Effect of temperature, pH, β- and HP-β-cds on the solubility and stability of flavanones: Naringenin and hesperetin

Formation of Hesperetin-Methylglyoxal Adducts in Food and In Vivo, and Their Metabolism In Vivo and Potential Health Impacts

Polyphenols with a typical meta-phenol structure have been intensively investigated for scavenging of methylglyoxal (MGO) to reduce harmful substances in food. However, less attention has been paid to the formation level of polyphenol-MGO adducts in foods and in vivo and their absorption, metabolism, and health impacts. In this study, hesperitin (HPT) was found to scavenge MGO by forming two adducts, namely, 8-(1-hydroxyacetone)-hesperetin (HPT-mono-MGO) and 6-(1-hydroxyacetone)-8-(1-hydroxyacetone)-hesperetin (HPT-di-MGO). These two adducts were detected (1.6-15.9 mg/kg in total) in cookies incorporated with 0.01%-0.5% HPT. HPT-di-MGO was the main adduct detected in rat plasma after HPT consumption. The adducts were absorbed 8-30 times faster than HPT, and they underwent glucuronidation and sulfation in vivo. HPT-mono-MGO would continue to react with endogenous MGO in vivo to produce HPT-di-MGO, which effectively reduced the cytotoxicity of HPT and HPT-mono-MGO. This study provided data on the safety of employing HPT as a dietary supplement to scavenge MGO in foods.

Encapsulation and Biological Activity of Hesperetin Derivatives with HP-β-CD

The encapsulation of insoluble compounds can help improve their solubility and activity. The effects of cyclodextrin encapsulation on hesperetin's derivatives (HHSB, HIN, and HTSC) and the physicochemical properties of the formed complexes were determined using various analytical techniques. The antioxidant (DPPH•, ABTS•+ scavenging, and Fe2+-chelating ability), cytotoxic, and antibacterial activities were also investigated. The inclusion systems were prepared using mechanical and co-evaporation methods using a molar ratio compound: HP-β-CD = 1:1. The identification of solid systems confirmed the formation of two inclusion complexes at hesperetin (CV) and HHSB (mech). The identification of systems of hesperetin and its derivatives with HP-β-CD in solutions at pHs 3.6, 6.5, and 8.5 and at various temperatures (25, 37 and 60 °C) confirmed the effect of cyclodextrin on their solubility. In the DPPH• and ABTS•+ assay, pure compounds were characterized by higher antioxidant activity than the complexes. In the FRAP study, all hesperetin and HHSB complexes and HTSC-HP-β-CD (mech) were characterized by higher values of antioxidant activity than pure compounds. The results obtained from cytotoxic activity tests show that for most of the systems tested, cytotoxicity increased with the concentration of the chemical, with the exception of HP-β-CD. All systems inhibited Escherichia coli and Staphylococcus aureus.

Naringenin and Hesperidin as Promising Alternatives for Prevention and Co-Adjuvant Therapy for Breast Cancer

Citrus (genus Citrus L.) fruits are essential sources of bioactive compounds with antioxidant properties, such as flavonoids. These polyphenolic compounds are divided into subclasses, in which flavanones are the most prominent. Among them, naringenin and hesperidin are emerging compounds with anticancer potential, especially for breast cancer (BC). Several mechanisms have been proposed, including the modulation of epigenetics, estrogen signaling, induction of cell death via regulation of apoptotic signaling pathways, and inhibition of tumor invasion and metastasis. However, this information is sparse in the literature and needs to be brought together to provide an overview of how naringenin and hesperidin can serve as therapeutic tools for drug development and as a successful co-adjuvant strategy against BC. This review detailed such mechanisms in this context and highlighted how naringenin and hesperidin could interfere in BC carcinogenesis and be helpful as potential alternative therapeutic sources for breast cancer treatment.

Recent Progress in the Hesperetin Delivery Regimes: Significance of Pleiotropic Actions and Synergistic Anticancer Efficacy

BACKGROUND

In the plant kingdom, flavonoids are widely distributed with multifunctional immunomodulatory actions. Hesperetin (HST) remains one of the well-studied compounds in this domain, initially perceived in citrus plants as an aglycone derivative of hesperidin (HDN).

