Rene LAFONT

Rene LAFONT


Research Focus & Metrics

Academic Career Length

36Years (1991-Present)

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

Representative Publications

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20 January 2007 in Ecotoxicology
Verified
Journal Article
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RLRené Lafont
René Lafont
MMMichel Mathieu
Michel Mathieu

29 April 2021 in Biomedicines
Verified
Journal Article
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LDLaurence Dinan
Laurence Dinan
WDWaly Dioh
Waly Dioh
SVStanislas Veillet
Stanislas Veillet
RLRené Lafont
René Lafont
There is growing interest in the pharmaceutical and medical applications of 20-hydroxyecdysone (20E), a polyhydroxylated steroid which naturally occurs in low but very significant amounts in invertebrates, where it has hormonal roles, and in certain plant species, where it is believed to contribute to the deterrence of invertebrate predators. Studies in vivo and in vitro have revealed beneficial effects in mammals: anabolic, hypolipidemic, anti-diabetic, anti-inflammatory, hepatoprotective, etc. The possible mode of action in mammals has been determined recently, with the main mechanism involving the activation of the Mas1 receptor, a key component of the renin–angiotensin system, which would explain many of the pleiotropic effects observed in the different animal models. Processes have been developed to produce large amounts of pharmaceutical grade 20E, and regulatory preclinical studies have assessed its lack of toxicity. The effects of 20E have been evaluated in early stage clinical trials in healthy volunteers and in patients for the treatment of neuromuscular, cardio-metabolic or respiratory diseases. The prospects and limitations of developing 20E as a drug are discussed, including the requirement for a better evaluation of its safety and pharmacological profile and for developing a production process compliant with pharmaceutical standards.

1 December 2021 in Encyclopedia
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Journal Article
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RLRené Lafont
René Lafont
CBChristine Balducci
Christine Balducci
LDLaurence Dinan
Laurence Dinan
Ecdysteroid: member of a class of polyhydroxylated steroids found in invertebrate animals (zooecdysteroids; moulting hormones), plants (phytoecdysteroids) and fungi (mycoecdysteroids). Over 500 structural analogues are currently known. Biosynthetically, they derive from C27-, C28- or C29-sterols. The most frequently encountered analogue (in arthropods and plants) is 20-hydroxyecdysone (2β,3β,14α,20R,22R,25-hexahydroxycholest-7-en-6-one). In arthropods, ecdysteroids occur universally and regulate development by inducing moulting and reproduction, where their action is mediated by high-affinity binding to an intracellular member of the class of nuclear receptor (NR) proteins (ecdysteroid receptor; EcR) dimerised with a second NR (USP/RxR). This receptor complex binds to specific DNA promoter sites and regulates gene expression. In plants, ecdysteroids are a class of secondary compounds, occurring in varying amounts in certain species, but not all in others. Phytoecdysteroids are believed to contribute to the reduction of invertebrate predation by acting as feeding deterrents or endocrine disruptors. Ecdysteroids also possess a wide range of positive pharmacological effects in mammals, where the mode of action involves moderate-affinity binding to plasma-membrane-bound receptors and not interaction with the classical NRs for vertebrate steroid hormones.

7 December 2020 in Oxidative Medicine and Cellular Longevity
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SCSerge Camelo
Serge Camelo
MLMathilde Latil
Mathilde Latil
SVStanislas Veillet
Stanislas Veillet
PDPierre J. Dilda
Pierre J. Dilda
RLRené Lafont
René Lafont
Age-related macular degeneration (AMD) is the commonest cause of severe visual loss and blindness in developed countries among individuals aged 60 and older. AMD slowly progresses from early AMD to intermediate AMD (iAMD) and ultimately late-stage AMD. Late AMD encompasses either neovascular AMD (nAMD) or geographic atrophy (GA). nAMD is defined by choroidal neovascularization (CNV) and hemorrhage in the subretinal space at the level of the macula. This induces a rapid visual impairment caused by the death of photoreceptor cells. Intravitreal injection of anti-vascular endothelial growth factor (VEGF) antibodies is the standard treatment of nAMD but adds to the burden of patient care. GA is characterized by slowly expanding photoreceptor, and retinal pigment epithelium (RPE) degeneration patches progressively leading to blindness. There is currently no therapy to cure GA. Late AMD continues to be an unmet medical need representing a major health problem with millions of patients worldwide. Oxidative stress and inflammation are recognized as some of the main risk factors to developing late AMD. The antioxidant formulation AREDS (Age-Related Eye Disease Studies), contains β-carotene, which has been replaced by lutein and zeaxanthin in AREDS2, are given to patients with iAMD but have a limited effect on the incidence of nAMD and GA. Thus, to avoid or slowdown the development of late stages of AMD (nAMD or GA), new therapies targeting iAMD are needed such as crocetin obtained through hydrolysis of crocin, an important component of saffron (Crocus sativus L.), and norbixin derived from bixin extracted from Bixa orellana seeds. We have shown that these apocarotenoids preserved more effectively RPE cells against apoptosis following blue light exposure in the presence of A2E than lutein and zeaxanthin. In this review, we will discuss the potential use of apocarotenoids to slowdown the progression of iAMD, to reduce the incidence of both forms of late AMD.

