Hesperetin Research Articles

Opposing Effect of Naringenin and Quercetin on the Junctional Compartment of MDCK II Cells to Modulate the Tight Junction.

Maintaining tight junction (TJ) integrity is important for epithelial cell barriers. Previously, the enhancement of TJ integrity, induced by citrus-derived flavonoids, naringin (NRG) and hesperidin (HSD), was demonstrated, but the effects of their aglycones naringenin (NAR) and hesperetin (HST), and the mechanisms, have not been systematically investigated. Here we compared three series of flavonoids related to NAR, HST, quercetin (QUE) and their glycosides with the Madin–Darby canine kidney (MDCK) II cell monolayers. The effect of flavonoids on the protein expression level of claudin (CLD)-2 and its subcellular localization were investigated. NAR, NRG, and HSD increased the CLD-2 localization at the TJ compartment, and its protein expression level. QUE and HST showed TJ-mitigating activity. Narirutin (NRT), neohesperidin (NHD) and rutin (RUT) did not affect the TJ. In addition, NAR and QUE induced an increase or decrease of the transepithelial electrical resistance (TEER) values of the MDCK II monolayers. Two known signaling pathways, phosphatidyl-inositol-3 kinase (PI3K) and 5′-AMP-activated protein kinase (AMPK), were further compared with NAR. Two-dimensional polyacrylamide electrophoresis (2D PAGE) analysis of whole-cell proteins treated with NAR, AICA-riboside (AMPK activator) and LY294002 (PI3K inhibitor) showed in both a distinct pattern. This suggests the target of NAR’s CLD-2 or zonula occludens-1 (ZO-1) modulation was unique.

Dextran–Hesperetin Conjugate as a Novel Biocompatible Medicine for Antimicrobial and Anticancer Applications

Hesperidin (HD), a bioflavanone glycoside, was isolated from orange peel and converted to hesperetin (HT) using a simple and efficient green procedure. Then dextran-hesperetin conjugate (Dex-HT) was prepared by free radical grafting reaction and the functionalization degree of it was assessed by the Folin–Ciocalteu method. The antioxidant activity of HD, HT and Dex-HT was tested by DPPH⋅ radical method. Presence of dextran as a backbone in the Dex-HT structure, improved antioxidant activities of the hesperetin. In addition, antimicrobial effect of these compounds was evaluated against some food pathogens (Listeria monocytogenes and Salmonella typhimurium). According to the results, L. monocytogenes was more sensitive to these compounds than S. typhimurium. Also, Dex-HT was more bacteriostatic than HD and HT. In addition, cytotoxic effect of Dex-HT against MCF-7(human breast adenocarcinoma), AGS (gastric adenocarcinoma) and normal fibroblast cells was determined in 48 and 72 h using MTT assay. The outcomes indicated that Dex-HT induced a significant dose-dependent cytotoxic effect on both AGS and MCF-7 cells. Moreover, Dex-HT showed a greater cytotoxic effect on MCF-7 cells than on AGS and normal cells. In this study, dextran, a biodegradeble carbohydrate polymer, was employed as a versatile scaffold to develop highly efficient antioxidant, antibacterial and anticancer hybrid material.

Metabolism study of hesperetin and hesperidin in rats by UHPLC-LTQ-Orbitrap MS n

Hesperidin (HPD) and hesperetin (HPT), as a kind of flavonone compounds, are abundant in citrus fruits with various pharmacological effects. HPD and HPT are not always consistent in some biological activities, even if they have the same skeletal structure. The aim of this study was to screen and identify HPT and HPD metabolites in rats using UHPLC-LTQ-Orbitrap MS n , compare the possible metabolism and provide the research basis for further understanding the similarities and differences in pharmacodynamics and pharmacokinetics of HPT and HPD. A total of 17 and 52 metabolites were identified in rats after oral administration of HPT or HPD, respectively. Three of HPT and HPD metabolites, glucuronidation, sulfation and diglucuronidation of HPT, were the same and could be the active components for the same pharmacodynamic action of them. We could find prototype in the urine sample of HPD group, but no prototypes in any samples of HPT group. There were hardly any general phase I metabolites of HPT, while 33 phase I metabolites of HPD could be identified. These data suggested that the poorer bioavailability of HPD compared with HPT.