OBSERVATIONS

Natural origin, low in vivo toxicity, and pleiotropic functional essence are the foremost fascinations for HST use as an anticancer drug. However, low aqueous solubility accompanied with a prompt degradation by intestinal and hepatocellular enzymes impairs HST physiological absorption.

MOTIVATION

Remedies attempted herein comprise the synthesis of derivatives and nanocarrier (NC)-mediated delivery. As the derivative synthesis aggravates the structural complexity, NC-driven HST delivery has emerged as a sustainable approach for its sustained release. Recent interest in HST has been due to its significant anticancer potential, characterized via inhibited cell division (proliferation), new blood vessel formation (angiogenesis), forceful occupation of neighboring cell's space (invasion), migration to erstwhile physiological locations (metastasis) and apoptotic induction. The sensitization of chemotherapeutic drugs (CDs) by HST is driven via stoichiometrically regulated synergistic actions. Purpose and Conclusion: This article sheds light on HST structure-function correlation and pleiotropic anticancer mechanisms, in unaided and NC-administered delivery in singular and with CDs synergy. The discussion could streamline the HST usefulness and long-term anticancer efficacy.

Natural Deep Eutectic Solvent-Based Matrix Solid Phase Dispersion (MSPD) Extraction for Determination of Bioactive Compounds from Sandy Everlasting (Helichrysum arenarium L.): A Case of Stability Study

In the present study, vortex-assisted matrix solid-phase dispersion (VA-MSPD) extraction was used to isolate the major bioactive compounds from H. arenarium. To reduce the negative environmental impact of the conventionally used organic solvents, four different choline chloride-based natural deep eutectic solvents (NADES) were investigated as possible eluents. The most influential VA-MSPD extraction parameters: stationary phase (adsorbent), adsorbent/sample ratio, vortex time, and volume of extraction solvent were systematically optimized. Ultrasound-assisted extraction with 80% MeOH was used as the standard method for the comparison of results. The stability of the obtained extracts was studied over a period of 0 to 60 days at three different temperatures (-18 °C, 4 °C, and 25 °C). All extracts were evaluated both spectrophotometrically (determination of total phenolic content (TPC) and antioxidant activity by ABTS and FRAP assay) and chromatographically (HPLC-UV). NADES based on choline chloride and lactic acid (ChCl-LA) was selected as the most effective extractant, with a determined TPC value of its extract of 38.34 ± 0.09 mg GA/g DW (27% higher than the methanolic VA-MSPD extract) and high antioxidant activity. The content of individual phenolic compounds (chlorogenic acid, dicaffeoylquinic acid isomers, naringenin isomers, and chalcones) in the ChCl-LA extract, determined by HPLC-UV, was comparable to that of the conventionally obtained one. Moreover, the stabilization effect of ChCl-LA was confirmed for the studied compounds: chlorogenic acid, naringenin-4'-O-glucoside, tomoroside A, naringenin-5-O-glucoside, isosalipurposide, and naringenin. The optimum VA-MSPD conditions for the extraction of H. arenarium polyphenols were: florisil/sample ratio of 0.5/1, a vortex time of 2 min, and an elution volume of ChCl-LA of 10 mL.

Review of factors affecting citrus polyphenol bioavailability and their importance in designing in vitro, animal, and intervention studies

Evidence from in vitro, animal, and human studies links citrus fruit consumption with several health-promoting effects. However, many in vitro studies disregard bioavailability data, a key factor determining responses in humans. Citrus (poly)phenol metabolism and bioavailability follow specific pathways that vary widely among individuals and are affected by several intrinsic (age, sex, gut microbiota, metabolic state, genetic polymorphisms) and extrinsic (food matrix, co-consumed food, (poly)phenol solubility, dose, food processing, lifestyle) factors. The gut microbiota is crucial to both absorption of citrus (poly)phenols and the production of catabolites, and absorption of both takes place mostly in the colon. Citrus (poly)phenol absorption can reach up to 100% in some individuals when the sum of the gut microbiota products are taken into account. This review emphasizes the importance of understanding citrus (poly)phenol absorption, metabolism, and bioavailability using evidence primarily derived from human studies in designing in vitro, animal, and further human clinical studies.

