The rutin/β-cyclodextrin interactions in fully aqueous solution: spectroscopic studies and biological assays

Antioxidant activity of an inclusion complex between rutin and β-cyclodextrin: experimental and quantum chemical studies

This study aims to synthesize a guest-host complex derived from rutin (Rut) and β-cyclodextrin (β-CD) (denoted as [Rut⊂β-CD]). The obtained substance was characterized by the FT-IR and DSC methods, signifying the formation of an inclusion complex between Rut and β-CD. Complex formation increased the antioxidant activity of rutin corresponding to the decrease of EC50 values from 1.547 × 10-5 mol L-1 to 1.227 × 10-5 mol L-1 according to the DPPH free radical scavenging test. The rutin-β-CD interaction energies were calculated in the vacuum and various solvents (e.g., water, ethanol, and dimethylsulfoxide) utilizing an accurate and broadly parametrized self-consistent tight-binding quantum chemical method (GFN2-xTB). The calculation results reveal the influence of solvent on the structural formation of the rutin-β-CD complex. In both the vacuum and aqueous solution, rutin can enter into the small-sized empty cavity of β-CD, albeit through different terminals, resulting in distinct preferential structures. The presence of organic solvents appears to reduce the interaction between rutin and β-CD, with the interaction strength following the order: water > ethanol > dimethyl sulfoxide.

Rutin/Sulfobutylether-β-Cyclodextrin as a Promising Therapeutic Formulation for Ocular Infection

Ocular pathologies present significant challenges to achieving effective therapeutic results due to various anatomical and physiological barriers. Natural products such as flavonoids, alone or in association with allopathic drugs, present many therapeutic actions including anticancer, anti-inflammatory, and antibacterial action. However, their clinical employment is challenging for scientists due to their low water solubility. In this study, we designed a liquid formulation based on rutin/sulfobutylether-β-cyclodextrin (RTN/SBE-β-CD) inclusion complex for treating ocular infections. The correct stoichiometry and the accurate binding constant were determined by employing SupraFit software (2.5.120) in the UV-vis titration experiment. A deep physical-chemical characterization of the RTN/SBE-β-CD inclusion complex was also performed; it confirmed the predominant formation of a stable complex (Kc, 9660 M-1) in a 1:1 molar ratio, with high water solubility that was 20 times (2.5 mg/mL) higher than the free molecule (0.125 mg/mL), permitting the dissolution of the solid complex within 30 min. NMR studies revealed the involvement of the bicyclic flavonoid moiety in the complexation, which was also confirmed by molecular modeling studies. In vitro, the antibacterial and antibiofilm activity of the formulation was assayed against Staphylococcus aureus and Pseudomonas aeruginosa strains. The results demonstrated a significant activity of the formulation than that of the free molecules.

Repairing of rutin to the toxicity of combined F-53B and chromium pollution on the biofilm formed by Pseudomonas aeruginosa

The wastewater discharge from the process of chrome plating, which contains 6:2 chlorinated polyfluorinated ether sulfonate (F-53B) and chromium (Cr), may be toxic to biofilm. In this study we found that the biofilm formed by Pseudomonas aeruginosa PAO1 was inhibited by exposure to a combination of F-53B and Cr(VI). The combined pollution damaged the cell membranes and the structure of the biofilm, and inhibited the production of the Pseudomonas quinolone-based signal, which affected biofilm formation. Moreover, the secretion of extracellular polymeric substances decreased as a result of this combined exposure. Exposure to F-53B and Cr(VI) individually or in combination could induce the excessive accumulation of intracellular reactive oxygen species (ROS), and the ROS positive rate of the bacteria increased under the treatment with 0.2 mmol/L of Cr(VI) and 250 nmol/L of F-53B, respectively. In addition, the activities of superoxide dismutase (SOD) and catalase (CAT) were enhanced for scavenging ROS in the bacteria that were exposed to Cr(VI) and F-53B. As an antioxidant, rutin was used to repair the toxicity of Cr(VI) and F-53B towards the biofilm formed by the bacteria. When rutin was added to the bacteria medium, with either Cr(VI) or F-53B as pollutant, or with the combined pollutants, the extracellular protein content of the bacteria recovered to 0.84, 0.94, and 0.85 times that of the control, respectively. Meanwhile, the accumulation of ROS and the activities of SOD and CAT decreased, which indicated that the addition of rutin can alleviate the oxidative stress and promote the antioxidant stress system.

Effect of ultrasound treatment on interactions of whey protein isolate with rutin

Rutin is a biologically active polyphenol, but its poor water solubility and low bioavailability limit its application to the food industry. We investigated the effect of ultrasound treatment on the properties of rutin (R) and whey protein isolate (WPI) using spectral and physicochemical analysis. The results revealed that there was covalent interaction between whey protein isolate with rutin, and the binding degree of whey isolate protein with rutin increased with ultrasound treatment. Additionally, solubility and surface hydrophobicity of WPI-R complex improved with ultrasonic treatment, and a maximum solubility of 81.9 % at 300 W ultrasonic power. The ultrasound treatment caused the complex to develop a more ordered secondary structure, resulting in a three-dimensional network structure with small and uniform pore sizes. This research could provide a theoretical reference for studying protein-polyphenol interactions and their applications in food delivery systems.