The Citrus Flavonoid Hesperetin Has an Inadequate Anti-Arrhythmic Profile in the ΔKPQ NaV1.5 Mutant of the Long QT Type 3 Syndrome.

Type 3 long QT syndromes (LQT3) are associated with arrhythmogenic gain-of-function mutations in the cardiac voltage-gated Na+ channel (hNaV1.5). The citrus flavanone hesperetin (HSP) was previously suggested as a template molecule to develop new anti-arrhythmic drugs, as it blocks slowly-inactivating currents carried by the LQT3-associated hNaV1.5 channel mutant R1623Q. Here we investigated whether HSP also has potentially beneficial effects on another LQT3 hNaV1.5 channel variant, the ΔKPQ, which is associated to lethal ventricular arrhythmias. We used whole-cell patch-clamp to record Na+ currents (INa) in HEK293T cells transiently expressing hNaV1.5 wild type or ΔKPQ mutant channels. HSP blocked peak INa and the late INa carried by ΔKPQ mutant channels with an effective concentration of ≈300 μM. This inhibition was largely voltage-independent and tonic. HSP decreased the rate of inactivation of ΔKPQ channels and, consequently, was relatively weak in reducing the intracellular Na+ load in this mutation. We conclude that, although HSP has potential value for the treatment of the R1623Q LQT3 variant, this compound is inadequate to treat the LQT3 associated to the ΔKPQ genetic variant. Our results underscore the precision medicine rationale of better understanding the basic pathophysiological and pharmacological mechanisms to provide phenotype- genotype-directed individualization of treatment.

Hesperetin improves diabetic coronary arterial vasomotor responsiveness by upregulating myocyte voltage-gated K+ channels.

Hesperetin (HSP) is a naturally occurring flavonoid. The present study aimed to investigate the potential vasomotor effects and mechanisms of HSP action on rat coronary arteries (RCAs) injured by diabetes or high glucose concentrations. HSP (100 mg/kg/day) was intragastrically administered to the rats for 8 weeks, which were rendered diabetic with a single intraperitoneal injection of 60 mg/kg streptozotocin (STZ). The vascular tone of RCAs was recorded using a wire myograph. The voltage-dependent K+ (Kv) currents were examined using patch clamping. The expression of Kv channels (Kv1.2 and Kv1.5) was examined by western blot analysis and reverse transcription-quantitative PCR (RT-qPCR). Diabetes induced contractile hypersensitivity and vasodilator hyposensitivity in RCAs, both of which were attenuated by the chronic administration of HSP. Patch clamp data revealed that chronic HSP treatment reduced diabetes-induced suppression of Kv currents in the myocytes. Western blot and RT-qPCR analyses revealed that chronic HSP administration increased the expression of Kv1.2, but not Kv1.5, in the RCAs of diabetic rats compared with those from non-diabetic rats. In vitro analysis showed that co-incubation with HSP ameliorated high-glucose-induced suppression of Kv currents and Kv 1.2 protein expression in the myocytes. Taken together, the present study demonstrated that HSP alleviated RCA vasomotor dysfunction as a result of diabetes in rats by upregulating the expression of myocyte Kv channels.

Insights into Interactions of Flavanones with Target Human Respiratory Syncytial Virus M2-1 Protein from STD-NMR, Fluorescence Spectroscopy, and Computational Simulations.

The human Respiratory Syncytial Virus (hRSV) is the most frequent agent of respiratory infections in infants and children with no currently approved vaccine. The M2-1 protein is an important transcriptional antitermination factor and a potential target for viral replication inhibitor development. Hesperetin (HST) and hesperidin (HSD) are flavonoids from the flavanone group, naturally found in citrus and have, as one of their properties, antiviral activity. The present study reports on the interactions between hRSV M2-1 and these flavanones using experimental techniques in association with computational tools. STD-NMR results showed that HST and HSD bind to M2-1 by positioning their aromatic rings into the target protein binding site. Fluorescence quenching measurements revealed that HST had an interaction affinity greater than HSD towards M2-1. The thermodynamic analysis suggested that hydrogen bonds and van der Waals interactions are important for the molecular stabilization of the complexes. Computational simulations corroborated with the experimental results and indicated that the possible interaction region for the flavonoids is the AMP-binding site in M2-1. Therefore, these results point that HST and HSD bind stably to a critical region in M2-1, which is vital for its biological function, and thus might play a possible role antiviral against hRSV.

