Formulation and Characterization of Quercetin-loaded Oil in Water Nanoemulsion and Evaluation of Hypocholesterolemic Activity in Rats

Preparation, characterization and antioxidant and anticancerous potential of Quercetin loaded β-glucan particles derived from mushroom and yeast

β-glucans are polysaccharides found in the cell walls of various fungi, bacteria and cereals. β-glucan have been found to show various kinds of anti-inflammatory, antimicrobial, antidiabetic antioxidant and anticancerous activities. In the present study, we have isolated β-glucan from the baker's yeast Saccharomyces cerevisiae and white button mushroom Agaricus bisporus and tested their antioxidant potential and anticancerous activity against prostate cancer cell line PC3. Particles were characterized with zeta sizer and further with FTIR that confirmed that the isolated particles are β-glucan and alginate sealing made slow and sustained release of the Quercetin from the β-glucan particles. Morphological analysis of the hollow and Quercetin loaded β-glucan was performed with the SEM analysis and stability was analyzed with TGA and DSC analysis that showed the higher stability of the alginate sealed particles. Assessments of the antioxidant potential showed that Quercetin loaded particles were having higher antioxidant activity than hollow β-glucan particles. Cell viability of the PC3 cells was examined with MTT assay and it was found that Quercetin loaded alginate sealed Agaricus bisporus derived β-glucan particles were having lowest IC50. Further ROS generation was found to increase in a dose dependent manner. Apoptosis detection was carried out with Propidium iodide and AO/EtBr staining dye which showed significant death in the cells treated with higher concentration of the particles. Study showed that particles derived from both of the sources were having efficient anticancer activity and showing a dose dependent increase in cell death in PC3 cells upon treatment.

Enhancing the Topical Antibacterial Activity of Fusidic Acid via Embedding into Cinnamon Oil Nano-Lipid Carrier

Presently, antimicrobial resistance is of great risk to remarkable improvements in health conditions and infection management. Resistance to various antibiotics has been considered a great obstacle in their usage, necessitating alternative strategies for enhancing the antibacterial effect. Combination therapy has been recognized as a considerable strategy that could improve the therapeutic influence of antibacterial agents. Therefore, the aim of this study was to combine the antibacterial action of compounds of natural origin like fusidic acid (FA) and cinnamon essential oil (CEO) for synergistic effects. A distinctive nanoemulsion (NE) was developed using cinnamon oil loaded with FA. Applying the Box-Behnken design (BBD) approach, one optimized formula was selected and integrated into a gel base to provide an FA-NE-hydrogel for optimal topical application. The FA-NE-hydrogel was examined physically, studied for in vitro release, and investigated for stability upon storage at different conditions, at room (25 °C) and refrigerator (4 °C) temperatures, for up to 3 months. Ultimately, the NE-hydrogel preparation was inspected for its antibacterial behavior using multidrug-resistant bacteria and checked by scanning electron microscopy. The FA-NE-hydrogel formulation demonstrated a pH (6.32), viscosity (12,680 cP), and spreadability (56.7 mm) that are acceptable for topical application. The in vitro release could be extended for 6 h, providing 52.0%. The formulation was stable under both test conditions for up to 3 months of storage. Finally, the FA-NE-hydrogel was found to inhibit the bacterial growth of not only Gram-positive but also Gram-negative bacteria. The inhibition was further elucidated by a scanning electron micrograph, indicating the efficiency of CEO in enhancing the antibacterial influence of FA when combined in an NE system.

