Multitargeting by curcumin as revealed by molecular interaction studies

Plant Polyphenols as Neuroprotective Agents in Parkinson's Disease Targeting Oxidative Stress

Parkinson's disease (PD) is the second most prevalent progressive neurodegenerative disorder characterized by the degeneration of dopaminergic neurons in the human midbrain. Various ongoing research studies are competing to understand the pathology of PD and elucidate the mechanisms underlying neurodegeneration. Current pharmacological treatments primarily focused on improving dopamine metabolism in PD patients, despite the side effects of long-term usage. In recent years, it is recognized that oxidative stress-mediated pathways lead to neurodegeneration in the brain, which is associated with the pathophysiology of PD. The importance of oxidative stress is often less emphasized when developing potential therapeutic approaches. Natural plant antioxidants have been shown to mediate the oxidative stress-induced effects in PD, which has gained considerable attention in both in vitro and in vivo studies. Yet, clinical trials on natural polyphenol compounds are limited, restricting the potential use of these compounds as an alternative treatment for PD. Therefore, this review provides an understanding of the oxidative stress-induced effects in PD by elucidating the underlying events contributing to oxidative stress and explore the potential use of polyphenols in improving the oxidative status in PD. Preclinical findings have supported the potential of polyphenols in providing neuroprotection against oxidative stress-induced toxicity in PD. However, limiting factors, such as safety and bioavailability of polyphenols, warrant further investigations so as to make them the potential target for clinical applications in the treatment and management of PD.

Cancer Related Anemia: An Integrated Multitarget Approach and Lifestyle Interventions

Cancer is often accompanied by worsening of the patient's iron profile, and the resulting anemia could be a factor that negatively impacts antineoplastic treatment efficacy and patient survival. The first line of therapy is usually based on oral or intravenous iron supplementation; however, many patients remain anemic and do not respond. The key might lie in the pathogenesis of the anemia itself. Cancer-related anemia (CRA) is characterized by a decreased circulating serum iron concentration and transferrin saturation despite ample iron stores, pointing to a more complex problem related to iron homeostatic regulation and additional factors such as chronic inflammatory status. This review explores our current understanding of iron homeostasis in cancer, shedding light on the modulatory role of hepcidin in intestinal iron absorption, iron recycling, mobilization from liver deposits, and inducible regulators by infections and inflammation. The underlying relationship between CRA and systemic low-grade inflammation will be discussed, and an integrated multitarget approach based on nutrition and exercise to improve iron utilization by reducing low-grade inflammation, modulating the immune response, and supporting antioxidant mechanisms will also be proposed. Indeed, a Mediterranean-based diet, nutritional supplements and exercise are suggested as potential individualized strategies and as a complementary approach to conventional CRA therapy.

A 3×3 visible-light cross-reactive sensor array based on the nanoaggregation of curcumin in different pH and buffers for the multivariate identification and quantification of metal ions

Here, a facilely constructed 3 × 3 visible-light cross reactive sensor array based on nanoaggregation of curcumin (Cur) is proposed for the identification and quantification of metal ions (MIs). Synthesis of nanocurcumin (NCur) was characterized by UV-Vis spectrophotometry, transmission electron microscopy (TEM) and Fourier transform infrared (FT-IR). The average particle size was estimated about 5.21 ± 1.13 nm) n = 50 (. Our sensor array consists of nine receptors with distinct but overlapping specificities for 11 MIs: Al³⁺, Cd²⁺, Co²⁺, Cu²⁺, Hg²⁺, Fe²⁺, Fe³⁺, Mn²⁺, Ni²⁺, Pb²⁺, and Zn²⁺. The receptors include the nine solutions of NCur at three buffers of phosphate, ammonium, and tris each at three pH of 7, 8, and 9 (in total 9 receptors). On account of different pH and buffers, NCur-MI binding affinities can be distinguished by monitoring the UV-Vis absorbance changes. These changes are optical fingerprints that can be used to identify each MI. The absorption values in sixteen wavelengths (i.e. 332, 352, 372, 392, 412, 432, 452, 472, 492, 512, 532, 552, 572, 592, 612, and 632 nm) are considered as analytical signals to quantitatively evaluate of the absorbance responses of the sensor array. A color difference map is provided to qualitatively visualize of the colorimetric sensor array responses. Under optimal conditions, the MIs are successfully discriminated in the range of 4-48 μmol L^-1. The limit of detections (LODs) values ranged from 0.47 (for Fe³⁺) to 1.40 μmol L^-1 (for Pb²⁺). Furthermore, two different mixing sets of the MIs are prepared for multivariate multicomponent analysis. Finally, the suggested sensor array is employed to evaluate its practicability in the discrimination of MIs in samples of river water and serum. Moreover, it can identify the MIs in these samples. The sensor array presents a simple, save time, cost-effective, and environmentally friendly method for the identification and quantification of MIs.

Repositioning antispasmodic drug Papaverine for the treatment of chronic myeloid leukemia

BACKGROUND

Papaverine is a benzylisoquinoline alkaloid from the plant Papaver somniferum (Opium poppy). It is approved as an antispasmodic drug by the US FDA and is also reported to have anti-cancer properties. Here, Papaverine's activity in chronic myeloid leukemia (CML) is explored using Saccharomyces cerevisiae, mammalian cancer cell lines, and in silico studies.

METHODS

The sensitivity of wild-type and mutant (anti-oxidant defense, apoptosis) strains of S. cerevisiae to the drug Papaverine was tested by colony formation, spot assays, and AO/EB staining. In vitro cytotoxic effect was investigated on HCT15 (colon), A549 (lung), HeLa (cervical), and K562 (Bcr-Abl positive CML), and RAW 264.7 cell lines; cell cycle, mitochondrial membrane potential, ROS detection analyzed in K562 cells using flow cytometry and apoptotic markers, Bcr-Abl signaling pathways examined by western blotting. Molecular docking and molecular dynamics simulation of Papaverine against the target Bcr-Abl were also carried out.

RESULTS

Investigation in S. cerevisiae evidenced Papaverine induces ROS-mediated apoptosis. Subsequent in vitro examination showed that CML cell line K562 was more sensitive to the drug Papaverine. Papaverine induces ROS generation, promotes apoptosis, and inhibits Bcr-Abl downstream signaling. Papaverine acts synergistically with the drug Imatinib. Furthermore, the docking and molecular dynamic simulation studies supported that Papaverine binds to the allosteric site of Bcr-Abl.

