ULK1 Mediated Autophagy-Promoting Effects of Rutin-Loaded Chitosan Nanoparticles Contribute to the Activation of NF-κB Signaling Besides Inhibiting EMT in Hep3B Hepatoma Cells.

Background: Liver cancer remains to be one of the leading causes of cancer worldwide. The treatment options face several challenges and nanomaterials have proven to improve the bioavailability of several drug candidates and their applications in nanomedicine. Specifically, chitosan nanoparticles (CNPs) are extremely biodegradable, pose enhanced biocompatibility and are considered safe for use in medicine. Methods: CNPs were synthesized by ionic gelation, loaded with rutin (rCNPs) and characterized by ultraviolet-visible spectroscopy (UV-Vis), Fourier-transform infrared spectroscopy (FTIR), dynamic light scattering (DLS) and transmission electron microscopy (TEM). The rCNPs were tested for their cytotoxic effects on human hepatoma Hep3B cells, and experiments were conducted to determine the mechanism of such effects. Further, the biocompatibility of the rCNPs was tested on L929 fibroblasts, and their hemocompatibility was determined. Results: Initially, UV-vis and FTIR analyses indicated the possible loading of rutin on rCNPs. Further, the rutin load was quantitatively measured using Ultra-Performance Liquid Chromatography (UPLC) and the concentration was 88 µg/mL for 0.22 micron filtered rCNPs. The drug loading capacity (LC%) of the rCNPs was observed to be 13.29 ± 0.68%, and encapsulation efficiency (EE%) was 19.55 ± 1.01%. The drug release was pH-responsive as 88.58% of the drug was released after 24 hrs at the lysosomal pH 5.5, whereas 91.44% of the drug was released at physiological pH 7.4 after 102 hrs. The cytotoxic effects were prominent in 0.22 micron filtered samples of 5 mg/mL rutin precursor. The particle size for the rCNPs at this concentration was 144.1 nm and the polydispersity index (PDI) was 0.244, which is deemed to be ideal for tumor targeting. A zeta potential (ζ-potential) value of 16.4 mV indicated rCNPs with good stability. The IC50 value for the cytotoxic effects of rCNPs on human hepatoma Hep3B cells was 9.7 ± 0.19 µg/mL of rutin load. In addition, the increased production of reactive oxygen species (ROS) and changes in mitochondrial membrane potential (MMP) were observed. Gene expression studies indicated that the mechanism for cytotoxic effects of rCNPs on Hep3B cells was due to the activation of Unc-51-like autophagy-activating kinase (ULK1) mediated autophagy and nuclear factor kappa B (NF-κB) signaling besides inhibiting the epithelial-mesenchymal Transition (EMT). In addition, the rCNPs were less toxic on NCTC clone 929 (L929) fibroblasts in comparison to the Hep3B cells and possessed excellent hemocompatibility (less than 2% of hemolysis). Conclusion: The synthesized rCNPs were pH-responsive and possessed the physicochemical properties suitable for tumor targeting. The particles were effectively cytotoxic on Hep3B cells in comparison to normal cells and possessed excellent hemocompatibility. The very low hemolytic profile of rCNPs indicates that the drug could be administered intravenously for cancer therapy.

Simultaneous assessment of absorption and pharmacokinetic characteristics of four active flavonoids from Chimonanthus nitens Leaf Granules using LC-MS determination: in vivo and in vitro.

A sensitive UPLC-HRMS method was developed and validated for simultaneous quantification of four active flavonoids from Chimonanthus nitens Leaf Granules (CNLG) in biological matrix. The method was utilized in pharmacokinetic study of the four flavonoids in rats as well as other evaluation assays in vitro. It was revealed that rutin, nicotiflorin, and astragalin had poor oral bioavailability in rats possibly due to low intestinal permeability and metabolism in intestinal flora. Kaempferol underwent rapid glucuronidation and sulphation in rat plasma with medium permeability coefficient. The results provided valuable data for future research and development of CNLG flavonoids.