Chemical Analysis and Molecular Modelling of Cyclodextrin-Formulated Propofol and Its Sodium Salt to Improve Drug Solubility, Stability and Pharmacokinetics (Cytogenotoxicity)

Propofol is a widely used general anesthetic in clinical practice, but its use is limited by its water-insoluble nature and associated pharmacokinetic and pharmacodynamic limitations. Therefore, researchers have been searching for alternative formulations to lipid emulsion to address the remaining side effects. In this study, novel formulations for propofol and its sodium salt Na-propofolat were designed and tested using the amphiphilic cyclodextrin (CD) derivative hydroxypropyl-β-cyclodextrin (HPβCD). The study found that spectroscopic and calorimetric measurements suggested complex formation between propofol/Na-propofolate and HPβCD, which was confirmed by the absence of an evaporation peak and different glass transition temperatures. Moreover, the formulated compounds showed no cytotoxicity and genotoxicity compared to the reference. The molecular modeling simulations based on molecular docking predicted a higher affinity for propofol/HPβCD than for Na-propofolate/HPβCD, as the former complex was more stable. This finding was further confirmed by high-performance liquid chromatography. In conclusion, the CD-based formulations of propofol and its sodium salt may be a promising option and a plausible alternative to conventional lipid emulsions.

Bilayered skin substitute incorporating rutin nanoparticles for antioxidant, anti-inflammatory, and anti-fibrotic effect

Hypertrophic scarring in large burns and delayed healing in chronic wounds are consequences of prolonged and aggravated inflammation, sustained infiltration of immune cells, free radical generation, and abundance of inflammatory mediators. Therefore, it is imperative to curb hyperinflammation to expedite wound healing. In this study, rutin nanoparticles (RNPs) were synthesized without an encapsulant and incorporated into eggshell membrane powder-crosslinked gelatin-chitosan cryogels to impart antioxidant and anti-inflammatory properties for treating hyperinflammation. The resultant nanoparticles were found to be 17.53 ± 4.03 nm in size and were stable at room temperature for a month with no visible sedimentation. RNPs were found to be non-cytotoxic and exhibited anti-inflammatory (by increasing IL-10 levels) and antioxidant properties (by controlling the generation of reactive oxygen species and enhancing catalase production in human macrophages). Additionally, RNPs were found to reduce α-SMA expression in fibroblasts, thereby demonstrating their anti-scarring effect. In vivo studies with a bilayered skin substitute constituting an RNP-incorporated cryogel proved that it is biocompatible, does not induce renal toxicity, aids wound healing, and induces better re-epithelialization than the control groups at the initial stages. Thus, RNP-incorporated cryogels containing bilayered skin substitutes are an advanced and novel alternative to commercial dermo-epidermal substitutes that lack anti-inflammatory or anti-scarring properties.

Bacteria-Induced Colloidal Encapsulation for Probiotic Oral Delivery

Probiotic oral delivery has crucial implications in biomedical engineering, but its oral bioavailability remains unsatisfactory because of the limited survival and colonization of probiotics in the harsh gastrointestinal tract. Here, a bacteria-induced encapsulation strategy is achieved by assembling metastable colloids to enhance the oral bioavailability of probiotics. The colloids (NTc) composed of amino-modified poly-β-cyclodextrin and tannic acid are formed based on the balance of host-guest interaction-driven attraction and electrostatic repulsion between colloids. Negatively charged probiotics electrostatically attract positively charged NTc to break the balance and induce further assembly surrounding the probiotics. Through a facile one-step mixing, 97% of bacteria are rapidly encapsulated into NTc shells within 10 s, with a high utilization rate of feeding colloids of 91%. More importantly, we show that the compact, thick, and positively charged NTc shells synergistically endow the encapsulated probiotics with strong resistance against simulated gastric fluid with an excellent survival rate of up to 19%, 7500 times superior to the commercial enteric material L100. Moreover, owing to the dynamically noncovalent and self-adaptive nature of host-guest interactions, NTc shells support the proliferation of the encapsulated EcN comparable with that of the naked EcN. In vitro and in vivo experiments also confirm that the NTc-encapsulated probiotics possess durable intestinal adhesion, continuous proliferation activity, enhanced oral bioavailability, good oral biosafety, and excellent therapeutic efficacy in a colitis mouse model. This facile bacteria-induced colloidal encapsulation strategy may extend to various microbes as oral bioagents for treating various diseases.

Protective effect of Hovenia dulcis Thunb. leaf extracts against ethanol-induced DNA damage in SH-SY5Y cells

ETHNOPHARMACOLOGICAL RELEVANCE

Hovenia dulcis Thunb. has been used as a medicinal herb for the treatment of hepatic diseases and alcohol intoxication.

AIM OF THE STUDY

The genotoxic effect and the antigenotoxic potential of ethanolic extract of H. dulcis leaves and its methanolic fraction were evaluated against ethanol-induced damages in SH-SY5Y cells.

MATERIALS AND METHODS

The phytochemical analysis and antioxidant activity of H. dulcis extracts were also assessed. In addition, a systems biology analysis was performed to investigate the molecular pathway of action of the H. dulcis leaves compounds.

RESULTS

The ethanolic extract and its methanolic fraction presented genotoxicity through comet assay at 0.5 and 0.25 mg/mL. On the other hand, both extracts showed protective action against ethanol at all concentrations. Additionally, an NBT assay was performed and demonstrated an ability of the extracts to reduce superoxide anion formation when SH-SY5Y cells were challenged with ethanol. HPLC analysis indicated the presence of quercitrin, isoquercitrin, and rutin. Further, system biology assays indicated a molecular action pathway, where the compounds from the leaves of H. dulcis, in addition to performing free radical scavenging activity, activate PP2A, and may inhibit the apoptosis pathway activated by ethanol-induced oxidative stress.

