Advances on nanoformulation approaches for delivering plant-derived antioxidants: A case of quercetin

Quercetin nanocrystals stabilized by glycyrrhizic acid for liver targeted drug delivery：Impact of glycyrrhizic acid concentrations

The purpose of this study was to investigate the impact of glycyrrhizic acid (GL) concentrations on in vitro and in vivo behavior of quercetin (QT) nanocrystals stabilized by GL (QT-NCs/GL), with a particular focus on its influence on liver targeted drug delivery. QT-NCs/GL with similar particle size around 200 nm were successfully prepared by media milling technique using different concentrations of GL, which were 10%, 20% and 40% (w/w) of the QT. The impact of GL concentrations on morphology, crystalline state, solubility, drug release, as well as pharmacokinetic behavior and liver distribution of QT-NCs/GL following intravenous administration were investigated. An oval and short rod nanoparticles were observed for all QT-NCs/GL by scanning electron microscope. X-ray powder diffraction results showed all QT-NCs/GL remained in crystalline state, but a reduced crystallinity was found with increase of GL concentrations. All QT-NCs/GL exhibited significant solubility increase and drug release improvement of QT as compared to raw QT. There was no significant difference in the plasma concentration-time curve and pharmacokinetic parameters of QT after intravenous of all QT-NCs/GL, except that the AUC0∼t of QT-NCs/GL-10% was significantly higher than that of QT-NCs/GL-20%. All QT-NCs/GL exhibited rapidly distribution of QT to liver with the maximum QT concentration more than 750 μg/g at 5 min after intravenous administration, and the AUC0∼t of QT for three formulations in liver were significant difference with the following order: QT-NCs/GL-40% > QT-NCs/GL-20% > QT-NCs/GL-10%. It could be concluded that different GL concentrations exhibited significant influence on liver targeted delivery of QT-NCs/GL, and more GL used in QT-NCs/GL may contribute more liver distribution of QT.

Stabilizing effect of quercetin upon bovine serum albumin as a model protein

Quercetin (QCT), an emerging class of flavonoid known for antioxidant and anti-inflammatory activities, has been studied for its protein stabilizing effect. After demonstrating ethanol (EtOH) - induced structural changes in bovine serum albumin (BSA), the stabilizing effect of QCT was studied using fluorescence, circular dichroism (CD) and Fourier transform infrared (FTIR) spectroscopic techniques. Morphological changes were examined using atomic force microscopy (AFM). EtOH triggered blue shift in fluorescence spectra of BSA and its intensity increased at higher percentage of alcohol. A reversal in this trend was recorded in the presence of QCT. This was interpreted as anti-amyloidogenic effect emanating from the binding of QCT to hydrophobic pockets of BSA. The value of binding constant (1.25 x 106 M-1; 298 K) is suggestive of strong binding affinity of QCT for BSA. The mode of QCT-induced fluorescence quenching was found to be mixed in nature. CD spectra showed that the protein conformation was altered and traces of alpha helix disappeared in the presence of EtOH. Contrarily, disruptive effect of EtOH was not visible upon incorporating QCT. This was further verifiable form the thermal CD data, which showed an upshift in the denaturation temperature of BSA. The data of thioflavin T assay and AFM further substantiated the protective effect of QCT.

Nanoquercetin based nanoformulations for triple negative breast cancer therapy and its role in overcoming drug resistance

Triple Negative Breast Cancer (TNBC) is a highly aggressive and treatment-resistant subtype of breast cancer, lacking the expression of estrogen, progesterone, and HER2 receptors. Conventional chemotherapy remains the primary treatment option, but its efficacy is often compromised by the development of drug resistance. Nanoquercetin has garnered the attention of researchers due to its potential in combating cancer. This antioxidant exhibits significant efficacy against various types of cancer, including blood, breast, pancreatic, prostate, colon, and oral cancers. Functioning as a potential anti-cancer agent, nanoquercetin impedes the development and proliferation of cancer cells, induces apoptosis and autophagy, and prevents cancer cell invasion and metastasis. Numerous processes, such as the inhibition of pathways linked to angiogenesis, inflammation, and cell survival, are responsible for these anticancer actions. Moreover, it shields DNA from degradation caused by radiation and other carcinogens. The cost-effectiveness of current cancer treatments remains a significant challenge in healthcare, imposing a substantial economic burden on societies worldwide. Preclinical studies and early-phase clinical trials indicate that nanoquercetin-based therapies could offer a significant advancement in the management of TNBC, providing a foundation for future research and clinical application in overcoming drug resistance and improving patient outcomes. This article examines the latest data on nanoquercetin's potent anti-cancer properties and interprets the accumulated research findings within the framework of preventive, predictive, and personalized (3P) medicine.