Effects of Quercetin Nanoemulsion on Cholesterol Efflux and MicroRNA-33/34a Expression in the Liver of Mice Fed with a High-Cholesterol Diet

Quercetin is a flavonoid widely present in plants; despite its beneficial physiological activity, it exhibits considerably low bioavailability. Nanoemulsion technology is used for improving the bioavailability of lipophilic phenolic compounds. This study aimed to investigate the potential effects of quercetin nanoemulsion (QN) on regulating the microRNA (miR)-33/34a pathway involved in cholesterol efflux in the liver of mice fed with a high-cholesterol (HC) diet. Subsequently, C57BL/6J mice were divided into four groups and fed a normal chow diet, HC diet supplemented with 1% cholesterol and 0.5% cholic acid, or HC diet supplemented with 0.05% QN or 0.1% QN for 6 weeks. Serum and hepatic lipid profiles were assayed using commercial enzymatic kits. Gene expression and miR levels were quantified using real-time quantitative reverse transcription polymerase chain reaction, and adenosine monophosphate-activated protein kinase (AMPK) activity was measured using an AMPK Kinase Assay kit. QN supplementation improved serum and liver lipid profiles. QN upregulated the mRNA levels of adenosine triphosphate (ATP)-binding cassette subfamily A1, ATP-binding cassette subfamily G1, and scavenger receptor class B type 1, which are related to cholesterol efflux. In the QN group, the hepatic AMPK activity increased, whereas miR-33, and miR-34a expression levels decreased. These results suggest that QN may enhance cholesterol efflux, at least partly through modulating AMPK activity and miR-33/34a expression in the liver.

Lipid-Based Delivery Systems for Flavonoids and Flavonolignans: Liposomes, Nanoemulsions, and Solid Lipid Nanoparticles

Herbal chemicals with a long history in medicine have attracted a lot of attention. Flavonolignans and flavonoids are considered as two classes of the above-mentioned compounds with different functional groups which exhibit several therapeutic capabilities such as antimicrobial, anti-inflammatory, antioxidant, antidiabetic, and anticancer activities. Based on the studies, high hydrophobic properties of the aforementioned compounds limit their bioavailability inside the human body and restrict their wide application. Nanoscale formulations such as solid lipid nanoparticles, liposomes, and other types of lipid-based delivery systems have been introduced to overcome the above-mentioned challenges. This approach allows the aforementioned hydrophobic therapeutic compounds to be encapsulated between hydrophobic structures, resulting in improving their bioavailability. The above-mentioned enhanced delivery system improves delivery to the targeted sites and reduces the daily required dosage. Lowering the required daily dose improves the performance of the drug by diminishing its side effects on non-targeted tissues. The present study aims to highlight the recent improvements in implementing lipid-based nanocarriers to deliver flavonolignans and flavonoids.

Recent Advances in Nanoformulations for Quercetin Delivery

Quercetin (QUE) is a flavonol that has recently received great attention from the research community due to its important pharmacological properties. However, QUE's low solubility and extended first-pass metabolism limit its oral administration. This review aims to present the potential of various nanoformulations in the development of QUE dosage forms for bioavailability enhancement. Advanced drug delivery nanosystems can be used for more efficient encapsulation, targeting, and controlled release of QUE. An overview of the primary nanosystem categories, formulation processes, and characterization techniques are described. In particular, lipid-based nanocarriers, such as liposomes, nanostructured-lipid carries, and solid-lipid nanoparticles, are widely used to improve QUE's oral absorption and targeting, increase its antioxidant activity, and ensure sustained release. Moreover, polymer-based nanocarriers exhibit unique properties for the improvement of the Absorption, Distribution, Metabolism, Excretion, and Toxicology (ADME(T)) profile. Namely, micelles and hydrogels composed of natural or synthetic polymers have been applied in QUE formulations. Furthermore, cyclodextrin, niosomes, and nanoemulsions are proposed as formulation alternatives for administration via different routes. This comprehensive review provides insight into the role of advanced drug delivery nanosystems for the formulation and delivery of QUE.

