Echinacea purpurea (L.) Moench is one of the most economically important medicinal plants, cultivated worldwide for its high medicinal value and with several industrial applications in both pharmaceutical and food industries. Thanks to its various phytochemical contents, including caffeic acid derivatives (CADs), E. purpurea extracts have antioxidant, anti-inflammatory, and immuno-stimulating properties. Among CADs, chicoric acid is one of the most important compounds which have shown important pharmacological properties. The present research was aimed at optimizing the production of chicoric acid in E. purpurea cell culture. Methyl jasmonate (MeJa) at different concentrations and for different duration of treatments was utilized as elicitor, and the content of total polyphenols and chicoric acid was measured. Several genes involved in the chicoric acid biosynthetic pathway were selected, and their expression evaluated at different time points of cell culture growth. This was performed with the aim of identifying the most suitable putative molecular markers to be used as a proxy for the early prediction of chicoric acid contents, without the need of expensive quantification methods. A correlation between the production of chicoric acid in response to MeJa and an increased response to oxidative stress was also proposed.

Croton lechleri Müll. Arg. is a traditional medicinal tree growing in South America, which produces a deep red sap known as Dragon’s Blood Sap (DBS) used for its many therapeutic benefits. DBS bioactivity is mainly due to the high content of proanthocyanidins (PAs), important plant secondary metabolites involved in plant defence, but also utilised as antioxidant for human health. Since the process to directly obtain DBS from the C. lechleri tree is expensive, time-consuming and strongly dependent on the environmental conditions, the use of plant cell cultures for DBS production seems to represent a suitable alternative. The aptitude of plant cell cultures to synthesize specific secondary metabolites can be elicited by different types of abiotic stresses. In this study, the C. lechleri main genes putatively involved in the PAs biosynthetic pathway were identified and their expression was evaluated in both calli in solid medium and cell culture suspensions to identify the most suitable predictive gene markers for PAs biosynthesis. C. lechleri cell cultures were grown and elicited by N-starvation to induce the production of PAs and were then monitored by assessing the expression of previously identified gene markers, by quantifying the content of PAs and measuring few phenotypical parameters. The results show a new perspective on how PA gene transcript abundance could be used to predict the biosynthesis of useful secondary metabolites in plant cell cultures and to speed up the screening of putative elicitors.

In the last years, the medicinal plant Perilla frutescens (L.) Britton has gained scientific interest because leaf extracts, due to the presence of rosmarinic acid and other polyphenols, have shown anti-allergic and skin protective potential in pre-clinical studies. Nevertheless, the lack of standardized extracts has limited clinical applications to date. In this work, for the first time, a standardized phytocomplex of P. frutescens, enriched in rosmarinic acid and total polyphenols, was produced through innovative in vitro cell culture biotechnology and tested. The activity of perilla was evaluated in an in vitro inflammatory model of human keratinocytes (HaCaT) by monitoring tight junctions, filaggrin, and loricrin protein levels, the release of pro-inflammatory cytokines and JNK MAPK signaling. In a practical health care application, the perilla biotechnological phytocomplex was tested in a multilayer model of vaginal mucosa, and then, in a preliminary clinical observation to explore its capacity to preserve vaginal mucosal integrity in women in peri-menopause. In keratinocytes cells, perilla phytocomplex demonstrated to exert a marked activity in epidermis barrier maintenance and anti-inflammatory effects, preserving tight junction expression and downregulating cytokines release through targeting JNK activation. Furthermore, perilla showed positive effects in retaining vaginal mucosal integrity in the reconstructed vaginal mucosa model and in vivo tests. Overall, our data suggest that the biotechnological P. frutescens phytocomplex could represent an innovative ingredient for dermatological applications.