A nonionic microemulsion co-loaded with atorvastatin and quercetin: Simultaneous spectroscopic analysis and payload release kinetics

In this study, we have co-loadedatorvastatin (ATR) and quercetin (QCT) in a nonionic microemulsion. After developing a derivative ratio spectrophotometric technique for simultaneous analysis of ATR and QCT, pseudoternary phase diagram was constructed utilizing1:4 d-α-tocopherol polyethylene glycol 1000 succinate (TPGS) and ethanol as surfactant and cosurfactant, respectively. Oleic acid was used as oil phase. Structural characterization of the formulation was carried out along a water dilution line created in monophasic region. Characterizations at these dilution points were performed using dynamic light scattering and polarized light microscopy. The average hydrodynamic size of the optimized formulation was found to be 18.9 nm and it did not change upon loading of ATR and QCT. In vitro release was assessed for the formulations loaded with different ratios of ATR and QCT, and the data were fitted to different mathematical models. Interestingly, we noticed differences in release kinetics during changes in dose ratios, particularly for QCT. Higuchi kinetics, observed at equal dose, shifted to Korsmeyer-Peppas model at higher QCT-ATR ratio (2:1 and 4:1). This difference is attributable to the ability of QCT molecules of overwhelming the interface at higher concentrations. Altogether, our observations highlight that the ratio of payloads should be selected carefully in order to avoid unpredictable release patterns.

Carbonization of quercetin into nanogels: a leap in anticoagulant development

Quercetin, a flavonoid abundantly found in onions, fruits, and vegetables, is recognized for its pharmacological potential, especially for its anticoagulant properties that work by inhibiting thrombin and coagulation factor Xa. However, its clinical application is limited due to poor water solubility and bioavailability. To address these limitations, we engineered carbonized nanogels derived from quercetin (CNGsQur) using controlled pyrolysis and polymerization techniques. This led to substantial improvements in its anticoagulation efficacy, water solubility, and biocompatibility. We generated a range of CNGsQur by subjecting quercetin to varying pyrolytic temperatures and then assessed their anticoagulation capacities both in vitro and in vivo. Coagulation metrics, including thrombin clotting time (TCT), activated partial thromboplastin time (aPTT), and prothrombin time (PT), along with a rat tail bleeding assay, were utilized to gauge the efficacy. CNGsQur showed a pronounced extension of coagulation time compared to uncarbonized quercetin. Specifically, CNGsQur synthesized at 270 °C (CNGsQur270) exhibited the most significant enhancement in TCT, with a binding affinity to thrombin exceeding 400 times that of quercetin. Moreover, variants synthesized at 310 °C (CNGsQur310) and 290 °C (CNGsQur290) showed the most substantial delays in PT and aPTT, respectively. Our findings indicate that the degree of carbonization significantly influences the transformation of quercetin into various CNGsQur forms, each affecting distinct coagulation pathways. Additionally, both intravenous and oral administrations of CNGsQur were found to extend rat tail bleeding times by up to fivefold. Our studies also demonstrate that CNGsQur270 effectively delays and even prevents FeCl3-induced vascular occlusion in a dose-dependent manner in mice. Thus, controlled pyrolysis offers an innovative approach for generating quercetin-derived CNGs with enhanced anticoagulation properties and water solubility, revealing the potential for synthesizing self-functional carbonized nanomaterials from other flavonoids for diverse biomedical applications.

Reactive oxygen species-scavenging nanomaterials for the prevention and treatment of age-related diseases

With increasing proportion of the elderly in the population, age-related diseases (ARD) lead to a considerable healthcare burden to society. Prevention and treatment of ARD can decrease the negative impact of aging and the burden of disease. The aging rate is closely associated with the production of high levels of reactive oxygen species (ROS). ROS-mediated oxidative stress in aging triggers aging-related changes through lipid peroxidation, protein oxidation, and DNA oxidation. Antioxidants can control autoxidation by scavenging free radicals or inhibiting their formation, thereby reducing oxidative stress. Benefiting from significant advances in nanotechnology, a large number of nanomaterials with ROS-scavenging capabilities have been developed. ROS-scavenging nanomaterials can be divided into two categories: nanomaterials as carriers for delivering ROS-scavenging drugs, and nanomaterials themselves with ROS-scavenging activity. This study summarizes the current advances in ROS-scavenging nanomaterials for prevention and treatment of ARD, highlights the potential mechanisms of the nanomaterials used and discusses the challenges and prospects for their applications.