11 January 2021 in Trials
Verified
Journal Article
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WDWaly Dioh
Waly Dioh
MCM. Chabane
M. Chabane
CTC. Tourette
C. Tourette
AAA. Azbekyan
A. Azbekyan
CMC. Morelot-Panzini
C. Morelot-Panzini
SAS. Agus
S. Agus
Objectives: As of December, 1st, 2020, coronavirus disease 2019 (COVID-19) caused by SARS-CoV-2, resulted in more than 1 472 917 deaths worldwide and death toll is still increasing exponentially. Many COVID-19 infected people are asymptomatic or experience moderate symptoms and recover without medical intervention. However, older people and those with comorbid hypertension, diabetes, obesity, or heart disease are at higher risk of mortality. Because current therapeutic options for COVID-19 patients are limited specifically for this elderly population at risk, Biophytis is developing BIO101 (20-hydroxyecdysone, a Mas receptor activator) as a new treatment option for managing patients with SARS-CoV-2 infection at the severe stage. The angiotensin converting enzyme 2 (ACE2) serves as a receptor for SARS-CoV-2. Interaction between ACE2 and SARS-CoV2 spike protein seems to alter the function of ACE2, a key player in the renin-angiotensin system (RAS). The clinical picture of COVID-19 includes acute respiratory distress syndrome (ARDS), cardiomyopathy, multiorgan dysfunction and shock, all of which might result from an imbalance of the RAS. We propose that RAS balance could be restored in COVID-19 patients through MasR activation downstream of ACE2 activity, with 20-hydroxyecdysone (BIO101) a non-peptidic Mas receptor (MasR) activator. Indeed, MasR activation by 20-hydroxyecdysone harbours anti-inflammatory, anti-thrombotic, and anti-fibrotic properties. BIO101, a 97% pharmaceutical grade 20-hydroxyecdysone could then offer a new therapeutic option by improving the respiratory function and ultimately promoting survival in COVID-19 patients that develop severe forms of this devastating disease. Therefore, the objective of this COVA study is to evaluate the safety and efficacy of BIO101, whose active principle is 20-hydroxyecdysone, in COVID-19 patients with severe pneumonia. Trial design: Randomized, double-blind, placebo-controlled, multi-centre, group sequential and adaptive which will be conducted in 2 parts. Part 1: Ascertain the safety and tolerability of BIO101 and obtain preliminary indication of the activity of BIO101, in preventing respiratory deterioration in the target population Part 2: Re-assessment of the sample size needed for the confirmatory part 2 and confirmation of the effect of BIO101 observed in part 1 in the target population. The study is designed as group sequential to allow an efficient run-through, from obtaining an early indication of activity to a final confirmation. And adaptive – to allow accumulation of early data and adapt sample size in part 2 in order to inform the final design of the confirmatory part of the trial. Participants: Inclusion criteria Age: 45 and above A confirmed diagnosis of COVID-19 infection, within the last 14 days, prior to randomization, as determined by PCR or other approved commercial or public health assay, in a specimen as specified by the test used. Hospitalized, in observation or planned to be hospitalized due to COVID-19 infection symptoms with anticipated hospitalization duration ≥3 days With evidence of pneumonia based on all of the following: Clinical findings on a physical examination Respiratory symptoms developed within the past 7 days With evidence of respiratory decompensation that started not more than 4 days before start of study medication and present at screening, meeting one of the following criteria, as assessed by healthcare staff: Tachypnea: ≥25 breaths per minute Arterial oxygen saturation ≤92% A special note should be made if there is suspicion of COVID-19-related myocarditis or pericarditis, as the presence of these is a stratification criterion Without a significant deterioration in liver function tests: ALT and AST ≤ 5x upper limit of normal (ULN) Gamma-glutamyl transferase (GGT) ≤ 5x ULN Total bilirubin ≤ 5×ULN Willing to participate and able to sign an informed consent form (ICF). Or, when relevant, a legally authorized representative (LAR) might sign the ICF on behalf of the study participant Female participants should be: at least 5 years post-menopausal (i.e., persistent amenorrhea 5 years in the absence of an alternative medical cause) or surgically sterile; OR Have a negative urine pregnancy test at screening Be willing to use a contraceptive method as outlined in inclusion criterion 9 from screening to 30 days after last dose. Male participants who are sexually active with a female partner must agree to the use of an effective method of birth control throughout the study and until 3 months after the last administration of the investigational product. (Note: medically acceptable methods of contraception that may be used by the participant and/or partner include combined oral contraceptive, contraceptive vaginal ring, contraceptive injection, intrauterine device, etonogestrel implant, each supplemented with a condom, as well as sterilization and vasectomy). Female participants who are lactating must agree not to breastfeed during the study and up to 14 days after the intervention. Male participants must agree not to donate sperm for the purpose of reproduction throughout the study and until 3 months after the last administration of the investigational product. For France only: Being affiliated with a European Social Security. Exclusion criteria Not needing or not willing to remain