LabCom PHYTOMAR’INNOV – PHYTOMAR

The project is organized into six tasks from T0 to T5:

Task T0 – LabCom setup phase (Duration: 6 months)
Task T1 – Selection and quality control of raw materials (TRL 2–3)
Task T2 – Development and characterization of polyphenolic extracts (TRL 3–4)
Task T3 – Evaluation of anti-infectious bioactivity (TRL 4–5)
Task T4 – Optimization of extractions and combination of extracts (TRL 5–6)
Task T5 – Galenic formulation development (TRL 6–7)

A selection of plant extracts of interest was made based on scientific literature, including their biomolecular composition (particularly their richness in phenolic compounds), and published clinical studies. For the clinical studies, we specifically focused on the quantity and quality of information involving plant extracts or biomolecules derived from specific plants.

Based on this initial step, the selection was narrowed down to two main categories:

Extracts that are already well-documented, with significant and relevant clinical results regarding anti-infectious effects.
Extracts presumed to have anti-infectious properties but with little to no robust scientific or clinical studies.
Twelve plant extracts were selected. These are commercially available from various companies and have been prepared using different extraction methods, typically provided in powder form, with a final composition either unknown or only partially known.

In addition, an initial phase of extract production on a small lab pilot scale (several tens of grams produced) was carried out based on literature, to produce extracts from the available plant materials.

The plant extracts were tested for anti-growth activity against about twenty target bacteria, either in solid media (diffusion test on agar plates) or in liquid media using 96-, 48-, or 24-well microplates. It was found that the diffusion-based activity test on agar did not work effectively; no antimicrobial activity could be demonstrated with this test because the active compounds in the extracts did not seem to diffuse into the agar and remained localized at the point of application.

Furthermore, the liquid media activity test is also limited and still requires optimization despite promising results. Pigments in certain extracts interfered in some conditions, making it difficult to accurately assess the anti-growth activity against target bacteria.

Despite these limitations, the anti-growth activity tests clearly demonstrated that certain extracts have real antimicrobial potential, particularly against high-risk, multi-drug-resistant bacteria, notably Gram-positive cocci. This work highlights the potential of certain extracts as candidates for the future development of natural-origin therapeutic formulations.

Ongoing work:

T1.2: Establishment of quality specifications, traceability, and control plans (traceability, safety, variability, quality markers)

T2.1: Extraction of biomasses by hydroalcoholic maceration (extracts not yet available)
T2.2: Identification and quantification of polyphenols (phlorotannins, flavonoids, phenolic acids, etc.) via HPLC-MS/UV

T3.1: Bioactivity evaluation: Antiviral tests (ACE2/Spike interactions, SARS/MERS/Covid pseudovirus assays)
T3.3: Evaluation of optimized extract combinations (isobolograms, synergies)

Deliverables / Results:
R3: Demonstrated antiviral activity
R4: Demonstrated antibacterial activity

Poster au Colloque MuFoPAM à Caen le 19,20,21 mai 2025
Poster au Coloque Microbiology Day à Talence le 27 mai 2025

The PHYTOMAR'INNOV Joint Laboratory aims at the sustainable creation of a laboratory of excellence for the eco-design of innovative active ingredients, composed of molecules derived from marine algal and plant resources, allowing the design of products for the prevention of infectious diseases, in particular viral and bacterial ones.
To date, there is no national laboratory of excellence specialising in the applications of marine algal and plant resources for the food supplement and/or antiviral and antimicrobial medical device markets. The PHYTOMAR'INNOV LabCom aims to become a visible reference in these fields. A voluntary policy of publications and dissemination of information on the innovations of LabCom PHYTOMAR'INNOV will serve this ambition.
The main objective, for the 54 months of this LabCom, will therefore be to develop anti-infectious active principles, composed of polyphenols, from marine algal and plant resources. These active ingredients, whose efficacy and mechanisms of action will have been demonstrated, could be used in the composition of formulations intended for the food supplement and medical device, antiviral and antimicrobial markets. In more detail, we will develop two solutions:
The first will be devoted to the development of an original combination of natural extracts rich in polyphenols for the prevention of coronavirus infection. The coronaviruses responsible for three epidemics of severe acute respiratory syndromes in humans over the last twenty years, Sars-CoVS in 2003, Mers-CoV in 2012 and finally Sars-Cov2 in 2019, will be the priority targets.
The second will be devoted to the development of an original combination of natural extracts rich in polyphenols for the prevention of bacterial infections. The bacterial strains that we will use in the project are widely encountered in various human pathologies of food, pulmonary or other origin. They are often multi-resistant to antibiotics and responsible for more or less serious infections. They are methicillin-resistant Staphylococcus aureus (MRSA) and extended-spectrum beta-lactamase- producing enterobacteria (EBLSE). Some species such as Escherichia coli or Klebsiella pneumoniae are particularly resistant to third generation cephalosporins (C3G) or carbapenems. We will also look at Pseudomonas aeruginosa, which is widespread in hospital-acquired infections, or Salmonella enterica serovar Typhimurium and Listeria monocytogenes, which are responsible for serious food- borne infections.