Severine Boisard

Dr. Severine Boisard


Research Focus & Metrics

Academic Career Length

5Years (2022-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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6 January 2022 in Plants
Verified
Journal Article
Open access
PDF file
TCThomas Charpentier
Thomas Charpentier
SBSeverine Boisard
Severine Boisard
ARAnne-Marie Le Ray
Anne-Marie Le Ray
DBDimitri Bréard
Dimitri Bréard
ACAmélie Chabrier
Amélie Chabrier
PRPascal Richomme
Pascal Richomme
Concentrated bud macerates (CBMs) are obtained from meristematic tissues such as buds and young shoots by maceration in a solvent composed of glycerin, water and ethanol (1/1/1/, v/v). Their traditional utilization in gemmotherapy has gained interest in the past years, and the knowledge of their chemical characterization can provide commercial arguments, particularly to secure their quality control. Therefore, an optimized method for phytochemical analysis including glycerol removal by a preliminary solid phase extraction (SPE) followed by compound identification using high performance liquid chromatography coupled with ultra-violet and tandem mass detectors (HPLC-UV-MS2) was developed. This method was applied on 5 CBMs obtained from Alnus glutinosa, Ribesnigrum, Rosmarinus officinalis, Rosa canina and Tilia tomentosa in order to determinate their chemical composition. Their antioxidant effects were also investigated by radical scavenging activity assays (DPPH and ORAC). Glycerol removal improved the resolution of HPLC chemical profiles and allowed us to perform TLC antioxidant screening. Our approach permitted the identification of 57 compounds distributed in eight major classes, three of them being common to all macerates including nucleosides, phenolic acids and glycosylated flavonoids. Quantification of the later class as a rutin equivalent (RE) showed a great disparity between Rosa canina macerate (809 mg RE/L), and the other ones (from 175 to 470 mg RE/L). DPPH and ORAC assays confirmed the great activity of Rosa canina (4857 and 6479 μmol TE/g of dry matter, respectively). Finally, phytochemical and antioxidant analysis of CBMs strengthened their phytomedicinal interest in the gemmotherapy field.

11 October 2022 in Talanta
Verified
Journal Article
Closed access
MMManon Meunier
Manon Meunier
DBDimitri Bréard
Dimitri Bréard
KAKhalijah Awang
Khalijah Awang
SBSeverine Boisard
Severine Boisard
DGDavid Guilet
David Guilet
ASAndreas Schinkovitz
Andreas Schinkovitz

13 April 2023 in Phytochemical Analysis
Verified
Journal Article
Open access
FAFrançois Azonwade
François Azonwade
BMBalthazar B. Mabanza‐Banza
Balthazar B. Mabanza‐Banza
ARAnne‐Marie Le Ray
Anne‐Marie Le Ray
DBDimitri Bréard
Dimitri Bréard
PBPatricia Blanchard
Patricia Blanchard
SBSeverine Boisard
Severine Boisard
Introduction: Propolis is a resinous natural substance collected by honeybees from buds and exudates of various trees and plants; it is widely accepted that the composition of propolis depends on the phytogeographic characteristics of the site of collection.Objectives: The aim of this study was to determine the phytochemical composition of ethanolic extracts from eight propolis batches collected in different regions of Benin (north, center, and south) and Congo, Africa.Material and methods: Characterization of propolis samples was performed by using different hyphenated chromatographic methods combined with carbon‐13 nuclear magnetic resonance (13C NMR) dereplication with MixONat software. Their antioxidant or anti‐advanced glycation end‐product (anti‐AGE) activity was then evaluated by using diphenylpicrylhydrazyl and bovine serum albumin assays, respectively.Results: Chromatographic analyses combined with 13C NMR dereplication showed that two samples from the center of Benin exhibited, in addition to a huge amount of pentacyclic triterpenes, methoxylated stilbenoids or phenanthrenoids, responsible for the antioxidant activity of the extract for the first one. Among them, combretastatins might be cytotoxic. For the second one, the prenylated flavanones known in Macaranga‐type propolis were responsible for its significant anti‐AGE activity. The sample from Congo was composed of many triterpene derivatives belonging to Mangifera indica species.Conclusion: Therefore, propolis from the center of Benin seems to be of particular interest, due to its antioxidant and anti‐AGE properties. Nevertheless, as standardization of propolis is difficult in tropical zones due to its great chemodiversity, a systematic phytochemical analysis is required before promoting the use of propolis in food and health products in Africa.

