNs effectively overcome limitations of curcumin and offer an effective strategy against gemcitabine-resistant CCA via CHOP-mediated pathways. These proniosomes are promising as an alternative treatment approach for CCA.

Nanocurcumin in myocardial infarction therapy: emerging trends and future directions

Myocardial infarction (MI) is the leading cause of morbidity and mortality worldwide. Curcumin has been observed to significantly reduce pathological processes associated with MI. Its clinical application is limited due to its low bioavailability, rapid degradation, and poor solubility. Advancements in nanotechnology can be used to enhance its therapeutic potentials in MI. Curcumin nano-formulation enhances its solubility, stability, and bioavailability, allowing more precise delivery to ischemic cardiac tissue. Curcumin nanoparticles have been observed to successfully reduce infarct size, maintain heart function by modulating essential molecular pathways in MI. Its liposomal formulations provide sustained release and higher tissue penetration with improved pharmacokinetics and enhanced therapeutic efficacy. Preclinical studies revealed that nanocurcumin drastically lower oxidative stress indicators, inflammatory cytokines, and cardiac damage. Micelles composed of polymers have demonstrated high biocompatibility and targeting capabilities with increased cardio-protective effects. Research and clinical trials are essential for comprehensive analysis and efficacy of curcumin-based nano-therapeutics in cardiovascular condition and lowering risk of MI.

Evaluation of curcumin nanoparticles of various sizes for targeting multidrug-resistant lung cancer cells via inhalation

INTRODUCTION

Inhalation drug delivery can deliver high doses of chemotherapeutic drugs to the lung tumor. This study evaluates the efficacy and the mechanistic pathways of nebulized Cur NPs at various sizes to treat multidrug resistant lung cancer.

METHODS AND RESULTS

Cur-NPs (30 nm and 200 nm) were nebulized separately onto the multidrug-resistant lung cancer cells (H69AR). Smaller NPs induced significantly higher cell death owing to a higher rate of particle internalization via dynamin-dependent clathrin-mediated endocytosis. Owing to the higher lysosome trafficking of Cur-NP30 nm compared to Cur-NP200 nm, oxidation of lysosome was higher (0.47 ± 0.08 vs 0.38 ± 0.08), contributing to significantly higher mitochondrial membrane potential loss (1.57 ± 0.17 vs 1.30 ± 0.11). MRP1 level in H69AR cells was reduced from 352 ± 12.3 ng/µg of protein (untreated cells) to 287 ± 12 ng/µg of protein (Cur-NP30 nm) and 303 ± 13.4 ng/µg of protein (Cur-NP200 nm). NF-κB, and various cytokine expressions were reduced after treatment with nebulized Cur-NPs.

CONCLUSIONS

Nebulized Cur-NPs formulations could be internalized into the H69AR cells. The Cur-NPs toxicity toward the H69AR was size and time-dependent. Cur-NP30 nm was more effective than Cur-NP200 nm to retain within the cells to exert higher oxidative stresss-induced cell death.

A Review on Current Aspects of Curcumin-Based Effects in Relation to Neurodegenerative, Neuroinflammatory and Cerebrovascular Diseases

Curcumin is among the most well-studied natural substances, known for its biological actions within the central nervous system, its antioxidant and anti-inflammatory properties, and human health benefits. However, challenges persist in effectively utilising curcumin, addressing its metabolism and passage through the blood-brain barrier (BBB) in therapies targeting cerebrovascular diseases. Current challenges in curcumin's applications revolve around its effects within neoplastic tissues alongside the development of intelligent formulations to enhance its bioavailability. Formulations have been discovered including curcumin's complexes with brain-derived phospholipids and proteins, or its liposomal encapsulation. These novel strategies aim to improve curcumin's bioavailability and stability, and its capability to cross the BBB, thereby potentially enhancing its efficacy in treating cerebrovascular diseases. In summary, this review provides a comprehensive overview of molecular pathways involved in interactions of curcumin and its metabolites, and brain vascular homeostasis. This review explores cellular and molecular current aspects, of curcumin-based effects with an emphasis on curcumin's metabolism and its impact on pathological conditions, such as neurodegenerative diseases, schizophrenia, and cerebral angiopathy. It also highlights the limitations posed by curcumin's poor bioavailability and discusses ongoing efforts to surpass these impediments to harness the full therapeutic potential of curcumin in neurological disorders.

The Novel Elemene Derivative, OMe-Ph-Elemene, Attenuates Oxidative Phosphorylation and Facilitates Apoptosis by Inducing Intracellular Reactive Oxygen Species

The incidence and mortality rates of colorectal cancer have been steadily increasing, making it one of the most prevalent cancers globally. Although current chemotherapy drugs have shown some efficacy in treating this disease, their associated side effects necessitate the development of more effective treatments and medications. The clinical application of elemene is widely utilized in tumor treatment; however, its efficacy is hindered by the requirement for high dosage and suboptimal anticancer effects. Thus, we have made modifications and enhancements to elemene, resulting in the development of a novel compound named (E)-8-(3,4,5-OMe-Ph)-β-Elemene (abbreviated as OMe-Ph-Elemene) that demonstrates significantly enhanced efficacy in suppressing colorectal cancer. We conducted an in vivo study and demonstrated the potential of OMe-Ph-Elemene in suppressing the growth of colorectal cancer xenograft tumors in zebrafish. The in vitro experiments revealed that OMe-Ph-Elemene effectively inhibited the proliferation and migration of colorectal cancer SW480 and HT-29 cells by inducing reactive oxygen species (ROS)-caused apoptosis and inhibiting mitochondrial oxidative phosphorylation. The mechanism was elucidated through high-throughput proteomic analysis and molecular biological analysis, revealing that OMe-Ph-Elemene induced cellular oxidative stress by downregulating CISD3 and promoted cell apoptosis by downregulating TRIAP1 and upregulating HMOX1. Furthermore, OMe-Ph-Elemene suppressed colorectal cancer cells' mitochondrial oxidative phosphorylation by downregulating NDUFA7. In summary, the utilization of the elemene parent nucleus structure has led to the derivation of a novel tumor suppressor compound characterized by high efficacy and low toxicity, thereby providing a significant reference for the development of innovative drugs for colorectal cancer treatment.

MnSOD Mimetics in Therapy: Exploring Their Role in Combating Oxidative Stress-Related Diseases

Reactive oxygen species (ROS) are double-edged swords in biological systems-they are essential for normal cellular functions but can cause damage when accumulated due to oxidative stress. Manganese superoxide dismutase (MnSOD), located in the mitochondrial matrix, is a key enzyme that neutralizes superoxide radicals (O2•-), maintaining cellular redox balance and integrity. This review examines the development and therapeutic potential of MnSOD mimetics-synthetic compounds designed to replicate MnSOD's antioxidant activity. We focus on five main types: Mn porphyrins, Mn salens, MitoQ10, nitroxides, and mangafodipir. These mimetics have shown promise in treating a range of oxidative stress-related conditions, including cardiovascular diseases, neurodegenerative disorders, cancer, and metabolic syndromes. By emulating natural antioxidant defenses, MnSOD mimetics offer innovative strategies to combat diseases linked to mitochondrial dysfunction and ROS accumulation. Future research should aim to optimize these compounds for better stability, bioavailability, and safety, paving the way for their translation into effective clinical therapies.

Promising and challenging phytochemicals targeting LC3 mediated autophagy signaling in cancer therapy

BACKGROUND

Phytochemicals possess a wide range of anti-tumor properties, including the modulation of autophagy and regulation of programmed cell death. Autophagy is a critical process in cellular homeostasis and its dysregulation is associated with several pathological conditions, such as cancer, neurodegenerative diseases, and diabetes. In cancer, autophagy plays a dual role by either promoting tumor growth or suppressing it, depending on the cellular context. During autophagy, autophagosomes engulf cytoplasmic components such as proteins and organelles. LC3-II (microtubule-associated protein 1 light chain 3-II) is an established marker of autophagosome formation, making it central to autophagy monitoring in mammals.

OBJECTIVE

To explore the regulatory role of phytochemicals in LC3-mediated autophagy and their potential therapeutic impact on cancer. The review emphasizes the involvement of autophagy in tumor promotion and suppression, particularly focusing on autophagy-related signaling pathways like oxidative stress through the NRF2 pathway, and its implications for genomic stability in cancer development.