Anti-inflammatory and antioxidant effects of nanoformulations composed of metal-organic frameworks delivering rutin and/or piperine natural agents.

Plant-derived natural medicines have been extensively studied for anti-inflammatory or antioxidant properties, but challenges to their clinical use include low bioavailability, poor solubility in water, and difficult-to-control release kinetics. Nanomedicine may offer innovative solutions that can enhance the therapeutic activity and control release kinetics of these agents, opening the way to translating them into the clinic. Two agents of particular interest are rutin (Ru), a flavonoid, and piperine (Pip), an alkaloid, which exhibit a range of pharmacological activities that include antioxidant and anti-inflammatory effects. In this work, nanoformulations were developed consisting of two metal-organic frameworks (MOFs) with surface modifications, Ti-MOF and Zr-MOF, each of them loaded with Ru and/or Pip. Both MOFs and nanoformulations were characterized and evaluated in vivo for anti-inflammatory and antioxidant effects. Loadings of ∼17 wt.% for a single pro-drug and ∼27 wt.% for dual loading were achieved. The release patterns for Ru and or Pip followed two stages: a zero-order for the first 12-hour stage, and a second stage of stable sustained release. At pH 7.4, the release patterns best fit to zero-order and Korsmeyer-Peppas kinetic models. The nanoformulations had enhanced anti-inflammatory and antioxidant effects than any of their elements singly, and those with Ru or Pip alone showed stronger effects than those with both agents. Results of assays using a paw edema model, leukocyte migration, and plasma antioxidant capacity were in agreement. Our preliminary findings indicate that nanoformulations with these agents exert better anti-inflammatory and antioxidant effects than the agents in their free form.

Tissue distribution and molecular docking research on the active components of Bidens bipinnata L. against hyperlipidemia.

Bidens bipinnata L. is a folk medicinal plant in China that shows significant antihyperlipidemia effectiveness. However, studies of the underlying mechanism study are lacking. In order to explore the potential action sites and the underlying mechanism of treating hyperlipidemic, this work undertook tissue distribution and molecular docking research on the markers of B. bipinnata L., which were obtained through serum pharmacochemistry and network database retrieval. The results showed that seven compounds (gallic acid, protocatechuic acid, rutin, hyperoside, bipinnate polyacetylenicloside, luteolin and quercetin) were screened out as markers. Owing to the diversity of chemical structures, they exhibited an inconsistent trend in tissue distribution. However, all of them had high levels in the liver and no specific distribution in other tissues. More interestingly, seven proteins-HMGCR (1HWK), NR3C1 (4P6W), CYP1A2 (2HI4), RXRA (4PP3), CES1 (1MX1), HSD11B1 (2RBE) and CYP1A1 (4I8V)-showed significant binding affinity with three or more markers, suggesting that they may be the target proteins of B. bipinnata L. This study preliminarily sheds light on the tissue distribution and targets of B. bipinnata L., providing some useful information on the underlying mechanisms of the antihyperlipidemia effect.

Formulation and evaluation of rutin-loaded solid lipid nanoparticles for the treatment of brain tumor.