in a healthcare facility during the study Moribund condition (death likely in days) or not expected to survive for >7 days – due to other and non-COVID-19 related conditions Participant on invasive mechanical ventilation via an endotracheal tube, or extracorporeal membrane oxygenation (ECMO), or high-flow Oxygen (delivery of oxygen at a flow of ≥16 L/min.). Participant is not able to take medications by mouth (as capsules or as a powder, mixed in water). Disallowed concomitant medication: Consumption of any herbal products containing 20-hydroxyecdysone and derived from Leuzea carthamoides; Cyanotis vaga or Cyanotis arachnoidea is not allowed (e.g. performance enhancing agents). Any known hypersensitivity to any of the ingredients, or excipients of the study medication, BIO101. Renal disease requiring dialysis, or known renal insufficiency (eGFR≤30 mL/min/1.73 m2, based on Cockcroft & Gault formula). In France only: Non-affiliation to compulsory French social security scheme (beneficiary or right-holder). Being under tutelage or legal guardianship. Participants will be recruited from approximately 30 clinical centres in Belgium, France, the UK, USA and Brazil. Maximum patients’ participation in the study will last 28 days. Follow-up of participants discharged from hospital will be performed through post-intervention phone calls at 14 (± 2) and 60 (± 4) days. Intervention and comparator: Two treatment arms will be tested in this study: interventional arm 350 mg b.i.d. of BIO101 (AP 20-hydroxyecdysone) and placebo comparator arm 350 mg b.i.d of placebo. Administration of daily dose is the same throughout the whole treatment period. Participants will receive the study medication while hospitalized for up to 28 days or until a clinical endpoint is reached (i.e., ‘negative’ or ‘positive’ event). Participants who are officially discharged from hospital care will no longer receive study medication. Main outcomes: Primary study endpoint: The proportion of participants with ‘negative’ events up to 28 days. ‘Negative’ events are defined as respiratory deterioration and all-cause mortality. For the purpose of this study, respiratory deterioration will be defined as any of the following: Requiring mechanical ventilation (including cases that will not be intubated due to resource restrictions and triage). Requiring extracorporeal membrane oxygenation (ECMO). Requiring high-flow oxygen defined as delivery of oxygen at a flow of ≥16 L/min. Only if the primary endpoint is significant at the primary final analysis the following Key secondary endpoints will be tested in that order: Proportion of participants with events of respiratory failure at Day 28 Proportion of participants with ‘positive’ events at Day 28. Proportion of participants with events of all-cause mortality at Day 28 A ‘positive’ event is defined as the official discharge from hospital care by the department due to improvement in participant condition. Secondary and exploratory endpoints: In addition, a variety of functional measures and biomarkers (including the SpO2 / FiO2 ratio, viral load and markers related to inflammation, muscles, tissue and the RAS / MAS pathways) will also be collected. Randomization: Randomization is performed using an IBM clinical development IWRS system during the baseline visit. Block-permuted randomization will be used to assign eligible participants in a 1:1 ratio. In part 1, randomization will be stratified by RAS pathway modulator use (yes/no) and co-morbidities (none vs. 1 and above). In Part 2, randomization will be stratified by centre, gender, RAS pathway modulator use (yes/no), co-morbidities (none vs. 1 and above), receiving Continuous Positive Airway Pressure/Bi-level Positive Airway Pressure (CPAP/BiPAP) at study entry (Yes/No) and suspicion of COVID-19 related myocarditis or pericarditis (present or not). Blinding (masking): Participants, caregivers, and the study team assessing the outcomes are blinded to group assignment. All therapeutic units (TU), BIO101 b.i.d. or placebo b.i.d., cannot be distinguished in compliance with the double-blind process. An independent data-monitoring committee (DMC) will conduct 2 interim analyses. A first one based on the data from part 1 and a second from the data from parts 1 and 2. The first will inform about BIO101 safety, to allow the start of recruitment into part 2 followed by an analysis of the efficacy data, to obtain an indication of activity. The second interim analysis will inform about the sample size that will be required for part 2, in order to achieve adequate statistical power. Numbers to be randomised (sample size) Number of participants randomized: up to 465, in total Part 1: 50 (to obtain the proof of concept in COVID-19 patients). Part 2: 310, potentially increased by 50% (up to 465, based on interim analysis 2) (to confirm the effects of BIO101 observed in part 1). Trial Status: The current protocol Version is V 10.0, dated on 24.09.2020. The recruitment that started on September 1st 2020 is ongoing and is anticipated to finish for the whole study by March2021. Trial registration: The trial was registered before trial start in trial registries: EudraCT, No. 2020-001498-63, registered May 18, 2020; and Clinicaltrials.gov, identifier NCT04472728, registered July 15, 2020. Full protocol: The full protocol is attached as an additional file, accessible from the Trials website (Additional file 1). In the interest in expediting dissemination of this material, the familiar formatting has been eliminated; this Letter serves as a summary of the key elements of the full protocol.