METHODS

The review focuses on a comprehensive analysis of bioactive compounds including Curcumin, Celastrol, Resveratrol, Kaempferol, Naringenin, Carvacrol, Farnesol, and Piperine. Literature on these compounds was examined to assess their influence on autophagy, LC3 expression, and tumor-related signaling pathways. A systematic literature search was conducted across databases including PubMed, Scopus, and Web of Science from inception to 2023. Studies were selected from prominent databases, focusing on their roles in cancer diagnosis and therapeutic interventions, particularly in relation to LC3-mediated mechanisms.

RESULTS

Phytochemicals have been shown to modulate autophagy through the regulation of LC3-II levels and autophagic flux in cancer cells. The interaction between autophagy and other cellular pathways such as oxidative stress, inflammation, and epigenetic modulation highlights the complex role of autophagy in tumor biology. For instance, Curcumin and Resveratrol have been reported to either induce or inhibit autophagy depending on cancer type, influencing tumor progression and therapeutic responses.

CONCLUSION

Targeting autophagy through LC3 modulation presents a promising strategy for cancer therapy. The dual role of autophagy in tumor suppression and promotion, however, necessitates careful consideration of the context in which autophagy is induced or inhibited. Future research should aim to delineate these context-specific roles and explore how phytochemicals can be optimized for therapeutic efficacy. Novel therapeutic strategies should focus on the use of bioactive compounds to fine-tune autophagy, thereby maximizing tumor suppression and inducing programmed cell death in cancer cells.

Natural Autophagy Activators to Fight Age-Related Diseases

The constant increase in the elderly population presents significant challenges in addressing new social, economic, and health problems concerning this population. With respect to health, aging is a primary risk factor for age-related diseases, which are driven by interconnected molecular hallmarks that influence the development of these diseases. One of the main mechanisms that has attracted more attention to aging is autophagy, a catabolic process that removes and recycles damaged or dysfunctional cell components to preserve cell viability. The autophagy process can be induced or deregulated in response to a wide range of internal or external stimuli, such as starvation, oxidative stress, hypoxia, damaged organelles, infectious pathogens, and aging. Natural compounds that promote the stimulation of autophagy regulatory pathways, such as mTOR, FoxO1/3, AMPK, and Sirt1, lead to increased levels of essential proteins such as Beclin-1 and LC3, as well as a decrease in p62. These changes indicate the activation of autophagic flux, which is known to be decreased in cardiovascular diseases, neurodegeneration, and cataracts. The regulated administration of natural compounds offers an adjuvant therapeutic alternative in age-related diseases; however, more experimental evidence is needed to support and confirm these health benefits. Hence, this review aims to highlight the potential benefits of natural compounds in regulating autophagy pathways as an alternative approach to combating age-related diseases.

4-Methylthiazole triggers apoptosis and mitochondrial disruption in HL-60 cells

BACKGROUND

Thiazole derivatives are gaining prominence in cancer research due to their potent anti-cancer effects and multifaceted biological activities. In leukemia research, these compounds are particularly studied for their ability to induce apoptosis, disrupt mitochondrial membrane potential (MMP), and modulate cell signaling pathways.

METHODS AND RESULTS

This study investigates the efficacy of 4-Methylthiazole in inducing apoptosis in HL-60 leukemia cells. Apoptosis was quantified via flow cytometry using FITC Annexin V and propidium iodide staining. Mitochondrial disruption was evaluated through alterations in mitochondrial membrane potential (MMP) as measured by the JC-1 assay. The compound significantly disrupted MMP, activated Caspase-3, and induced the release of Cytochrome C, all of which are critical markers of apoptosis (****p < 0.0001, ***p < 0.001, **p < 0.01, *p < 0.05). Additionally, treatment with 4-Methylthiazole markedly reduced CD45 and CD123 surface markers, indicating significant phenotypic alterations in leukemia cells (****p < 0.0001). High-dose treatment with 4-Methylthiazole significantly increased ROS levels, suggesting elevated oxidative stress and the presence of intracellular free radicals, contributing to its cytotoxic effects (*p < 0.05). A significant rise in TNF-α levels was observed post-treatment, indicating a pro-inflammatory response that may further inhibit leukemia cell viability. While IL-6 levels remained unchanged, a dose-dependent decrease in IL-10 levels was noted, suggesting a reduction in immunosuppressive conditions within the tumor microenvironment (*p < 0.05).

CONCLUSIONS

Overall, 4-Methylthiazole targets leukemia cells through multiple apoptotic mechanisms and modifies the immune landscape of the tumor microenvironment, enhancing its therapeutic potential. This study highlights the need for further clinical investigation to fully exploit the potential of thiazole derivatives in leukemia treatment.

Potential Roles and Mechanisms of Curcumin and its Derivatives in the Regulation of Ferroptosis

Ferroptosis is a recently discovered iron-dependent mode of oxidatively regulated cell death. It is not only associated with a wide range of diseases, but it is also a key component of many signaling pathways. In general, ferroptosis is a double-edged sword. On one hand, it induces nonapoptotic destruction of cancer cells, but on the other, it may lead to organ damage. Therefore, ferroptosis can be drug-targeted as a novel means of therapy. The properties of curcumin have been known for many years. It has a positive impact on the treatment of diseases such as cancer and inflammation. In this review, we focus on the regulation of ferroptosis by curcumin and its derivatives and review the main mechanisms by which curcumin affects ferroptosis. In conclusion, curcumin is a ferroptosis inducer with excellent anticancer efficacy, although it also exhibits organ protective and reparative effects by acting as a ferroptosis inhibitor. The differential regulation of ferroptosis by curcumin may be related to dose and cell type.

Autophagy in Its (Proper) Context: Molecular Basis, Biological Relevance, Pharmacological Modulation, and Lifestyle Medicine

Autophagy plays a critical role in maintaining cellular homeostasis and responding to various stress conditions by the degradation of intracellular components. In this narrative review, we provide a comprehensive overview of autophagy's cellular and molecular basis, biological significance, pharmacological modulation, and its relevance in lifestyle medicine. We delve into the intricate molecular mechanisms that govern autophagy, including macroautophagy, microautophagy and chaperone-mediated autophagy. Moreover, we highlight the biological significance of autophagy in aging, immunity, metabolism, apoptosis, tissue differentiation and systemic diseases, such as neurodegenerative or cardiovascular diseases and cancer. We also discuss the latest advancements in pharmacological modulation of autophagy and their potential implications in clinical settings. Finally, we explore the intimate connection between lifestyle factors and autophagy, emphasizing how nutrition, exercise, sleep patterns and environmental factors can significantly impact the autophagic process. The integration of lifestyle medicine into autophagy research opens new avenues for promoting health and longevity through personalized interventions.

Self-assembled nanodrug delivery systems for anti-cancer drugs from traditional Chinese medicine

Traditional Chinese medicine (TCM) is a combination of raw herbs and herbal extracts with a plethora of documented beneficial bioactivities, which has unique advantages in anti-tumor therapy, and many of its major bioactive molecules have been identified in recent years due to advances in chemical separation and structural analysis. However, the major chemical classes of plant-derived bioactive compounds frequently possess chemical properties, including poor water solubility, stability, and bioavailability, that limit their therapeutic application. Alternatively, natural small molecules (NSMs) containing these components possess modifiable groups, multiple action sites, hydrophobic side chains, and a rigid skeleton with self-assembly properties that can be exploited to construct self-assembled nanoparticles with therapeutic effects superior to their individual constituents. For instance, the construction of a self-assembled nanodrug delivery system can effectively overcome the strong hydrophobicity and poor in vivo stability of NSMs, thereby greatly improving their bioavailability and enhancing their anti-tumor efficacy. This review summarizes the self-assembly methods, mechanisms, and applications of a variety of NSMs, including terpenoids, flavonoids, alkaloids, polyphenols, and saponins, providing a theoretical basis for the subsequent research on NSMs and the development of SANDDS.

CP41, a novel curcumin analogue, induces apoptosis in endometrial cancer cells by activating the H3F3A/ proteasome-MAPK signaling pathway and enhancing oxidative stress

AIMS

Curcumin is a natural compound and has good antitumor properties, but its clinical use is limited by its low bioavailability. We constructed the derivative CP41 (3,5-bis(2-chlorobenzylidene)-1-piperidin-4-one) by enhancing the bioavailability of curcumin while retaining its antitumor properties.

MAIN METHODS

CCK-8 (Cell Counting Kit-8) was used to detect the effect of CP41 on cell proliferation; Western blotting, immunofluorescence, immunoprecipitation, quantitative PCR and enzyme-linked immunosorbent assay were used to evaluate the expression of subcutaneous tumor-related molecules in cells and mice.

