Pharmacokinetics, bioavailability, metabolism and excretion of δ-viniferin in rats

Phytochemical profiling, antiviral activities, molecular docking, and dynamic simulations of selected Ruellia species extracts

The antiviral properties of the flowering aerial extracts of Ruellia tuberosa and Ruellia patula were investigated through phytochemical profiling via LC-MS/MS and HPLC techniques. Qualitative LC-MS/MS analyses identified seventy-seven metabolites from both Ruellia species. R. tuberosa had the highest phenolic content (49.3%), whereas R. patula had the highest flavonoid content (57.8%). Additionally, quantitative HPLC investigations of the compounds identified by LC-MS/MS were performed using the available standard compounds. The main constituents in the R. tuberosa extract was found to be catechin (5321.63 µg/g), gallic acid (2878.71 µg/g), and ellagic acid (2530.79 µg/g), whereas the major compounds in the R. patula extract was found to be rutin (11,074.19 µg/g) and chlorogenic acid (3157.35 µg/g). Furthermore, the antiviral activities of both Ruellia species against HAdV-40, herpes simplex type 2 and H1N1 were evaluated. These findings demonstrated that R. tuberosa was more active than R. patula against all tested viruses, except for the HSV-2 virus, against which R. patula showed greater activity than R. tuberosa, with IC50 values of 20, 65, 22.59, and 13.13 µg/ml for R. tuberosa flowering aerial parts and 32.26, 11.66, and 23.03 µg/ml for R. patula flowering aerial parts, respectively for HAdV-40, herpes simplex type 2, and H1N1. Additionally, computational docking and molecular dynamics simulations were used to assess the molecular interactions between the bioactive compounds and specific viral targets. The combined findings from the in-vitro and in-silico experiments comprehensively evaluated the antiviral activities of both Ruellia species extracts.

Antiviral properties of trans-δ-viniferin derivatives against enveloped viruses

Over the last century, the number of epidemics caused by RNA viruses has increased and the current SARS-CoV-2 pandemic has taught us about the compelling need for ready-to-use broad-spectrum antivirals. In this scenario, natural products stand out as a major historical source of drugs. We analyzed the antiviral effect of 4 stilbene dimers [1 (trans-δ-viniferin); 2 (11',13'-di-O-methyl-trans-δ-viniferin), 3 (11,13-di-O-methyl-trans-δ-viniferin); and 4 (11,13,11',13'-tetra-O-methyl-trans-δ-viniferin)] obtained from plant substrates using chemoenzymatic synthesis against a panel of enveloped viruses. We report that compounds 2 and 3 display a broad-spectrum antiviral activity, being able to effectively inhibit several strains of Influenza Viruses (IV), SARS-CoV-2 Delta and, to some extent, Herpes Simplex Virus 2 (HSV-2). Interestingly, the mechanism of action differs for each virus. We observed both a direct virucidal and a cell-mediated effect against IV, with a high barrier to antiviral resistance; a restricted cell-mediated mechanism of action against SARS-CoV-2 Delta and a direct virustatic activity against HSV-2. Of note, while the effect was lost against IV in tissue culture models of human airway epithelia, the antiviral activity was confirmed in this relevant model for SARS-CoV-2 Delta. Our results suggest that stilbene dimer derivatives are good candidate models for the treatment of enveloped virus infections.

Chemistry, Biosynthesis and Pharmacology of Viniferin: Potential Resveratrol-Derived Molecules for New Drug Discovery, Development and Therapy

Viniferin is a resveratrol derivative. Resveratrol is the most prominent stilbenoid synthesized by plants as a defense mechanism in response to microbial attack, toxins, infections or UV radiation. Different forms of viniferin exist, including alpha-viniferin (α-viniferin), beta-viniferin (β-viniferin), delta-viniferin (δ-viniferin), epsilon-viniferin (ε-viniferin), gamma-viniferin (γ-viniferin), R-viniferin (vitisin A), and R2-viniferin (vitisin B). All of these forms exhibit a range of important biological activities and, therefore, have several possible applications in clinical research and future drug development. In this review, we present a comprehensive literature search on the chemistry and biosynthesis of and the diverse studies conducted on viniferin, especially with regards to its anti-inflammatory, antipsoriasis, antidiabetic, antiplasmodic, anticancer, anti-angiogenic, antioxidant, anti-melanogenic, neurodegenerative effects, antiviral, antimicrobial, antifungal, antidiarrhea, anti-obesity and anthelminthic activities. In addition to highlighting its important chemical and biological activities, coherent and environmentally acceptable methods for establishing vinferin on a large scale are highlighted to allow the development of further research that can help to exploit its properties and develop new phyto-pharmaceuticals. Overall, viniferin and its derivatives have the potential to be the most effective nutritional supplement and supplementary medication, especially as a therapeutic approach. More researchers will be aware of viniferin as a pharmaceutical drug as a consequence of this review, and they will be encouraged to investigate viniferin and its derivatives as pharmaceutical drugs to prevent future health catastrophes caused by a variety of serious illnesses.

