Modulatory role of rutin on 2,5-hexanedione-induced chromosomal and DNA damage in rats: validation of computational predictions

Scientific opinion on the renewal of the authorisation of proFagus Smoke R709 (SF-008) as a smoke flavouring Primary Product

The EFSA Panel on Food Additives and Flavourings (FAF) was requested to evaluate the safety of the smoke flavouring Primary Product proFagus Smoke R709 (SF-008), for which a renewal application was submitted in accordance with Article 12(1) of Regulation (EC) No 2065/2003. This opinion refers to the assessment of data submitted on chemical characterisation, dietary exposure and genotoxicity of the Primary Product. ProFagus Smoke R709 is obtained by pyrolysis of beech and oak wood as main source materials. The panel concluded that the compositional data provided on the Primary Product are adequate. At the maximum proposed use levels, dietary exposure estimates calculated with DietEx ranged from 0.8 to 12.2 mg/kg body weight (bw) per day at the mean and from 2.3 to 51.4 mg/kg bw per day at the 95th percentile. The Panel concluded that three components in the Primary Product raise a potential concern for genotoxicity. In addition, a potential concern for genotoxicity was identified for the unidentified part of the mixture. The Primary Product contains furan-2(5H)-one, for which a concern for genotoxicity was identified in vivo upon oral administration. Considering that the exposure estimates for this component are above the TTC of 0.0025 μg/kg bw per day for DNA-reactive mutagens and/or carcinogens, the panel concluded that the Primary Product raises concern with respect to genotoxicity.

Scientific opinion on the renewal of the authorisation of Smoke Concentrate 809045 (SF-003) as a smoke flavouring Primary Product

The EFSA Panel on Food Additives and Flavourings (FAF) was requested to evaluate the safety of the smoke flavouring Primary Product Smoke Concentrate 809045 (SF-003), for which a renewal application was submitted in accordance with Article 12(1) of Regulation (EC) No 2065/2003. This opinion refers to the assessment of data submitted on chemical characterisation, dietary exposure and genotoxicity of the Primary Product. Product Smoke Concentrate 809045 is obtained by pyrolysis of beech wood. The Panel concluded that the compositional data provided on the Primary Product are adequate. At the maximum proposed use levels, dietary exposure estimates calculated with DietEx ranged from 0.1 to 1.5 mg/kg body weight (bw) per day at the mean and from 0.2 to 5.2 mg/kg bw per day at the 95th percentile. The Panel concluded that eleven components in the Primary Product raise a potential concern for genotoxicity. In addition, a potential concern for genotoxicity was identified for the unidentified part of the mixture. The Primary Product contains furan-2(5H)-one and benzene-1,2-diol, for which a concern for genotoxicity was identified in vivo upon oral administration. Considering that the exposure estimates for these two components are above the threshold of toxicological concern (TTC) of 0.0025 μg/kg bw per day for DNA-reactive mutagens and/or carcinogens, the Panel concluded that the Primary Product raises concern with respect to genotoxicity.

Towards Substitution of Hexane as Extraction Solvent of Food Products and Ingredients with No Regrets

Hexane is a solvent used extensively in the food industry for the extraction of various products such as vegetable oils, fats, flavours, fragrances, colour additives or other bioactive ingredients. As it is classified as a "processing aid", it does not have to be declared on the label under current legislation. Therefore, although traces of hexane may be found in final products, especially in processed products, its presence is not known to consumers. However, hexane, and in particular the n-hexane isomer, has been shown to be neurotoxic to humans and has even been listed as a cause of occupational diseases in several European countries since the 1970s. In order to support the European strategy for a toxic-free environment (and toxic-free food), it seemed important to collect scientific information on this substance by reviewing the available literature. This review contains valuable information on the nature and origin of the solvent hexane, its applications in the food industry, its toxicological evaluation and possible alternatives for the extraction of natural products. Numerous publications have investigated the toxicity of hexane, and several studies have demonstrated the presence of its toxic metabolite 2,5-hexanedione (2,5-HD) in the urine of the general, non-occupationally exposed population. Surprisingly, a tolerable daily intake (TDI) has apparently never been established by any food safety authority. Since hexane residues are undoubtedly found in various foods, it seems more than necessary to clearly assess the risks associated with this hidden exposure. A clear indication on food packaging and better information on the toxicity of hexane could encourage the industry to switch towards one of the numerous other alternative extraction methods already developed.

