Recent Advances in Liposomal Drug Delivery System of Quercetin for Cancer Targeting: A Mechanistic Approach

Therapeutic Implications of Dietary Polyphenols-Loaded Nanoemulsions in Cancer Therapy

Cancer is one of the major causes of death worldwide, even the second foremost cause related to non-communicable diseases. Cancer cells typically possess several cellular and biological processes including, persistence, propagation, differentiation, cellular death, and expression of cellular-type specific functions. The molecular picture of carcinogenesis and progression is unwinding, and it appears to be a tangled combination of processes occurring within and between cancer cells and their surrounding tissue matrix. Polyphenols are plant secondary metabolites abundant in fruits, vegetables, cereals, and other natural plant sources. Natural polyphenols have implicated potential anticancer activity by various mechanisms involved in their antitumor action, including modulation of signaling pathways majorly related to cellular proliferation, differentiation, relocation, angiogenesis, metastatic processes, and cell death. The applications of polyphenols have been limited due to the hydrophobic nature and lower oral bioavailability that could be possibly overcome through encapsulating them into nanocarrier-mediated delivery systems, leading to improved anticancer activity. Nanoemulsions (NEs) possess diverse feasible properties, including greater surface area, modifiable surficial charge, higher half-life, site-specific targeting, and formulation imaging capability necessary to create a practical therapeutic impact, and have drawn increased attention in cancer therapy research. This review has summarized and discussed the basic concepts, classification, delivery approaches, and anticancer mechanism of various polyphenols and polyphenols-encapsulated nanoemulsions with improved cancer therapy.

Cannabidiol-Loaded Nanocarriers and Their Therapeutic Applications

Cannabidiol (CBD), one of the most promising constituents isolated from Cannabis sativa, exhibits diverse pharmacological actions. However, the applications of CBD are restricted mainly due to its poor oral bioavailability. Therefore, researchers are focusing on the development of novel strategies for the effective delivery of CBD with improved oral bioavailability. In this context, researchers have designed nanocarriers to overcome limitations associated with CBD. The CBD-loaded nanocarriers assist in improving the therapeutic efficacy, targetability, and controlled biodistribution of CBD with negligible toxicity for treating various disease conditions. In this review, we have summarized and discussed various molecular targets, targeting mechanisms and types of nanocarrier-based delivery systems associated with CBD for the effective management of various disease conditions. This strategic information will help researchers in the establishment of novel nanotechnology interventions for targeting CBD.

Flavonoids as new regulators of mitochondrial potassium channels: contribution to cardioprotection

Objectives

Acute myocardial ischemia is one of the major causes of illness in western society. Reduced coronary blood supply leads to cell death and loss of cardiomyocyte population, resulting in serious and often irreversible consequences on myocardial function. Mitochondrial potassium (mitoK) channels have been identified as fine regulators of mitochondrial function and, consequently, in the metabolism of the whole cell, and in the mechanisms underlying the cardioprotection. Interestingly, mitoK channels represent a novel putative target for treating cardiovascular diseases, particularly myocardial infarction, and their modulators represent an interesting tool for pharmacological intervention. In this review, we took up the challenge of selecting flavonoids that show cardioprotective properties through the activation of mitoK channels.

Key findings

A brief overview of the main information on mitoK channels and their participation in the induction of cytoprotective processes was provided. Then, naringenin, quercetin, morin, theaflavin, baicalein, epigallocatechin gallate, genistein, puerarin, luteolin and proanthocyanidins demonstrated to be effective modulators of mitoK channels activity, mediating many beneficial effects.

Summary

The pathophysiological role of mitoK channels has been investigated as well as the impact of flavonoids on this target with particular attention to their potential role in the prevention of cardiovascular disorders.

Molecular insights and therapeutic implications of nanoengineered dietary polyphenols for targeting lung carcinoma: part I

Lung cancer is the second leading cause of cancer-related mortality globally, and non-small-cell lung cancer accounts for most lung cancer cases. Nanotechnology-based drug-delivery systems have exhibited immense potential in lung cancer therapy due to their fascinating physicochemical characteristics, in vivo stability, bioavailability, prolonged and targeted delivery, gastrointestinal absorption and therapeutic efficiency of their numerous chemotherapeutic agents. However, traditional chemotherapeutics have systemic toxicity issues; therefore, dietary polyphenols might potentially replace them in lung cancer treatment. Polyphenol-based targeted nanotherapeutics have demonstrated interaction with a multitude of protein targets and cellular signaling pathways that affect major cellular processes. This review summarizes the various molecular mechanisms and targeted therapeutic potentials of nanoengineered dietary polyphenols in the effective management of lung cancer.

