1074 Mimosa pudica plant cell culture extracts (mimosine free) exhibit anti-inflammatory activities and inhibit the responses in vitro

Mimosa pudica has been used for decades in SE-Asia to treat inflammation. However mimosine, a well-known toxic molecule, was found invariably in the natural plant extracts. By plant cell culture metabolic engineering, we were able to inhibit intracellularly mimosine expression. It was under HPLC detection level i.e 5 ng per gr dry weight (DW) of cell extract (E13) compared to 2160 ng per gr DW in natural leaves extract (E11). (i) RAW264.7 murine macrophages were incubated with 50 μg DW/ml of E13 or E11, or 1μM Dexamethasone for 1 H and were stimulated with LPS for 24 H. Quantifications of NO, IL-6 and TNFα were performed by Griess, ELISA and Luminex techniques respectively. Similarly to Dexa, E13 and E11 inhibit NO and IL-6. TNFα expression was reduced by E13 and Dexa, in contrast it was increased by E11. (ii) In a Th2 induced model, NHEK cells were incubated with 0, 0.75 and 1.5 mg DW/ml of WO1 a similarly prepared E13 extract for 1 H and were stimulated by (poly I:C + TNFα + IL-4 + IL-13) for 24 H. mRNA quantification of AMP, cytokines and chemokines by RT-qPCR has shown: a dose dependent increase of S100A7 , RNASE7, DEF304A and a significant decrease of IL-1β and CXCL-8. Finally, TSLP and TLR-3 both known to be involved in pruritus were highly down-regulated. In conclusion, mimosine free plant cells culture extracts exhibit anti-inflammatory activities and counteract Th2 responses. This high added value eco extracts could be potentially incorporated in topic formulations for treating inflammatory skin diseases.