Quantification of the Quercetin Nanoemulsion Technique Using Various Parameters

Natural antioxidant polyphenolic compounds obtained from different plants are considered antioxidants for curing various chronic pathological diseases such as cardiovascular disorders and cancer. Quercetin (a polyphenolic flavonol) has attracted much attention from dietitians and medicinal chemists due to its wide variety of pharmacological activities, including anti-diabetic, anti-hypertensive, anti-carcinogenic, anti-asthmatic, anti-viral, and antioxidant activities. Furthermore, structurally, it is well suited to stabilize emulsions. The present review depicts the important role of the quercetin nanoemulsion technique, used to enhance the solubility of target materials both in vivo and in vitro as well as to decrease the risk of degradation and metabolism of drugs. Researchers have used cryo-TEM to study the morphology of quercetin nanoemulsions. The effects of various parameters such as pH, salts, and solvent concentration on quercetin nanoemulsion have been investigated for quercetin nanoemulsion. Many studies have used UV–Vis spectroscopy and HPLC for the characterization of these particles such as solubility, stability, and encapsulating efficiency.

Pearls before Swine: Plant-Derived Wastes to Produce Low-Cholesterol Meat from Farmed Pigs-A Bibliometric Analysis Combined to Meta-Analytic Studies

Due to environmental and human factors, there is a growing amount of agri-food waste worldwide. The European Commission is incentivizing a zero-waste policy by 2025, pushing to find a "second life" for at least the avoidable ones. In this review, after summarizing the nutritional values of pork and the importance of its inclusion in human diet, a phylogenetic analysis was conducted to investigate potential differences in the structure and activity of HMGCR, which is a key enzyme in cholesterol metabolism. In addition, a bibliometric analysis combined with visual and meta-analytical studies on 1047 scientific articles was conducted to understand whether the inclusion of agro-food waste could affect the growth performance of pigs and reduce cholesterol levels in pork. Although some critical issues were highlighted, the overall data suggest a modern and positive interest in the reuse of agri-food waste as swine feed. However, although interesting and promising results have been reported in several experimental trials, further investigation is needed, since animal health and meat quality are often given marginal consideration.

Development of Phosphatidylcholine/Tween 80 based biocompatible clove oil-in-water nanoemulsion as a green nanocarrier for controlled herbicide delivery

Recently, the development of ecofriendly and biocompatible agrochemical delivery systems has garnered widespread attention because of their great potential in sustainable agri-food applications. Atrazine (ATZ) is a globally used herbicide used to control weeds, but it suffers from poor aqueous solubility, poor efficacy, and environmental loss. Herein, we report a novel, eco-friendly and biocompatible clove oil-based nanoemulsion as a green nanocarrier to enhance the solubility, bioavailability, and control release of ATZ. Food grade surfactants, Tween 80 and Phosphatidylcholine (PC) were used to formulate clove oil nanoemulsion with size <200 nm using ultrasonic emulsification technique, without any use of organic solvent. The ATZ encapsulation efficiency in NEm was greater than 95%. DLS confirms the nanosize (106 nm) and monodispersity of NEm. HRTEM reveals the spherical morphology of the nanodroplets. FTIR and DSC confirm the successful incorporation of ATZ inside the NEm oil droplet core. ATZ loaded NEm showed excellent thermal and storage stability, low Ostwald ripening rate, slow and sustained herbicide release behavior, which is of vital importance for an herbicide formulation. The release rate was better than commercial ATZ and free ATZ formulations. Results from herbicidal activity assays demonstrate that ATZ NEm exhibited excellent herbicidal activity even at low concentrations as compared to commercial ATZ analogs. In consideration of biocompatible excipients, free of organic solvent, and a simple fabrication process, ATZ loaded clove oil NEm can hold great potential in weed control and sustainable agri-food applications.

Fabrication and Evaluation of Quercetin Nanoemulsion: A Delivery System with Improved Bioavailability and Therapeutic Efficacy in Diabetes Mellitus