KEY FINDINGS

Our results showed that CP41 inhibited the proliferation of endometrial cancer cells by suppressing the proliferation of AN3CA and HEC-1-B cells. We found that CP41 significantly increased H3F3A and inhibited proteasome activity, which activated MAPK signaling and led to apoptosis. Further experiments showed that H3F3A is a potential target of CP41. Correlation analysis showed that H3F3A was positively correlated with the sensitivity to chemotherapeutic agents in endometrial cancer. CP41 significantly induced reactive oxygen species (ROS) levels and activated endoplasmic reticulum stress, which led to apoptosis. The safety profile of CP41 was also evaluated, and CP41 did not cause significant drug toxicity in mice.

SIGNIFICANCE

CP41 showed stronger antitumor potency than curcumin, and its antitumor activity may be achieved by inducing ROS and activating H3F3A-mediated apoptosis.

Biophysical study of DC electric field induced stable formation of albumin-gold nanoparticles corona and curcumin binding

Targeted drug delivery (TDD) is a method of delivering optimum concentrations of pharmaceutical substances in the tissue to achieve the desired therapeutic effect. Hence, TDD systems are considered as an emerging strategy to deliver the drug at the specific site of the tissues/cells. The nanoparticle-protein corona as a drug delivery vehicle has demonstrated immense benefits including potential theragnostic, improved pharmacodynamics and targeted drug delivery. In the present investigation, efforts have been to establish stable and functionalized Bovine serum albumin-gold nanoparticle (BSA-GNP) corona (conjugates) using a Direct Current (DC) electric field. With the application of DC electric field (DEF) across the BSA-GNP solution, the formation of BSA-GNP corona/conjugate takes place which was characterized using various biophysical techniques such a Dynamic Light Scattering (DLS), UV Visible spectroscopy, Fluorescence spectroscopy, electrophoresis, etc. Furthermore, the DEF engineered BSA-GNP corona was loaded/interacted with curcumin (CUR). The size of the BSA-GNP corona was increased with increasing DC voltage (5-30 V) at constant concentration of BSA. The strong and stable binding of curcumin with BSA-GNP corona was revealed by the techniques used in the investigation; however, binding affinity of CUR was decreased for 30 V DEF exposed BSA-GNP conjugate. The biocompatible experimental data confirms the nontoxic nature of BSA-GNP corona. This investigation adds a new and novel physical method for the preparation of protein-nanoparticle corona for various applications including drug delivery.

[Regulation of mitophagy and mitochondrial biogenesis by monocarbonyl analogues of curcumin in the cerebral cortex of rats in experimental Alzheimer's disease]

OBJECTIVE

To evaluate the effect of monocarbonyl analogues of curcumin on changes in the processes of mitophagy and mitochondrial biogenesis in the cerebral cortex of rats with experimental Alzheimer's disease.

MATERIAL AND METHODS

Alzheimer's disease was modeled in Wistar rats of both sexes by injection of β-amyloid fragments into the hippocampus of the animal. Compounds (1E, 4E)-1.5-bis (3.4.5-trimethoxyphenyl) penta-1.4-diene-3-one (AZBAX4 code) and (1E, 4E)-1.5-bis (2.4.6-trimethoxyphenyl) penta-1.4-diene-3-one (AZBAX6 code) at a dose of 20 mg/ kg (orally) and the reference drug donepezil at a dose of 50 mg/kg (orally) were administered for 30 days, after which changes in the activity of succinate dehydrogenase, cytochrome-c oxidase and citrate synthase as enzymatic biomarkers of mitochondrial biogenesis and mitophagy, respectively, were evaluated in the mitochondrial fraction of the cerebral cortex.

RESULTS

The administration of AZBAX4 and AZBAX6 compounds led to an increase in the activity of succinate dehydrogenase; cytochrome-c oxidase, as well as citrate synthase in relation to the same indicators of the group of untreated animals. The use of the analyzed compounds was equally effective in both female and male rats. At the same time, it should be noted that the analyzed compounds significantly exceeded the activity level of the reference donepezil.

CONCLUSION

AZBAX4 and AZBAX6 contribute to an increase in the intensity of mitochondrial biogenesis and mitophagy reactions in the cerebral cortex of rats with Alzheimer's disease, which makes them potentially effective neuroprotective compounds.

An Update on Potential Molecular Biomarkers of Dietary Phytochemicals Targeting Lung Cancer Interception and Prevention

Since ancient times, dietary phytochemicals are known for their medicinal properties. They are broadly classified into polyphenols, terpenoids, alkaloids, phytosterols, and organosulfur compounds. Currently, there is considerable interest in their potential health effects against various diseases, including lung cancer. Lung cancer is the leading cause of cancer deaths with an average of five-year survival rate of lung cancer patients limited to just 14%. Identifying potential early molecular biomarkers of pre-malignant lung cancer cells may provide a strong basis to develop early cancer detection and interception methods. In this review, we will discuss molecular changes, including genetic alterations, inflammation, signal transduction pathways, redox imbalance, epigenetic and proteomic signatures associated with initiation and progression of lung carcinoma. We will also highlight molecular targets of phytochemicals during lung cancer development. These targets mainly consist of cellular signaling pathways, epigenetic regulators and metabolic reprogramming. With growing interest in natural products research, translation of these compounds into new cancer prevention approaches to medical care will be urgently needed. In this context, we will also discuss the overall pharmacokinetic challenges of phytochemicals in translating to humans. Lastly, we will discuss clinical trials of phytochemicals in lung cancer patients.

Endoplasmic Reticulum-Targeted Aggregation-Induced Emission Luminogen for Synergetic Tumor Ablation with Glibenclamide

Photodynamic therapy based on fluorescence illumination of subcellular organelles and in situ bursts of reactive oxygen species (ROS) has been recognized as a promising strategy for cancer theranostics. However, the short life of ROS and unclarified anticancer mechanism seriously restrict the application. Herein, we rationally designed and facilely synthesized a 2,6-dimethylpyridine-based triphenylamine (TPA) derivative TPA-DMPy with aggregation-induced emission (AIE) features and production of type-I ROS. Except for its selective binding to the endoplasmic reticulum (ER), TPA-DMPy, in synergy with glibenclamide, a medicinal agent used against diabetes, induced significant apoptosis of cancer cells in vitro and in vivo. Additionally, TPA-DMPy greatly incited the release of calcium from ER upon light irradiation to further aggravate the depolarization of ER membrane potential caused by glibenclamide, thus inducing fatal ER stress and crosstalk between ER and mitochondria. Our study extends the biological design and application of AIE luminogens and provides new insights into discovering novel anticancer targets and agents.

GingerenoneA overcomes dexamethasone resistance by activating apoptosis and inhibiting cell proliferation in pediatric T-ALL cells

Plant-based combination strategies have been widely considered in cancer therapy to attenuate chemotherapeutics side effects. The anti-leukemic effect of the whole ginger extract was previously portrayed by our team, and the current study is centered around the cytotoxicity and mechanism of action of a phenolic subsidiary of ginger, GingerenoneA, on pediatric acute lymphoblastic leukemia. GingernoneA imposed, dose-dependently, inhibitory effects on the viability of T and B leukemia cell lines confirmed by MTT assays. Resistance to Dexamethasone, a mostly used chemotherapeutic in acute lymphoblastic leukemia treatments, was overcome by GingernoneA. A synergistic effect of Dexamethasone and GingrenoneA on T leukemia cell lines and patient primary cells was confirmed. Annexin-V/PI and acridine orange/ethidium bromide staining illustrated dose-dependent apoptosis in CCRF-CEM cells developed by GingerenoneA. The intrinsic and extrinsic apoptosis induction and antiproliferative attribution of GingerenoneA were validated by western blot and qPCR. Despite the supposed loss of function in CCRF-CEM cells, TP53 showed increased expression levels and functional activity upon treatment with GingernoneA. Bioinformatic studies revealed the conceivable impact of GingerenoneA on the reactivity of mutant P53 through its binding to Cys124. Our findings may provide novel strategies for therapeutic intervention to ameliorate pALL outcomes.