Trans-ε-Viniferin Encapsulation in Multi-Lamellar Liposomes: Consequences on Pharmacokinetic Parameters, Biodistribution and Glucuronide Formation in Rats

Trans-ε-viniferin (εVin) is a resveratrol dimer exhibiting promising biological activities for human health. Its bioavailability being low, the development of encapsulation methods would be used to overcome this issue. The aim of this study was to measure the consequences of the encapsulation of εVin in multilamellar liposomes on its pharmacokinetic parameters, metabolism and tissue distribution in rats. After oral administration of εVin (20 mg/kg body weight), either as free or encapsulated forms, plasmas were sequentially collected (from 0 to 4 h) as well as liver, kidneys and adipose tissues (4 h after administration) and analyzed by LC-HRMS. The glucuronide metabolites (εVG) were also produced by hemisynthesis for their quantification in plasma and tissues. The encapsulation process did not significantly modify the pharmacokinetic parameters of εVin itself. However, a significant increase of the T1/2 was noticed for εVG after administration of the encapsulated form as compared to the free form. An accumulation of εVin and εVG in adipose tissues was noticed, and interestingly a significant increase of the latter in the mesenteric one after administration of the encapsulated form was highlighted. Since adipose tissues could represent storage depots, and encapsulation allows for prolonging the exposure time of glucuronide metabolites in the organism, this could be of interest to promote their potential biological activities.

Plasma pharmacokinetics of isorhapontigenin, a novel derivative of stilbenes, in mice by LC-MS/MS method

Isorhapontigenin (ISO), a novel derivative of stilbene compound, possessess good pharmacological activities such as antiviral, antioxidant, and anticancer. The purpose of this study is to investigate the pharmacokinetic of ISO in mice plasma, after oral administration of three doses (40, 80, and 160 mg/kg). Isorhapontigenin was detected by liquid chromatography-tandem mass spectrometry (LC-MS/MS), and a reliable LC-MS/MS assay for ISO in mice plasma was developed. The method was linear over a concentration range of 5-2000 ng/ml, and the lower limit of quantification was 5 ng/ml. The results indicated that there was a linear relationship between AUC_(0-t), AUC_(0-∞), and C_max of ISO and dosages. ISO underwent quick absorption and elimination in mice.

Comprehensive characterization of in vivo metabolic profile of Polygalae radix based on ultra-high-performance liquid chromatography-tandem mass spectrometry

In this study, a novel analysis strategy for progressively targeted screening and characterization of drug ingredients from in vitro to in vivo was proposed based on ultra-high performance liquid chromatography-tandem mass spectrometry for comprehensive characterization of in vivo metabolic profile of Polygalae radix (PR). First, an in vitro chemical profile of PR was described with the assistance of UNIFI™ software. The characteristic neutral small molecule losses were summarized to distinguish different chemical structures in the PR extract. Second, the in vitro intestinal microflora metabolism model was applied to describe an in vitro metabolic profile of the main ingredients of PR. The metabolic rule and metabolites were integrated for subsequent targeted screening of metabolites in vivo. Finally, an integrated strategy was established and applied to screen and characterize the major absorbed components in vivo, including blood, urine, brain, feces, and liver, based on the prototypes and metabolic rules obtained in vitro. As a result, in vitro and in vivo metabolic profiles of PR were effectively depicted. A total of 136 compounds were isolated and identified from the crude extract in vitro, and 12 compounds were reported for the first time based on the proposed fragmentations. A total of 13, 32, and 3 compounds were identified and characterized in the dosed plasma, liver, and brain, respectively. A total of 40 and 73 compounds were identified in urine and feces, respectively. This strategy not only provided a comprehensive insight into the chemical and metabolic profiles of PR but also presented a new perspective for the discovery of new drugs for medicinal application.

Tissular Distribution and Metabolism of trans-ε-Viniferin after Intraperitoneal Injection in Rat

Background: Recent studies showed that trans-ε-viniferin (ε-viniferin), a trans-resveratrol dehydrodimer, has anti-inflammatory and anti-obesity effects in rodents. The main purpose of this work was to assess the tissue distribution study of ε-viniferin and its metabolites after intraperitoneal (IP) administration in rat. Methods: After IP injection of 50 mg/kg, ε-viniferin and its metabolites were identified and quantified in plasma, liver, kidneys, adipose tissues, urine, and faeces by Liquid Chromatography-High Resolution Mass Spectrometry (LC-HRMS). Results: ε-Viniferin underwent a rapid hepatic metabolism mostly to glucuronides but also to a lesser extent to sulphate derivatives. The highest glucuronide concentrations were found in liver followed by plasma and kidneys whereas only traces amounts were found in adipose tissues. In contrast the highest ε-viniferin areas under concentration (AUC) and mean residence times (MRT) values were found in white adipose tissues. Finally, much lower levels of ε-viniferin or its metabolites were found in urine than in faeces, suggesting that biliary excretion is the main elimination pathway. Conclusion: A rapid and large metabolism of ε-viniferin and a high bioaccumulation in white adipose tissues were observed. Thus, these tissues could be a reservoir of the native form of ε-viniferin that could allow its slow release and a sustained presence within the organism.

