From the production of targeted metabolites to the complete valorization of Coleus forskohlii Briq. using aeroponic cultivation.
Résumé
Accessing plant resources to extract compounds of interest can sometimes be difficult. To facilitate this access and limits environmental impact of transport, cultivation strategies can be developed. Coleus forskohlii Briq. a member of the Lamiaceae family (Ali Khan, 2012), used in Indian and Chinese traditional medicine and rich in diterpenoids, is widely cultivated for forskolin production. Indeed, this diterpenoid which presents anti-inflammatory activity (Suresh et al., 2018) and activate adenylate cyclase (Seamon & Daly, 1981) is the major compound of interest, and it is found in the roots. In this regard, aeroponic cultivation of C. forskohlii had been developed in Region Centre Val de Loire (France) to facilitate access to the resources and more particularly to the roots. However, the phytochemical composition and the biological properties of a cultivated plant, that grows off-ground under another climate with less abiotic stress, when compared with the wild one, may vary. The first part of this study focused on optimizing the cultivation conditions to maximize forskolin production. Aeroponic cultivation has been realised for 18 weeks under various stresses. The quantification of forskolin using UHPLC-ELSD indicates that the use of LED lighting compared to the control 3-fold improve the total quantity of forskolin produced. Then a methodology employing non-targeted metabolomics approaches through UHPLC-HRMS/MS have been implemented to study the impact of this stress on other root metabolites. This methodology has been extended to the aerial part to explore potential co-valorization routes.