The primary requirement for curing cancer is the delivery of essential drug load at the cancer microenvironment with therapeutic efficacy. Considering this, the present study aims to formulate "Rutin"-encapsulated solid lipid nanoparticles (SLNs) for effective brain delivery across the blood-brain barrier (BBB). Rutin-loaded SLNs were fabricated by oil-in-water microemulsion technique and were characterized for their physicochemical properties. The in vivo biodistribution study of rutin-loaded SLNs was studied using Rattus norvegicus rats. Subsequently, in silico molecular docking and dynamic calculations were performed to examine the binding affinity as well as stability of rutin at the active site of target protein "epidermal growth factor receptor (EGFR)." Formulated rutin-loaded SLNs were predominantly spherical in shape with an average particle diameter of 100 nm. Additionally, the biocompatibility and stability have been proved in vitro. The presence and biodistribution of rutin in vivo after 54 h of injection were observed as 15.23 ± 0.32% in the brain, 8.68 ± 0.63% in the heart, 4.78 ± 0.28% in the kidney, 5.04 ± 0.37% in the liver, 0.92 ± 0.04% in the lung, and 11.52 ± 0.65% in the spleen, respectively. Molecular docking results revealed the higher binding energy of - 150.973 kJ/mol of rutin with EGFR. Molecular dynamic simulation studies demonstrated that rutin with EGFR receptor complex was highly stable at 30 ns. The observed results exemplified that the formulated rutin-loaded SLNs were stable in circulation for a period up to 5 days. Thus, rutin-encapsulated SLN formulations can be used as a promising vector to target tumors across BBB. Graphical abstract.

Characterization and Evaluation of the Solubility and Oral Bioavailability of Rutin-Ethanolate Solvate.

Rutin has many biological activities, but poor solubility and absorption limit its oral application. This study aimed to investigate the characterization of metastable rutin-ethanolate and its solubility and oral bioavailability. In this research, a soluble rutin/CH3CH2OH solvate (Form Π) was prepared by solvent crystallization. High-performance liquid chromatography, gas chromatograph, and 1H-NMR showed that Form Π was formed by rutin and ethanol in a molar ratio of 1:1. The changes of Fourier transform infrared spectroscopy and 1H-NMR spectrum and the density functional theory (DFT) calculation predicted hydrogen bond formation between 4'-O of rutin and -OH of ethanol. The results of morphology, solid state CP/MAS 13C-NMR, X-ray diffraction, and differential scanning calorimetry (DSC) revealed that Form Π is a novel polymorph that differs from Form Ι (rutin trihydrate). Form Π can be stored for a long time under sealed and dry conditions at 40°C but would gradually transform into Form Ι under humid conditions. Although Form Π is a new metastable polymorph relative to Form Ι, Form Π has better solubility and faster dissolution rate. Moreover, the bioavailability of Form Π was 2.04 times higher than that of Form Ι. This outcome implied that Form Π would be a prospective raw material of oral preparation.

Antioxidant activity and bioaccessibility of phenolic compounds in white, red, blue, purple, yellow and orange edible flowers through a simulated intestinal barrier.

This study assessed the phenolics and their bioaccessibility through an in vitro digestion system coupled to a simulated intestinal barrier in eight edible flowers of distinct colors, namely mini rose, torenia, mini daisy, clitoria, cosmos, cravine, begonia and tagete. The antioxidant activity of the flowers before in vitro digestion, in their derived dialyzed and non-dialyzed fractions was evaluated using distinct approaches. All flowers presented in their composition phenolic acids, stilbenes, flavanol, anthocyanin, flavonol and flavanone, however distinct compounds and contents were found in each flower. The bioaccessibility varied among the phenolics and within the flower source (p < 0.05). Cosmos presented the highest (p < 0.05) content of phenolics and activity in ORAC assay before in vitro digestion and in dialyzed and non-dialyzed fraction; the observed activity was correlated (r = 0.9) to its major compounds, hesperidin and rutin, as well as to caftaric acid and procyanidin B2. Mini rose displayed the highest antioxidant activity in FRAP and DPPH assays before in vitro digestion; its dialyzed and non-dialyzed fraction showed the highest activity in FRAP, correlated to pelargonidin 3,5-diglucoside, catechin, epicatechin galate, epicagocatechin galate, procyanidin A2, quercitin 3-glucoside and trans-resveratrol (r = 0.9). In DPPH assay, mini rose showed the highest activity in the non-dialyzed fraction, while cravine showed the highest activity in the dialyzed fraction, which was mainly correlated to syringic acid (r = 1.0), pelargonidin 3,5-diglucoside and epicatechin (r = 0.9). Results show great variability in the phenolic composition and their bioaccessibility among the edible flowers studied. Our findings indicate cosmos and mini rose as sources of bioaccessible phenolics with great antioxidant activity.