Hesperetin as an adjuvant augments protective anti‐tumour immunity responses in B16F10 melanoma by stimulating cytotoxic CD8+ T cells

Hesperetin (HES) is a dihydroflavone with the molecular formula of C16H14O6. It has been reported that Hesperetin has antioxidant and anticancer effects. Recent studies showed that it can also regulate immune responses. To assess its potential function as a vaccine adjuvant, we formulated HES with inactivated B16F10 melanoma cells and determined whether it would enhance the activation of antigen-presenting cells by experiments in vivo and in vitro. We found that HES activated the PI3K-Akt signalling pathway in antigen-presenting cells (APCs), enhanced cytotoxic T lymphocyte (CTL) responses and deactivated tolerogenic T cells. We also observed that inactivated B16F10 cells in combination with HES vaccine inhibited the growth of mice tumours, resulting in improved overall survival compared to the effects of inactivated B16F10 cell vaccine. To verify that CD8+ T cells play a key role in inhibiting the development of melanoma, we transferred the sorted CD8+ T cells from immunized mice to B16F10 challenged models and found that the survival rate of tumour-bearing mice was significantly prolonged. Taken together, these results suggest that hesperetin can be used as a potential adjuvant to improve tumour immune responses and antigen immunogenicity.

Hesperetin upregulates Fas/FasL expression and potentiates the antitumor effect of 5-fluorouracil in rat model of hepatocellular carcinoma

ABSTRACT This study aimed to investigate the antitumor efficacy of hesperetin (HST) either alone or combined with 5-fluorouracil (5-FU) in thioacetamide (TAA)-induced hepatocellular carcinoma (HCC) in rats. Moreover, possible HST molecular mechanism(s) of action were investigated. Sixty male Sprague-Dawley rats were randomized into six groups (n = 10/group); normal control (no treatment), HCC (TAA), HCC/carboxymethyl cellulose (CMC) (TAA+CMC), HST (TAA+HST in CMC), 5-FU (TAA+5-FU), HST/5-FU (TAA+HST+5-FU). Serum levels of liver enzymes (ALT and AST), bilirubin, albumin, total protein and alpha-Fetoprotein (AFP) along with hepatic contents of hepatic glutathione and mal0ndialdhyde were measured. Gene expression of Fas, FasL, caspase-8, caspase-3 and Bcl-2 were measured using real-time polymerase chain reaction. Histopathological examination was used to assess nodule size, fibrosis ratio and necroinflammatory score. HST showed improvements in hepatic functions, decreased levels of AFP and oxidative stress and restricted HCC progression. HST activated apoptosis through inducing Fas and FasL and inhibiting Bcl-2 gene expressions. Furthermore, HST/5-FU combination surpassed the results obtained from either HST or 5-FU groups. In conclusion, HST exerted its antitumor effect through induction of Fas/FasL apoptotic pathway and reduction of oxidative stress. HST and 5-FU combination provided prominent synergistic effects, thus it can be regarded as promising combination therapy for HCC.

Cortico-Hippocampal Memory Enhancing Activity of Hesperetin on Scopolamine-Induced Amnesia in Mice: Role of Antioxidant Defense Systems, Cholinergic Neurotransmission and Expression of BDNF