Liposomal Drug Delivery And Its Potential Impact On Cancer Research

Liposomes are one of the most versatile drug carriers due to their functional properties, such as higher biocompatibility, the ability to encapsulate hydrophilic and hydrophobic products, and higher biodegradability. Liposomes are a better and more significant nanocarrier for cancer therapy. The key to developing a better cancer-targeted nanocarrier is the development of targeted liposomes using various approaches. Several traditional and novel liposome preparation methods are briefly discussed in this mini-review. The current state of liposome targeting, active and passive liposome targeting in cancer therapy, ligand directed targeting (antibody, aptamer, and protein/peptide-mediated targeting), and other miscellaneous approaches such as stimuli-responsive liposome-based targeting, autophagy inhibition mediated targeting, and curcumin loaded liposomal targeting are all discussed within. All of this gathered and compiled information will shed new light on liposome targeting strategies in cancer treatment and will pique the interest of aspiring researchers and academicians.

Antitumor and hepatoprotective effect of Cuscuta reflexa Roxb. in a murine model of colon cancer

ETHNOPHARMACOLOGICAL RELEVANCE

Cuscuta reflexa Roxb. (C. reflexa) is a well-known traditional herbal plant, with numerous inherent therapeutic potentials including anticancer, antitumor, antibacterial, analgesic, anthelmintic, laxative and others. Moreover, the anticancer and antitumor potentials of this herb are ongoing with several trails, thus an attempt was made to assess the anticancer and hepatoprotective potentials of traditional C. reflexa herbs.

METHOD

The dried ethanolic extract of C. reflexa was tested for acute oral toxicity in the treated animals subsequently their behavioral, neurological, and autonomic profiles changes were observed. The preliminary anti-cancer effects of extracts against 1, 2- Dimethyl hydrazine (DMH) induced animals were assessed through barium enema X-ray, colonoscopy, and Aberrant crypt foci (ACF) studies. The blood samples of the animals (treated and untreated) were collected and their in-vitro histological parameters were evaluated by the experienced technician.

RESULTS

It was observed that C. reflexa significantly reduced Disease activity indexing (DAI) level and ACF counting, as well as demonstrated similar activity as of the standard drug 5-Fluorouracil (5-FU). Histopathological results revealed that the apoptotic bodies decreased in the DMH-induced group (group II) during cancer progression while in 5-FU treated (group III) and C. reflexa treated (group IV and V) animals the apoptotic bodies were increased. Inversely, the mitotic bodies increased in group II animals and reduced in group III, IV, and V animals. In the colonic section, DMH-induced cancer assay exhibited significant effects on the levels of hemoglobin, Packed cell volume (PCV), Red blood cell (RBC) counts, Mean corpuscular hemoglobin concentration (MCHC), Mean corpuscular volume (MCV), and Mean cell hemoglobin (MCH), and was found to be less in group II animals whereas administration of C. reflexa efficiently recovered back the loss probably by healing the colon damage/depletion of cancer progression. Moreover, compared to the group II animals, the neutrophil count was within the normal range in C. reflexa administered group.

CONCLUSIONS

In the present study, the major hematological parameters significantly increased within DMH treated animals and exhibited extensive damage in the hepatic regions. Moreover, the histopathological findings demonstrated that the C. reflexa extracts potentially reduced the cell proliferation, with no toxicity. The C. reflexa extracts exhibited impending anti-cancer activity as well as protected the hepatic cells and thus could be potentially used in the management of colon or colorectal cancer and hepatic impairments.

O-Glycoside quercetin derivatives: Biological activities, mechanisms of action, and structure-activity relationship for drug design, a review

Quercetin as a valuable natural flavonoid has shown extensive biological activities, including anticancer, antioxidant, antibacterial, antiinflammatory, anti-Alzheimer, antifungal, antiviral, antithalassemia, iron chelation, antiobesity, antidiabetic, antihypertension, and antiphospholipase A2 (PLA2) activities, by the modulation of various targets and signaling pathways that have attracted much attention. However, the low solubility and poor bioavailability of quercetin have limited its applications; therefore, the researchers have tried to design and synthesize many new derivatives of quercetin through different strategies to modify quercetin restrictions and improve its biological activities. This review categorized the O-glycoside derivatives of Quercetin into two main classes, 3-O-glycoside and other O-glycoside derivatives. Also, it studied biological activities, structure-activity relationship (SAR), and the action mechanism of O-glycoside quercetin derivatives. Overall, we summarized past and present research for discovering new potent lead compounds.