Effect of rutin on retinal VEGF, TNF-α, aldose reductase, and total antioxidant capacity in diabetic rats: molecular mechanism and ocular pharmacokinetics.

PURPOSE: The current study was conducted to explore the potential of rutin in preventing sight-threatening diabetic retinopathy. METHODS: Wistar albino rats (either sex) weighing 200-225 g were intraperitoneally injected with 45 mg/kg streptozotocin (pH 4.5). Rats having blood glucose ≥ 300 mg/dL were divided into two groups (n = 8; each group). Group I served as diabetic control and received normal saline p.o. Group II received rutin 50 mg/kg p.o. for 24 weeks. At the end of 24 weeks, retinal fundus and fluorescein imaging were done, rats were killed, and retinal biochemical assessments were conducted. Moreover, ocular pharmacokinetics of rutin was assessed in the normal rats after a single oral dose of 50 mg/kg. RESULTS: Rutin treatment significantly (p < 0.001) lowered retinal vascular endothelial growth factor, tumor necrosis factor-α, and aldose reductase. Rutin treatment significantly (p < 0.001) elevated the levels of total antioxidant capacity of the retinas. Fundus examination of rutin-treated group showed significantly lower tortuosity index and normal fluorescein angiography. Rutin was detected in the retina as well as in aqueous humor of normal rats. CONCLUSION: Rutin treatment significantly arrested the biochemical disturbances of diabetic retinopathy. The distribution of orally ingested rutin in ocular tissues further substantiate its site-specific action.

Establishment of modified biopharmaceutics classification system absorption model for oral Traditional Chinese Medicine (Sanye Tablet).

ETHNOPHARMACOLOGICAL RELEVANCE: As one of the new drugs of traditional Chinese medicine, Sanye Tablet is employed as a hypolipidemic in the traditional medicine, but the biopharmaceutical properties of the drug is still unclear. AIM OF THE STUDY: Through the study of biopharmaceutical properties, the classical biopharmaceutics classification system (BCS) can be used to classify and predict the in vivo absorption properties. On this basis, the biopharmaceutical properties closely related to traditional Chinese medicine preparations are added and a modified BCS model is established to predict and judge the absorption degree of traditional Chinese medicine compound. MATERIALS AND METHODS: Representative components of Sanye Tablet were selected and subjected to different in vitro tests. The experimental results were compared with the results of the BCS to evaluate the accuracy and applicability to Sanye Tablet. We take parameters of dissolution and stability based on product characteristics into account. A "modified-BCS" was developed and the results of the improved method and the classic method were compared. Also the ability of each classification system to predict and determine the extent of absorption of the Chinese herbal compound was investigated based on the absolute bioavailability of representative components. RESULTS: For classic BCS, the five representative components (except for nuciferine) are all class III, nuciferine is class I/II obtained by Caco-2 cell assay and class III/IV obtained by everted gut sac assay. For modified BCS, paeoniflorin is class III, rutin, hyperoside and salvianolic acid B are class III/IV, and nuciferine is class I/II based on Caco-2 cell assay, class III/IV based on everted gut sac assay. Nuciferine is the best of the five components, with absolute bioavailability reaching 61.91% based on in vivo bioavailability test. CONCLUSIONS: The five representative components (except for nuciferine) are all class III/IV, which correlates well with the absolute bioavailability results and demonstrates that they are poorly absorbed substances. The correlation between the classification results obtained using the "modified-BCS" and absorption in the body is better than the correlation obtained using the classic method, suggesting that the improved BCS is more suitable for the characterization of Sanye Tablet. These results indicate that the oral formulation of Sanye Tablet is a BCS III/IV drug.

Chitosan coated chlorogenic acid and rutincomposite phospholipid liposomes: Preparation, characterizations, permeability and pharmacokinetic.

