Acmella oleracea (L.) R.K. Jansen, a herb native from Brazil, it is traditionally used in the culinary and to treat toothaches. Spilanthol is believed to be responsible for the anesthetic and anti-inflammatory effects presented by this species and therefore possess high therapeutic value [1]. Our study aimed to evaluate the cytotoxicity and the effect of spilanthol in human gingival fibroblast (HGF-1) focusing on the inflammatory pathway. Human gingival fibroblasts, HGF-1 (ATCC® CRL-2014) were seeded in 96 well plates and incubated with different concentrations of spilanthol (1-1000 µM) for 24, 48, and 72 h. Toxicity was evaluated using fluorometric quantification of cellular viability (Promega CellTiter-Blue). Cytokine production was analyzed by Human Inflammatory Cytokine Multi-Analyte ELISArray (Qiagen, MEH-004A) and gene expression profile was performed by RT2 Profiler PCR Array using The Human Inflammatory Response & Autoimmunity (Qiagen, PAHS-077Z). A decrease in cell viability was observed in cells exposed at the highest concentration tested (1000 µM) and in a time-dependent manner (Figure 1). Five out of 84 genes related to inflammatory and immune response were down-regulated when the cells were treated with 20 µM of spilanthol (fold change ≥2 and p-value < 0.05). The expression of some genes (e.g., SELE, CCL17, IL-9) were significantly down-regulated by spilanthol. However, Spilanthol (20 and 200 µM) did not affect the cytokine and chemokines levels in HGF-1 supernatant when compared to control. In conclusion, Spilanthol is a promising naturally occurring agent displaying low toxicity and anti-inflammatory activity. The putative pathway by which spilanthol affect inflammation process may involve the downregulation of cytokines and chemokine receptors.
Acknowledgements: Capes (grant # 006211/2015-01) and Fapesp (grant #2014/06461-2).
[1] Barbosa AF, de Carvalho MG, Smith RE, Sabaa-Srur AUO. Braz. J. Pharmacog. 2016;26(1):128-33.
