Functional Physiology of Bio-Resources (BioFonc)

 

      Medicinal and aromatic plants remain an inexhaustible source of biologically active substances, so the field of phytotherapy has been oriented towards obtaining phyto-medicines in the face of the limits on the use of chemical drugs. This development represents an essential step in the growth of an entire sector linked to the needs not only of pharmacopoeia, but also of the agri-food, cosmetics and perfume industries.

      As a result, medicinal plants are attracting increasing interest in scientific research into their use and their therapeutic virtues. Of particular interest are phenolic compounds, whose antioxidant properties are currently the focus of considerable research worldwide.

 

      Tunisia's flora lists only 2103 species in 115 families and 742 genera (Cardinale et al., 2002). These species belong to the Labiatae, Zygophyllaceae, Liliaceae, Solanaceae, Umbelliferae, Rosaceae, Myrtaceae, Anacardiaceae and other families. With the exception of certain forest species such as Rosemary (Rosmarinus officinalis L.), Myrtle (Myrtus communis L.), Pistachio (Pistacia lentiscus L.) and Thyme (Thymus capitatus L.), which are used in small-scale industrial operations, the rest of the plants are still very little exploited.

       Medicinal and aromatic plants are currently in great demand in traditional medicine and the pharmaceutical, food and cosmetics industries. The World Health Organization (WHO) reports that 80% of rural populations use medicinal plants for primary care, and that 25% of modern pharmacopoeia drugs are based on medicinal plants. However, most of the species used come from spontaneous populations, and very few appropriate crops have been planted.

        Natural populations are often located in fragile environments (irregular rainfall, poor soil quality). They are overgrazed and cleared. Excessive exploitation of the species and the weakening of their biotope are gradually leading to a profound change in the structure and dynamics of populations, which are becoming increasingly fragmented.

Interest in the study of these plants as a genuine source of pharmacological activity has grown worldwide. Indeed, the majority of marketed medicines are derived from them. Medicinal plants represent an inexhaustible source of remedies for various diseases.

         Polyphenols are a family of organic molecules produced by the plant kingdom. They are characterized by the presence of several phenolic groups associated in more or less complex structures, generally of high molecular weight. These compounds are the products of secondary plant metabolism. Polyphenols are becoming increasingly important, not least because of their beneficial effects on health. Indeed, their antioxidant power is attracting increasing interest in the prevention and treatment of inflammatory, cardiovascular and, above all, digestive diseases. They are generally used as food additives and in the agri-food, pharmaceutical and cosmetics industries.

         Phytotherapy is practised throughout the world as an alternative or complementary medicine. Used for centuries as the one and only form of medicine, it has become the main source of the active ingredients used in allopathic medicine. It is from purified extracts of the plant's constituents that chemists have been able to synthesize the active ingredients of most of the world's chemical medicines. Today, pharmacologists and drug industry professionals agree that chemistry alone is no longer sufficient to develop the medicines of the future. Chemical medicines - or allopathic medicines - are doomed to disappear, to be replaced by new so-called biological medicines and their generics, biosimilars. Today, over 40% of the medicines used in developed countries to combat serious and emerging diseases are biologics.

         This new concept of developing plant-based medicines and food supplements gives phytomedicines a new lease of life, and enables us to value and conserve not only our natural wealth, but also our ancestral customs and traditions as a basis for innovation, nature conservation and development.

Part of this project aims to improve the nutritional and health quality of food, which represents a priority demand from consumers. The development of new ingredients adapted to this evolution, derived from medicinal and aromatic plant valorization processes and contributing to the preservation or even improvement of health capital, is of particular interest. In this context, aromatic plants occupy a prominent place insofar as they present a proven antioxidant potential that could allow us to free ourselves from the use of synthetic antioxidants. Although increasingly controversial due to the potential health risks they present, synthetic antioxidants such as BHA (Butylhydroxyanisole) or BHT (Butylhydroxytoluene) cover a very large part of the food antioxidant sector. Concerns have been expressed by the FDA (Food and Drug Administration) regarding the possible toxicity of BHT in extrahepatic tissues. Furthermore, these molecules have been listed as chemicals of potential concern due to their toxicity to aquatic organisms and their bioaccumulation potential. Their substitution with compounds of natural origin therefore constitutes both a health and environmental issue. In this context, one of the objectives of this project is to enhance the antioxidant potential of a plant extract for food uses.