CONCLUSIONS

This work is important to indicate potential antigenotoxic and antioxidant properties of H. dulcis leaves, and its use can be investigated against DNA damage induced by ethanol.

Bergamot Essential Oil: A Method for Introducing It in Solid Dosage Forms

Bergamot essential oil (BEO) possess antimicrobial, antiproliferative, anti-inflammatory, analgesic, neuroprotective, and cardiovascular effects. However, it is rich in volatile compounds, e.g., limonene, that are susceptible to conversion and degradation reactions. The aim of this communication was to prepare a conjugate based on a quaternary ammonium chitosan derivative (QA-Ch) and methyl-βCD (MCD), coded as BEO/QA-Ch-MCD, to encapsulate BEO in order to stabilize its volatile compounds, eliminate its unpleasant taste, and convert the oil in a solid dosage form. The obtained conjugate, BEO/QA-Ch-MCD, was highly soluble and had a percentage of extract association efficiency (AE %), in terms of polyphenols and limonene contents, of 22.0 ± 0.9 and 21.9 ± 1.2, respectively. Moreover, stability studies under UV stress in simulated gastric fluid showed that BEO/QA-Ch-MCD was more able to protect polyphenols and limonene from degradation compared to free BEO or BEO complexed with MCD (BEO/MCD). The complexation and subsequent lyophilization allowed the transformation of a liquid into a solid dosage form capable of eliminating the unpleasant taste of the orally administered oil and rendering the solid suitable to produce powders, granules, tablets, etc. These solid oral dosage forms, as they come into contact with physiological fluids, could generate nanosized agglomerates able to increase the stability of their active contents and, consequently, their bioavailability.

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.

A Comparative Study of Rutin and Rutin Glycoside: Antioxidant Activity, Anti-Inflammatory Effect, Effect on Platelet Aggregation and Blood Coagulation

The effects of rutin and rutin glycoside with different solubility were compared on antioxidant activity and anti-inflammatory effects in vitro and the effects on platelet aggregation and blood coagulation in vitro and in vivo. Rutin glycoside (consisting of rutin mono-glucoside and rutin di-glucoside) was prepared via enzymatic transglycosylation from rutin. Rutin glycoside showed a higher effect than rutin on radical scavenging activity in antioxidant assays. Rutin showed a higher toxicity than rutin glycoside in murine macrophage RAW264.7 cells. They had similar effects on the levels of nitric oxide (NO), prostaglandin E (PGE) 2 and pro-inflammatory cytokines (such as tumor necrosis factor (TNF)-α, and interleukin (IL)-6) in the cells. Both rutin and rutin glycosides similarly reduced the rate of platelet aggregation compared to controls in vitro. They also similarly delayed prothrombin time (PT) and activated partial thromboplastin time (APTT) in an in vitro blood coagulation test. The effect of repeated administration of rutin and rutin glycoside was evaluated in vivo using SD rats. The platelet aggregation rate of rutin and the rutin glycoside administered group was significantly decreased compared to that of the control group. On the other hand, PT and APTT of rutin and rutin glycoside group were not significantly delayed in vivo blood coagulation test. In conclusion, rutin and rutin glycoside showed differences in antioxidant activities in vitro, while they were similar in the reduction of NO, PGE2, TNF-α and IL-6 in vitro. Rutin and rutin glycoside also showed similar platelet aggregation rates, and blood coagulation both in vitro and in vivo condition. Comparing in vitro and in vivo, rutin and rutin glycoside were effective on platelet aggregation both in vitro and in vivo, but only in vitro on blood coagulation.

Investigating crystallization tendency, miscibility, and molecular interactions of drug-polymer systems for the development of amorphous solid dispersions

Crystallization tendencies, thermal analysis [i.e. glass transition temperature (T_g)], crystallinity, and melting point depression, along with theoretical calculations such as solubility parameter, of five different drugs [i.e. curcumin (CUR), indomethacin (IND), flutamide (FLU), dipyridamole (DIP), and griseofulvin (GRI)] in the absence and presence of four different polymers in various drug-polymer ratios were determined and analyzed. Physical states of the drug in the solid dispersions (SDs) and their stability were characterized by X-ray diffraction and modulated differential scanning calorimetry. Infrared (IR) and Raman were used in selected systems (i.e. CUR, DIP, and GRI systems) to explore the role of drug-polymer interactions in the amorphization of SDs. The crystallization tendencies of pure drugs were categorized as low (CUR, IND), moderate (FLU), and high (DIP, GRI). In the presence of selected polymers, the crystallization tendency of the drugs changed, though a high polymer concentration was required for high crystallization-tendency drugs [i.e. DIP and GRI (>50% w/w)]. Polymers showing a greater effect on the crystallization tendency of drugs were found to have higher drug-polymer miscibility and stronger molecular interactions. Drug-polymer systems selected from the investigation of physical mixtures formed stable amorphous solid dispersions (ASD). Furthermore, the rank order of the crystallization tendency of drug-polymer systems correlated well with those on miscibility and molecular interactions. Those rank orders also correlated well with the stability of prepared/reported SDs. Hence, the developed approach has significant potential to be a rational screening method for the development of amorphous SDs.