NOTCH1-mutated chronic lymphocytic leukemia displays high endoplasmic reticulum stress response with druggable potential

Introduction

Constitutive activation of NOTCH1-wild-type (NT1-WT) signaling is associated with poor outcomes in chronic lymphocytic leukemia (CLL), and NOTCH1 mutation (c.7541_7542delCT), which potentiates NOTCH1 signaling, worsens the prognosis. However, the specific mechanisms of NOTCH1 deregulation are still poorly understood. Accumulative evidence mentioned endoplasmic reticulum (ER) stress/unfolded protein response (UPR) as a key targetable pathway in CLL. In this study, we investigated the impact of NOTCH1 deregulation on CLL cell response to ER stress induction, with the aim of identifying new therapeutic opportunities for CLL.

Methods

We performed a bioinformatics analysis of NOTCH1-mutated (NT1-M) and NT1-WT CLL to identify differentially expressed genes (DEGs) using the rank product test. Quantitative real-time polymerase chain reaction (qPCR), Western blotting, cytosolic Ca2+, and annexin V/propidium iodide (PI) assay were used to detect curcumin ER stress induction effects. A median-effect equation was used for drug combination tests. The experimental mouse model Eμ-TCL1 was used to evaluate the impact of ER stress exacerbation by curcumin treatment on the progression of leukemic cells and NOTCH1 signaling.

Results and discussion

Bioinformatics analysis revealed gene enrichment of the components of the ER stress/UPR pathway in NT1-M compared to those in NT1-WT CLL. Ectopic expression of NOTCH1 mutation upregulated the levels of ER stress response markers in the PGA1 CLL cell line. Primary NT1-M CLL was more sensitive to curcumin as documented by a significant perturbation in Ca2+ homeostasis and higher expression of ER stress/UPR markers compared to NT1-WT cells. It was also accompanied by a significantly higher apoptotic response mediated by C/EBP homologous protein (CHOP) expression, caspase 4 cleavage, and downregulation of NOTCH1 signaling in NT1-M CLL cells. Curcumin potentiated the apoptotic effect of venetoclax in NT1-M CLL cells. In Eμ-TCL1 leukemic mice, the administration of curcumin activated ER stress in splenic B cells ex vivo and significantly reduced the percentage of CD19+/CD5+ cells infiltrating the spleen, liver, and bone marrow (BM). These cellular effects were associated with reduced NOTCH1 activity in leukemic cells and resulted in prolonged survival of curcumin-treated mice. Overall, our results indicate that ER stress induction in NT1-M CLL might represent a new therapeutic opportunity for these high-risk CLL patients and improve the therapeutic effect of drugs currently used in CLL.

Review on Additives in Hydrogels for 3D Bioprinting of Regenerative Medicine: From Mechanism to Methodology

The regeneration of biological tissues in medicine is challenging, and 3D bioprinting offers an innovative way to create functional multicellular tissues. One common way in bioprinting is bioink, which is one type of the cell-loaded hydrogel. For clinical application, however, the bioprinting still suffers from satisfactory performance, e.g., in vascularization, effective antibacterial, immunomodulation, and regulation of collagen deposition. Many studies incorporated different bioactive materials into the 3D-printed scaffolds to optimize the bioprinting. Here, we reviewed a variety of additives added to the 3D bioprinting hydrogel. The underlying mechanisms and methodology for biological regeneration are important and will provide a useful basis for future research.

Curcumin supplementation increases longevity and antioxidant capacity in Caenorhabditis elegans

Curcumin is well known as a potent antioxidant and free radical scavenger and has great potential for anti-aging applications. In this study, we investigate the molecular mechanism of curcumin in prolonging the lifespan of C. elegans. Four concentrations of curcumin (10, 25, 50, and 100 µM) were administered, and the optimal treatment concentration was determined by analyzing the nematode lifespan, physiology, and biochemistry. Additionally, RNA-seq and qRT-PCR were performed to explore the antioxidant effect of curcumin and its underlying mechanism. Results revealed that curcumin could significantly improve the survival capacity of C. elegans without influencing its growth. Curcumin was observed to significantly decrease the levels of reactive oxygen species (ROS) under extreme conditions such as heat stress and paraquat stress. In addition, curcumin increased the amount of nematode mitochondrial DNA (mtDNA) replication. RNA-seq results revealed that the underlying mechanism of curcumin in C. elegans is related to the mitogen-activated protein kinase (MAPK) pathway. qRT-PCR results confirmed that the expression of oxidative stress-related genes (sod-1, sod-2, sod-3, gst-4) was increased, and the expression of MAPK signaling pathway-related genes (sek-1, pmk-1, nsy-1) was significantly downregulated. Furthermore, the administration of curcumin extended the lifespan of nematodes, potentially through the enhancement of oxidative stress resistance and the downregulation of the MAPK signaling pathway. These findings improve our understanding of both lifespan extension and the potential mechanism of curcumin in C. elegans.

PEG 400:Trehalose Coating Enhances Curcumin-Loaded PLGA Nanoparticle Internalization in Neuronal Cells

This work proposes a combination of polyethylene glycol 400 (PEG) and trehalose as a surface modification approach to enhance PLGA-based nanoparticles as a drug carrier for neurons. PEG improves nanoparticles' hydrophilicity, and trehalose enhances the nanoparticle's cellular internalization by inducing a more auspicious microenvironment based on inhibiting cell surface receptor denaturation. To optimize the nanoprecipitation process, a central composite design was performed; nanoparticles were adsorbed with PEG and trehalose. PLGA nanoparticles with diameters smaller than 200 nm were produced, and the coating process did not considerably increase their size. Nanoparticles entrapped curcumin, and their release profile was determined. The nanoparticles presented a curcumin entrapment efficiency of over 40%, and coated nanoparticles reached 60% of curcumin release in two weeks. MTT tests and curcumin fluorescence, with confocal imaging, were used to assess nanoparticle cytotoxicity and cell internalization in SH-SY5Y cells. Free curcumin 80 µM depleted the cell survival to 13% at 72 h. Contrariwise, PEG:Trehalose-coated curcumin-loaded and non-loaded nanoparticles preserved cell survival at 76% and 79% under the same conditions, respectively. Cells incubated with 100 µM curcumin or curcumin nanoparticles for 1 h exhibited 13.4% and 14.84% of curcumin's fluorescence, respectively. Moreover, cells exposed to 100 µM curcumin in PEG:Trehalose-coated nanoparticles for 1 h presented 28% fluorescence. In conclusion, PEG:Trehalose-adsorbed nanoparticles smaller than 200 nm exhibited suitable neural cytotoxicity and increased cell internalization proficiency.

Calcium signaling in lysosome-dependent cell death

Calcium is a crucial messenger of intracellular and extracellular signals, regulating a great variety of cellular processes such as cell death, proliferation, and metabolism. Inside the cell, calcium signaling is one of the main interorganelle communication mediators, with central functional roles at the endoplasmic reticulum (ER), mitochondria, Golgi complex, and lysosomes. Lysosomal function is highly dependent on lumenal calcium and most of the lysosomal membrane-localised ion channels regulate several lysosomal functions and properties such as lumenal pH. One of these functions configures a specific type of cell death involving lysosomes, named lysosome-dependent cell death (LDCD), which contributes to maintenance of tissue homeostasis, development and pathology when deregulated. Here, we cover the fundamental aspects of LDCD with a special focus on recent advances in calcium signaling in LDCD.

The dual role of heme oxygenase in regulating apoptosis in the nervous system of Drosophila melanogaster

Accumulating evidence from mammalian studies suggests the dual-faced character of heme oxygenase (HO) in oxidative stress-dependent neurodegeneration. The present study aimed to investigate both neuroprotective and neurotoxic effects of heme oxygenase after the ho gene chronic overexpression or silencing in neurons of Drosophila melanogaster. Our results showed early deaths and behavioral defects after pan-neuronal ho overexpression, while survival and climbing in a strain with pan-neuronal ho silencing were similar over time with its parental controls. We also found that HO can be pro-apoptotic or anti-apoptotic under different conditions. In young (7-day-old) flies, both the cell death activator gene (hid) expression and the initiator caspase Dronc activity increased in heads of flies when ho expression was changed. In addition, various expression levels of ho produced cell-specific degeneration. Dopaminergic (DA) neurons and retina photoreceptors are particularly vulnerable to changes in ho expression. In older (30-day-old) flies, we did not detect any further increase in hid expression or enhanced degeneration, however, we still observed high activity of the initiator caspase. In addition, we used curcumin to further show the involvement of neuronal HO in the regulation of apoptosis. Under normal conditions, curcumin induced both the expression of ho and hid, which was reversed after exposure to high-temperature stress and when supplemented in flies with ho silencing. These results indicate that neuronal HO regulates apoptosis and this process depends on ho expression level, age of flies, and cell type.