7 May 2025 in Poultry Science
Verified
Journal Article
Open access
FAFatima Zohra ABERKANE
Fatima Zohra ABERKANE
PEPaul Engler
Paul Engler
SBSeverine Boisard
Severine Boisard
MBMohammed el Amine Benarbia
Mohammed el Amine Benarbia
DGDavid Guilet
David Guilet
In laying hens, maintaining optimal bone health and development from the early stages is crucial, as it directly affects their egg-laying efficiency, overall welfare and productivity. Studies have shown that grape polyphenols from Vitis vinifera enhance bone health in both humans and animals. Still, the mechanisms behind this effect remain unclear, given the diversity of grape polyphenols and their varying mechanisms of action. The objective of this study was to investigate the effect of a standardized dry grape extract (SDGE) on bone quality and metabolome of future laying hens reared in commercial conditions. Therefore, 36300 day-old pullets were randomly divided into two barns on the same farm site. Both received the same diet, with the addition of 30 mg/kg of SDGE (Nor-Grape®, Nor-Feed, France) from day 1 until week 17 in the supplemented group (SDGE). At the end of the supplementation period, several bone quality parameters were analyzed on 50 individuals per group. Additionally, non-targeted metabolomics on plasma and bones were performed to uncover the impact of SDGE supplementation on pullet's metabolome. Results demonstrated that keel bone deformity tended to improve following SDGE supplementation (P = 0.10). Moreover, SDGE intake significantly increased bone dry and mineral content, compared to the control group (P < 0.05) and tended to increase calcium (Ca) (P = 0.074) and phosphorus (P) content (P = 0.055). On the other hand, non-targeted metabolomics on plasma samples revealed an impact on fatty acids and glycerophospholipid metabolisms while bone samples analysis uncovered pathways related to sphingolipid and estrogen mediated signaling pathways. Overall, this study suggests novel mechanisms related to estrogen signaling through lipid metabolism in SDGE supplemented pullets and highlights that nutritional intervention with SDGE in early developmental stage of future laying hens improves their bone health prior to entry into the laying phase, thus proving a useful tool in bone health management.

1 December 2023 in Nutraceuticals
Verified
Journal Article
Open access
PDF file
DBDimitri Bréard
Dimitri Bréard
HEHelene Esselin
Helene Esselin
LBLucie Bugeia
Lucie Bugeia
SBSeverine Boisard
Severine Boisard
DGDavid Guilet
David Guilet
CRChristophe Ripoll
Christophe Ripoll
Gemmotherapy, a natural therapy based on bud macerates, has recently gained importance in the field of food supplements. However, two coexisting extraction methods employ a glycerin-based solvent, either in a binary or ternary solvent mixture. The absence of an official method for bud preparation leads to non-standardized bud macerates. Given this context, this study aimed to (i) assess the influence of solvent composition on the chemical profile of olive young shoot macerates obtained using glycerin-based solvents or using different solvent extractions and (ii) to compare the two coexisting traditional bud extraction methods described by Dr Pol Henry and by the European Pharmacopoeia. A comprehensive phytochemical analysis of all macerates was conducted using HPLC-DAD-ELSD-MS2, identifying 50 metabolites divided into 7 classes through dereplication. The extracts obtained with the solvent described by the European Pharmacopoeia (ethanol/glycerin) and by Dr Pol Henry (water/ethanol/glycerin) appeared to be the most diversified in terms of metabolite distribution and possessed higher rates of secondary metabolites. These observations reinforce the interest in a glycerin-based solvent mixture for bud extraction in gemmotherapy. In addition, the difference in composition between the two traditional solvents was highlighted. Indeed, iridoids were predominant in both macerates, representing about 50% of the chemical composition, but differences were observed from one macerate to another regarding the proportions of the other chemical classes. This emphasizes the necessity for standardized gemmotherapy macerates.

26 June 2026 in bioRxiv
Verified
Preprint
Open access
EBEtienne Brémand
Etienne Brémand
FBFranck Bastide
Franck Bastide
JCJustine Colou
Justine Colou
NDNicolas Denancé
Nicolas Denancé
SBSeverine Boisard
Severine Boisard
TGThomas Guillemette
Thomas Guillemette
Trichoderma species are widely used as biological control agents due to their ability to parasitize plant pathogens. However, substantial variability in mycoparasitic performance exists among strains, even within the same species, and the underlying molecular mechanisms remain poorly understood. Here, we performed comparative genomic and transcriptomic analyses of six Trichoderma atroviride strains exhibiting contrasting mycoparasitic performance (weakly or highly parasitic; WP or HP) against Alternaria brassicicola , Rhizoctonia solani , and Globisporangium ultimum . Comparative genomics revealed limited strain-specific differences, mainly restricted to NLR (NOD-like receptor) repertoires, with certain NLR-coding genes absent from WP strain genomes compared to HP strains, while overall genomic variation remained low. In contrast, transcriptomic analyses revealed strong differences in gene expression dynamics between HP and WP strains. Co-expression network analysis identified two modules associated with mycoparasitic performance. The first was specifically induced in response to pathogen contact and was enriched in genes encoding cell wall-degrading enzymes, with stronger expression in HP strains. The second module was more broadly overexpressed in HP strains across all conditions and included genes involved in detoxification and defense-related pathways. In addition, this module encompassed genes involved in specialized metabolite biosynthesis and effector-like protein secretion, with WP and HP strains differentially expressing distinct gene subsets within these categories. Together, these results provide a comprehensive framework for identifying the molecular drivers of mycoparasitic performance in T. atroviride . This study deepens our understanding of the functional diversity within the species and establishes a robust foundation for the future development of molecular markers to predict strain efficiency.