A Flavonoid-Rich Extract of Sambucus nigra L. Reduced Lipid Peroxidation in a Rat Experimental Model of Gentamicin Nephrotoxicity

The use of gentamicin (GM) is limited due to its nephrotoxicity mediated by oxidative stress. This study aimed to evaluate the capacity of a flavonoid-rich extract of Sambucus nigra L. elderflower (SN) to inhibit lipoperoxidation in GM-induced nephrotoxicity. The HPLC analysis of the SN extract recorded high contents of rutin (463.2 ± 0.0 mg mL−1), epicatechin (9.0 ± 1.1 µg mL−1), and ferulic (1.5 ± 0.3 µg mL−1) and caffeic acid (3.6 ± 0.1 µg mL−1). Thirty-two Wistar male rats were randomized into four groups: a control group (C) (no treatment), GM group (100 mg kg−1 bw day−1 GM), GM+SN group (100 mg kg−1 bw day−1 GM and 1 mL SN extract day−1), and SN group (1 mL SN extract day−1). Lipid peroxidation, evaluated by malondialdehyde (MDA), and antioxidant enzymes activity—superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPX)—were recorded in renal tissue after ten days of experimental treatment. The MDA level was significantly higher in the GM group compared to the control group (p < 0.0001), and was significantly reduced by SN in the GM+SN group compared to the GM group (p = 0.021). SN extract failed to improve SOD, CAT, and GPX activity in the GM+SN group compared to the GM group (p > 0.05), and its action was most probably due to the ability of flavonoids (rutin, epicatechin) and ferulic and caffeic acids to inhibit synthesis and neutralize reactive species, to reduce the redox-active iron pool, and to inhibit lipid peroxidation. In this study, we propose an innovative method for counteracting GM nephrotoxicity with a high efficiency and low cost, but with the disadvantage of the multifactorial environmental variability of the content of SN extracts.

Modulatory Effect of Rutin on the Antitumor Activity and Genotoxicity of Cisplatin in Tumor-Bearing Mice

Purpose: Cisplatin is a cancer chemotherapeutic drug that has been extensively used in the treatment of a variety of cancers. However, the full usage of cisplatin is limited due to its treatment associated development of multiple side effects in the host. In the present study, the modulatory effect of rutin, a type of flavonoid, on the cisplatin mediated antitumor activity and allied genotoxicity in ascites Dalton’s lymphoma (DL)-bearing mice were investigated.

Methods: The antitumor activity was determined by calculating the percent increase in the life span of mice, cell viability and scanning electron microscopy (SEM) of DL cells. Further, the modulatory effect of rutin on the cisplatin-induced genotoxic effects in the same DL-bearing mice was assessed by the analysis of micronuclei, chromosomal aberration and sperm abnormality.

Results: The combination treatment of mice with rutin and cisplatin showed a considerable increase in the life span of the DL-bearing mice depicting better antitumor efficacy. SEM of these DL cells showed severe membrane deformities in DL cells such as fusion of cell membrane, membrane blebbing, cell shrinkage, membrane folding and loss in microvilli from the tumor cell surface which may lead to cell death. Cisplatin alone treatment caused an increase in the frequency of chromosomal aberrations, micronuclei and sperms abnormality. However, the combination treatment of DL-bearing mice with rutin and cisplatin comparatively reduced these genotoxic effects.

Conclusion: The overall findings suggest that rutin enhances the cisplatin-mediated antitumor activity and cytotoxicity against DL cells and at the same time diminishes the genotoxic effects induced by cisplatin in the DL-bearing mice.

Rutin-protected BisGMA-induced cytotoxicity, genotoxicity, and apoptosis in macrophages through the reduction of the mitochondrial apoptotic pathway and induction of antioxidant enzymes

Bisphenol-A-glycidyldimethacrylate (BisGMA) is a resin monomer frequently used in dentin restorative treatments. The leakage of BisGMA monomer from BisGMA-based polymeric resins can lead to cytotoxicity in macrophages. Rutin has various beneficial bioeffects, including antioxidation and antiinflammation. In this study, we found that pretreatment of RAW264.7 macrophages with rutin-inhibited cytotoxicity induced by BisGMA in a concentration-dependent manner. BisGMA-induced apoptosis, which was detected by levels of phosphatidylserine from the internal to the external membrane and formation of sub-G1, and genotoxicity, which was detected by cytokinesis-blocked micronucleus and single-cell gel electrophoresis assays, were inhibited by rutin in a concentration-dependent manner. Rutin suppressed the BisGMA-induced activation of caspase-3 and -9 rather than caspase-8. Rutin inhibited the activation of the mitochondrial apoptotic pathway, including cytochrome C release and mitochondria disruption, after macrophages were treated with BisGMA. Finally, BisGMA-induced reactive oxygen species (ROS) generation and antioxidant enzyme (AOE) deactivation could be reversed by rutin. Parallel trends were observed in the elevation of AOE activation and inhibition of ROS generation, caspase-3 activity, mitochondrial apoptotic pathway activation, and genotoxicity. These results suggested that rutin suppressed BisGMA-induced cytotoxicity through genotoxicity, the mitochondrial apoptotic pathway, and relatively upstream factors, including reduction of ROS generation and induction of AOE.