8 May 2015 in Phytochemical Analysis
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Journal Article
Open access
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LGLouis Guibout
Louis Guibout
NMNilufar Mamadalieva
Nilufar Mamadalieva
CBChristine Balducci
Christine Balducci
JGJean‐Pierre Girault
Jean‐Pierre Girault
RLRené Lafont
René Lafont
Introduction: Ajuga turkestanica is a plant used in traditional medicine for its high ecdysteroid content, including the presence of the particularly active turkesterone, which possess efficient anabolic activity.Objectives: To isolate and identify minor ecdysteroids present in a semi‐purified plant fraction containing ca. 70% turkesterone.Material and Methods: Multi‐step preparative HPLC (combining RP‐ and NP‐HPLC systems) was used to purify the different components present in the turkesterone fraction. Isolated compounds were identified by high‐resolution mass spectrometry and 2D‐NMR.Results: Fourteen ecdysteroids (including turkesterone and 20‐hydroxyecdysone) were isolated. Seven of these, all bearing an 11α‐hydroxy group, were previously unreported.Conclusion: Ajuga turkestanica ecdysteroids are characterised by the abundance of 11α‐hydroxylated compounds and by the simultaneous presence of 24C, 27C, 28C and 29C ecdysteroids. It is expected that even more ecdysteroids are to be found in this plant since the starting material for this study lacked the less polar ecdysteroids. The simultaneous presence of 20‐hydroxyecdysone and turkesterone (its 11α‐hydroxy analogue) as the two major ecdysteroids suggests that every ecdysteroid is probably present in both 11α‐hydroxy and 11‐deoxy forms. Copyright © 2015 John Wiley & Sons, Ltd.