Resveratrol dimer trans-ε-viniferin prevents rotaviral diarrhea in mice by inhibition of the intestinal calcium-activated chloride channel

We previously identified, by a natural-product screen, resveratrol oligomers as inhibitors of the cystic fibrosis transmembrane conductance regulator (CFTR) chloride channel. Here, we report the resveratrol dimer trans-ε-viniferin (TV) and tetramer r-2-viniferin (RV) as inhibitors of the intestinal calcium-activated chloride channel (CaCC) and demonstrate their antisecretory efficacy in a neonatal mouse model of rotaviral diarrhea. Short-circuit measurements show inhibition of CaCC current in the human colonic cell line HT-29 by TV and RV with IC₅₀∼1 and 20μM, respectively. TV primarily inhibited the physiologically relevant, long-term CaCC current following agonist stimulation, without effect on cytoplasmic Ca²⁺ signaling. TV and RV inhibited short-circuit current in mouse colon as well. In a neonatal mouse model of rotaviral secretory diarrhea produced by oral inoculation with rotavirus, 2μg TV or 11μg RV inhibited secretory diarrhea by >50%, without effect on the rotaviral infection. Our results support the antisecretory efficacy of non-toxic, natural-product resveratrol oligomers for diarrheas produced by CaCC activation. Because these compounds also inhibit the CFTR chloride channel, they may be useful for antisecretory therapy of a wide range of diarrheas.

Gnetin-C and other resveratrol oligomers with cancer chemopreventive potential

Resveratrol has been extensively studied to investigate its biological effects, including its chemopreventive potential against cancer. Over the past decade, various resveratrol oligomers, both naturally occurring and synthetic, have been described. These resveratrol oligomers result from the polymerization of two or more resveratrol units to form dimers, trimers, tetramers, or even more complex derivatives. Some oligomers appear to have antitumor activities that are similar or superior to monomeric resveratrol. In this review, we discuss resveratrol oligomers with anticancer potential, with emphasis on well-characterized compounds, such as the dimer gnetin-C and other oligomers from Gnetum gnemon, whose safety, pharmacokinetic, and biological activities have been studied in humans.

In Vitro Glucuronidation and Sulfation of ε-Viniferin, a Resveratrol Dimer, in Humans and Rats

ε-Viniferin is a resveratrol dimer that possesses antioxidant or anti-inflammatory activities. However little is known about the metabolism of this oligostilbene. This study was thus undertaken as a first approach to identify and characterize the metabolites of ε-viniferin and to describe the kinetic profile of their appearance in humans and rats. The glucuronides and sulfates of ε-viniferin were first obtained by chemical hemi-synthesis and were fully characterized by UPLC-MS and NMR spectroscopy. Then, ε-viniferin was incubated with human or rat S9 liver fractions that led to the formation of four glucuronoconjugates and four sulfoconjugates. In both species, ε-viniferin was subjected to an intense metabolism as 70 to 80% of the molecule was converted to glucuronides and sulfates. In humans, the hepatic clearance of ε-viniferin (V_max/K_m) for glucuronidation and sulfation were 4.98 and 6.35 µL/min/mg protein, respectively, whereas, in rats, the hepatic clearance for glucuronidation was 20.08 vs. 2.59 µL/min/mg protein for sulfation. In humans, three major metabolites were observed: two glucuronides and one sulfate. By contrast, only one major glucuronide was observed in rats. This strong hepatic clearance of ε-viniferin in human and rat could explain its poor bioavailability and could help to characterize its active metabolites.

A simple and sensitive liquid chromatography-tandem mass spectrometry method for trans-ε-viniferin quantification in mouse plasma and its application to a pharmacokinetic study in mice

In this study, a simple and sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the quantification of trans-ε-viniferin in small volumes (10μl) of mouse plasma using chlorpropamide as an internal standard was developed and validated. Plasma samples were precipitated with acetonitrile and separated using an Eclipse Plus C₁₈ column (100×4.6mm, 1.8-μm) with a mobile phase consisting of 0.1% formic acid in acetonitrile and 0.1% formic acid in water (60:40v/v) at a flow rate of 0.5ml/min. A triple quadrupole mass spectrometer operating in positive ion mode with selected reaction-monitoring mode was used to determine trans-ε-viniferin and chlorpropamide transitions of 455.10→215.05 and 277.00→111.00, respectively. The lower limit of quantification was 5ng/ml with a linear range of 5-2500ng/ml (r≥0.9949). All validation data, including the selectivity, precision, accuracy, recovery, dilution integrity, and stability, conformed to the acceptance requirements. No matrix effects were observed. The developed method was successfully applied to pharmacokinetic studies of trans-ε-viniferin following intravenous (2.5mg/kg), intraperitoneal (2.5, 5 and 10mg/kg), and oral (40mg/kg) administration in mice. This is the first report on the pharmacokinetic properties of trans-ε-viniferin. The results provide a meaningful basis for evaluating the pre-clinical or clinical applications of trans-ε-viniferin.