Alzheimer disease (AD) is an age related neurodegenerative disease causing severe cognitive and memory decline in elderly people. Flavonoids play neuroprotective role by inhibiting and/or modifying the self-assembly of the amyloid-β (Aβ) or tau peptide into oligomers and fibrils. This study sought to investigate the effect of hesperetin (HPT) on scopolamine-induced memory impairments in mice. Mice were orally pretreated with HPT (1, 5 or 50 mg/kg) or vehicle (normal saline; 10 ml/kg) for 3 consecutive days. One hour post-treatment on day 3, scopolamine (3 mg/kg, i.p.) was administered 5 min before locomotor activity (open field test) and memory function (novel object recognition test (NORT) for 2 consecutive days and Morris water maze task (MWM) for 5 consecutive days). Levels of oxidative stress markers / brain derived neurotrophic factors (BDNF) and acetylcholinesterase activity were determined in the hippocampus and prefrontal cortex after completion of MWM task. Scopolamine caused no significant change in mice exploration of the familiar or novel object in the test session whereas the HPT-treated mice spent more time exploring the novel object more than familiar object in NORT. Scopolamine also increased the escape latency in acquisition phase and decreases time spent in target quadrant in probe phase which were ameliorated by the pretreatment with HPT. Scopolamine-induced alteration of oxidant-antioxidant balance, acetylcholinesterase activity and neurogenesis in the hippocampus and prefrontal cortex were attenuated by HPT treatment. This study showed that HPT ameliorated non-spatial/spatial learning and memory impairment by scopolamine possibly through enhancement of antioxidant defense, cholinergic and BDNF signaling.

Nanoencapsulation of hesperetin using basil seed mucilage nanofibers: Characterization and release modeling

Hesperetin (HSP) was incorporated into basil seed mucilage (BSM)/polyvinyl alcohol (PVA) nanofibers using an electrospinning method. Encapsulation efficiency values of 96 ± 12, 93 ± 10, and 89 ± 11% and loading capacity values of 10 ± 1, 14 ± 1, and 18 ± 1% were obtained for 10, 15, and 20% (w/w) HSP loaded nanofibers, respectively. Physicochemical properties of nanofibers were measured using scanning electron microscopy, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction and thermogravimetric analysis. Results showed good incorporation of hesperetin in encapsulant. Nanofibers had diameters of 66–210 nm and HSP loaded nanofibers had diameters of 82–320 nm. No chemical reaction between functional groups of ingredients during electrospinning was observed using FTIR and an increase in thermal resistance of HSP was observed using thermogravimetric analysis. Release behavior was investigated using second order, Higuchi, Korsmeyer-Peppas, Hixson-Crowell and Weibull models and data fitted both Fickian and non-Fickian mechanisms. The results suggested that the BSM/PVA nanofibers could be used as a carrier for encapsulation of bioactive ingredients in the food industry with high encapsulation efficiency and physical stability.

Boronic-targeted albumin-shell oily-core nanocapsules for synergistic aromatase inhibitor/herbal breast cancer therapy

Multi-modality strategies of albumin-mediated drug accumulation in tumor, boronate-based active tumor targeting and synergistic cancer therapy were combined together for effective treatment of breast cancer. Herein we report the development of albumin-shell oily-core nanocapsules (NCs), loaded with novel combination of hydrophobic drugs, exemestane (EXE) and hesperetin (HES), for targeted breast cancer therapy. This protein-lipid nanohybrid carrier was successfully fabricated using a simple protein-coating method based on the electrostatic adsorption of negatively charged albumin shell onto the oily core containing cationic surfactant. While EXE was directly encapsulated into the oily core, HES was pre-formulated in the form of phospholipid complex before solubilization in oily phase. In addition to albumin-mediated binding to albondin and SPARC, phenylboronic acid was chemically coupled to the albumin shell to confer additional tumor targeting. The targeted nanocarrier (TNC) demonstrated enhanced internalization into MCF-7 breast cancer cells resulting in synergistic cytotoxic activity with a combination index (CI) of 0.662 and dose reduction index (DRI) of 8.22 and 1.84 for EXE and HES, respectively. In vivo, TNC displayed superior anti-cancer activity in tumor-bearing mice compared to their non-targeted counterparts and the free drug combination. A significant reduction of both tumor volume (7-folds) and Ki67 expression (3-folds) was obtained by the targeted nanocarriers compared to positive control. Overall, the boronic-targeted albumin NCs offer a promising platform for hydrophobic drug combination against cancer therapy.