Maillard induced glycation of β-casein for enhanced stability of the self-assembly micelles against acidic and calcium environment

Bovine β-casein (β-CN) has attracted increasingly interest as biocompatible nanocarrier for hydrophobic flavonoid due to its self-assembly ability to form micelles. This paper reported Maillard induced glycation reaction of β-CN using dextran in order to improve stability of naringenin-loaded β-CN micelles under acidic and high calcium environments. Our results showed that solubility of β-CN-graft-dextran was remarkable increased at acidic pH and the conjugation with 20 kDa dextran had the highest level of graft degree. Glycation restrained β-CN from aggregating around pH 5.0 where was close to the isoelectric point, forming spherical micelles with irregular and rough surfaces, which were significantly larger than the micelles at pH 7.0. β-CN-graft-dextran also overcame destabilization of the micelles induced by excess calcium and had no impact on the chelating ability of calcium. These findings appeared to be promising for future applications of modified β-CN-graft-dextran based on Maillard reaction as fairly stable nanocarrier under extreme condition.

Structural Investigation of Hesperetin-7-O-Glucoside Inclusion Complex with β-Cyclodextrin: A Spectroscopic Assessment

Flavonoids are biologically active natural products of great interest for their potential applications in functional foods and pharmaceuticals. A hesperetin-7-O-glucoside inclusion complex with β-cyclodextrin (HEPT7G/βCD; SunActive^® HCD) was formulated via the controlled enzymatic hydrolysis of hesperidin with naringinase enzyme. The conversion rate was nearly 98%, estimated using high-performance liquid chromatography analysis. The objective of this study was to investigate the stability, solubility, and spectroscopic features of the HEPT7G/βCD inclusion complex using Fourier-transform infrared (FTIR), Raman, ultraviolet–visible absorption (UV–vis), ¹H- and ¹³C- nuclear magnetic resonance (NMR), differential scanning calorimetry (DSC), liquid chromatography/mass spectroscopy (LC–MS), scanning electron microscopy (SEM), and powdered X-ray diffraction (PXRD) spectroscopic techniques including zeta potential, Job’s plot, and phase solubility measurements. The effects of complexation on the profiles of supramolecular interactions in analytic features, especially the chemical shifts of β-CD protons in the presence of the HEPT7G moiety, were evaluated. The stoichiometric ratio, stability, and solubility constants (binding affinity) describe the extent of complexation of a soluble complex in 1:1 stoichiometry that exhibits a greater affinity and fits better into the β-CD inner cavity. The NMR spectroscopy results identified two different configurations of the HEPT7G moiety and revealed that the HEPT7G/βCD inclusion complex has both –2S and –2R stereoisomers of hesperetin-7-O-glucoside possibly in the –2S/–2R epimeric ratio of 1/1.43 (i.e., –2S: 41.1% and –2R: 58.9%). The study indicated that encapsulation of the HEPT7G moiety in β-CD is complete inclusion, wherein both ends of HEPT7G are included in the β-CD inner hydrophobic cavity. The results showed that the water solubility and thermal stability of HEPT7G were apparently increased in the inclusion complex with β-CD. This could potentially lead to increased bioavailability of HEPT7G and enhanced health benefits of this flavonoid.

Bioavailability of Hesperidin and Its Aglycone Hesperetin—Compounds Found in Citrus Fruits as a Parameter Conditioning the Pro-Health Potential (Neuroprotective and Antidiabetic Activity)—Mini-Review

Hesperidin and hesperetin are polyphenols that can be found predominantly in citrus fruits. They possess a variety of pharmacological properties such as neuroprotective and antidiabetic activity. However, the bioavailability of these compounds is limited due to low solubility and restricts their use as pro-healthy agents. This paper described the limitations resulting from the low bioavailability of the presented compounds and gathered the methods aiming at its improvement. Moreover, this work reviewed studies providing pieces of evidence for neuroprotective and antidiabetic properties of hesperidin and hesperetin as well as providing a detailed look into the significance of reported modes of action in chronic diseases. On account of a well-documented pro-healthy activity, it is important to look for ways to overcome the problem of poor bioavailability.