In order to research and enhance bioavailability of chlorogenic acid and rutin(CA-R) via the oral route, chitosan coated composite phospholipid liposomes (C-CPLs) were applied to study on preparation, permeability and pharmacokinetic of C-CA-R-CPLs. TheC-CA-R-CPLs were prepared by the method of ethanol injection. The entrapment efficiency (EE), average particle sizes, polymer disperse index (PDI), zeta potential, shape and in vitro drug release were investigated to characterize physicochemical parameters of C-CA-R-CPLs. The penetration properties from C-CA-R-CPLs were studied through Caco-2 cells model and the pharmacokinetics in Sprague-Dawley (SD) rats were evaluated by rat jugular vein intubation tube. The EE of C-CA-R-CPLs of CA and R was 91.3±2.13% and 92.6±2.44%, particle size of C-CA-R-CPLs was 176.7±2.3 nm, PDI was 0.207±0.014 and zeta potential of 12.61±1.33 mV. CA-R-CPLs and C-CA-R-CPLs were spherical or elliptical sphere and the bilayer of the CPL was observed obviously under transmission electron. The Cmax, t1/2 and AUC0-12 h values of CA and R for groups of C-CA-R-CPLs were significantly increased.In conclusion, TheC-CA-R-CPLs as a novel nano-formulation have potential to be used to enhance the oral bioavailability of poorlywater-soluble drugs after oral administration.

Nano-lipid Complex of Rutin: Development, Characterisation and In Vivo Investigation of Hepatoprotective, Antioxidant Activity and Bioavailability Study in Rats.

The current study was aimed to develop an amphiphilic drug-lipid nano-complex of rutin:egg phosphatidylcholine (EPC) to enhance its poor absorption and bioavailability, and investigated the impact of the complex on hepatoprotective and antioxidant activity. Rutin nano-complexes were prepared by solvent evaporation, salting out and lyophilisation methods and compared for the complex formation. For the selected lyophilisation method, principal solvent DMSO, co-solvent (t-butyl alcohol) and rutin:EPC ratios (1:1, 1:2 and 1:3) were selected after optimisation. The properties of the nano-complexes such as complexation, thermal behaviour, surface morphology, molecular crystallinity, particle size, zeta potential, drug content, solubility, in vitro stability study, in vitro drug release, in vitro and in vivo antioxidant study, in vivo hepatoprotective activity and oral bioavailability/pharmacokinetic studies were investigated. Rutin nano-complexes were developed successfully via the lyophilisation method and found to be in nanometric range. Rutin nano-complexes significantly improved the solubility and in vitro drug release, and kinetic studies confirmed the diffusion-controlled release of the drug from the formulation. The nano-complex showed better antioxidant activity in vitro and exhibited well in vitro stability in different pH media. The in vivo study showed better hepatoprotective activity of the formulation compared to pure rutin at the same dose levels with improved oral bioavailability. Carbon tetrachloride (CCl4)-treated animals (group II) failed to restore the normal levels of serum hepatic marker enzymes and liver antioxidant enzyme compared to the nano-complex-treated animals. The results obtained from solubility, hepatoprotective activity and oral bioavailability studies proved the better efficacy of the nano-complex compared to the pure drug.

Investigation into the Emerging Role of the Basic Amino Acid L-Lysine in Enhancing Solubility and Permeability of BCS Class II and BCS Class IV Drugs.