Rutin-Loaded Solid Lipid Nanoparticles: Characterization and In Vitro Evaluation

This study was aimed at preparing and characterizing solid lipid nanoparticles loading rutin (RT-SLNs) for the treatment of oxidative stress-induced diseases. Phospholipon 80H® as a solid lipid and Polysorbate 80 as surfactant were used for the SLNs preparation, using the solvent emulsification/diffusion method. We obtained spherical RT-SLNs with low sizes, ranging from 40 to 60 nm (hydrodynamic radius) for the SLNs prepared starting from 2% and 5% (w/w) theoretical amount. All prepared formulations showed negative zeta-potential values. RT was efficiently encapsulated within SLNs, obtaining high encapsulation efficiency and drug content percentages, particularly for SLNs prepared with a 5% theoretical amount of RT. In vitro release profiles and analysis of the obtained data applying different kinetic models revealed Fickian diffusion as the main mechanism of RT release from the SLNs. The morphology of RT-SLNs was characterized by scanning electron microscopy (SEM), whereas the interactions between RT and the lipid matrix were investigated by Raman spectroscopy, evidencing spectral modifications of characteristic bands of RT due to the establishment of new interactions. Finally, antioxidant activity assay on human glioblastoma astrocytoma (U373) culture cells showed a dose-dependent activity for RT-SLNs, particularly at the highest assayed dose (50 μM), whereas the free drug showed the lesser activity.

Physico-Chemical and Pharmaco-Technical Characterization of Inclusion Complexes Formed by Rutoside with β-Cyclodextrin and Hydroxypropyl-β-Cyclodextrin Used to Develop Solid Dosage Forms

The aim of our study was to obtain rutoside (RUT) inclusion complexes in β-cyclodextrin (β-CD) and in hydroxypropyl-β-cyclodextrin (HP-β-CD), in a 1:1 molar ratio, using the lyophilization method of complexation in solution. The complexes were confirmed and characterized, in comparison with the raw materials and their simple physical mixtures, by SEM, DSC, and FT-IR analyses. The antioxidant activity of the compounds was assessed by using the 2,2-diphenyl-1-picryl-hydrazyl (DPPH) and 2’-azino-bis(3-ethylbenzothiazolin-6-sulfonic) acid (ABTS) radicals, determining the radical scavenging activity, and by ferric reducing antioxidant power (FRAP) assay. The results revealed superior antioxidant ability for the inclusion complexes towards rutoside alone. The inclusion complexes were used as active ingredients in formulations of immediate-release tablets. The preformulation studies were performed on the powders for direct compression obtained after mixing the active ingredients with the excipients (Avicel PH 102, Polyplasdone XL-10, magnesium stearate, and talc). The materials were assessed for particle size, flowability, compressibility, and moisture content, establishing they are suitable for a direct compression process. The tablets were characterized regarding their pharmaco-technical properties and the results proved that the formulations lead to high-quality delivery systems, showing a good mechanical resistance with a low friability, excellent disintegration times, and satisfying dissolution rate. The performances were very similar for both formulations and the physico-mechanical properties of the tablets are not influenced by type of the used cyclodextrin, but the RUT- HP-β-CD tablets presented a higher dissolution rate.

Laser light as a promising approach to improve the nutritional value, antioxidant capacity and anti-inflammatory activity of flavonoid-rich buckwheat sprouts

Buckwheat sprouts are rich in several nutrients such as antioxidant flavonoids that have a positive impact on human health. Although there are several studies reported the positive impact of laser light on crop plants, no studies have applied laser light to enhance the nutritive values of buckwheat sprouts. Herein, the contents of health-promoting minerals, metabolites and enzymes as well as the antioxidant and anti-inflammatory activities were determined in laser-treated (He-Ne laser, 632 nm, 5 mW) common buckwheat (CBW) and tartarybuckwheat (TBW) sprouts. Out of 49 targeted minerals, vitamins, pigments and antioxidants, more than 35 parameters were significantly increased in CBW and/or TBW sprouts by laser light treatment. Also, laser light boosted the antioxidant capacity and anti-inflammatory activities through inhibiting cyclooxygenase-2 and lipoxygenase activities, particularly in TBW sprouts. Accordingly, laser light could be recommended as a promising method to improve the nutritional and health-promoting values of buckwheat sprouts.

Therapeutic benefits of rutin and its nanoformulations

BACKGROUND

Rutin as a natural flavonoid compound has revealed an extensive range of therapeutic potentials.

PURPOSE

The current paper is focused on the numerous studies on rutin nanoformulations regarding its broad spectrum of therapeutic potentials.

STUDY AND METHODS

A review was conducted in electronic databases (PubMed) to identify relevant published literature in English. No restrictions on publication date were imposed.

RESULTS

The literature search provided 7,078 results for rutin. Among them, 25 papers were related to the potential biological activities of rutin nanoformulations. Polymeric nanoparticles were the most studied nanoformulations for rutin (14 titles) and lipid nanoparticles (5 titles) were in second place. The reviewed literature showed that rutin has been used as an antimicrobial, antifungal, and anti-allergic agent. Improving the bioavailability of rutin using novel drug-delivery methods will help the investigators to use its useful effects in the treatment of various chronic human diseases.

CONCLUSION

It can be concluded that the preparation of rutin nanomaterials for the various therapeutic objects confirmed the enhanced aqueous solubility as well as enhanced efficacy compared to conventional delivery of rutin. However, more investigations should be conducted to confirm the improved bioavailability of the rutin nanoformulations.

