Saponins from saffron corms inhibit the secretion of pro-inflammatory cytokines at both protein and gene levels

Corms are obtained as a by-product during the cultivation of saffron (Crocus sativus). In a project aimed at the valorization of this waste product, we observed that a 70% EtOH extract of the corms and particularly a Diaion HP-20 methanolic fraction thereof inhibited the TNF-α/IFN-γ-induced secretion and gene expression of the chemokines IL-8, MCP-1 and RANTES in human HaCaT cells. The effects were partly stronger than those of the positive control hydrocortisone.

After semi-preparative HPLC separation of the methanolic fraction, the activity could be assigned to a major broad peak in the ELSD trace. For preparative isolation, the 70% EtOH extract was partitioned between n-butanol and water. Separation of the n-butanol-soluble fraction by centrifugal partition chromatography (CPC), followed by preparative HPLC on RP-18 and HILIC columns afforded a series of bidesmosidic glycosides of echinocystic acid bearing a fatty acid residue attached to the glycosidic moiety at C-28. The main components were identified as azafrines 1 and 2 [1].

Saffron saponins significantly inhibited TNF-α/IFN-γ-induced secretion of RANTES in human HaCaT cells at 1 μM (p < 0.001). Some of them further lowered TNF-α/IFN-γ-induced gene expression.

Saffron corm extracts and their saponin constituents may have a potential for the development of new cosmetic and/or medicinal products against inflammatory skin conditions.

Fig. 1

• References

• 1 Rubio-Moraga H, Gerwig GJ, Castro-Diȧz NC, Jimeno ML, Escribano J, Fernȧndez JA, Kamerling JP. Triterpenoid saponins from corms of Crocus sativus: Localization, extraction and characterization. Indus Crops Prod 2011; 34: 1401-1409