Equine Muscle Derived Mesenchymal Stem Cells Loaded with Water-Soluble Curcumin: Modulation of Neutrophil Activation and Enhanced Protection against Intracellular Oxidative Attack

We investigated the antioxidant potential of equine mesenchymal stem cells derived from muscle microbiopsies (mdMSCs), loaded by a water-soluble curcumin lysinate incorporated into hydroxypropyl-β-cyclodextrin (NDS27). The cell loading was rapid and dependent on NDS27 dosage (14, 7, 3.5 and 1 µM). The immunomodulatory capacity of loaded mdMSCs was evaluated by ROS production, on active and total myeloperoxidase (MPO) degranulation and neutrophil extracellular trap (NET) formation after neutrophil stimulation. The intracellular protection of loaded cells was tested by an oxidative stress induced by cumene hydroperoxide. Results showed that 10 min of mdMSC loading with NDS27 did not affect their viability while reducing their metabolism. NDS27 loaded cells in presence of 14, 7 µM NDS27 inhibited more intensively the ROS production, the activity of the MPO released and bound to the NET after neutrophil stimulation. Furthermore, loaded cells powerfully inhibited intracellular ROS production induced by cumene as compared to control cells or cyclodextrin-loaded cells. Our results showed that the loading of mdMSCs with NDS27 significantly improved their antioxidant potential against the oxidative burst of neutrophil and protected them against intracellular ROS production. The improved antioxidant protective capacity of loaded mdMSCs could be applied to target inflammatory foci involving neutrophils.

The Role of Singlet Oxygen in Photoreactivity and Phototoxicity of Curcumin

Curcumin is a plant-derived yellow-orange compound widely used as a spice, dye and food additive. It is also believed to have therapeutic effects against different disorders. On the other hand, there are data showing its phototoxicity against bacteria, fungi and various mammalian cells. Since the mechanism of its phototoxic action is not fully understood, we investigated here the phototoxic potential of curcumin in liposomal model membranes and in HaCaT cells. First, detection of singlet oxygen (¹ O₂ ) luminescence proved that curcumin generates ¹ O₂ upon blue light irradiation in organic solvent and in liposomes. Then, HPLC-EC(Hg) measurements revealed that liposomal and cellular cholesterol is oxidized by ¹ O₂ photogenerated by curcumin. Enrichment of liposome membranes with curcumin significantly increased the oxygen photo-consumption rate compared to the control liposomes as determined by EPR oximetry. Cytotoxicity measurements, mitochondrial membrane potential analyses and protein hydroperoxides detection confirmed strong phototoxic effects of curcumin in irradiated HaCaT cells. These data show that since curcumin is advertised as a valuable dietary supplement, or a component of cosmetics for topical use, caution should be recommended especially when skin is exposed to light.

Cellular mitophagy: Mechanism, roles in diseases and small molecule pharmacological regulation

Cellular mitophagy means that cells selectively wrap and degrade damaged mitochondria through an autophagy mechanism, thus maintaining mitochondria and intracellular homeostasis. In recent years, mitophagy has received increasing attention as a research hotspot related to the pathogenesis of clinical diseases, such as neurodegenerative diseases, cardiovascular diseases, cancer, metabolic diseases, and so on. It has been found that the regulation of mitophagy may become a new direction for the treatment of some diseases. In addition, numerous small molecule modulators of mitophagy have also been reported, which provides new opportunities to comprehend the procedure and potential of therapeutic development. Taken together, in this review, we summarize current understanding of the mechanism of mitophagy, discuss the roles of mitophagy and its relationship with diseases, introduce the existing small-molecule pharmacological modulators of mitophagy and further highlight the significance of their development.

Phytochemical Targeting of Mitochondria for Breast Cancer Chemoprevention, Therapy, and Sensitization

Breast cancer is a common and deadly disease that causes tremendous physical, emotional, and financial burden on patients and society. Early-stage breast cancer and less aggressive subtypes have promising prognosis for patients, but in aggressive subtypes, and as cancers progress, treatment options and responses diminish, dramatically decreasing survival. Plants are nutritionally rich and biologically diverse organisms containing thousands of metabolites, some of which have chemopreventive, therapeutic, and sensitizing properties, providing a rich source for drug discovery. In this study we review the current landscape of breast cancer with a central focus on the potential role of phytochemicals for treatment, management, and disease prevention. We discuss the relevance of phytochemical targeting of mitochondria for improved anti-breast cancer efficacy. We highlight current applications of phytochemicals and derivative structures that display anti-cancer properties and modulate cancer mitochondria, while describing future applicability and identifying areas of promise.

Pegylated Curcumin Derivative: Water-Soluble Conjugates with Antitumor and Antibacterial Activity

During the past years, the synthesis of polymer prodrug structures, based on natural phytochemical compounds with a great range of valuable biological properties, has become a promising solution in cancer prevention, imaging, and detection. Curcumin (Curc) remains one of the most studied natural products, due to the impressive palette of biological properties and the possibility to be easily loaded in various micro- and nanostructures and chemically modified. In this study, pegylated curcumin derivatives were prepared by a direct esterification reaction between poly(ethylene glycol)diacid (PEG of 600 g/mol molar mass, PEG₆₀₀) and Curc in the presence of N,N'-dicyclohexylcarbodiimide (PEG₆₀₀-Curc). The successful reaction resulted in a water-soluble stable product that was characterized by infrared spectroscopy (Fourier transform infrared (FT-IR)) and proton (¹H) and carbon (¹³C) NMR. The effect of the pH values of buffer solutions on PEG₆₀₀-Curc spectral properties (absorption and photoluminescence) was investigated by UV-vis and fluorescence spectrophotometry. Based on the biological tests, it was confirmed that PEG₆₀₀-Curc exhibits cytotoxic activity against Graffi cell lines, as a function of the Curc concentration in the conjugate and the incubation time. PEG₆₀₀-Curc antibacterial activity was validated in microbiological tests against pathogenic microorganisms such as Staphylococcus aureus. Most importantly, despite the covalent attachment of Curc to PEG and the slight reduction in the therapeutic index of the conjugate, both the anticancer and antimicrobial activities remain the highest reported, thus opening the gate for further, more clinically oriented studies.

Optimization of Anti-SARS-CoV-2 Treatments Based on Curcumin, Used Alone or Employed as a Photosensitizer

Curcumin, the bioactive compound of the spice Curcuma longa, has already been reported as a potential COVID-19 adjuvant treatment due to its immunomodulatory and anti-inflammatory properties. In this study, SARS-CoV-2 was challenged with curcumin; moreover, curcumin was also coupled with laser light at 445 nm in a photodynamic therapy approach. Curcumin at a concentration of 10 μM, delivered to the virus prior to inoculation on cell culture, inhibited SARS-CoV-2 replication (reduction >99%) in Vero E6 cells, possibly due to disruption of the virion structure, as observed using the RNase protection assay. However, curcumin was not effective as a prophylactic treatment on already-infected Vero E6 cells. Notably, when curcumin was employed as a photosensitizer and blue laser light at 445 nm was delivered to a mix of curcumin/virus prior to the inoculation on the cells, virus inactivation was observed (>99%) using doses of curcumin that were not antiviral by themselves. Photodynamic therapy employing crude curcumin can be suggested as an antiviral option against SARS-CoV-2 infection.

Curcumin Induces Apoptosis of Chemoresistant Lung Cancer Cells via ROS-Regulated p38 MAPK Phosphorylation

This study aimed to challenge chemoresistance by curcumin (CUR) with drug-selected human lung cancer A549 sublines that continuously proliferate in the present of docetaxel (DOC) and vincristine (VCR). Their sensitivities to CUR were measured by MTT assay and the particular intracellular reactive oxygen species (ROS) was detected by fluorescence activated cell sorting (FACS) analysis. Apoptosis was analyzed by Annexin V assay of the flow cytometry. Inhibitors and RNA interference were used to examine the signaling pathway regulated by the kinases. The obtained data demonstrated that CUR induces chemoresistant cell apoptosis by generating ROS and application of N-acetylcysteine (NAC) blocks ROS production, resulting in apoptosis suppression. Phosphorylation of extracellular regulated kinase (ERK), p38 MAPK, and eIF-2α were increased but c-Jun N-terminal kinase (JNK) did not increase when chemoresistant cells were treated with CUR. Downregulation of ERK and p38 MAPK phosphorylation by their inhibitors had no effect on CUR-induced apoptosis. Interestingly, the knockdown of p38 MAPK with shRNA significantly reduced CUR-induced apoptosis on the chemoresistant sublines. Phosphorylation of the eIF-2α protein was inhibited when p38 MAPK was knocked down in DOC-resistant A549 cells, but a high level of phosphorylated eIF-2α protein remained on the VCR-resistant A549 cells when p38 MAPK was knocked down. These data confirmed that CUR-augmented ROS potently induced apoptosis via upregulated p38 MAPK phosphorylation. Therefore, activated p38 MAPK is considered a pro-apoptotic signal for CUR-induced apoptosis of chemoresistant human lung cancer cells.