Cortico-hippocampal memory enhancing activity of hesperetin on scopolamine-induced amnesia in mice: role of antioxidant defense system, cholinergic neurotransmission and expression of BDNF.

Alzheimer disease (AD) is an age related neurodegenerative disease causing severe cognitive and memory decline in elderly people. Flavonoids play neuroprotective role by inhibiting and/or modifying the self-assembly of the amyloid-β (Aβ) or tau peptide into oligomers and fibrils. This study sought to investigate the effect of hesperetin (HPT) on scopolamine-induced memory impairments in mice. Mice were orally pretreated with HPT (1, 5 or 50mg/kg) or vehicle (normal saline; 10ml/kg) for 3 consecutive days. One hour post-treatment on day 3, scopolamine (3mg/kg, i.p.) was administered 5min before locomotor activity (open field test) and memory function (novel object recognition test (NORT) for 2 consecutive days and Morris water maze task (MWM) for 5 consecutive days). Levels of oxidative stress markers / brain derived neurotrophic factors (BDNF) and acetylcholinesterase activity were determined in the hippocampus and prefrontal cortex after completion of MWM task. Scopolamine caused no significant change in mice exploration of the familiar or novel object in the test session whereas the HPT-treated mice spent more time exploring the novel object more than familiar object in NORT. Scopolamine also increased the escape latency in acquisition phase and decreases time spent in target quadrant in probe phase which were ameliorated by the pretreatment with HPT. Scopolamine-induced alteration of oxidant-antioxidant balance, acetylcholinesterase activity and neurogenesis in the hippocampus and prefrontal cortex were attenuated by HPT treatment. This study showed that HPT ameliorated non-spatial/spatial learning and memory impairment by scopolamine possibly through enhancement of antioxidant defense, cholinergic and BDNF signaling.

The study of drug resistance properties of ABCG2 (ATP-binding cassette G2) in contact with thymoquinone, gallic acid, and hesperetin antioxidants

Introduction: ATP-binding cassette (ABC) transporters are a group of intra membrane proteins that play key roles in the transmission and exchange of vital compounds on both sides of the membrane. These proteins can specially transport anti-cancer drugs out of cancer cells. ABCG2 is a member of this family that is extremely expressed in many cancers. This study, aims to evaluate the binding affinity of three antioxidants thymoquinone (TQ), gallic acid (GA), and hesperetin (HP) to ABCG2 compared with an anti-cancer drug, mitoxantrone (Mit), to export cells. Methods: The PDB file of ABCG2 was obtained from the protein data bank server (http://www.rcsb.org) with ID: 5NJ3. After 200 stages of molecular docking running on ABCG2 protein in AutoDock v.4.2 software, the amino acids involved in the binding site of each compound were identified using the LigPlot+ software. Results: HP had the lowest (-6.36 kcal/mol) and GA had the highest (-3.93 kcal/mol) binding energy in comparison with Mit (-0.06 kcal/mol) for binding to ABCG2. Effective concentration required to perform the reaction between ABCG2 was higher in GA (1.31 mM) than TQ (42.69 μM) and HP (21.74 μM). GA, HP, and TQ formed 17, 18, and 22 hydrogen and hydrophobic bonds at the binding site of ABCG2. Conclusion: It seems that GA has the lowest affinity to make contact with ABCG2 binding site. So, GA tends to remain in the cell but TQ and HP tend to leave the cell easily via ABCG2 transporter.

Protective effects of hesperetin on lipopolysaccharide-induced acute lung injury by targeting MD2

Inflammation plays an important role in acute lung injury (ALI). Hesperetin (HES), a natural flavanone and an aglycone of hesperidin, has established potent anti-inflammatory activity. The aim of this study was to evaluate the potential protective effect of HES on lipopolysaccharide (LPS)-induced ALI in mice and to illuminate its possible directly target. Results indicated that HES pretreatment significantly attenuated LPS-induced pulmonary pathological injury, total protein concentration, markedly decreased the number of neutrophils and the levels of inflammatory cytokines, TNF-α and IL-6, in ALI model in vivo and in vitro. Meanwhile, pretreatment with HES dramatically reduced myeloperoxidase (MPO) activity in LPS-induced ALI mice. Additionally, using molecular docking and co-immunoprecipitation assay, HES showed a directly bind with myeloid differentiation 2 (MD2), in which HES could inhibit MAPK activation, regulate IκB degradation, block the interaction MD2 and its co-receptor Toll-like receptor 4 (TLR4). Taken together, HES showed a significantly protective effect against LPS-induced ALI, which might be associated with MD2 protein. These results attested HES worthy of further progress into an adjunctive potential drug for the treatment for ALI.