New application of rutin: Repair the toxicity of emerging perfluoroalkyl substance to Pseudomonas stutzeri

Per- and polyfluoroalkyl substances (PFASs) are toxic to microorganisms, thereby affecting microbial communities in sludge and soil, but how to repair the toxicity of microorganisms remains unclear. In this study, rutin, an antioxidant, was added into a culture medium with an aerobic denitrification bacteria, Pseudomonas stutzeri, under the exposure of sodium perfluorononyloxy-benzenesulfonate (OBS) to evaluate the repair mechanisms of rutin to the toxicity of OBS to the bacteria. The results showed that rutin could repair the damage of OBS to cell structures, and reduce the death rates of the bacteria under OBS exposure. The dosage of rutin reduced the effect on the inhibition of denitrification ability of P. stutzeri under OBS exposure. Compared with the bacteria exposed to single OBS, the dosage of rutin resulted in that the death rates recovered from 96.2% to 66.4%, the growth inhibition rate decreased from 46.5% to 15.8%, the total nitrogen removal rate recovered from 66.9% to 100%, and the NO₂^- content recovered from 34.5 mg/L to 0.22 mg/L. The expressions of key denitrification genes (napA, nirS, norB, nosZ) were recovered after adding rutin under OBS exposure. Rutin changed the positive rate of reactive oxygen species, the relative superoxide dismutase and catalase activities in the bacteria which exposed to OBS. The mechanism by which rutin repaired the toxicity of OBS to P. stutzeri related to inhibiting the activities of antioxidant and denitrification enzymes rather than affecting the expressions of genes involved in these enzymes. This study sheds light on the repair method of micro-organics and reveals the repair mechanisms under PFASs exposure.

Phenolic and Anthocyanin Compounds and Antioxidant Activity of Tamarillo (Solanum betaceum Cav.)

This study examined phenolics and anthocyanins present in Amber, Laird’s Large and Mulligan cultivars of tamarillo that were cultivated in Whangarei, Northland of New Zealand. Samples were further separated by their tissue types, peel and pulp. Using LC-MS/MS, twelve polyphenols were quantified and six (ellagic acid, rutin, catechin, epicatechin, kaempferol-3-rutinoside and isorhamnetin-3-rutinoside) were detected for the first time in tamarillo. Mulligan cultivar showed the highest amounts of phenolic and anthocyanin compounds and the highest antioxidant activity. Phenolic compounds were mostly synthesized from shikimic acid route, and chlorogenic acid dominated the profile regardless of cultivar and tissue types. Anthocyanin profile was dominated by delphinidin-3-rutinoside in pulp. Higher amounts of anthocyanins were detected in this study, which may be explained by favourable growth conditions (high light intensity and low temperature) for anthocyanin biosynthesis in New Zealand. Higher antioxidant activity and total phenolic content in peels than in pulps were found when assessed by Cupric Ion-Reducing Antioxidant Capacity (CUPRAC), Ferric Reducing Ability of Plasma (FRAP) and Folin–Ciocalteu assays, and a positive correlation (r > 0.9, p ≤ 0.01) between the three assays was observed. Current findings endorse that tamarillo has a great bioactive potential to be developed further as a functional ingredient with considerable levels of antioxidant compounds and antioxidant activity.

Preparation, Evaluation and Characterization of Rutin-Chitooligosaccharide Complex

Rutin possesses a wide range of application prospects with various bioactivities. However, its bitter and water-insoluble properties restrict its application in the field of functional foods. A new complex of rutin and chitooligosaccharide (Rutin-COS) was prepared via spray-drying method (100 °C, 1 L/h) and freeze-drying method (-80 °C, 24 h), respectively. The water solubility, bitterness, antioxidant and antibacterial activities of Rutin-COS were evaluated, and the complexation of Rutin-COS was characterized by SEM, ¹H-NMR and ROESY. Compared to freeze-drying method, spray-drying method was more effective for preparing stable Rutin-COS complex. The spray-dried Rutin-COS showed increased water solubility, weakened bitterness, enhanced antioxidant and antibacterial activity compared to rutin. The Rutin-COS complex was demonstrated to be formed through hydrogen bonds between the A, B rings of rutin and COS.

Comprehensive Fractionation of Antioxidants and GC-MS and ESI-MS Fingerprints of Celastrus hindsii Leaves

Background: In this study, column chromatography was applied to separate active fractions from the ethyl acetate extract of Celastrus hindsii, a medicinal plant widely used in Southern China, Northern Vietnam, Myanmar, and Malaysia. Methods: Fourteen fractions from different dilutions of chloroform and methanol were separated by column chromatography and examined for biological activities. Results: It was found that a dilution of 50–70% methanol in chloroform yielded the highest total phenolics, flavonoids, and antioxidant activities (1,1-dipheny1-2-picrylhydrazyl (DPPH), 2,2-azinobis (3-ehtylbenzothiazoline-6-sulfonic acid), diammonium salt (ABTS) radical scavenging activity, and β-carotene bleaching method measured by lipid peroxidation inhibition). In addition, by gas chromatography-mass spectrometry (GC-MS) and electrospray ionization-mass spectrometry (ESI-MS) analyses, fifteen principal compounds from bioactive fractions belonging to fatty acids, amides, flavonoids, sterols, terpenes, and phenols were identified. Of these compounds, α-amyrin, β-amyrin, hydrazine carboxamide, hexadecanoic acid, fucosterol, (3β)-D:C-friedours-7-en-3-ol, rutin, and 2-hydroxy-1-ethyl ester accounted for maximal quantities, whilst concentrations of other constituents were <5%. Conclusions: It is suggested that these identified compounds may greatly contribute to the antioxidant capacity of C. hindsii as well as its potential pharmaceutical properties.