CONCLUSION

The data presented here have added support to the concept of polypharmacology of existing drugs and natural compounds to interact with more than one target. This study provides a proof-of-concept for repositioning Papaverine as an anti-CML drug.

Carbon-based Nanomaterials and Curcumin: A Review of Biosensing Applications

Curcumin, the main active constituent of turmeric (Curcuma longa L.), is a naturally occurring phenolic compound with a wide variety of pharmacological activities. Although it has multiple pharmaceutical properties, its bioavailability and industrial usage are hindered due to rapid hydrolysis and low water solubility. Due to the growing market of curcumin, exact determination of curcumin in trade and human biological samples is important for monitoring therapeutic actions. Different nanomaterials have been suggested for sensing curcumin; and in this case, carbon-based nanomaterials (CNMs) are one of the most outstanding developments in nanomedicine, biosensing, and regenerative medicine. There are a considerable number of reports which have shown interesting potential of CNMs-based biosensors in the sensitive and selective detection of curcumin. Therefore, this review aims to increase understanding the interaction of curcumin with CNMs in the context of biosensing.

Can Natural Polyphenols Help in Reducing Cytokine Storm in COVID-19 Patients?

SARS-CoV-2 first emerged in China during late 2019 and rapidly spread all over the world. Alterations in the inflammatory cytokines pathway represent a strong signature during SARS-COV-2 infection and correlate with poor prognosis and severity of the illness. The hyper-activation of the immune system results in an acute severe systemic inflammatory response named cytokine release syndrome (CRS). No effective prophylactic or post-exposure treatments are available, although some anti-inflammatory compounds are currently in clinical trials. Studies of plant extracts and natural compounds show that polyphenols can play a beneficial role in the prevention and the progress of chronic diseases related to inflammation. The aim of this manuscript is to review the published background on the possible effectiveness of polyphenols to fight SARS-COV-2 infection, contributing to the reduction of inflammation. Here, some of the anti-inflammatory therapies are discussed and although great progress has been made though this year, there is no proven cytokine blocking agents for COVID currently used in clinical practice. In this regard, bioactive phytochemicals such as polyphenols may become promising tools to be used as adjuvants in the treatment of SARS-CoV-2 infection. Such nutrients, with anti-inflammatory and antioxidant properties, associated to classical anti-inflammatory drugs, could help in reducing the inflammation in patients with COVID-19.

The assessment of antidiabetic properties of novel synthetic curcumin analogues: α-amylase and α-glucosidase as the target enzymes

Diabetes mellitus is a metabolic disorder characterized by high blood glucose levels and instability in carbohydrate metabolism. For treating diabetes, one important therapeutic approach is reducing the postprandial hyperglycemia which can be managed by delaying the absorption of glucose through inhibition of the carbohydrate-hydrolyzing enzymes, α-amylase (α-Amy) and α-glucosidase (α-Gls) in the digestive tract. In this work, a new class of curcumin derivatives incorporating pyrano[2,3-d]pyrimidine heterocycles was synthesized using a multicomponent reaction between curcumin, aldehydes, and barbituric acid. Using UV-Vis spectroscopic method, the synthetic compounds were assessed for their inhibitory properties against α-Amy and α-Gls enzymes. Also, the antioxidant potential of these compounds was measured spectroscopically and compared with Trolox which is known as a gold standard to measure antioxidant capacity. The results of present study suggest that the curcumin derivatives were able to efficiently inhibit both yeast and mammalian α-Gls. In comparison with the antidiabetic medicine acarbose, the synthetic curcumin derivatives were also capable to inhibit more effectively the yeast α-Gls. The partial inhibitory effects of these compounds against pancreatic α-Amy were also important in the terms of avoiding development of the possible gastrointestinal side effects. Moreover, some of the curcumin derivatives indicated stronger antioxidant activity than Trolox. Overall, these synthetic curcumin analogues might be considered as novel molecular templates for development of efficient antidiabetic compounds with promising inhibitory activities against α-Amy and α-Gls enzymes.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s40200-020-00685-z.

pH-shifting encapsulation of curcumin in egg white protein isolate for improved dispersity, antioxidant capacity and thermal stability

Curcumin (Cur) has many functions, such as antioxidant and anti-inflammatory. However, its poor solubility and thermal stability at aqueous solutions limit its application in the food industry. In this study, egg white protein isolate (EPI) was complexed with Cur via a pH-shifting method. The effects of ultimate pH (from 5.0 to 7.0) on the physicochemical properties of the complex were studied. Cur could reach 84.4% encapsulation efficiency at pH 6.0. Meanwhile, the EPI complex could remain stable at pH 7.0 after 30 days and protect Cur from thermal degradation, thereby improving the Cur retention rate with the increasing ultimate pH. Compared with those of EPI and free Cur, the antioxidant capacity of the complex was enhanced effectively. The EPI-Cur complex was certified using UV-vis and fluorescence spectra. The fluorescence results indicated that Cur and EPI are combined through a static quenching and with a strong affinity of 1.8 × 10⁵ M^-1 at pH 6.0. In summary, this work provides a biocompatible and straightforward method for the development of nanoparticles based on egg white protein isolates, which can be used as a promising carrier for insoluble nutritional compounds.

Free Radicals as a Double-Edged Sword: The Cancer Preventive and Therapeutic Roles of Curcumin

Free radicals, generally composed of reactive oxygen species (ROS) and reactive nitrogen species (RNS), are generated in the body by various endogenous and exogenous systems. The overproduction of free radicals is known to cause several chronic diseases including cancer. However, increased production of free radicals by chemotherapeutic drugs is also associated with apoptosis in cancer cells, indicating the dual nature of free radicals. Among various natural compounds, curcumin manifests as an antioxidant in normal cells that helps in the prevention of carcinogenesis. It also acts as a prooxidant in cancer cells and is associated with inducing apoptosis. Curcumin quenches free radicals, induces antioxidant enzymes (catalase, superoxide dismutase, glutathione peroxidase), and upregulates antioxidative protein markers-Nrf2 and HO-1 that lead to the suppression of cellular oxidative stress. In cancer cells, curcumin aggressively increases ROS that results in DNA damage and subsequently cancer cell death. It also sensitizes drug-resistant cancer cells and increases the anticancer effects of chemotherapeutic drugs. Thus, curcumin shows beneficial effects in prevention, treatment and chemosensitization of cancer cells. In this review, we will discuss the dual role of free radicals as well as the chemopreventive and chemotherapeutic effects of curcumin and its analogues against cancer.