Amorphous Inclusion Complexes: Molecular Interactions of Hesperidin and Hesperetin with HP-Β-CD and Their Biological Effects

This study aimed at obtaining hesperidin (Hed) and hesperetin (Het) systems with HP-β-CD by means of the solvent evaporation method. The produced systems were identified using infrared spectroscopy (FT-IR), X-ray powder diffraction (XRPD), and differential scanning calorimetry (DSC). Moreover, in silico docking and molecular dynamics studies were performed to assess the most preferable site of interactions between tested compounds and HP-β-CD. The changes of physicochemical properties (solubility, dissolution rate, and permeability) were determined chromatographically. The impact of modification on biological activity was tested in an antioxidant study as well as with regards to inhibition of enzymes important in pathogenesis of neurodegenerative diseases. The results indicated improvement in solubility over 1000 and 2000 times for Hed and Het, respectively. Permeability studies revealed that Hed has difficulties in crossing biological membranes, in contrast with Het, which can be considered to be well absorbed. The improved physicochemical properties influenced the biological activity in a positive manner by the increase in inhibitory activity on the DPPH radical and cholinoesterases. To conclude the use of HP-β-CD as a carrier in the formation of an amorphous inclusion complex seems to be a promising approach to improve the biological activity and bioavailability of Hed and Het.

Preparation, characterization of naringenin, β-cyclodextrin and carbon quantum dot antioxidant nanocomposites

In this work, naringenin loaded β-cyclodextrin and carbon quantum dots composite nanoparticles were successfully fabricated. The results showed that incorporation of carbon quantum dots not only enhanced antioxidant activities of nanoparticles but also improved encapsulation efficiency of naringenin. Further, the formation of composite nanoparticles was confirmed by a series of characterization methods. The zeta-potential and Fourier transform infrared spectroscopy data proved that electrostatic interaction and hydrogen bonding are dominant forces to form nanoparticles. X-Ray Diffraction experiment revealed that the material state of the formed naringenin-β-CD-CQDs nanoparticles is amorphous in opposition to the crystalline state of naringenin, β-CD and naringenin-β-CD inclusion complex. Finally, antioxidant activity analyses against DPPH, ABTS⁺ and Fe²⁺ chelating, showed an enhanced antioxidant activity of the formed composite nanoparticles compared to their constituents. These results indicated that naringenin can be effectively entrapped in β-cyclodextrin and carbon quantum dots, forming composite nanoparticles with improved antioxidant properties.

Four Citrus Flavanones Exert Atherosclerosis Alleviation Effects in ApoE-/- Mice via Different Metabolic and Signaling Pathways

Citrus flavanones have the potential to alleviate atherosclerosis. The metabolism and anti-atherosclerosis signaling pathways of four citrus flavanones (naringin, naringenin, hesperidin, and hesperetin) were compared in ApoE^-/- mice. Naringin had the most potent anti-atherogenic effect, followed by hesperidin, naringenin, and hesperetin with reductions of 55.92, 34.98, 42.87, and 24.70% in the atherosclerotic plaque rate compared with the control, respectively. Oral naringin mainly existed in the intestine due to the high water solubility of 7-O-nohesperidoside and alleviated atherosclerosis mainly by enhancing bile acid synthesis in the gut microbiota-FXR/FGF15-CYP7A1 pathway. The other three flavanones mainly alleviated atherosclerosis in the liver after absorption from the intestine. Hesperidin upregulates ABCA1 by 1.8-fold to enhance cholesterol reverse transport, while the aglycones naringenin and hesperetin inhibited cholesterol synthesis via downregulating HMGCR by 2.4- and 2.3-fold, respectively. Hesperetin was more resistant to absorption than naringenin due to the existence of a 4'-methoxyl group and had relatively weak effects on atherosclerosis. The alleviation of atherosclerosis by the four citrus flavanones was tightly related to differences in their in vivo metabolism and signaling pathways. This provides new insights into the anti-atherosclerotic mechanisms of food functional flavanones and guidance for the design of novel, efficient strategies for preventing atherosclerosis based on citrus flavanones.