Modeling a pH-sensitive Zein-co-acrylic acid hybrid hydrogels loaded 5-fluorouracil and rutin for enhanced anticancer efficacy by oral delivery

The combination of natural and synthetic polymeric materials grafted hydrogels offer great potential as oral therapeutic systems because of its intrinsic biocompatibility, biodegradability, protect labile drugs from metabolism and controlled release properties. Hence, in the present study, we aimed to prepare and optimize oral delivered pH-responsive Zein-co-acrylic acid hydrogels incorporated with 5-fluorouracil (5-Fu) and rutin (Ru) for effective anticancer activity with less toxicity. In this study, graft polymerization technique is adopted to formulate hydrogels with various ratios of Zein, acrylic acid, N, N-methylene bisacrylamide, and ammonium persulphate as an initiator. The optimized formulation was identified based on the cross-linking, chemical interactions, intrinsic viscosity (η), dynamic swelling (Q) at pH 1.2, diffusion coefficient (D), sol-gel fraction (%), and porosity (%). The selected optimized formulation has shown significant improvement in drugs loading and encapsulation efficiency, releasing at pH 1.2 and pH 7.4. Drug release kinetics studies confirmed the controlled release properties of hydrogels. Hydrogels were porous and the drug loading of 5-Fu and Ru was found to be 12.13% and 10.86%, respectively, whereas encapsulation efficiency of 5-Fu and Ru was 89.35% and 81.47%, respectively. Furthermore, form the in vitro cytotoxic screening, it was found that 52.5 µg mL-1 5-Fu and Ru-loaded hydrogel impacted 50% of cell death at 24 h, there by significantly arresting the proliferation of MDA-MB-231 and MCF-7 breast cancer cell lines. Altogether, the optimized pH-responsive hydrogels make them favorable carrier for anticancer drugs for oral delivery.

Mass Spectrometry as a Complementary Approach for Noncovalently Bound Complexes Based on Cyclodextrins

An important and well-designed solution to overcome some of the problems associated with new drugs is provided by the molecular encapsulation of the drugs in the cyclodextrins (CDs) cavity, yielding corresponding inclusion complexes (ICs). These types of non-covalent complexes are of current interest to the pharmaceutical industry, as they improve the solubility, stability and bioavailability of the guest molecules. This review highlights several methods for cyclodextrin ICs preparation and characterization, focusing mostly on the mass spectrometry (MS) studies that have been used for the detection of noncovalent interactions of CDs inclusion complexes and binding selectivity of guest molecules with CDs. Furthermore, the MS investigations of several ICs of the CD with antifungal, antioxidants or fluorescent dyes are presented in greater details, pointing out the difficulties overcome in the analysis of this type of compounds.

Rutin Attenuates Vancomycin-Induced Nephrotoxicity by Ameliorating Oxidative Stress, Apoptosis, and Inflammation in Rats

Nephrotoxicity is the major limiting factor for the clinical use of vancomycin (VCM) for treatment of serious infections caused by multiresistant Gram-positive bacteria. This study investigated the renal protective activity of rutin in a rat model of VCM-induced kidney injury in male Wistar rats. VCM administered intraperitoneally at 200 mg/kg twice daily for 7 successive days resulted in significant elevation of blood urea nitrogen and creatinine, as well as urinary N-acetyl-β-D-glucosaminidase. Coadministration of VCM with oral rutin at 150 mg/kg significantly reduced these markers of kidney damage. Rutin also significantly attenuated VCM-induced oxidative stress, inflammatory cell infiltration, apoptosis, and decreased interleukin-1β and tumor necrosis factor alpha levels (all P < 0.05 or 0.01) in kidneys. Renal recovery from VCM injury was achieved by rutin through increases in Nrf2 and HO-1 and a decrease in NF-κB expression. Our results demonstrated a protective effect of rutin on VCM-induced kidney injury through suppression of oxidative stress, apoptosis, and downregulation of the inflammatory response. This study highlights a role for oral rutin as an effective intervention to ameliorate nephrotoxicity in patients undergoing VCM therapy.

Application of a computational model of natural deep eutectic solvents utilizing the COSMO-RS approach for screening of solvents with high solubility of rutin

The screening of natural deep eutectic solvents (NADES) to identify those with the ability to strongly solvate rutin was conducted using the COSMO-RS methodology. A NADES model was constructed that took into account the possible ionic and neutral forms of its constituents. The distributions of all forms were computed based on the equilibrium constants of neutralization reactions between amino and carboxylic acids. The proposed model was validated against the experimental solubilities of 15 NADES. A linear relationship between these data and the estimated activity coefficient values was found. The screening encompassed 126 different NADES. It was found that ten of them outperformed the best reference system. The most effective two-component solvent comprised proline combined with 2,3-diaminosuccinic acid, and the solubility of rutin in this solvent was found to be 130% greater than its solubility in the best reference system. The amino acids associated with the highest rutin solubilities were all cyclic, and the use of carboxylic acids with two carboxyl groups and a main chain consisting of two methylene groups with two amino substituents was observed to yield the best rutin solubilities. Because of the acidic properties of rutin, the presence of basic sites on the components of the NADES generally leads to enhanced solubility.