New Polyphenol-Containing LDL Nano-Preparations in Oxidative Stress and DNA Damage: A Potential Route for Cell-Targeted PP Delivery

Low-density lipoprotein (LDL) preparations of the chosen polyphenols (PPs) were prepared for the first time in the literature. The solubility of the PPs in the lipidic core of the LDL increased with the increase of their lipophilicity. The anti-/pro-oxidative properties and toxicity of LDL-entrapped PPs toward A 2780 human ovarian cancer cells were examined. The obtained preparations were found to be stable in PBS, and characterized by low toxicity. A binding affinity study revealed that the uptake of PP-loaded LDL particles is non-receptor-specific under experimental conditions. The antioxidative potential of the obtained PPs-doped LDL preparations was shown to be higher than for the PPs themselves, probably due to facilitating transport of LDL preparations into the cellular milieu, where they can interact with the cellular systems and change the redox status of the cell. The PPs-loaded LDL displayed the highest protective effect against Fenton-type reaction induced oxidative DNA damage.

A Green Chemosensor for Colorimetric Determination of Phosphate Ion in Soil, Bone, and Water Samples Using Curcumin Nanoparticles

This article presents a sensitive and straightforward colorimetric chemosensor for the determination of phosphate ion utilizing curcumin nanoparticles (CUNPs) as the sensing system. The color of as-prepared CUNPs can be changed from yellow to orange upon adding iron(III) ions due to the formation of a complex with CUNPs. However, in the presence of phosphate ions, iron(III) ions prefer to bind to phosphate ions and, subsequently the color of CUNPs is selectively recovered because of releasing the iron(III) ions from the CUNPs-iron(III) complex. Therefore, in this work the selective color changing of the CUNPs-iron(III) system upon the addition of phosphate ions was used for the quantitative sensing of phosphate ions. Various factors, such as the pH, concentration of iron(III) and volume of CUNPs, were examined and the optimum conditions were established. A linear calibration graph over the range of 10 - 400 ng mL^-1 for phosphate (r = 0.9995) was achieved using the optimal conditions. The limit of detection (LOD) of the proposed method for phosphate was 7.1 ng mL^-1 and the relative standard deviation (RSD) for measuring 50 ng mL^-1 of phosphate was 3.7% (n = 8). The developed method was applied for the measurement of phosphate in water, soil, and bone samples. Satisfactory results were obtained.

Identification of proteasome inhibitors using analysis of gene expression profiles

Inhibitors of the 20S proteasome such as bortezomib (Velcade_®) and carfilzomib (Kypriolis_®) are in clinical use for the treatment of patients with multiple myeloma and mantle cell lymphoma. In an attempt to identify novel inhibitors of the ubiquitin-proteasome system (UPS) we used the connectivity map (CMap) resource, based on alterations of gene expression profiles by perturbagens, and performed COMPARE analyses of drug sensitivity patterns in the NCI₆₀ panel. Cmap analysis identified a large number of small molecules with strong connectivity to proteasome inhibition, including both well characterized inhibitors of the 20S proteasome and molecules previously not described to inhibit the UPS. A number of these compounds have been reported to be cytotoxic to tumor cells and were tested for their ability to decrease processing of proteasome substrates. The antibiotic thiostrepton and the natural products celastrol and curcumin induced strong accumulation of polyubiquitinated proteasome substrates in exposed cells. Other compounds elicited modest increases of proteasome substrates, including the protein phosphatase inhibitor BCI-Cl and the farnesyltransferase inhibitor manumycin A, suggesting that these compounds inhibit proteasome function. Induction of chaperone expression in the absence of proteasome inhibition was observed by a number of compounds, suggesting other effects on the UPS. We conclude that the combination of bioinformatic analyses and cellular assays resulted in the identification of compounds with potential to inhibit the UPS.

Micronutrients and bioactive compounds in the immunological pathways related to SARS-CoV-2 (adults and elderly)

The new coronavirus pandemic is affecting the entire world with more than 25 million confirmed cases in August 2020 according to the World Health Organization. It is known that the virus can affect several tissues and can progress to a respiratory failure in severe cases. To prevent the progression to this stage of the disease and minimize all the damage caused by coronavirus (SARS-CoV-2) the immune system must be in its integrity. A healthy nutritional status are fundamental to efficient immunological protection and consequently a good response to SARS-CoV-2. Micronutrients and bioactive compounds perform functions in immune cells that are extremely essential to stop SARS-CoV-2. Their adequate consumption is part of a non-pharmacological intervention to keep the immune system functioning. This review has as main objective to inform how micronutrients and bioactive compounds could act in the essential immunological pathways could stop SARS-CoV-2, focusing on the functions that have already established in the literature and transposing to this scenario.

The Multi-Faceted Effect of Curcumin in Glioblastoma from Rescuing Cell Clearance to Autophagy-Independent Effects

The present review focuses on the multi-faceted effects of curcumin on the neurobiology glioblastoma multiforme (GBM), with a special emphasis on autophagy (ATG)-dependent molecular pathways activated by such a natural polyphenol. This is consistent with the effects of curcumin in a variety of experimental models of neurodegeneration, where the molecular events partially overlap with GBM. In fact, curcumin broadly affects various signaling pathways, which are similarly affected in cell degeneration and cell differentiation. The antitumoral effects of curcumin include growth inhibition, cell cycle arrest, anti-migration and anti-invasion, as well as chemo- and radio-sensitizing activity. Remarkably, most of these effects rely on mammalian target of rapamycin (mTOR)-dependent ATG induction. In addition, curcumin targets undifferentiated and highly tumorigenic GBM cancer stem cells (GSCs). When rescuing ATG with curcumin, the tumorigenic feature of GSCs is suppressed, thus counteracting GBM establishment and growth. It is noteworthy that targeting GSCs may also help overcome therapeutic resistance and reduce tumor relapse, which may lead to a significant improvement of GBM prognosis. The present review focuses on the multi-faceted effects of curcumin on GBM neurobiology, which represents an extension to its neuroprotective efficacy.