Effect of stoichiometry upon the characteristics of quercetin-arginine cocrystals formulated through solution crystallization

OBJECTIVE

The aim of this study is to demonstrate the effect of stoichiometry upon characteristics of quercetin-arginine (QCT-Arg) cocrystals.

SIGNIFICANCE

Quercetin (QCT) is a most abundant flavonoid in vegetables and fruits and has been widely used as an antioxidant. However, its oral bioavailability remains low due to poor aqueous solubility. We illustrate that QCT-Arg cocrystals formulated through an optimized stoichiometry can be a useful approach for its solubilization.

METHOD

Cocrystals were prepared using solvent evaporation method. Characterizations were performed through microscopic, spectroscopic, and thermal techniques. The stoichiometry was confirmed from the binary phase diagram which was prepared using thermograms derived from differential scanning calorimetric experiments.

RESULT

Cocrystal formation was accompanied by the conversion of isotropic phase into anisotropic one. Thread-like cocrystals were formed, regardless of QCT-Arg stoichiometry and solvent's polarity. Spectral analyses suggested that cocrystal structure was held together by hydrogen bonding between QCT and Arg. We ruled out the existence of eutectic mixture based on the observation of two eutectic points in the binary phase diagram.

CONCLUSION

Morphology of cocrystals remained unaffected by the solvent type, stoichiometry and the presence of surfactant. We noticed that the cocrystals could improve the aqueous solubility of QCT.

Combination of Nanodelivery Systems and Constituents Derived from Novel Foods: A Comprehensive Review

Novel Food is a new category of food, regulated by the European Union Directive No. 2015/2283. This latter norm defines a food as "Novel" if it was not used "for human consumption to a significant degree within the Union before the date of entry into force of that regulation, namely 15 May 1997". Recently, Novel Foods have received increased interest from researchers worldwide. In this sense, the key areas of interest are the discovery of new benefits for human health and the exploitation of these novel sources of materials in new fields of application. An emerging area in the pharmaceutical and medicinal fields is nanotechnology, which deals with the development of new delivery systems at a nanometric scale. In this context, this review aims to summarize the recent advances on the design and characterization of nanodelivery systems based on materials belonging to the Novel Food list, as well as on nanoceutical products formulated for delivering compounds derived from Novel Foods. Additionally, the safety hazard of using nanoparticles in food products, i.e., food supplements, has been discussed in view of the current European regulation, which considers nanomaterials as Novel Foods.

Minocycline in depression not responding to first-line therapy: A systematic review and meta-analysis

BACKGROUND

Major depressive disorder is often resistant to first-line treatment, with around 30% failing to respond to traditional therapy. Treatment-resistant depression results in prolonged hospitalization and healthcare costs. Anti-inflammatory drugs have shown promising results in depression not responding to initial therapy. Minocycline has anti-inflammatory properties and crosses the blood-brain barrier. It has demonstrated varied results in several randomized controlled trials (RCTs).

METHODS

We assessed the efficacy of minocycline compared to placebo in depression not responding to one first-line antidepressant via a systematic review and meta-analysis. We performed a comprehensive literature search across PubMed, Cochrane, and Scopus for RCTs. We visualized the results using forest plots and drapery plots. We assessed and explored heterogeneity using I2, prediction interval, and meta-regression. Then, we rated the certainty of the evidence.

RESULTS

Four RCTs revealed a non-significant difference in depression severity [-3.93; 95% CI: -16.14 to 8.28], rate of response [1.15; 0.33-4.01], and rate of remission [0.94; 0.44-2.01]. However, the reduction in depression severity is significant at a trend of P < .1. The high between-study heterogeneity (I2 = 78%) for depression severity could be answered by meta-regression (P = .02) for the duration of therapy.

CONCLUSION

There is no significant difference with minocycline compared to placebo for depression not responding to first-line antidepressant therapy. However, the treatment response varies with treatment duration and patients' neuroinflammatory state. Thus, larger and longer RCTs, especially in diverse disease subgroups, are needed for further insight. This is needed to allow greater precision medicine in depression and avoid elevated healthcare expenditure associated with hit-and-trial regimens.

REGISTRATION

CRD42023398476 (PROSPERO).

Effect of quercetin on steroidogenesis and folliculogenesis in ovary of mice with experimentally-induced polycystic ovarian syndrome

INTRODUCTION

Polycystic Ovary syndrome (PCOS) affects the health of many women around theworld. Apart from fundamental metabolic problems connected to PCOS, focus of our study is on the role of quercetin on genes relevant to steroidogenesis and folliculogenesis.