Uptake and time-dependent subcellular localization of native and micellar curcumin in intestinal cells

Uptake into intestinal cells and intracellular distribution into metabolically competent organelles, such as the endoplasmic reticulum, are important processes potentially limiting the bioavailability of xenobiotics. The incorporation of curcumin into polysorbate 80 micelles improves its naturally low oral bioavailability in humans. Here, we investigated uptake and time-dependent localization of curcumin in intestinal cells when administered as native or micellar formulation. Differentiated Caco-2 cells were incubated with 200 μmol/L native or micellar curcumin for up to 180 min and cellular uptake was quantified. Intracellular curcumin was detected already after 30 min and did not differ significantly between formulations or over time. Subcellular localization of native and micellar curcumin in Caco-2 cells was studied by density gradient centrifugation. After 30 min, curcumin from both formulations was mainly associated with mitochondria and lysosomes, after 180 min native curcumin was associated with mitochondria and peroxisomes, micellar curcumin with peroxisomes only. Uptake and localization of native and micellar curcumin in intestinal cells do not differ significantly and consequently do not explain differences in bioavailability in humans. The temporary co-localization with lysosomes is in agreement with the previously proposed role of endocytosis in cellular uptake of curcumin and warrants further investigation.

Dimethoxycurcumin Acidifies Endolysosomes and Inhibits SARS-CoV-2 Entry

The pandemic of coronavirus disease 2019 (COVID-19) caused by infection by severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) continues to take a huge toll on global health. Although improving, currently there are only limited therapies against SARS-CoV-2. Curcumin, a natural polyphenol, exerts antiviral effects against a wide variety of viruses and can inhibit SARS-CoV-2 entry. However, undesirable physicochemical and pharmacokinetic properties of curcumin limit its clinical application. Here, we determined the effects of dimethoxycurcumin (DiMC), a methylated analog of curcumin with improved bioavailability, on the entry of SARS-CoV-2. DiMC blocked entry of pseudo-SARS-CoV-2 into Calu-3 human non-small cell lung adenocarcinoma cells and Vero E6 green monkey kidney epithelial cells. Mechanistically, DiMC acidified lysosomes, enhanced lysosome degradation capabilities, and promoted lysosome degradation of angiotensin converting enzyme 2 (ACE2), a major receptor for SARS-CoV-2 entry, as well as pseudo-SARS-CoV-2 and the SARS-CoV-2 S1 protein. Furthermore, other lysosome acidifying agents, including the TRPML1 agonist ML-SA1 and the BK channel activator NS1619, also blocked the entry of pseudo-SARS-CoV-2. Thus, the anti-SARS-CoV-2 potential of DiMC and lysosome acidifying agents might be explored further as possible effective therapeutic strategies against COVID-19.

Curcumin and NCLX inhibitors share anti-tumoral mechanisms in microsatellite-instability-driven colorectal cancer

BACKGROUND AND AIMS

Recent evidences highlight a role of the mitochondria calcium homeostasis in the development of colorectal cancer (CRC). To overcome treatment resistance, we aimed to evaluate the role of the mitochondrial sodium-calcium-lithium exchanger (NCLX) and its targeting in CRC. We also identified curcumin as a new inhibitor of NCLX.

METHODS

We examined whether curcumin and pharmacological compounds induced the inhibition of NCLX-mediated mitochondrial calcium (mtCa2+) extrusion, the role of redox metabolism in this process. We evaluated their anti-tumorigenic activity in vitro and in a xenograft mouse model. We analyzed NCLX expression and associations with survival in The Cancer Genome Atlas (TCGA) dataset and in tissue microarrays from 381 patients with microsatellite instability (MSI)-driven CRC.

RESULTS

In vitro, curcumin exerted strong anti-tumoral activity through its action on NCLX with mtCa2+ and reactive oxygen species overload associated with a mitochondrial membrane depolarization, leading to reduced ATP production and apoptosis. NCLX inhibition with pharmacological and molecular approaches reproduced the effects of curcumin. NCLX inhibitors decreased CRC tumor growth in vivo. Both transcriptomic analysis of TCGA dataset and immunohistochemical analysis of tissue microarrays demonstrated that higher NCLX expression was associated with MSI status, and for the first time, NCLX expression was significantly associated with recurrence-free survival.

CONCLUSIONS

Our findings highlight a novel anti-tumoral mechanism of curcumin through its action on NCLX and mitochondria calcium overload that could benefit for therapeutic schedule of patients with MSI CRC.

Toxicity of curcumin nanoparticles towards alveolar macrophage: Effects of surface charges

Curcumin has been used for chronic lung diseases management due to its diversified molecular actions. However, the potential cytotoxicity which occurs in cells following the exposure to high concentrations of curcumin has been overlooked. This study evaluated the toxic events of curcumin nanoparticles (Cur-NPs) with alterable surface polarity in alveolar macrophages (NR8383). We aimed to establish the correlation between the toxicity of Cur-NPs with different surface charges and the internalization mechanisms of the NPs. Toxicity data showed that positively charged Cur-NPs (IC₅₀: 9.77 ± 0.5 μg/mL) was the most potent against NR8383, followed by negatively charged Cur-NPs (IC₅₀:13.33 ± 0.9 μg/mL) and neutral Cur-NPs (IC₅₀:18.68 ± 1.2 μg/mL). Results from mitochondrial membrane potential, ATP content and intracellular ROS in NR8383 showed similar ranking to the toxicity assay. The predominant uptake pathway for positively and negatively charged Cur-NPs was via clathrin-mediated endocytosis, while neutral Cur-NPs was internalized via phagocytosis, micropinocytosis and clathrin-mediated endocytosis. Positively charged Cur-NPs mediates the cytotoxicity of NR8383 via lysosomal and mitochondrial-associated destabilization upon entry. In conclusion, the cytotoxicity of Cur-NPs on NR8383 is surface-charge dependent, which in turn is associated to the uptake pathway and localization of Cur-NPs in cells.

Encapsulation of Alpha-Lipoic Acid in Functional Hybrid Liposomes: Promising Tool for the Reduction of Cisplatin-Induced Ototoxicity

In this study, in order to address the drawback of cisplatin (CDDP)-induced ototoxicity, we propose a straightforward strategy based on the delivery of a sulfur-based antioxidant, such as lipoic acid (LA), to HEI-OC1 cells. To this aim, hybrid liposomes (LA@PCGC) with a spherical shape and a mean diameter of 25 nm were obtained by direct sonication of LA, phosphatidylcholine and a gelatin-curcumin conjugate in a physiological buffer. LA@PCGC were found to be stable over time, were quickly (i.e., by 1 h) taken up by HEI-OC1 cells, and guaranteed strong retention of the bioactive molecule, since LA release was less than 20%, even after 100 h. Cell viability studies showed the efficiency of LA@PCGC for stabilizing the protective activity of LA. Curcumin residues within the functional liposomes were indeed able to maintain the biological activity of LA, significantly improving (up to 2.19-fold) the viability of HEI-OC1 cells treated with 5 μM CDDP. Finally, LA@PCGC was incorporated within an alginate-based injectable hydrogel carrier to create a formulation with physical chemical features suitable for potential ear applications.