Protective potential of curcumin in L-NAME-induced hypertensive rat model: AT1R, mitochondrial DNA synergy

BACKGROUND & OBJECTIVES

Hypertension can be induced by inhibiting nitric oxide synthesis with L-NAME, which also has a role in oxidative stress. Curcumin has strong antioxidant property. Our aim was to examine the possible preventive role of curcumin on renal dysfunction secondary to hypertension.

MATERIAL & METHODS

Twenty-four adult male Albino rats were divided in four groups: normal (N); curcumin (C; received curcumin 100 mg/kg/day by oral gavage for 10 weeks); hypertensive (H; received L-NAME 40 mg/kg/day in their drinking water for 4 weeks); and hypertensive-curcumin (HC; received L-NAME and curcumin). Arterial blood pressure was evaluated non-invasively for 4 weeks. Rats were then sacrificed for assessment of oxidative stress (catalase, lipid peroxidase, reduced glutathione and superoxide dismutase), renal function and structure, and biomarkers of apoptosis (Bcl-2 and caspase-3). AT1R expression and renal mtDNA integrity were also assessed.

RESULTS

Curcumin attenuated the effects of L-NAME on blood pressure and renal function. The renal histopathological changes observed in the L-NAME group were improved by curcumin administration. The expression of Bcl2 and caspase-3 was improved associated with downregulation of AT1R in curcumin treated groups. The antioxidant markers and mtDNA fragmentation show marked increase in hypertensive group which significantly decreased after curcumin treatment.

CONCLUSION

Curcumin improved blood pressure elevation renal dysfunction. These improvements mediated through anti-oxidant capabilities and downregulation of AT1R favoring reduced apoptosis and preserved mitochondrial DNA.

Curcumin derivative C212 inhibits Hsp90 and eliminates both growing and quiescent leukemia cells in deep dormancy

BACKGROUND

Relapsed leukemia following initial therapeutic response and remission is difficult to treat and causes high patient mortality. Leukemia relapse is due to residual quiescent leukemia cells that escape conventional therapies and later reemerge. Eliminating not only growing but quiescent leukemia cells is critical to effectively treating leukemia and preventing its recurrence. Such dual targeting therapeutic agents, however, are lacking in the clinic. To start tackling this problem, encouraged by the promising anticancer effects of a set of curcumin derivatives in our earlier studies, we examined in this work the effects of a 4-arylmethyl curcumin derivative (C212) in eliminating both growing and quiescent leukemia cells.

METHODS

We analyzed the effects of C212 on the growth and viability of growing and quiescent leukemia cells using MTS, apoptosis, cell cycle and cell tracking assays. The effects of C212 on the quiescence depth of leukemia cells were measured using EdU incorporation assay upon growth stimulation. The mechanisms of C212-induced apoptosis and deep dormancy, particularly associated with its inhibition of Hsp90 activity, were studied using molecular docking, protein aggregation assay, and Western blot of client proteins.

RESULTS

C212, on the one hand, inhibits growing leukemia cells at a higher efficacy than curcumin by inducing apoptosis and G2/M accumulation; it, on the other hand, eliminates quiescent leukemia cells that are resistant to conventional treatments. Furthermore, C212 drives leukemia cells into and kills them at deep quiescence. Lastly, we show that C212 induces apoptosis and drives cells into deep dormancy at least partially by binding to and inhibiting Hsp90, leading to client protein degradation and protein aggregation.

CONCLUSION

C212 effectively eliminates both growing and quiescent leukemia cells by inhibiting Hsp90. The property of C212 to kill quiescent leukemia cells in deep dormancy avoids the risk associated with awaking therapy-resistant subpopulation of quiescent leukemia cells during treatments, which may lead to the development of novel therapies against leukemia relapse. Video abstract.

Preparation and Characterization of Liposomal β-Caryophyllene (Rephyll) by Nanofiber Weaving Technology and Its Effects on Delayed Onset Muscle Soreness (DOMS) in Humans: A Randomized, Double-Blinded, Crossover-Designed, and Placebo-Controlled Study

Delayed onset muscle soreness (DOMS) is a complex spreading out, which is related to swelling of muscles, tenderness, rigidity, pain, disruption of muscle fiber, alteration in the kinematics of joint, acute tissue damage, and reduction in power and strength. β-Caryophyllene (BCP), a potent phytocannabinoid, could play an important role in managing DOMS because of its wide diversity of biological activities, particularly its anti-inflammatory activity; however, its poor stability in light, temperature, high volatility, and insolubility can restrict the medical practices. In this study, liposomal β-caryophyllene (Rephyll) was designed and established in powder form constructed by the nanofiber weaving technology to improve the bioavailability of BCP with improved stability. Rephyll was characterized by Fourier transform infrared spectroscopy, transmission electron microscopy, and differential scanning calorimetry studies. Encapsulation efficiency, loading capacity, and in vitro release studies revealed that Rephyll can be an auspicious drug delivery arrangement for BCP. The effects of Rephyll were evaluated by a randomized, double-blinded, crossover-designed, placebo-controlled study. The oral consumption of Rephyll significantly reduced the pain visual assessment score, revealing that Rephyll effectively reduced DOMS with improved recovery without any side effects due to the bioavailable form of the phytocannabinoid BCP in the liposomal powder formulation.

Does Curcumin Have a Role in the Interaction between Gut Microbiota and Schistosoma mansoni in Mice?

There is strong correlation between changes in abundance of specific bacterial species and several diseases including schistosomiasis. Several studies have described therapeutic effects of curcumin (CUR) which may arise from its regulative effects on intestinal microbiota. Thus, we examined the impact of CUR on the diversity of intestinal microbiota with/without infection by Schistosoma mansoni cercariae for 56 days. Enterobacteriaceae was dominating in a naive and S. mansoni infected mice group without CUR treatment, the most predominant species was Escherichia coli with relative density (R.D%) = 80.66% and the least one was Pseudomonas sp. (0.52%). The influence of CUR on murine microbiota composition was examined one week after oral administration of high (40) and low (20 mg/kg b.w.) CUR doses were administered three times, with two day intervals. CUR induced high variation in the Enterobacteriaceae family, characterized by a significant (p < 0.001) reduction in E. coli and asignificant (p < 0.001) increase in Pseudomonas sp. in both naïve and S. mansoni-infected mice, compared to untreated mice, in a dose-dependent manner. Additionally, our study showed the effects of high CUR doses on S. mansoni infection immunological and parasitological parameters. These data support CUR’s ability to promote Pseudomonas sp. known to produce schistosomicidal toxins and offset the sequelae of murine schistosomiasis.