Cytotoxic and Enzyme Inhibitory Potential of Two Potentilla species (P. speciosa L. and P. reptans Willd.) and Their Chemical Composition

In this work, the biological and chemical fingerprints of three extracts (ethyl acetate, methanol, and water) from two Potentilla species (Potentilla reptans and P. speciosa) were investigated. Antioxidant, enzyme inhibitory, and cytotoxic activities were performed for the biological fingerprint. For the chemical characterization, total bioactive components, and individual phenolic components were determined using photometric and HPLC methods, respectively. The main identified phenolic compounds in these extracts were rutin and catechin. Methanol and water extracts contained the highest total phenolic and flavonoid content. The results of antioxidant assays showed that methanol and water extracts displayed higher antioxidant activity compared to the ethyl acetate extract. Generally, methanol and water extracts exhibited higher biological activities correlated with higher levels the bioactive components. For P. speciosa, the methanol extract exhibited the highest enzyme inhibitory activity (except BChE inhibitory activity). P. reptans exhibited also high antiproliferative activity against MCF-7 cells whilst P. speciosa had weak to moderate activity against both of A549 and MCF-7 cell lines. The results suggest that Potentilla species could be potential candidates for developing new phyto-pharmaceuticals and functional ingredients.

Enantioselective recognition of radezolid by cyclodextrin modified capillary electrokinetic chromatography and electronic circular dichroism

A method for the enantioseparation of radezolid (RAD), an analogue of a truly new class of antibacterial agents, oxazolidinones, was developed based on capillary electrokinetic chromatography using a cyclodextrin as a chiral pseudophase (CD-cEKC). The mechanism of RAD separation, together with its precursor, were investigated to directly define the relationship between the oxazolidinone structure and the complexation process. During the development of the method, anionic single isomer cyclodextrins were tested. They were ranked in order from hydrophilic to hydrophobic as follows: heptakis-(2,3-dihydroxy-6-sulfo)-β-cyclodextrin (HS-β-CD), heptakis-(2,3-diacetyl-6-sulfo)-β-cyclodextrin (HDAS-β-CD) and heptakis-(2,3-dimethyl-6-sulfo)-β-cyclodextrin (HDMS-β-CD). Experiments were performed at pH values of 2.5, 6.6, 8.2 and 9.6. The cyclodextrins that had an acetyl or methyl group at the C2 and C3 positions, referred to as HDAS-β-CD and HDMS-β-CD, respectively, exhibited partial and baseline separation of enantiomers in a low pH buffer. However, higher temperatures were required for HDAS-β-CD and acetonitrile addition was required for HDMS-β-CD. During the experiments, different organic solvents, varying in their amphiprotic or aprotic nature, were tested. The best results for the separation of enantiomers using the CD-cEKC method were obtained with 40mM HDMS-β-CD dissolved in a 50mM phosphate buffer (pH 2.5) with the addition of acetonitrile (65:35, v/v) at 27°C, reversed polarity and a voltage equal to 28kV. The apparent binding constants for each enantiomer to HDAS-β-CD or HDMS-β-CD were calculated. Finally, the stereochemistry of (S) and (R)-RAD and the behaviour of selected complex formations were established using electronic circular dichroism.

Preparation and tableting of long-term stable amorphous rutin using porous silica

Amorphous state of drugs increases the oral bioavailability, but typically faces physical stability problems. Amorphous rutin was generated and physically stabilized by encapsulating inside mesopores of porous AEROPERL® 300 Pharma and named as rutin CapsMorph® in this study. AEROPERL® 300 Pharma was loaded with rutin dissolved in DMSO containing Tween 80, and subsequently the solvent evaporated (wetness impregnation method). The loading process was monitored by light microscopy and scanning electron microscopy (SEM). X-ray diffraction (XRD) and differential scanning calorimetry (DSC) were used to confirm the amorphous state in AEROPERL® 300 Pharma. A loading of 20% of the rutin-AEROPERL® 300 Pharma mixture was obtained. The amorphous state proved to be stable over 2years of storage at room temperature. Due to the amorphous state and the nanosize of the rutin in the mesopores, the kinetic saturation solubility increased to about 4mg/ml (water, 0.1MHCl, pH 6.8PBS) compared to the maximum observed thermodynamic equilibrium solubility of rutin raw drug powder of only 74.48±1.42μg/ml in pH 6.8PBS (=increase by factor about 54). The dissolution velocity also increased distinctly, e.g. about 96.1% of rutin dissolution from CapsMorph® powder in water within 5min compared to less than 40% of raw drug powder after 3h. Tablets were produced with rutin CapsMorph®, raw drug powder and their dissolution velocity compared to a marketed product. About 83.0-95.6% were released from the rutin CapsMorph® tablet within 5min, compared to 42.7-52.5% from the marketed tablet after 3h (water, 0.1MHCl, pH 6.8PBS). After dissolution the supersaturation level of rutin CapsMorph® remained over about 2h, then solubility slowly reduced, but remained after 48h still multifold above the thermodynamic rutin solubility. This should be sufficient for many poorly soluble drugs to achieve a sufficient bioavailability. For optimal exploitation of the supersaturation, a multiple step release system could be used, e.g. release of CapsMorph® particles every 2-3h.