The current study was intended to fabricate and evaluate ultrasonically assisted quercetin nanoemulsion (Que-NE) for improved bioavailability and therapeutic effectiveness against diabetes mellitus in rats. Ethyl oleate, Tween 20, and Labrasol were chosen as oil, surfactant, and cosurfactant, respectively. Box–Behnken design (BBD) was employed to study the influence of process variables such as % surfactant and cosurfactant mixture (Smix) (5 to 7%), % amplitude (20–30%) and sonication time (2.5–7.5 min) on droplet size, polydispersibility index (PDI), and % entrapment efficiency (%EE) were studied. The optimization predicted that 9% Smix at 25% amplitude for 2.5 min would produce Que-NE with a droplet size of 125.51 nm, 0.215 PDI, and 87.04% EE. Moreover, the optimized Que-NE exhibited appreciable droplet size and PDI when stored at 5, 30, and 40 °C for 45 days. Also, the morphological characterization by transmission electron microscope (TEM) indicated the spherical shape of the optimized nanoemulsion. Furthermore, the Que-NE compared to pure quercetin exhibited superior release and enhanced oral bioavailability. The streptozocin-induced antidiabetic study in rats revealed that the Que-NE had remarkable protective and therapeutic properties in managing body weight, blood glucose level, lipid profile, and tissue injury markers, alongside the structure of pancreatic β-cells and hepatocytes being protected. Thus, the developed Que-NE could be of potential use as a substitute strategy for diabetes.

Innovative Delivery Systems Loaded with Plant Bioactive Ingredients: Formulation Approaches and Applications

Plants constitute a rich source of diverse classes of valuable phytochemicals (e.g., phenolic acids, flavonoids, carotenoids, alkaloids) with proven biological activity (e.g., antioxidant, anti-inflammatory, antimicrobial, etc.). However, factors such as low stability, poor solubility and bioavailability limit their food, cosmetics and pharmaceutical applications. In this regard, a wide range of delivery systems have been developed to increase the stability of plant-derived bioactive compounds upon processing, storage or under gastrointestinal digestion conditions, to enhance their solubility, to mask undesirable flavors as well as to efficiently deliver them to the target tissues where they can exert their biological activity and promote human health. In the present review, the latest advances regarding the design of innovative delivery systems for pure plant bioactive compounds, extracts or essential oils, in order to overcome the above-mentioned challenges, are presented. Moreover, a broad spectrum of applications along with future trends are critically discussed.

Therapeutic Potential of Quercetin to Alleviate Endothelial Dysfunction in Age-Related Cardiovascular Diseases

The vascular endothelium occupies a catalog of functions that contribute to the homeostasis of the cardiovascular system. It is a physically active barrier between circulating blood and tissue, a regulator of the vascular tone, a biochemical processor and a modulator of coagulation, inflammation, and immunity. Given these essential roles, it comes to no surprise that endothelial dysfunction is prodromal to chronic age-related diseases of the heart and arteries, globally termed cardiovascular diseases (CVD). An example would be ischemic heart disease (IHD), which is the main cause of death from CVD. We have made phenomenal advances in treating CVD, but the aging endothelium, as it senesces, always seems to out-run the benefits of medical and surgical therapies. Remarkably, many epidemiological studies have detected a correlation between a flavonoid-rich diet and a lower incidence of mortality from CVD. Quercetin, a member of the flavonoid class, is a natural compound ubiquitously found in various food sources such as fruits, vegetables, seeds, nuts, and wine. It has been reported to have a wide range of health promoting effects and has gained significant attention over the years. A growing body of evidence suggests quercetin could lower the risk of IHD by mitigating endothelial dysfunction and its risk factors, such as hypertension, atherosclerosis, accumulation of senescent endothelial cells, and endothelial-mesenchymal transition (EndoMT). In this review, we will explore these pathophysiological cascades and their interrelation with endothelial dysfunction. We will then present the scientific evidence to quercetin's anti-atherosclerotic, anti-hypertensive, senolytic, and anti-EndoMT effects. Finally, we will discuss the prospect for its clinical use in alleviating myocardial ischemic injuries in IHD.