Quercetin derivatives: Drug design, development, and biological activities, a review

More studies are needed to develop new drugs for problems associated with drug resistance and unfavorable side effects. The natural flavonoid of quercetin revealed a wide range of biological activities by the modulation of various targets and signaling pathways. However, quercetin's low solubility and poor bioavailability have restricted its applicability; as a result, researchers have attempted to design and synthesize numerous novel quercetin derivatives using various methodologies in order to modify quercetin's constraints; the physico-chemical properties of quercetin's molecular scaffold make it appealing for drug development; low molecular mass and chemical groups are two of these characteristics. Therefore, the biological activities of quercetin derivatives, as well as the relationship between activity and chemical structure and their mechanism of action, were investigated. These quercetin-based molecules could be valuable in the creation and discovery of medications for a number of diseases.

Quercetin inhibits the proliferation of multiple myeloma cells by upregulating PTPRR expression

Multiple myeloma (MM) is an incurable disease characterized by malignant plasma cell clonal expansion in the bone marrow; therefore, inhibiting the proliferation of plasma cells is an important approach to overcome the progression of MM. Quercetin (Que) is a promising flavonoid with broad-spectrum anti-tumor activity against various cancers, including MM; however, the underlying mechanism is not yet understood. The present study aimed to reveal the gene expression profile of Que-treated MM cells and clarify its potential mechanism. The 30% inhibitory concentration (IC30) of Que against MM cells was calculated, and the proliferation rate was significantly reduced after Que treatment. Next, 495 dysregulated genes were identified via RNA sequencing in Que-treated MM cells. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes analyses indicated that the dysregulated genes were enriched in various apoptosis-related GO terms and amino acid metabolism-related pathways. qPCR validation showed that protein tyrosine phosphatase receptor-type R (PTPRR) had the highest verified log2 FC (abs) among the top 15 dysregulated genes. Overexpression of PTPRR increased the sensitivity of MM cells against Que, significantly inhibiting their proliferation and colony formation ability; silencing of PTPRR showed the opposite results. Furthermore, bioinformatics analyses and PPI network construction of PTPRR indicated that dephosphorylation of ERK might be the potential pathway for the PTPRR-induced inhibition of MM cell proliferation. In summary, our study identified the gene expression profile in Que-treated MM cells and demonstrated that the upregulation of PTPRR was one of the important mechanisms for the Que-induced inhibition of MM cell proliferation.

Cytoprotective effects of the flavonoid quercetin by activating mitochondrial BKCa channels in endothelial cells

Mitochondrial potassium channels have been implicated in cytoprotective mechanisms. Activation of the mitochondrial large-conductance Ca²⁺-regulated potassium (mitoBK_Ca) channel is important for protecting brain tissue against stroke damage as well as heart tissue against ischemia damage. In this paper, we examine the effect of the natural flavonoid quercetin as an activator of the mitoBK_Ca channel. Quercetin has a beneficial effect on many processes in the human body and interacts with many receptors and signaling pathways. We found that quercetin acts on mitochondria as a mitoBK_Ca channel opener. The activation observed with the patch-clamp technique was potent and increased the channel open probability from approximately 0.35 to 0.95 at + 40 mV in the micromolar concentration range. Moreover, quercetin at a concentration of 10 µM protected cells by reducing damage from treatment factors (tumor necrosis factor α and cycloheximide) by 40%, enhancing cellular migration and depolarizing the mitochondrial membrane. Moreover, the presence of quercetin increased the gene expression and protein level of the mitoBK_Ca β3 regulatory subunit. The observed cytoprotective effects suggested the involvement of BK_Ca channel activation. Additionally, the newly discovered mitoBK_Ca activator quercetin elucidates a new mitochondrial pathway that is beneficial for vascular endothelial cells.

Comparison of Polysaccharides as Coatings for Quercetin-Loaded Liposomes (QLL) and Their Effect as Antioxidants on Radical Scavenging Activity

Liposomes are microstructures containing lipid and aqueous phases employed in the encapsulation and delivery of bioactive agents. Quercetin-loaded liposomes (QLLs) were coated with three different polysaccharides and then tested as radical scavengers. Lactose (LCQLL), chitosan (CCQLL), and inulin (ICQLL) were employed as coating materials. Particle size determined by light scattering, showed primary size of 200 nm for all samples, while a secondary particle size of 600 nm was observed for CCQLL. Scanning electron microscopy (SEM) evidenced particle aggregation with the addition of the polysaccharide coating. Transmission electron microscopy (TEM) revealed the layered microstructure of liposomes composed of at least two layers, and primary particle size below 100 nm. QLL showed higher antioxidant activity than the coated liposomes. This behavior was attributed to the chemical interaction between quercetin and the corresponding coating polysaccharide in the layered structure, which traps the quercetin and keeps it unavailable for radical scavenging. From the three polysaccharides, lactose showed a better performance as coating material in the antioxidant activity, which suggested that the smaller size of the disaccharide molecule resulted in a faster releasing of the quercetin in the solution. Thus, LCQLL is an advantageous way to deliver quercetin for antioxidant purposes, where the low stability in delivered media of quercetin loaded liposomes is commonly compromised.