BACKGROUND: The search for a simple and scalable approach that can improve the two key biopharmaceutical processes (solubility and permeability) for BCS Class II and BCS Class IV has still been unmet need. PURPOSE: In this study, L-lysine was investigated as a potential excipient to tackle problems with solubility and permeability. Bendazac (Class II); quercetin and rutin (Class IV) were employed. METHODS: Drugs-lysine complexes in 1:1 M ratios were prepared by co-precipitation and co-grinding; characterized for solubility, partition coefficient, DSC, FTIR, SEM, dissolution rate and permeability. Chemical stability of quercetin-lysine and rutin-lysine was studied by assessing antioxidant capacity using Trolox and CUPRAC assays. RESULTS AND CONCLUSION: Drugs-lysine salt/complexes were confirmed. Solubility enhancement factors ranged from 68- to 433-fold increases and dissolution rates were also significantly enhanced by up to 6-times, compared with drugs alone. With the exception of rutin-lysine, Papp for bendazac-lysine and quercetin-lysine enhanced by 2.3- to 4-fold. Papp for quercetin (Class IV) benefited more than bendazac (Class II) when complexed with lysine. This study warrants the use of L-lysine as a promising excipient for enhanced solubility and permeability of Class II and Class IV, providing that the solubility of the drug is ensured at 'the door step' of absorption sites.

Nanocrystals for improved dermal drug delivery.

Nanocrystals are composed of 100% active and possess an increased aqueous solubility and dissolution velocity when compared to larger sized materials. Nanocrystals can be used to improve the bioavailability of poorly soluble actives not only for oral, but also for topical application. In this study nanocrystals of different sizes were produced and the influence of size on dermal penetration was investigated. The influence of different excipients and vehicles on the penetration efficacy upon dermal application was also investigated. Results confirm that dermal penetration of poorly soluble actives increases with decreasing size of the nanocrystals. Unexpectedly, it was observed that many classical penetration enhancers failed to promote the penetration of actives from nanocrystals. Also hydrogels were found to be non-suitable vehicles for the formulation of nanocrystals. As most suitable vehicles for nanocrystals oleogels and creams were identified.

Rutin-phospholipid complex in polymer matrix for long-term delivery of rutin via skin for the treatment of inflammatory diseases.

The drug with poor oral bioavailability necessitates the development of novel carrier for efficient drug delivery. This paper reports the rutin-phospholipid complex in polymer matrix for sustained delivery of rutin via the skin for the treatment of acute and chronic inflammatory diseases. Rutin in phospholipid complex (RNPs) are better soluble and permeable than the free rutin. The RNPs-loaded polymeric matrix patch with moderate adhesiveness was developed for convenient means of long term drug application on the skin. The patch was analysed for physicochemical properties, ex vivo skin permeability and in vivo efficacy in rat paw oedema model. The skin targeting efficacy was analysed by CLSM study. Optimized formulation (F2) showed 31 ± 2.32% and 26.56 ± 5.52% skin permeation at 24 h across excised rat skin and human cadaver skin, respectively. The sustained anti-inflammatory effect of the patch formulation in rat paw oedema model confirmed its unique in vivo efficacy over the conventional diclofenac gel. The CLSM study confirmed the localization of RNPs in the dermis for sustained anti-inflammatory effect. Our results suggest that the developed patch has a potential for long term site specific delivery of rutin in arthritic patients.

Formulation and characterization of chitosan encapsulated phytoconstituents of curcumin and rutin nanoparticles.

Curcumin and Rutin are natural polyphenolic molecules exhibits several pharmacological actives like antibacterial, anticancer, antioxidant, chemo-preventive and anti-inflammatory properties. However till date, no studies have been reported on their combination efficacy, especially in treating multi-drug resistance of cancers because of their poor solubility and bioavailability. Hence in the present study, an attempt has been made to load both these drugs into a single nanoparticlulate system to enhance their bioavailability and efficacy. This novel formulation was prepared by solvent evaporation technique and was evaluated for particle size and shape using Zeta Sizer, Scanning Electron Microscopy (SEM) and Fourier Transform Infra Red (FT-IR) Spectroscopy. The optimized formulation was further subjected to in vitro and in vivo evaluations. The prepared nanoparticles were in the size range of 25-100nm and the release profile was found to be Non -Fickian transport. In-vivo pharmacokinetic studies were carried in rabbits and the pharmacokinetic profile was studied. The results indicate that oral bioavailability of Curcumin and Rutin has been increased to 3.06 and 4.24 folds respectively when compared to their pure drugs. This data suggest that the present novel nanoparticles loaded with these combinational drugs may have better therapeutic potential in treating drug resistant cancers.