METHODS

Eighteen mature parkes strain mice (4-5 weeks old) weighing18-21 g were randomly divided into three groups of six each as follows: Group I serves as the control and was given water and a regular chow diet ad lib for 66 days; group II was given oral gavage administration of letrozole (LETZ) (6 mg/kgbw) for 21 days to induce PCOS and was left untreated for 45 days; For three weeks, Group III received oral gavage dose of LETZ (6 mg/kg), after which it received Quercetin (QUER) (125 mg/kg bw orally daily) for 45 days.

RESULTS

In our study we observed that mice with PCOS had irregular estrous cycle with increased LH/FSH ratio, decreased estrogen level and decline in expression of Kitl, Bmp1, Cyp11a1, Cyp19a1, Ar, lhr, Fshr and Esr1 in ovary. Moreover, we observed increase in the expression of CYP17a1, as well as increase in cholesterol, triglycerides, testosterone, vascular endothelial growth factor VEGF and insulin levels. All these changes were reversed after the administration of quercetin in PCOS mice.

DISCUSSION

Quercetin treatment reversed the molecular, functional and morphological abnormalities brought on due to letrozole in pathological and physiological setting, particularly the issues of reproduction connected to PCOS. Quercetin doesn't act locally only but it acts systematically as it works on Pituitary (LH/FSH)- Ovary (gonad hormones) axis. the Side effects of Quercetin have to be targeted in future researches. Quercetin may act as a promising candidate for medical management of human PCOS.

Phytochemical Screening and In Vitro Evaluation of the Antioxidant Potential of Dichloromethane Extracts of Strychnos henningsii Gilg. and Ficus sycomorus L

Medicinal plants are a rich source of antioxidants such as flavonoids, phenols, tannins, and alkaloids among others and are currently used as alternative and complementary drugs in the management of stress-related disorders. Strychnos henningsii and Ficus sycomorus have been traditionally used by the people of Mbeere, Embu county, Kenya, as medicine for the treatment of various oxidative stress-related disorders such as diabetes and rheumatism; however, no empirical data are available to authenticate the said claim. The aim of this study was to evaluate preliminary phytochemical screening and in vitro antioxidant activity of dichloromethane (DCM) leaf extract of S. henningsii and stem bark extract of F. sycomorus using DPPH, hydrogen peroxide, and ferric reducing power assays; total flavonoids and phenolic compounds were also determined by colorimetric assay and Folin–Ciocalteu reaction, respectively. Phytochemical screening showed that both extracts possessed saponins, flavonoids, phenols, steroids, alkaloids, and cardiac glycosides; however, terpenoids were found to be absent in S. henningsii. The total phenolic and flavonoid content of the DCM stem bark extract of F. sycomorus was lower than that of the leaf extract of S. henningsii. These extracts significantly exhibited strong antioxidant activities at different concentrations tested. The IC50 values of S. henningsii and F. sycomorus were 0.325 mg/ml and 0.330 mg/ml for hydrogen peroxide and 0.068 mg/ml and 0.062 mg/ml for DPPH, respectively. Both DCM leaf and stem bark extracts of S. henningsii and F. sycomorus were found to have strong ferric reducing power. Therefore, both extracts showed significant nonenzyme-based antioxidant activities. The two plants possess phytochemicals that have significant antioxidant properties.

Redox Imbalance as a Common Pathogenic Factor Linking Hearing Loss and Cognitive Decline

Experimental and clinical data suggest a tight link between hearing and cognitive functions under both physiological and pathological conditions. Indeed, hearing perception requires high-level cognitive processes, and its alterations have been considered a risk factor for cognitive decline. Thus, identifying common pathogenic determinants of hearing loss and neurodegenerative disease is challenging. Here, we focused on redox status imbalance as a possible common pathological mechanism linking hearing and cognitive dysfunctions. Oxidative stress plays a critical role in cochlear damage occurring during aging, as well as in that induced by exogenous factors, including noise. At the same time, increased oxidative stress in medio-temporal brain regions, including the hippocampus, is a hallmark of neurodegenerative disorders like Alzheimer's disease. As such, antioxidant therapy seems to be a promising approach to prevent and/or counteract both sensory and cognitive neurodegeneration. Here, we review experimental evidence suggesting that redox imbalance is a key pathogenetic factor underlying the association between sensorineural hearing loss and neurodegenerative diseases. A greater understanding of the pathophysiological mechanisms shared by these two diseased conditions will hopefully provide relevant information to develop innovative and effective therapeutic strategies.