A natural product solution to aging and aging-associated diseases

Aging is a natural biological progress accompanied by the gradual decline in physiological functions, manifested by its close association with an increased incidence of human diseases and higher vulnerability to death. Those diseases include neurological disorders, cardiovascular diseases, diabetes, and cancer, many of which are currently without effective cures. Even though aging is inevitable, there are still interventions that can be developed to prevent/delay the onset and progression of those aging-associated diseases and extend healthspan and/or lifespan. Here, we review decades of research that reveals the molecular pathways underlying aging and forms the biochemical basis for anti-aging drug development. Importantly, due to the vast chemical space of natural products and the rich history of herb medicines in treating human diseases documented in different cultures, natural products have played essential roles in aging research. Using several of the most promising natural products and their derivatives as examples, we discuss how natural products serve as an inspiration resource that helped the identification of key components/pathways underlying aging, their mechanisms of action inside the cell, and the functional scaffolds or targeting mechanisms that can be learned from natural products for drug engineering and optimization. We argue that natural products might eventually provide a solution to aging and aging-associated diseases.

Facile Approach to Fabricate a Chemical Sensor Array Based on Nanocurcumin-Metal Ions Aggregates: Detection and Identification of DNA Nucleobases

Here, a three-channel absorbance sensor array based on the nanocurcumin-metal ion (NCur-MI) aggregates is designed for the detection and identification of deoxyribonucleic acid nucleobases (DNA NBs) for the first time. For this purpose, the binding affinities of some of MIs (i.e., Co2+, Cr3+, Cu2+, Fe2+, Fe3+, Hg2+, Mn2+, Ni2+, V3+, and Zn2+) to the NCur to induce the aggregation were evaluated under various experimental conditions. Further studies reveal that in the presence of DNA NBs, the aggregates of NCur-Co2+, NCur-Ni2+, and NCur-Zn2+ show the diverse absorbance responses to the deaggregation of NCur depending on the binding affinity of each of DNA NBs to the metal ions Co2+, Ni2+, and Zn2+. These responses are distinguishable from one another. Thus, clear differentiation among the DNA NBs is achieved by linear discriminant analysis and hierarchical clustering analysis to generate clustering maps. The discriminatory capacity of the sensor array for the identification of the DNA NBs is tested in the ranges of 2.4-16 and 5.6-10.4 μM. Furthermore, a mixed set of the DNA NBs was prepared for multivariate multicomponent analysis. Finally, the practicability of the sensor array is confirmed by the discrimination of the DNA NBs in an animal DNA sample. It should be noted that the proposed array is the first example to fabricate an NCur-based sensor array for the simultaneous detection of DNA NBs.

Enhancing Aqueous Solubility and Antibacterial Activity of Curcumin by Complexing with Cell-Penetrating Octaarginine

Bacterial resistance to antimicrobial drugs is one of the biggest threats to human health and novel drugs, and strategies are needed to obviate this resistance crisis. An innovative strategy for designing novel antimicrobial drugs is based on the hybridization of an antimicrobial agent with a second functional entity. Here, we use a cell-penetrating peptide-octaarginine (R8) as the second functional entity and develop a complex or hybrid of R8 and curcumin that possibly targets the bacterial cell membrane. Minimum inhibitory concentration assays show that the antibacterial activity of the complex is enhanced in a synergistic manner and rapid killing kinetics are obtained, emphasizing a bactericidal mode of action. In addition, electron microscopy images reveal bacterial membrane disruption by the complex. The R8-curcumin complex also displays activity against HeLa cells.

Recent progress of bacterial FtsZ inhibitors with a focus on peptides

In recent years, the rise of antibiotic resistance has become a primary health problem. With the emergence of bacterial resistance, the need to explore and develop novel antibacterial drugs has become increasingly urgent. Filamentous temperature-sensitive mutant Z (FtsZ), a crucial cell division protein of bacteria, has become a vital antibacterial target. FtsZ is a filamentous GTPase; it is highly conserved in bacteria and shares less than 20% sequence identity with the eukaryotic cytoskeleton protein tubulin, indicating that FtsZ-targeting antibacterial agents may have a low cytotoxicity toward eukaryotes. FtsZ can form a dynamic Z-ring in the center of the cell resulting in cell division. Furthermore, disturbance in the assembly of FtsZ may affect cellular dynamics and bacterial cell survival, making it a fascinating target for drug development. This review focuses on the recent discovery of FtsZ inhibitors, including peptides, natural products, and other synthetic small molecules, as well as their mechanism of action, which could facilitate the discovery of novel FtsZ-targeting clinical drugs in the future.

Curcumin Conjugates of Non-steroidal Anti-Inflammatory Drugs: Synthesis, Structures, Anti-proliferative Assays, Computational Docking, and Inflammatory Response

In an effort to combine the anti-proliferative effect of CUR-BF2 and CUR compounds with anti-inflammatory benefits of non-steroidal anti-inflammatory drugs (NSAIDs), a library of the bis- and mono-NSAID/CUR-BF2 and NSAID/CUR conjugates were synthesized by coupling flufenamic acid, flurbiprofen, naproxen, indomethacin, and ibuprofen to diversely substituted hydroxy-benzaldehydes via an ester linkage, and by subsequent reaction with acetylacetone-BF2 to form the bis- and the mono-NSAID/CUR-BF2 adducts. Since conversion to NSAID/CUR by the previously developed decomplexation protocol showed limited success, a set of NSAID/CUR conjugates were independently prepared by directly coupling the NSAIDs with parent curcumin. The bis-NSAID/CUR-BF2 and bis-NSAID-CUR hybrids exhibited low cytotoxicity in NCI-60 assay, and in independent cell viability assay on colorectal cancer (CRC) cells (HCT116, HT29, DLD-1, RKO, SW837, CaCo2) and in normal CR cells (CCD841CoN). By contrast, the mono-naproxin and mono-flurbiprofen CUR-BF2 adducts exhibited remarkable anti-proliferative and apoptopic activity in NCI-60 assay most notably against HCT-116 (colon), OVCAR-3 (ovarian), and ACHN (renal) cells. Computational molecular docking calculations showed favorable binding energies to HER2, VEGFR2, BRAF, and Bcl-2 as well as to COX-1 and COX-2, which in several cases exceeded known inhibitors. The main interactions between the ligands and the proteins were hydrophobic, although several hydrogen bonds were also observed. A sub-set of six compounds that had exhibited little or no cytotoxicity were tested for their anti-inflammatory response with THP-1 human macrophages in comparison to parent NSAIDs or parent curcumin.