Stabilization of a non-aqueous self-double-emulsifying delivery system of rutin by fat crystals and nonionic surfactants: preparation and bioavailability study.

Literature examples of non-aqueous Pickering emulsions stabilized by fat crystals are very rare. Moreover, the applications of rutin are limited due to its low solubility in both water and oils (less than 0.10 mg g-1 and 0.25 mg g-1, respectively). Thus, herein, we developed an optimum formulation of a non-aqueous self-double-emulsifying delivery system (SDEDS) containing rutin and evaluated its oral bioavailability. The new formulation stabilized by fat crystals (glycerol monostearate, GMS) and nonionic surfactants was prepared via a two-step emulsification process. The presence of a mixture of GMS crystals and nonionic surfactants effectively improves the stability of the emulsions. The non-aqueous SDEDS spontaneously forms oil-in-oil-in-water (O/O/W) double emulsions in the gastrointestinal environment with the inner oil phase mainly containing the active ingredients. It is stable at both 4 °C and 25 °C for 30 days and could enhance the dissolution properties of the active ingredients. Furthermore, the protection of rutin against digestion-mediated precipitation was observed when the formulation contained a high concentration of GMS crystals. The oral absolute bioavailability of rutin obtained from SDEDS (8.62%) is 1.76-fold higher than that of the actives suspension (4.90%). Thus, the non-aqueous SDEDS is an attractive candidate for the encapsulation of water-insoluble and simultaneously oil-insoluble nutrients (such as rutin) and for use in oral delivery applications.

In Vivo Hypoglycemic Studies of Polyherbal Phytoceuticals, Their Pharmacokinetic Studies and Dose Extrapolation by Allometric Scaling.

BACKGROUND: This work reports the safety profiling, in vivo hypoglycemic and pharmacokinetic studies of three phytoceuticals viz. conventional and sustained release tablets and microspheres each containing a polyherbal product phytocomposite (PHC) as the active ingredient. PHC is prepared from the leaf extracts of Ficus benghalensis: Syzigium cumini: Ocimum sanctum mixed in the weight ratio of 1:1:2. Further no observed adverse effect level (NOAEL), maximum recommended starting dose (MRSD) in human and prediction of human pharmacokinetic parameters have been accomplished by allometric equations. METHODS: Acute and sub chronic studies of the phytoceuticals were done as per OECD and in vivo hypoglycemic studies in STZ induced diabetic rats. Plasma concentrations of the active constituent rutin (pharmacologically active compound of PHC) were determined by HPLC and other pharmacokinetic parameters using PK Solver. Repeated dose toxicity was carried out to determine the NOAEL value, MRSD estimated using allometric formulas of body surface area and clearance (CL) and volume of distribution (Vd) predicted by allometric equations of single species scaling. RESULTS: Phytoceuticals showed a wide range of safety profile with a significant lowering of blood gluco-lipid level. The values of the pharmacokinetic parameters for different doses of phytoceuticals showed that the active concentration was maintained in plasma level and each formulation complied with their relevant quality criteria. NOAEL value was 5000 mg/kg/body weight and MRSD was 4864.86 mg. CONCLUSION: Phytoceuticals prepared are safe and effectively controlled blood gluco lipid level. Animal to human dose extrapolation and prediction of human pharmacokinetic parameters by allometry was convenient.

Modulation of iron transport, metabolism and reactive oxygen status by quercetin-iron complexes in vitro.