Nanocrystalline solid dispersions (NSD) of hesperetin (HRN) for prevention of 7, 12-dimethylbenz[a]anthracene (DMBA)-induced breast cancer in Sprague-Dawley (SD) rats

Breast cancer is the most commonly diagnosed cancer and the leading cause of cancer death in females as per the global cancer project (GLOBOCAN 2018) estimates of breast cancer incidence and mortality produced by the International Agency for Research on Cancer (IARC). In 2018, there will be 2,088,849 new cases of breast cancer and 626,679 cases of deaths due to breast cancer in 5 regions (Americas, Africa, Europe, Asia and Oceania) at 20 sites of the world. Epidemiologic studies on diet and cancer have guided the search for some nutraceuticals acting as anti-cancer agents. Hesperetin (HRN), the aglycone of hesperidin, a glycoside found in citrus fruits, has been reported to have anti-cancer effects by apoptosis induction and inhibition of cell proliferation in cancer cells. However, poor solubility of HRN has limited its absorption while deviating from its therapeutic benefit. The present study aimed to develop nanocrystalline solid dispersions (NSD) of HRN and evaluating the oral bioavailability in rats. The study also evaluated the efficacy of NSDs against the carcinogenic activity of DMBA in female rats. NSDs were optimized using design of experiments (DoE) and multivariate analysis (MVA) tools. The optimized NSD formulation showed an average particle size (Zavg) of 558.2 ± 68.1 nm and ~70% release in 30 min. The in vivo pharmacokinetic study also construed remarkable improvement (3.3 and 2.1-fold increase in Cmax and AUC0–∞) in rate and extent of absorption and 4-fold reduction in Tmax by the optimized NSD formulation. In vivo chemoprevention study construed superior efficacy of the NSD formulation by reducing the tumor burden, delaying the onset of tumors and reducing the tumor weight and volume in DMBA-induced breast cancer rats. In conclusion, we present a simple NSD formulation of HRN with enhanced bioavailability and superior chemopreventive efficacy.

Anticonvulsant effects of hesperetin in animal model of pentylenetetrazole-induced-seizures

Anticonvulsant effects of hesperetin in animal model of pentylenetetrazole-induced-seizures

66 - Hesperetin mitigates isoproterenol induced cardiac hypertrophy by augmenting Nrf2/ARE signaling pathway

Background Cardiac hypertrophy characterized by excessive oxidative stress leading to collagen deposition, predisposes the heart to failure (HF) if left unresolved. Thus, understanding the signaling mechanisms involved in excessive extracellular matrix deposition is necessary to prevent cardiac remodeling and HF. Here, we tested a hypothesis that hesperetin (HES), a polyphenolic phyto-chemical mediated augmentation of Nrf2/antioxidant signaling suppresses oxidative stress, thereby ameliorates pathological cardiac remodeling. Methods Cardiac hypertrophy was induced in male Wistar rats by subcutaneous injections of isoproterenol (5 mg/kg body weight) for seven days. Basic biochemical assays were carried out to evaluate the Nrf2-dependent antioxidant signaling and oxidative stress markers (i.e. lipid peroxides, protein carbonyls). Protein expression of Nrf2 and its downstream target genes were also studied. Results Our results demonstrate that hesperetin pre-treated rats showed a significant reduction in the heart weight to body weight ratio (p Conclusions Our results conclude that hesperetin could be a potential therapeutic agent targets Nrf2 signaling, thereby ameliorates ISO-induced oxidative stress and prevents pathological cardiac remodelling.

Solid Dispersion of Hesperetin Co-crystals Synergistically Attenuates Hepatic Toxicity of Carbon Tetrachloride Oxidative Stress in Rats.