Effect of the application of an edible film with turmeric (Curcuma longa L.) on the oxidative stability of meat

The aim of this study was to develop an edible alginate-based film produced with turmeric (EFT), as an active compound, and evaluate its antioxidant capacity for application in fresh pork loin, beef loin, and chicken breast. The EFT was characterized by barrier parameters, color, and mechanical, structural, and antioxidant properties. Meat samples with and without EFT were stored at 4°C and analyzed at 2-day intervals. The meat samples with EFT showed significant differences (p < .05) in color (CIE L*a*b*) and exhibited lower TBARS values compared with those without EFT. The addition of turmeric in the film, besides affecting its physicochemical and structural properties, contributed an important antioxidant effect for the meat.

The Use of Curcumin as a Complementary Therapy in Ulcerative Colitis: A Systematic Review of Randomized Controlled Clinical Trials

The objective of this study was to systematically review the literature to verify the efficacy and safety of curcumin as a complementary therapy for the maintenance or induction of remission in patients with inflammatory bowel disease (IBD). A comprehensive search was conducted by two independent authors in MEDLINE (PubMed), Scopus, Web of Science, the Cochrane Library, Lilacs, Food Science and Technology Abstracts, and ScienceDirect. The search terms “curcumin”, “curcuma”, “inflammatory bowel disease”, “proctocolitis”, “crohn disease”, and “inflammation” were combined to create search protocols. This study considered randomized controlled trials (RCTs) published in any language before March 2020 that evaluated the effects of curcumin on inflammatory activity and the maintenance or remission of IBD patients. After duplicates were removed, 989 trials were identified, but only 11 met the eligibility criteria. Five of these were considered to be biased and were excluded. Therefore, six trials were considered in this review. All the studies included in the systematic review were placebo-controlled RCTs conducted on individuals with ulcerative colitis (UC). All the RCTs reported that curcumin was well tolerated and was not associated with any serious side effects. Studies show that curcumin may be a safe, effective therapy for maintaining remission in UC when administered with standard treatments. However, the same cannot be stated for Crohn’s disease due to the lack of low bias risk studies. Further studies with larger sample sizes are needed before curcumin can be recommended as a complementary therapy for UC.

Topological and system-level protein interaction network (PIN) analyses to deduce molecular mechanism of curcumin

Curcumin is an important bioactive component of turmeric and also one of the important natural products, which has been investigated extensively. The precise mode of action of curcumin and its impact on system level protein networks are still not well studied. To identify the curcumin governed regulatory action on protein interaction network (PIN), an interectome was created based on 788 key proteins, extracted from PubMed literatures, and constructed by using STRING and Cytoscape programs. The PIN rewired by curcumin was a scale-free, extremely linked biological system. MCODE plug-in was used for sub-modulization analysis, wherein we identified 25 modules; ClueGo plug-in was used for the pathway’s enrichment analysis, wherein 37 enriched signalling pathways were obtained. Most of them were associated with human diseases groups, particularly carcinogenesis, inflammation, and infectious diseases. Finally, the analysis of topological characteristic like bottleneck, degree, GO term/pathways analysis, bio-kinetics simulation, molecular docking, and dynamics studies were performed for the selection of key regulatory proteins of curcumin-rewired PIN. The current findings deduce a precise molecular mechanism that curcumin might exert in the system. This comprehensive in-silico study will help to understand how curcumin induces its anti-cancerous, anti-inflammatory, and anti-microbial effects in the human body.

Influence of curcumin on performance and post-exercise recovery

Intense exercise, especially involving eccentric contractions, causes muscle damage concomitant with increased reactive oxygen species (ROS), which can lead to increased fatigue and decrements in physical performance. Additionally, inflammatory cytokines and advanced glycation end-products (AGEs) are produced as a result of eccentric exercise and may further lead to decreased exercise performance. Nutritional interventions may provide an avenue to respond to and reduce the symptoms associated with muscle damage. Of recent interest, curcumin, the main constituent in the spice turmeric, has been the focus of various studies considering post-exercise recovery. Curcumin has potent anti-oxidant and anti-inflammatory properties and can reduce the accumulation of AGEs. This review considers the current evidence for curcumin to impact muscle recovery following exercise to improve performance and the potential mechanisms of action. To date, clinical studies have considered the potential role of curcumin to reduce muscular damage following treadmill running (downhill and flat), conventional walking/running, cycling (acute and chronic), single-leg jumping (downhill), and eccentric muscular fitness exercises of the upper and lower body (single- and double-leg). Studies have been conducted in sedentary to highly active men and women, both young and old, with supplementation duration lasting from a single, acute dose to daily dosages for three months. Various curcumin-based interventions have improved self-perceived measures of pain and tenderness, reduced evidence of muscle damage, ameliorated inflammatory markers, increased markers of antioxidant capacity, diminished markers of oxidative stress, reduced markers of AGEs, and attenuated loss in mean power of single-leg sprints. However, these findings have not been consistently reported.