Comparative study of antioxidant activity and validated RP-HPTLC analysis of rutin in the leaves of different Acacia species grown in Saudi Arabia

The present study assessed the comparative antioxidant potential of the ethanol extract (EE) of leaves of four Acacia species (Acacia salicina, AS; Acacia laeta, AL; Acacia hamulosa AH; and Acacia tortilis, AT) grown in Saudi Arabia, including RP-HPTLC quantification of antioxidant biomarker rutin. In vitro DPPH radical scavenging and β-carotene-linoleic acid bleaching assays showed the promising antioxidant activities of Acacia extracts: ASEE (IC₅₀: 60.39 and 324.65 μg/ml) >ALEE (IC₅₀: 217.06 and 423.36 μg/ml) >ATEE (IC₅₀: 250.13 and 747.50 μg/ml) >AHEE (IC₅₀: 255.83 and 417.28 μg/ml). This was comparable to rutin tested at 500 μg/ml. Further, a RP- HPTLC densitometric method was developed (acetonitrile:water; 6:4; v/v) using glass-backed RP-18 silica gel F₂₅₄ plate, and scanned at UV max 254 nm. The method was validated as per the ICH guidelines. Analysis of the validated RP-HPTLC displayed an intense peak (R_f = 0.65 ± 0.004) of rutin that was estimated (μg/mg dry weight) to be highest in ASEE (10.42), followed by ALEE (2.67), AHEE (1.36) and ATEE (0.31). Taken together, presence of rutin strongly supported the high antioxidant property of the tested Acacia species, especially Acacia salicina. The developed RP-HPTLC method therefore, affirms its application in the quality control of commercialized herbal drugs or formulation containing rutin.

Protective effects of Fraxinus xanthoxyloides (Wall.) leaves against CCl4 induced hepatic toxicity in rat

BACKGROUND

Leaves and root bark of Fraxinus xanthoxyloides Wall. (Oleaceae) are used locally for the treatment of jaundice, malaria and pneumonia. Decoction of stem, twigs and bark is used in pain, internal injuries, rheumatism and in bone fracture. In this investigation we have evaluated the methanol extract of leaves for its hepatoprotective potential against CCl4 induced hepatic injuries in rat.

METHODS

Powder of F. xanthoxyloides leaves was extracted with methanol (FXM) and subjected for the determination of polyphenolics through HPLC-DAD analysis. Sprague-Dawley (Rattus novergicus) male rats were divided into eight groups (six rats in each). Group I: non-treated control; Group II: vehicle treated (DMSO plus olive oil) while Group III- VI treated with 1 ml/kg body weight (bw) of CCl4 (30 % in olive oil) for 30 days (15 dosages) to induce the hepatic injuries. Group IV: treated with silymarin (100 mg/kg bw); Group V and VI with FXM (200, 400 mg/kg bw) on alternate days with CCl4 treatment. Group VII and VIII was administered with FXM (200, 400 mg/kg bw) alone (15 dosages). After 30 days the serum was evaluated for liver function enzymes and biochemical markers, liver samples for antioxidant enzymes, biochemical markers, comet assay and for histopathology.

RESULTS

HPLC-DAD analysis of FXM revealed the existence of rutin and caffeic acid. In CCl4 treated rats the level of alanine transaminase (ALT), aspartate transaminase (AST), total bilirubin was significantly increased while the albumin concentration in serum was decreased as compared to control group. The level of hepatic antioxidant enzymes, catalase (CAT), peroxidase (POD), superoxide dismutase (SOD), glutathione-S-transferase (GST) and glutathione reductase (GSR) was significantly decreased against the control group. Further, significant decrease in GSH while increase in lipid peroxides (TBARS), H2O2, DNA damages and comet length was induced with CCl4 in hepatic tissues of rat. In contrast, co-administration of FXM and silymarin restored the biochemical and histopathological status of the liver.

CONCLUSION

Results of present investigation revealed that F. xanthoxyloides leaves possibly protect the liver against CCl4 induced injuries like silymarin by its antioxidant constituents.

Synergistic antioxidant action of vitamin E and rutin SNEDDS in ameliorating oxidative stress in a Parkinson's disease model

PURPOSE

Oxidative stress is the leading cause in the pathogenesis of Parkinson's disease. Rutin is a naturally occurring strong antioxidant molecule with wide therapeutic applications. It suffers from the problem of low oral bioavailability which is due to its poor aqueous solubility.

METHODS

In order to increase the solubility self-nanoemulsifying drug delivery systems (SNEDDS) of rutin were prepared. The oil, surfactant and co-surfactant were selected based on solubility/miscibility studies. Optimization was done by a three-factor, four-level (34) Box-Behnken design. The independent factors were oil, surfactant and co-surfactant concentration and the dependent variables were globule size, self-emulsification time, % transmittance and cumulative percentage of drug release. The optimized SNEDDS formulation (RSE6) was evaluated for various release studies. Antioxidant activity was assessed by various in vitro tests such as 2,2-diphenyl-1-picrylhydrazyl and reducing power assay. Oxidative stress models which had Parkinson's-type symptoms were used to determine the antioxidant potential of rutin SNEDDS in vivo. Permeation was assessed through confocal laser scanning microscopy.

RESULTS

An optimized SNEDDS formulation consisting of Sefsol + vitamin E-Solutol HS 15-Transcutol P at proportions of 25:35:17.5 (w/w) was prepared and characterized. The globule size and polydispersity index of the optimized formulation was found to be 16.08 ± 0.02 nm and 0.124 ± 0.01, respectively. A significant (p < 0.05) increase in the percentage of drug release was achieved in the case of the optimized formulation as compared to rutin suspension. Pharmacokinetic study showed a 2.3-fold increase in relative oral bioavailability. The optimized formulation had significant in vitro and in vivo antioxidant activity.

CONCLUSION

Rutin SNEDDS have been successfully prepared and they can serve as an effective tool in enhancing the oral bioavailability and efficacy of rutin, thus helping in ameliorating oxidative stress in neurodegenerative disorders like Parkinson's disease.