Encapsulation of Hydrophobic and Low-Soluble Polyphenols into Nanoliposomes by pH-Driven Method: Naringenin and Naringin as Model Compounds

Naringenin and naringin are a class of hydrophobic polyphenol compounds and both have several biological activities containing antioxidant, anti-inflammatory and anti-tumor properties. Nevertheless, they have low water solubility and bioavailability, which limits their biological activity. In this study, an easy pH-driven method was applied to load naringenin or naringin into nanoliposomes based on the gradual reduction in their water solubility after the pH changed to acidity. Thus, the naringenin or naringin can be embedded into the hydrophobic region within nanoliposomes from the aqueous phase. A series of naringenin/naringin-loaded nanoliposomes with different pH values, lecithin contents and feeding naringenin/naringin concentrations were prepared by microfluidization and a pH-driven method. The naringin-loaded nanoliposome contained some free naringin due to its higher water solubility at lower pH values and had a relatively low encapsulation efficiency. However, the naringenin-loaded nanoliposomes were predominantly nanometric (44.95–104.4 nm), negatively charged (−14.1 to −19.3 mV) and exhibited relatively high encapsulation efficiency (EE = 95.34% for 0.75 mg/mL naringenin within 1% w/v lecithin). Additionally, the naringenin-loaded nanoliposomes still maintained good stability during 31 days of storage at 4 °C. This study may help to develop novel food-grade colloidal delivery systems and apply them to introducing naringenin or other lipophilic polyphenols into foods, supplements or drugs.

Liposomal nanodelivery systems generated from proliposomes for pollen extract with improved solubility and in vitro bioaccessibility

This study offers a suitable and easy proliposome-liposome method that enhances the encapsulation ability of liposome structures on poor water-soluble extracts. Pollen phenolic extract (PPE) was studied to show applicability in the proposed method. The poor water-soluble PPE (0.2%, w/v) was encapsulated by liposomes generated from proliposomes (P-liposomes) that were prepared via high-pressure homogenization technique without using any organic solvents and high temperature. Only a few drops of ethanol were used to dissolve poor water-soluble compounds in PPE during the preparation of P-liposomes. The trace amount of ethanol maintained the improvement of PPE solubility in P-liposome dispersion, hence the in vitro bioaccessibility and bioactivity of PPE incorporated in P-liposomes increased. Thus, higher encapsulation efficiency was found in P-liposomes compared to conventional liposomes (C-liposomes) in which the EE was 75 and 73%, respectively. To increase the physical stability of liposome structures, the surface of both P-liposomes and C-liposomes was covered with chitosan. There were found small changes between P-liposomes and C-liposomes in terms of mean diameter size and zeta potential. On the other hand, the bioactivity of encapsulated PPE showed differences in P-liposomes and C-liposomes. The antioxidant capacity of PPE in P-liposomes enhanced approximately two times in CUPRAC and three times in DPPH assays. Also, in vitro bioaccessibility of PPE in P-liposomes increased approximately 4 and 2 folds, respectively, regarding total phenolics and flavonoids. To our knowledge, this is the first report about the increment of encapsulation behavior of liposome structures on low water-soluble extract within an aqueous media.

Nutraceuticals in the Treatment of Pulmonary Arterial Hypertension

Pulmonary arterial hypertension (PAH) is a severe disease characterized by the loss and obstructive remodeling of the pulmonary arterial wall, causing a rise in pulmonary arterial pressure and pulmonary vascular resistance, which is responsible for right heart failure, functional decline, and death. Although many drugs are available for the treatment of this condition, it continues to be life-threatening, and its long-term treatment is expensive. On the other hand, many natural compounds present in food have beneficial effects on several cardiovascular conditions. Several studies have explored many of the potential beneficial effects of natural plant products on PAH. However, the mechanisms by which natural products, such as nutraceuticals, exert protective and therapeutic effects on PAH are not fully understood. In this review, we analyze the current knowledge on nutraceuticals and their potential use in the protection and treatment of PAH, as well as whether nutraceuticals could enhance the effects of drugs used in PAH through similar mechanisms.