BODIPY-Tagged Platinum(II) Curcumin Complexes for Endoplasmic Reticulum-Targeted Red Light PDT

[Pt(RB)(Cur)]NO₃ (RBC), [Pt(IRB)(Cur)]NO₃ (IRBC), and [Pt(L)(Cur)]NO₃ (PBC), where HCur is curcumin, L is 1-benzyl-2-(2-pyridyl)benzimidazole, and RB and IRB are red-light-active non-iodo and diiodo-BODIPY tagged to L, respectively, were synthesized and characterized, and their anticancer activities were studied (BODIPY, boron-dipyrromethene). RBC and IRBC displayed BODIPY-centered absorption bands within 615-635 nm along with the respective curcumin bands at 445 and 492 nm in 10% dimethyl sulfoxide (DMSO)-Dulbecco's phosphate-buffered saline (DPBS). Emission bands were observed at 723 and 845 nm for RBC and IRBC, respectively, in 10% DMSO-DPBS. RBC (Φ_Δ, 0.27) and IRBC (Φ_Δ, 0.40) generated singlet oxygen in red light (λ = 642 nm) as evidenced from 1,3-diphenylisobenzofuran (DPBF) titrations. The formation of ¹O₂ from BODIPY and HO^• from the curcumin was evidenced from the mechanistic pUC19 DNA photocleavage studies. The BODIPY complexes showed photocytotoxicity in A549, HeLa, and MDA-MB-231 cells while being less toxic in the dark [IC₅₀: 1.3-6.9 μM, red light; 7.2-12.8 μM, 400-700 nm visible light]. The emissive RBC displayed localization in the endoplasmic reticulum (ER). Apoptotic cell death was evidenced from the Annexin-V/fluorescein isothiocyanate (FITC)/propidium iodide (PI) assay and green fluorescence in red light in the Fluo-4 AM assay due to ER stress, and mitochondrial dysfunction was evidenced from the 5,5,6,6'-tetrachloro-1,1',3,3'-tetraethylbenzimidazolylcarbocyanine iodide (JC-1) assay in A549 cells.

PLGA-Based Curcumin Delivery System: An Interesting Therapeutic Approach in the Treatment of Alzheimer's Disease

Progressive degeneration and dysfunction of the nervous system because of oxidative stress, aggregations of misfolded proteins, and neuroinflammation are the key pathological features of neurodegenerative diseases. Alzheimer's disease is a chronic neurodegenerative disorder driven by uncontrolled extracellular deposition of β-amyloid (Aβ) in the amyloid plaques and intracellular accumulation of hyperphosphorylated tau protein. Curcumin is a hydrophobic polyphenol with noticeable neuroprotective and anti-inflammatory effects that can cross the blood-brain barrier. Therefore, it is widely studied for the alleviation of inflammatory and neurological disorders. However, the clinical application of curcumin is limited due to its low aqueous solubility and bioavailability. Recently, nano-based curcumin delivery systems are developed to overcome these limitations effectively. This review article discusses the effects and potential mechanisms of curcumin-loaded PLGA nanoparticles in Alzheimer's disease.

Regulation of Heme Oxygenase and Its Cross-Talks with Apoptosis and Autophagy under Different Conditions in Drosophila

Heme oxygenase (HO) is one of the cytoprotective enzymes that can mitigate the effects of oxidative stress. Here, we found that the ho mRNA level oscillates in the brain of Drosophila melanogaster with two minima at the beginning of the day and night. This rhythm was partly masked by light as its pattern changed in constant darkness (DD). It followed a similar trend in the clock mutant per⁰¹ under light/dark regime (LD12:12); however, differences between time points were not statistically significant. In older flies (20 days old), the rhythm was vanished; however, 15 days of curcumin feeding restored this rhythm with an elevated ho mRNA level at all time points studied. In addition, flies exposed to paraquat had higher ho expression in the brain, but only at a specific time of the day which can be a protective response of the brain against stress. These findings suggest that the expression of ho in the fly’s brain is regulated by the circadian clock, light, age, exposure to stress, and the presence of exogenous antioxidants. We also found that HO cross-talks with apoptosis and autophagy under different conditions. Induction of neuronal ho was accompanied by increased transcription of apoptosis and autophagy-related genes. However, this trend changed after exposure to curcumin and paraquat. Our results suggest that HO is involved in the control of apoptotic and autophagic key processes protecting the brain against oxidative damage.

Curcumin and Carnosic Acid Cooperate to Inhibit Proliferation and Alter Mitochondrial Function of Metastatic Prostate Cancer Cells

Anticancer activities of plant polyphenols have been demonstrated in various models of neoplasia. However, evidence obtained in numerous in vitro studies indicates that proliferation arrest and/or killing of cancer cells require quite high micromolar concentrations of polyphenols that are difficult to reach in vivo and can also be (geno)toxic to at least some types of normal cells. The ability of certain polyphenols to synergize with one another at low concentrations can be used as a promising strategy to effectively treat human malignancies. We have recently reported that curcumin and carnosic acid applied at non-cytotoxic concentrations synergistically cooperate to induce massive apoptosis in acute myeloid leukemia cells, but not in normal hematopoietic and non-hematopoietic cells, via sustained cytosolic calcium overload. Here, we show that the two polyphenols can also synergistically suppress the growth of DU145 and PC-3 metastatic prostate cancer cell cultures. However, instead of cell killing, the combined treatment induced a marked inhibition of cell proliferation associated with G₀/G₁ cell cycle arrest. This was preceded by transient elevation of cytosolic calcium levels and prolonged dissipation of the mitochondrial membrane potential, without generating oxidative stress, and was associated with defective oxidative phosphorylation encompassing mitochondrial dysfunction. The above effects were concomitant with a significant downregulation of mRNA and protein expression of the oncogenic kinase SGK1, the mitochondria-hosted mTOR component. In addition, a moderate decrease in SGK1 phosphorylation at Ser422 was observed in polyphenol-treated cells. The mTOR inhibitor rapamycin produced a similar reduction in SGK1 mRNA and protein levels as well as phosphorylation. Collectively, our findings suggest that the combination of curcumin and carnosic acid at potentially bioavailable concentrations may effectively target different types of cancer cells by distinct modes of action. This and similar combinations merit further exploration as an anticancer modality.

The type-1 ribosome-inactivating protein OsRIP1 triggers caspase-independent apoptotic-like death in HeLa cells

Ribosome-inactivating proteins (RIPs) are capable of removing a specific adenine from 28S ribosomal RNA, thus inhibiting protein biosynthesis in an irreversible manner. In this study, recombinant OsRIP1, a type 1 RIP from rice (Oryza sativa L.), was investigated for its anti-proliferative properties. Human cervical cancer HeLa cells were incubated in the presence of OsRIP1 for 24-72 h. OsRIP1 treatment yielded an anti-proliferation response of the HeLa cells and resulted in apoptotic-like blebbing of the plasma membrane without causing DNA fragmentation. OsRIP1 labeled with FITC accumulated at the cell surface. Pull-down assays identified ASPP1 (Apoptosis-Stimulating Protein of p53 1) and IFITM3 (interferon-induced transmembrane protein 3) as potential interaction partners for OsRIP1. Transcript levels for several critical genes related to different signaling pathways were quantified by RT-qPCR. OsRIP1 provoked HeLa cells to undergo caspase-independent cell death, associated with a significant transcriptional upregulation of the apoptotic gene PUMA, interferon regulatory factor 1 (IRF1) and the autophagy-related marker LC3. No changes in caspase activities were observed. Together, these data suggest that apoptotic-like events were involved in OsRIP1-driven caspase-independent cell death that might trigger the IRF1 signaling pathway and LC3-mediated autophagy.

Curcumin in combination with homoharringtonine suppresses lymphoma cell growth by inhibiting the TGF-β/Smad3 signaling pathway

Both homoharringtonine (HHT) and curcumin exhibit anti-proliferative effects on lymphoma cells, but the effects of combined HHT and curcumin treatment remain unclear. Here, we investigated the effects of HHT/curcumin combination on the proliferation, apoptosis, and invasion in lymphoma cells. CCK-8, flow cytometry, and transwell assays were used to assess proliferation, apoptosis, and invasion of U937 and Raji cells. p-Smad3, E-cadherin, and N-cadherin expression were also measured in Raji cells using Western blot assays. Combination of HHT and curcumin synergistically inhibited U937 and Raji cell proliferation and invasion. In addition, the combination treatment markedly increased apoptosis of Raji cells as evidenced by increased Bax, cleaved caspase 3, and cleaved caspase 9 expression. Meanwhile, the combination treatment promoted anti-tumor mechanisms in Raji cells as indicated by decreases in p-Smad3 and N-cadherin and increases in E-cadherin. In vivo experiments showed that the combination treatment suppressed tumor growth in a mouse Raji xenograft model. Our findings indicate that combination of HHT and curcumin inhibited lymphoma cell growth by downregulating the TGF-β/Smad3 pathway. These results suggest that HHT combined with curcumin might be a promising therapeutic approach for the treatment of lymphoma.