Hesperetin (HSP) is a low water-soluble flavanone aglycone with low bioavailability. This study aimed at enhancing the hepatoprotective effects of HSP by a combinatory technique based on solid dispersions of co-crystals of HSP. Co-crystals were prepared using citric acid, tartaric acid, caffeine and isonicotinamide (INM) using two methods of solvent evaporation and co-grinding. The solid dispersion of co-crystals with different ratio of INM, PVP K30 and drug was prepared by the solvent evaporation method. The resulting material was characterized by DSC, XRD, FTIR and SEM, their saturated solubility and dissolution rate were compared to the pure drug. Finally, liver toxicity was induced in rats by carbon tetrachloride (CCl4) and mice were treated with different formulations of HSP. The liver function was tested by measurement of glutamate pyruvate transaminase (SGPT), glutamate oxaloacetate transaminase (SGOT), serum alkaline phosphatase (ALP) and bilirubin as well as histopathological tests. Although saturation solubility of HSP was enhanced about 5 times by co-crystals of HSP/INM (1:2), solid dispersions of the co-crystals of HSP obtained from PVP K30 and INM enhanced it up to 200 folds. Functional parameters of liver in rats pretreated with a solid dispersion of co-crystals of HSP were significantly lower than those with pure HSP and co-crystals of INM/HSP with 2:1 ratio. Furthermore, this formulations reduced liver damage effectively compared with the CCL4 group. Solid dispersion of HSP co-crystals synergistically attenuates hepatic toxicity of carbon tetrachloride oxidative stress in rats more effectively than its solid dispersions or co-crystals alone.

Inhibition of α-amylase by flavonoids: Structure activity relationship (SAR)

Flavonoids are recognized to regulate animals' food digestion processes trough interaction with digestive enzymes. The binding capacity of hesperetin (HES), luteolin (LUT), quercetin (QUE), catechin (CAT) and rutin (RUT) with pancreatic α-amylase were evaluated, using UV-Vis spectroscopy, fluorescence and molecular docking. Using p-nitrophenyl-α-d-maltopentoside (pNPG5) as substrate analog, LUT showed the best inhibitory capacity, even better than that of the positive control, acarbose (ACA). A mixed-type inhibition was observed for HES, LUT and QUE, a competitive-type for ACA, while no inhibition was observed with CAT and RUT. In agreement with kinetic results, α-amylase presented a higher affinity for LUT, when analyzed by fluorescence quenching. The binding of flavonoids to amylase followed a static mechanism, where the binding of one flavonoid per enzyme molecule was observed. Docking analysis showed that flavonoids bound near to enzyme active site, while ACA bound in another site behind the catalytic triad. Extrinsic fluorescence analysis, together with docking analysis pointed out that hydrophobic interactions regulated the flavonoid-α-amylase interactions. The present study provides evidence to understand the relationship of flavonoids structure with their inhibition mechanism.

In vitro Antifungal Effects of Hesperetin and Silibinin

Background: Increasing resistance of microorganisms against available antimicrobial agents is of major concern among scientists and clinicians worldwide. To overcome the resistance and other drawbacks of the current antimicrobial drugs and to obtain more efficacious drugs, an antimicrobial drug having a novel mode of action should be developed. The flavonoid compounds have demonstrated for their therapeutic potential as antimicrobial agents previously. Aim: To evaluate the antifungal efficacy of plant derived compounds such as hesperetin (HSP) and silibinin (SBN) compounds in vitro. Materials and Methods: In this study, we evaluated the antifungal effect of two plant derived flavonoid compounds i.e., SBN and HSP against Candida albicans, Candida tropicalis, Malassezia furfur, Aspergillus niger, Penicillium oxalicum. The disk diffusion test was performed to test the antifungal effect of HSP and SBN with three different concentrations i.e., 15, 20, 25 mg/ml of HSP and SBN. The antifungal efficacy was studied for 72 h. Results: Our results indicate that SBN has significant antifungal effect than that of HSP. The high sensitivity of these compounds was found against C. albicans, C. tropicalis. Conclusion: These drugs could be good candidate to combine with regular antimicrobial agents.