Selective targeting of cancer signaling pathways with nanomedicines: challenges and progress

Cancer is one of the leading causes of death worldwide. Regardless of advances in understanding the molecular mechanics of cancer, its treatment is still lacking and the death rates for many forms of the disease remain the same as six decades ago. Although a variety of therapeutic agents and strategies have been reported, these therapies often failed to provide efficient therapy to patients as a consequence of the inability to deliver right and adequate chemotherapeutic agents to the right place. However, the situation has started to revolutionize substantially with the advent of novel 'targeted' nanocarrier-based cancer therapies. Such therapies hold great potential in cancer management as they are biocompatible, tailored to specific needs, tolerated and deliver enough drugs at the targeted site. Their use also enhances the delivery of chemotherapeutics by improving biodistribution, lowering toxicity, inhibiting degradation and increasing cellular uptake. However, in some instances, nonselective targeting is not enough and the inclusion of a ligand moiety is required to achieve tumor targeting and enhanced drug accumulation at the tumor site. This contemporary review outlines the targeting potential of nanocarriers, highlighting the essentiality of nanoparticles, tumor-associated molecular signaling pathways, and various biological and pathophysiological barriers.

Crystal Growth and Kinetic Behaviour of Pseudoalteromonas espejiana Assisted Biosynthesized Gold Nanoparticles

Pseudoalteromonas espejiana (P. espejiana) is a marine bacterium known for its high resistance to alkalinity. The ability of P. espejiana to reduce Au (III) and biosynthesize gold nanoparticles (AuNPs) is found positive and was confirmed using UV-VIS, EDS, SEM, and TEM studies. Previously, many studies have been reported regarding the crystalline nature of AuNPs; therefore, this research aims at studying the crystal growth behaviour of AuNPs through DLS and TEM studies. Spherically shaped and monodispersed, AuNPs ranging between 5 to 160 nm were obtained with an average particle size of 62 nm. Also, to achieve maximum production of AuNPs, the reaction kinetic study was performed using an ICP-OES method and the effect of various parameters including pH, temperature, rpm, and concentration of substrate was analyzed. During the biosynthesis process, an appropriate phase of nucleation, crystal growth, and saturation was observed and this helped to determine the rate constants and order of reaction. The parameters such as pH profile (pH 9), temperature (30°C), agitation speed (150 rpm), and enzyme substrate ratio (2 : 3) were found to be the best fits for maximum production of low size AuNPs. This demonstrates that in initial few hours, a quick conversion of the ionic gold precursor takes place into metallic gold nuclei, trailed by crystal growth via coalescence of small nuclei. Subsequently, it can be concluded that coalescence processes drive the crystal growth process of AuNPs over a time interval and finally leads to saturation and no newer particle formation in the solution.

Stimuli-Responsive Polymeric Nanocarriers for Drug Delivery, Imaging, and Theragnosis

In the past few decades, polymeric nanocarriers have been recognized as promising tools and have gained attention from researchers for their potential to efficiently deliver bioactive compounds, including drugs, proteins, genes, nucleic acids, etc., in pharmaceutical and biomedical applications. Remarkably, these polymeric nanocarriers could be further modified as stimuli-responsive systems based on the mechanism of triggered release, i.e., response to a specific stimulus, either endogenous (pH, enzymes, temperature, redox values, hypoxia, glucose levels) or exogenous (light, magnetism, ultrasound, electrical pulses) for the effective biodistribution and controlled release of drugs or genes at specific sites. Various nanoparticles (NPs) have been functionalized and used as templates for imaging systems in the form of metallic NPs, dendrimers, polymeric NPs, quantum dots, and liposomes. The use of polymeric nanocarriers for imaging and to deliver active compounds has attracted considerable interest in various cancer therapy fields. So-called smart nanopolymer systems are built to respond to certain stimuli such as temperature, pH, light intensity and wavelength, and electrical, magnetic and ultrasonic fields. Many imaging techniques have been explored including optical imaging, magnetic resonance imaging (MRI), nuclear imaging, ultrasound, photoacoustic imaging (PAI), single photon emission computed tomography (SPECT), and positron emission tomography (PET). This review reports on the most recent developments in imaging methods by analyzing examples of smart nanopolymers that can be imaged using one or more imaging techniques. Unique features, including nontoxicity, water solubility, biocompatibility, and the presence of multiple functional groups, designate polymeric nanocues as attractive nanomedicine candidates. In this context, we summarize various classes of multifunctional, polymeric, nano-sized formulations such as liposomes, micelles, nanogels, and dendrimers.