Antisickling Effects of Quercetin may be Associated with Modulation of Deoxyhaemoglobin, 2, 3-bisphosphoglycerate mutase, Redox Homeostasis and Alteration of Functional Chemistry in Human Sickle Erythrocytes

It is now glaring that sickle cell anaemia is still one of the highest leading inbred hemoglobinopathy amongst Africans. This study examined the antisickling effects of quercetin via modulation of deoxy-haemoglobin, redox homeostasis and alteration of functional chemistry in human sickle erythrocyte using in silico and in vitro models while espousing preventive and curative approaches. Quercetin was docked against deoxy-haemoglobin and 2, 3-bisphosphoglycerate mutase, with binding energies (−30.427 and −21.106 kcal/mol) and Ki of 0.988μM and 0.992μM at their catalytic sites via strong hydrophobic and hydrogen bond interactions. Induction of sickling was done using 2% metabisulphite at 3h. Treatment with quercetin prevented sickling outstandingly at 5.0μg/mL and reversed same at 7.5μg/mL, 83.6% and 75.9%, respectively. Quercetin also significantly (P<0.05) maintained the integrity of erythrocyte membrane apparently from the observed % haemolysis relative to untreated. Quercetin significantly (P<0.05) prevented and counteracted lipid peroxidation while stimulating GSH and CAT levels which were detected to considerably (P<0.05) increase with simultaneous significant (P<0.05) reduction in SOD level based on curative approach. Umpiring from our FTIR results, a favorable alteration in the part of functional chemistry in terms of shifts (bend and stretches) and functional groups were observed relative to the induced erythrocyte/untreated. Thus, antisickling effects of quercetin may be associated with modulation of deoxy-haemoglobin, redox homeostasis and alteration of functional chemistry in human sickle erythrocytes.

Sickling-preventive effects of rutin is associated with modulation of deoxygenated haemoglobin, 2,3-bisphosphoglycerate mutase, redox status and alteration of functional chemistry in sickle erythrocytes

Sickle cell anaemia is a hereditary disease branded by an upsurge in generation of ROS, irregular iron release and little or no antioxidant activity which can lead to cellular injuries due to oxidative stress resulting in severe symptoms including anaemia and pain. The disease is caused by a mutated version of the gene that helps make haemoglobin, the protein that carries oxygen in red blood cells. We used in silico and in vitro experiments to examine the antisickling effects of rutin for the first time by means of before and after induction approaches in sickle erythrocytes. Rutin was docked against deoxy-haemoglobin and 2,3-bisphosphoglycerate mutase, revealing binding energies (-27.329 and -25.614 kcal/mol) and Ki of 0.989μM and 0.990 μM at their catalytic sites through strong hydrophobic and hydrogen bond interactions. Sickling was thereafter, induced at 3 h with 2% metabisulphite. Rutin prevented sickling maximally at 12.3μM and reversed same at 16.4μM, by 78.5% and 69.9%, one-to-one. Treatment with rutin significantly (P < 0.05) reinvented the integrity of erythrocytes membrane as evident from the practical % haemolysis compared to induced erythrocytes. Rutin also significantly (P < 0.05) prevented and reversed lipid peroxidation relative to untreated. Likewise, GSH, CAT levels were observed to significantly (P < 0.05) increase with concomitant significant (P < 0.05) decrease in SOD activity based on administration of rutin after sickling induction approach. Furthermore, FTIR results showed that treatment with rutin favourably altered the functional chemistry, umpiring from shifts and functional groups observed. It can thus be deduced that, antisickling effects of rutin may be associated with modulation of deoxy-haemoglobin, 2,3-bisphosphoglycerate mutase, alteration of redox homeostasis and functional chemistry of sickle erythrocytes.

In silico design and synthesis of targeted rutin derivatives as xanthine oxidase inhibitors

Background

Xanthine oxidase is an important enzyme of purine catabolism pathway and has been associated directly in pathogenesis of gout and indirectly in many pathological conditions like cancer, diabetes and metabolic syndrome. In this research rutin, a bioactive flavonoid was explored to determine the capability of itself and its derivatives to inhibit xanthine oxidase.

Objective

To develop new xanthine oxidase inhibitors from natural constituents along with antioxidant potential.

Method

In this report, we designed and synthesized rutin derivatives hybridized with hydrazines to form hydrazides and natural acids to form ester linkage with the help of molecular docking. The synthesized compounds were evaluated for their antioxidant and xanthine oxidase inhibitory potential.

Results

The enzyme kinetic studies performed on rutin derivatives showed a potential inhibitory effect on XO ability in competitive manner with IC₅₀ value ranging from 04.708 to 19.377 µM and RU3a₃ was revealed as most active derivative. Molecular simulation revealed that new rutin derivatives interacted with the amino acid residues PHE798, GLN1194, ARG912, GLN 767, ALA1078 and MET1038 positioned inside the binding site of XO. Results of antioxidant activity revealed that all the derivatives showed very good antioxidant potential.

Conclusion

Taking advantage of molecular docking, this hybridization of two natural constituent could lead to desirable xanthine oxidase inhibitors with improved activity.

Electronic supplementary material

The online version of this article (10.1186/s13065-019-0585-8) contains supplementary material, which is available to authorized users.