Isorhamnetin Promotes MKN-45 Gastric Cancer Cell Apoptosis by Inhibiting PI3K-Mediated Adaptive Autophagy in a Hypoxic Environment

A tumor-related hypoxic microenvironment can promote the proliferation of gastric cancer cells, and hypoxic-induced autophagy is the main mechanism of protection against hypoxia in gastric cancer cells. Isorhamnetin (ISO) is a chemical substance derived from plants, mainly from the sea buckthorn. Previous studies have shown that ISO has antitumor effects, but the effects of ISO against gastric cancer in a hypoxic environment are still unknown. In this study, we investigated the effects of ISO against gastric cancer in a hypoxic environment and the mechanisms underlying ISO-induced gastric cancer cell death. The results show that ISO targeted PI3K and blocked the PI3K-AKT-mTOR signaling pathway, significantly inhibiting gastric cancer cell autophagy in a hypoxic environment, inhibiting cell proliferation, decreasing mitochondrial membrane potential, and promoting mitochondria-mediated apoptosis. ISO, a functional food component, is a promising candidate for the treatment of gastric cancer.

Promising role of curcumin against viral diseases emphasizing COVID-19 management: A review on the mechanistic insights with reference to host-pathogen interaction and immunomodulation

Curcumin has already acknowledged immense interest from both medical and scientific research because of its multifaceted activity. To date, the promising effects of curcumin were perceived against numerous inflammatory diseases. Besides, curcumin's role as a medicine has been studied in many virus infections like influenza, HIV, etc. There is a need to analyze the cellular mechanisms of curcumin including host-pathogen interaction and immunomodulatory effects, to explore the role of curcumin against COVID-19. With this background, our study suggests that curcumin can prevent COVID-19 infections by inhibiting the pathogen entry, viral genome replication and steps in the endosomal pathway along with inhibition of T-cell signalling by impairing the autophagy-mediated antigen-presenting pathway. This review explicit the possible mechanisms behind curcumin-induced cellular immunity and a therapeutive dosage of curcumin suggesting a preventive strategy against COVID-19.

Mechanisms of curcumin-based photodynamic therapy and its effects in combination with electroporation: An in vitro and molecular dynamics study

Photodynamic therapy (PDT) and electrochemotherapy (ECT) are two methods designed to enhance the anticancer potential of various drugs. Various clinical trials proved the efficacy of both ECT and PDT in melanoma treatment. Curcumin is a natural polyphenolic compound with high anticancer potential against melanoma due to its light absorption properties and toxicity towards cancer cells; however, high reactivity and amphipathic structure of curcumin are limiting its utility. This study aimed to propose the most effective protocol for antimelanoma combination of both therapies (PDT and ECT) in the context of curcumin. The in vitro studies were carried on melanotic melanoma (A375), amelanotic melanoma (C32) and fibroblast (HGF) cell lines. In molecular dynamics studies curcumin presented the single-layer localization in the water-membrane interphase. Further, the mass spectrometry studies exposed that during the PDT treatment curcumin is degraded to vanillin, feruloylmethane, and ferulic acid. Instant ECT with curcumin followed by PDT is the most efficient approach due to its selective genotoxicity towards malignant cells. The metabolic activity of fibroblasts decreased, however, at the same time the fragmentation of DNA did not occur. Additionally, instant PDT with curcumin followed by ECT after 3 h of incubation was a therapy selective towards melanotic melanoma.

Priming of mesenchymal stem cells with a hydrosoluble form of curcumin allows keeping their mesenchymal properties for cell-based therapy development

Mesenchymal stem cells are increasingly studied for their use as drug‐carrier in addition to their intrinsic potential for regenerative medicine. They could be used to transport molecules with a poor bioavailability such as curcumin in order to improve their clinical usage. This natural polyphenol, well‐known for its antioxidant and anti‐inflammatory properties, has a poor solubility that limits its clinical potential. For this purpose, the use of NDS27, a curcumin salt complexed with hydroxypropyl‐beta‐cyclodextrin (HPβCD), displaying an increased solubility in aqueous solution, is preferred. This study aims to evaluate the uptake of NDS27 into skeletal muscle‐derived mesenchymal stem cells (mdMSCs) and the effects of such uptake onto their mesenchymal properties. It appeared that the uptake of NDS27 into mdMSCs is concentration‐dependent and not time‐dependent. The use of a concentration of 7 µmol/L which does not affect the viability and proliferation also allows preservation of their adhesion, invasion and T cell immunomodulatory abilities.

Improved Dermal and Transdermal Delivery of Curcumin with SmartFilms and Nanocrystals

Poor aqueous solubility of active compounds is a major issue in today's drug delivery. In this study the smartFilm-technology was exploited to improve the dermal penetration efficacy of a poorly soluble active compound (curcumin). Results were compared to the dermal penetration efficacy of curcumin from curcumin bulk suspensions and nanocrystals, respectively. The smartFilms enabled an effective dermal and transdermal penetration of curcumin, whereas curcumin bulk- and nanosuspensions were less efficient when the curcumin content was similar to the curcumin content in the smartFilms. Interestingly, it was found that increasing numbers of curcumin particles within the suspensions increased the passive dermal penetration of curcumin. The effect is caused by an aqueous meniscus that is created between particle and skin if the dispersion medium evaporates. The connecting liquid meniscus causes a local swelling of the stratum corneum and maintains a high local concentration gradient between drug particles and skin. Thus, leading to a high local passive dermal penetration of curcumin. The findings suggest a new dermal penetration mechanism for active compounds from nano-particulate drug delivery systems, which can be the base for the development of topical drug products with improved penetration efficacy in the future.

Synthesis of Bioactive Diarylheptanoids from Alpinia officinarum and Their Mechanism of Action for Anticancer Properties in Breast Cancer Cells

An efficient synthesis of the Alpinia officinarum-derived diarylheptanoids, viz., enantiomers of a β-hydroxyketone (1) and an α,β-unsaturated ketone (2) was developed starting from commercially available eugenol. Among these, compound 2 showed a superior antiproliferative effect against human breast adenocarcinoma MCF-7 cells. Besides reducing clonogenic cell survival, compound 2 dose-dependently increased the sub G1 cell population and arrested the G2-phase of the cell cycle, as revealed by flow cytometry. Mechanistically, compound 2 acts as an intracellular pro-oxidant by generating copious amounts of reactive oxygen species. Compound 2 also induced both loss of mitochondrial membrane potential (MMP) as well as lysosomal membrane permeabilization (LMP) in the MCF-7 cells. The impaired mitochondrial and lysosomal functions due to reactive oxygen species (ROS)-generation by compound 2 may contribute to its apoptotic property.

Curcumin Encapsulated in Crosslinked Cyclodextrin Nanoparticles Enables Immediate Inhibition of Cell Growth and Efficient Killing of Cancer Cells

The efficiency of anti-cancer drugs is commonly determined by endpoint assays after extended incubation times, often after days. Here we demonstrate that curcumin encapsulated in crosslinked cyclodextrin nanoparticles (CD-NP) acts extremely rapidly on cell metabolism resulting in an immediate and complete inhibition of cell growth and in efficient cancer-cell killing only few hours after incubation. This early onset of anti-cancer action was discovered by live-cell high-throughput fluorescence microscopy using an environmental stage. To date, only very few examples of covalently crosslinked nanoscale CD-based (CD-NP) drug carriers exist. Crosslinking cyclodextrins enables the adsorption of unusually high payloads of hydrophobic curcumin (762 µg CC/mg CD-NP) reflecting a molar ratio of 2.3:1 curcumin to cyclodextrin. We have investigated the effect of CD-NP encapsulated curcumin (CD-CC-NP) in comparison to free, DMSO-derived curcumin nanoparticles (CC-NP) on 4 different cell lines. Very short incubations times as low as 1 h were applied and cell responses after medium change were subsequently followed over two days. We show that cell proliferation is inhibited nearly immediately in all cell lines and that a cell- and concentration dependent cancer-cell killing occurs. Anti-cancer effects were similar with free and encapsulated curcumin, however, encapsulation in CD-NP drastically extends the long-term photostability and anti-cancer activity of curcumin. Curcumin-sensitivity is highest in HeLa cells reaching up to 90% cell death under these conditions. Sensitivity decreased from HeLa to T24 to MDA MB-231 cells. Strikingly, the immortalized non-cancerous cell line MCF-10A was robust against curcumin concentrations that were highly toxic to the other cell lines. Our results underline the potential of curcumin as gentle and yet effective natural anti-cancer agent when delivered solvent-free in stabilizing and biocompatible drug carriers such as CD-NP that enable efficient cellular delivery.