The anti-inflammatory and antioxidant effects of acute consumption of pigmented rice in humans

The pathogenesis of lifestyle diseases has been significantly correlated to high levels of oxidative stress and pro-inflammation. The antioxidant and anti-inflammatory properties of polyphenols in coloured rice varieties could have potential to neutralize oxidative stress and modulate inflammatory responses. A cross-over design, randomised, dietary intervention human clinical trial was conducted on a pre-screened healthy population (n = 24) investigating the antioxidant and anti-inflammatory potential of pigmented rice (purple, red and brown) varieties. Post baseline blood samples collection volunteers consumed a serve of cooked pigmented rice. Blood samples were collected at 30-minutes, 1, 2 and 4-hours post rice consumption. A one-week wash-out period between each supplementation bout (rice variety) was conducted. Blood and biochemical parameters were analysed on baseline blood samples. Antioxidant activity, malondialdehyde (MDA) and a pro-inflammatory cytokine panel were analysed on the blood samples collected. Post purple rice consumption, antioxidant activity increased (p < 0.0001) by 70.5% and maintained elevated for all time points. The red rice variety Yunlu29, significantly (p < 0.005) reduced MDA levels by 9.2% at the 30-minute time point. Purple rice demonstrated a significant (p < 0.05) decrease by 4.0% at the 30-minute time point only. Purple rice significantly decreased TNF-α levels at the 1-hour (p < 0.05) and 4-hour (p < 0.005) time points by 21.9% and 25.4% respectively. IL-6 concentrations were significantly reduced at 1 and 2-hour post Purple (p < 0.05; 11.7%) and Yunlu29 (red) (p < 0.01; 14.1%) consumption respectively. The brown rice variety did not affect any parameters tested. The outcomes of this study, highlight that polyphenols found in pigmented rice may play a key role in targeting specific oxidative stress and inflammatory therapeutic pathways. Pigmented rice varieties may serve as a potential functional food in reducing risk factors associated with lifestyle diseases.

Ameliorative effect of curcumin against lead acetate-induced hemato-biochemical alterations, hepatotoxicity, and testicular oxidative damage in rats

Lead, toxic heavy metal of global concern, induces toxicity in various organs via oxidative stress. Thereby, in this study, the protective role of curcumin against lead acetate-induced toxicity was evaluated. Thirty-two male albino rats were allocated equally into four groups and orally administered with corn oil as a vehicle (Cont.), curcumin (CUR) (400 mg/kg bw), lead acetate (LA) (100 mg/kg bw), and lead acetate plus curcumin (LA + CUR). All rats had received their treatments daily for 4 weeks. The results revealed that LA toxicity induced normocytic normochromic anemia with significant leukocytosis and lymphocytosis. Moreover, LA-intoxicated rats showed a marked elevation in the liver enzyme activities, serum cholesterol, and triglyceride levels. In contrast, sero-immunological parameters, total protein, albumin, globulin, and testosterone levels were significantly reduced compared to the control rats. Additionally, LA-induced hepatic and testicular oxidative damage revealed by marked increased in MDA level with prominent reduction in the antioxidant system. The gene expression of the hepatic pro-inflammatory markers and testicular steroidogenic biomarkers including LHR and aromatase were significantly upregulated; meanwhile, the expressions of testicular StAR, CYP17a, 3B-HDS, SR-B1, and P450SCC were significantly downregulated in the LA-intoxicated group. Curcumin treatment could partially improve the hematological, biochemical, and histopathological alterations induced by LA. Also, it was observed that curcumin significantly restored hepatic pro-inflammatory markers and testicular steroidogenic enzymes. In conclusion, curcumin has antioxidant, anti-inflammatory, and immunomodulatory effects and is able to minimize the LA-induced oxidative damage in rats.

Polypyrrole/Carbon Nanotube Freestanding Electrode with Excellent Electrochemical Properties for High-Performance All-Solid-State Supercapacitors

In this study, a facile and environmentally friendly method was used to prepare a freestanding supercapacitor electrode displaying excellent areal capacitance and good cycle life performance. First, we prepared polypyrrole nanoparticles (PPyNP) through a simple in situ chemical polymerization using the plant-derived material curcumin as a bioavailable template. A PPyNP/f-CNT freestanding composite electrode of high mass loading (ca. 14 mg cm^-2) was prepared after blending the mixtures of the prepared PPyNP and functionalized CNTs (f-CNTs). The performance of the as-prepared material as a supercapacitor electrode was evaluated in a three-electrode setup using aqueous 1 M H₂SO₄ as the electrolyte. The PPyNP/f-CNT freestanding composite electrode exhibited a high areal capacitance of 4585 mF cm^-2 and a corresponding volumetric capacitance of 176.35 F cm^-3 at a current density of 2 mA cm^-2. A symmetric all-solid-state supercapacitor assembled using two identical pieces of PPyNP/f-CNT composite electrodes exhibited maximum areal energy and power density of 129.24 μW h cm^-2 and 12.5 mW cm^-2, respectively. Besides, this supercapacitor device exhibited good cycle life performance, with 79.03% capacitance retention after 10,000 charge/discharge cycles. These results suggest practical applications for these PPyNP/f-CNT freestanding composite electrode-based symmetric all-solid-state supercapacitors.

Therapeutic Potential of Curcumin in the Treatment of Glioblastoma Multiforme

Glioblastoma multiforme (GBM) is the most common primary malignant brain tumor. Despite standard multimodality treatment, the highly aggressive nature of GBM makes it one of the deadliest human malignancies. The anti-cancer effects of dietary phytochemicals like curcumin provide new insights to cancer treatment. Evaluation of curcumin's efficacy against different malignancies including glioblastoma has been a motivational research topic and widely studied during the recent decade. In this review, we discuss the recent observations on the potential therapeutic effects of curcumin against glioblastoma. Curcumin can target multiple signaling pathways involved in developing aggressive and drug-resistant features of glioblastoma, including pathways associated with glioma stem cell activity. Notably, combination therapy with curcumin and chemotherapeutics like temozolomide, the GBM standard therapy, as well as radiotherapy has shown synergistic response, highlighting curcumin's chemo- and radio-sensitizing effect. There are also multiple reports for curcumin nanoformulations and targeted forms showing enhanced therapeutic efficacy and passage through blood-brain barrier, as compared with natural curcumin. Furthermore, in vivo studies have revealed significant anti-tumor effects, decreased tumor size and increased survival with no notable evidence of systemic toxicity in treated animals. Finally, a pharmacokinetic study in patients with GBM has shown a detectable intratumoral concentration, thereby suggesting a potential for curcumin to exert its therapeutic effects in the brain. Despite all the evidence in support of curcumin's potential therapeutic efficacy in GBM, clinical reports are still scarce. More studies are needed to determine the effects of combination therapies with curcumin and importantly to investigate the potential for alleviating chemotherapy- and radiotherapy-induced adverse effects.