Ocular Delivery of Polyphenols: Meeting the Unmet Needs

Nature has become one of the main sources of exploration for researchers that search for new potential molecules to be used in therapy. Polyphenols are emerging as a class of compounds that have attracted the attention of pharmaceutical and biomedical scientists. Thanks to their structural peculiarities, polyphenolic compounds are characterized as good scavengers of free radical species. This, among other medicinal effects, permits them to interfere with different molecular pathways that are involved in the inflammatory process. Unfortunately, many compounds of this class possess low solubility in aqueous solvents and low stability. Ocular pathologies are spread worldwide. It is estimated that every individual at least once in their lifetime experiences some kind of eye disorder. Oxidative stress or inflammatory processes are the basic etiological mechanisms of many ocular pathologies. A variety of polyphenolic compounds have been proved to be efficient in suppressing some of the indicators of these pathologies in in vitro and in vivo models. Further application of polyphenolic compounds in ocular therapy lacks an adequate formulation approach. Therefore, more emphasis should be put in advanced delivery strategies that will overcome the limits of the delivery site as well as the ones related to the polyphenols in use. This review analyzes different drug delivery strategies that are employed for the formulation of polyphenolic compounds when used to treat ocular pathologies related to oxidative stress and inflammation.

Recent Advances in Nanoencapsulation of Phytochemicals to Combat Obesity and Its Comorbidities

An increasing epidemic of obesity has become a serious public health concern primarily because it contributes to pathogenesis of many chronic diseases including type 2 diabetes, cardiovascular disease, hepatobiliary disease, obstructive sleep apnea, kidney disease, some types of cancer, among others. Consumption of a variety of phytochemicals has emerged as a promising potential for combating obesity and its comorbidities. However, the generally low aqueous solubility, stability, bioavailability, and target specificity of phytochemicals, along with their side-effects and toxicity seen when used at high doses, have restricted their clinical applications. As a solution, phytochemicals can be encapsulated into nanoparticles to increase their stability and solubility, enhance their bioavailability, protect them from premature degradation in the body, prolong their circulation time, and thus enhance their antiobesity activity. In this perspective, we summarize the problems and limitations of the prominent phytochemicals (epigallocatechin gallate, trans-resveratrol, curcumin, and quercetin), the major biocompatible and biodegradable nanoparticles, and the efficacy of nanoencapsulated forms of these phytochemicals in combating obesity and its comorbidities.

Therapeutic Potential of Quercetin as an Antiatherosclerotic Agent in Atherosclerotic Cardiovascular Disease: A Review

Atherosclerotic cardiovascular disease (ASCVD) is one of the diseases with the highest morbidity and mortality globally. It causes a huge burden on families and caregivers and high costs for medicine and surgical interventions. Given expensive surgeries and failures of most conventional treatments, medical community tries to find a more cost-effective cure. Thus, attentions have been primarily focused on food or herbs. Quercetin (Qu) extracted from food, a flavonoid component, develops potentials of alternative or complementary medicine in atherosclerosis. Due to the wide range of health benefits, researchers have considered to apply Qu as a natural compound in therapy. This review is aimed to identify the antiatherosclerosis functions of Qu in treating ASCVD such as anti-inflammatory, antioxidant properties, effects on endothelium-dependent vasodilation, and blood lipid-lowering.

Food-Grade Nanoemulsions: Preparation, Stability and Application in Encapsulation of Bioactive Compounds

Nanoemulsions have attracted significant attention in food fields and can increase the functionality of the bioactive compounds contained within them. In this paper, the preparation methods, including low-energy and high-energy methods, were first reviewed. Second, the physical and chemical destabilization mechanisms of nanoemulsions, such as gravitational separation (creaming or sedimentation), flocculation, coalescence, Ostwald ripening, lipid oxidation and so on, were reviewed. Then, the impact of different stabilizers, including emulsifiers, weighting agents, texture modifiers (thickening agents and gelling agents), ripening inhibitors, antioxidants and chelating agents, on the physicochemical stability of nanoemulsions were discussed. Finally, the applications of nanoemulsions for the delivery of functional ingredients, including bioactive lipids, essential oil, flavor compounds, vitamins, phenolic compounds and carotenoids, were summarized. This review can provide some reference for the selection of preparation methods and stabilizers that will improve performance in nanoemulsion-based products and expand their usage.