SCOPE: Excess free-iron is detrimental to health through its ability to participate in free radical generation and amplification of oncogenic pathways. The study aims were to identify polyphenols with iron-chelating potential. METHODS AND RESULTS: Of four polyphenols tested quercetin demonstrated potent iron binding with the physiological outcome dictated by the location of interaction. In the presence of extracellular iron and quercetin, ferritin expression and cellular iron concentrations decreased suggesting the resulting quercetin-iron complex is not internalised. However, in the relative absence of extracellular iron, quercetin becomes internalised and complexes with both intracellular iron, and iron which subsequently becomes absorbed as indicated by increased cellular 59 Fe post pre-culture with quercetin. This increased intracellular iron complexed to quercetin does not associate with the labile iron pool and cells behave as though they are iron deficient (increased transferrin receptor-1 and iron regulatory protein-2 expression and low ferritin expression). Additionally, a suppression in reactive oxygen species was observed. CONCLUSION: Quercetin, an exogenous iron chelator, is able to render the cell functionally iron-deficient which not only provides a therapeutic platform for chelating excess free luminal iron but also may be of use in limiting processes such as cancer-cell growth, inflammation and bacterial infections, which all require iron.

Intravenous rutin in rat exacerbates isoprenaline-induced cardiotoxicity likely due to intracellular oxidative stress.

OBJECTIVES: Rutin, quercetin-3-O-rutinoside, a natural flavonol glycoside, has shown various in vitro benefits with potential use treating human diseases, especially cardiovascular system disorders. Antioxidant properties are assumed to underlie the majority of these benefits. Yet rutin pro-oxidant properties have been reported as well. Our research group has recently shown aggravating effects on isoprenaline (ISO)-induced cardiotoxicity in Wistar:Han rats after 24 hours. METHODS: This study was designed to examine in more detail the reasons for the negative effects of rutin (11.5 and 46 mg/kg, i.v.) after administration of ISO (100 mg/kg, s.c.) in rats within 2 hours of continuous experiment and in the H9c2 cardiomyoblast-derived cell line. RESULTS: Like our previous findings, rutin did not (11.5 or 46 mg/kg, i.v.) reduce the ISO-induced mortality within 2 hours although the lower dose significantly reduced cardiac troponin T (cTnT) and partly improved the histological findings. In contrast, the higher dose increased the mortality in comparison with solvent (1.26% w/v sodium bicarbonate). This was not caused by any specific haemodynamic disturbances. It appears to be associated with oxidative stress as rutin enhanced intracellular reactive oxygen species formation in vitro and had the tendency to increase it in vivo. CONCLUSIONS: Rutin, likely due to its pro-oxidative effects, can exacerbate catecholamine cardiotoxicity depending on the dose used.

Natural Deep Eutectic Solvents (NADES) as a Tool for Bioavailability Improvement: Pharmacokinetics of Rutin Dissolved in Proline/Glycine after Oral Administration in Rats: Possible Application in Nutraceuticals.

There is a need for innovation in plant-derived pharmaceuticals, food supplements and nutraceutical products regarding the use of more eco-sustainable solvents for their extraction. Furthermore, the poor oral bioavailability of several phytochemicals with health promoting effects stimulates the research in the field of pharmaceutical formulations. Natural Deep Eutectic Solvents (NADES) are formed by natural compounds, and can be considered as future solvents being especially useful for the preparation of nutraceuticals and food-grade extracts. In this paper various NADES were prepared using sugars, aminoacids and organic acids. Rutin (quercetin-3-O-α-l-rhamnopyranosyl-(1→6))-ß-d-glucopyranose) was used as a model compound to study NADES. Moreover, the effect of various eutectic mixtures on rutin's water solubility was studied. Proline/glutamic acid (2:1) and proline/choline chloride (1:1) mixtures have a solubility comparable to ethanol. The proline/glutamic acid (2:1) eutectic containing rutin was used in a pharmacokinetic study in Balb/c mice while bioavailability was compared to oral dosing of water suspension. Plasmatic levels of rutin were measured by HPLC-MS/MS showing increased levels and longer period of rutin permanence in plasma of NADES treated animals. This paper reports the possible use of non-toxic NADES for pharmaceutical and nutraceutical preparations.