Sarco/Endoplasmic Reticulum Calcium ATPase Inhibitors: Beyond Anticancer Perspective

The sarco/endoplasmic reticulum calcium ATPase (SERCA), which plays a key role in the maintenance of Ca²⁺ ion homeostasis, is an extensively studied enzyme, the inhibition of which has a considerable impact on cell life and death decision. To date, several SERCA inhibitors have been thoroughly studied and the most notable one, a derivative of the sesquiterpene lactone thapsigargin, is gradually approaching a clinical application. Meanwhile, new compounds with SERCA-inhibiting properties of natural, synthetic, or semisynthetic origin are being discovered and/or developed; some of these might also be suitable for the development of new drugs with improved performance. This review brings an up-to-date comprehensive overview of recently discovered compounds with the potential of SERCA inhibition, discusses their mechanism of action, and highlights their potential clinical applications, such as cancer treatment.

Curcumin's Nanomedicine Formulations for Therapeutic Application in Neurological Diseases

The brain is the body's control center, so when a disease affects it, the outcomes are devastating. Alzheimer's and Parkinson's disease, and multiple sclerosis are brain diseases that cause a large number of human deaths worldwide. Curcumin has demonstrated beneficial effects on brain health through several mechanisms such as antioxidant, amyloid β-binding, anti-inflammatory, tau inhibition, metal chelation, neurogenesis activity, and synaptogenesis promotion. The therapeutic limitation of curcumin is its bioavailability, and to address this problem, new nanoformulations are being developed. The present review aims to summarize the general bioactivity of curcumin in neurological disorders, how functional molecules are extracted, and the different types of nanoformulations available.

Highlighting Curcumin-Induced Crosstalk between Autophagy and Apoptosis as Supported by Its Specific Subcellular Localization

Curcumin, a major active component of turmeric (Curcuma longa, L.), is known to have various effects on both healthy and cancerous tissues. In vitro studies suggest that curcumin inhibits cancer cell growth by activating apoptosis, but the mechanism underlying the anticancer effect of curcumin is still unclear. Since there is a recent consensus about endoplasmic reticulum (ER) stress being involved in the cytotoxicity of natural compounds, we have investigated using Image flow cytometry the mechanistic aspects of curcumin's destabilization of the ER, but also the status of the lysosomal compartment. Curcumin induces ER stress, thereby causing an unfolded protein response and calcium release, which destabilizes the mitochondrial compartment and induce apoptosis. These events are also associated with secondary lysosomal membrane permeabilization that occurs later together with an activation of caspase-8, mediated by cathepsins and calpains that ended in the disruption of mitochondrial homeostasis. These two pathways of different intensities and momentum converge towards an amplification of cell death. In the present study, curcumin-induced autophagy failed to rescue all cells that underwent type II cell death following initial autophagic processes. However, a small number of cells were rescued (successful autophagy) to give rise to a novel proliferation phase.

Synthesis, Anticancer Activity, and Preliminary Pharmacokinetic Evaluation of 4,4-Disubstituted Curcuminoid 2,2-bis(Hydroxymethyl)Propionate Derivatives

Compound 1 is a curcumin di-O-2,2-bis(hydroxymethyl)propionate that shows significant in vitro and in vivo inhibitory activity against MDA-MB-231 cells with eight to ten-fold higher potency than curcumin. Here, we modified the α-position (C-4 position) of the central 1,3-diketone moiety of 1 with polar or nonpolar functional groups to afford a series of 4,4-disubstituted curcuminoid 2,2-bis(hydroxymethyl)propionate derivatives and evaluated their anticancer activities. A clear structure-activity relationship of compound 1 derivatives focusing on the functional groups at the C-4 position was established based on their anti-proliferative effects against the MDA-MB-231 and HCT-116 cell lines. Compounds 2-6 are 4,4-dimethylated, 4,4-diethylated, 4,4-dibenzylated, 4,4-dipropargylated and 4,4-diallylated compound 1, respectively. Compounds 2m-6m, the ester hydrolysis products of compounds 2-6, respectively, were synthesized and assessed for anticancer activity. Among all compound 1 derivatives, compound 2 emerged as a potential chemotherapeutic agent for colon cancer due to the promising in vivo anti-proliferative activities of 2 (IC50 = 3.10 ± 0.29 μM) and its ester hydrolysis product 2m (IC50 = 2.17 ± 0.16 μM) against HCT-116. The preliminary pharmacokinetic evaluation of 2 implied that 2 and 2m are main contributors to the in vivo efficacy. Compound 2 was further evaluated in an animal study using HCT-116 colon tumor xenograft bearing nude mice. The results revealed a dose-dependent efficacy that led to tumor volume reductions of 27%, 45%, and 60% at 50, 100, and 150 mg/kg doses, respectively. The established structure-activity relationship and pharmacokinetic outcomes of 2 is the guidance for future development of 4,4-disubstituted curcuminoid 2,2-bis(hydroxymethyl)- propionate derivatives as anticancer drug candidates.

Curcumin-loaded polysaccharides-based complex particles obtained by polyelectrolyte complexation and ionic gelation. I-Particles obtaining and characterization

Curcumin has essential therapeutic benefits, but it is insoluble in water and thus has low bioavailability. This study aimed to immobilize curcumin into new polysaccharide-based microparticles (gellan, i-carrageenan, and chitosan) to increase its stability and bioavailability. Curcumin-loaded complex microparticles were obtained from three polysaccharides, of different ionic character, by ionic cross-linking and polyelectrolyte complexation. The immobilization efficiency was between 85.75% and 97.25%. The microparticles were characterized morphologically by SEM, and it was observed that the microparticles containing the i-carrageenan had a more pronounced porosity of the matrix. The swelling degree values at pH = 7.4 were superior to those obtained at pH = 6.8 or pH = 2 and depend on both the cross-linking degree and particles morphology. The polysaccharides microparticles, curcumin, and constituent polysaccharides were characterized by FT-IR spectroscopy. The curcumin release kinetics was studied in three different pH media, and the release efficiency ranged between 65.1% and 97.9% at pH = 7.4, between 60.2% and 82.2% at pH = 6.8 and between 56.1% and 64.0% at pH = 2. These microparticles can be intended for oral administration, having as therapeutic target the colon, for the controlled release of curcumin, since they can overcome the gastric barrier without the degradation of the active principle, which is protected by the polymer matrix.

Curcumin–polymer conjugates with dynamic boronic acid ester linkages for selective killing of cancer cells

A phenylboronic acid (PBA)-containing copolymer was synthesized via the Hantzsch reaction and radical polymerization. Curcumin was dynamically included in this PBA-containing polymer to selectively kill cancer cells.