Distinct growth and extractive methods of Acmellaoleracea (L.) R.K. Jansen rising different concentrations of spilanthol: An important bioactive compound in human dietary

Abstract

Acmella oleracea, commonly known as jambú, is a great source of spilanthol, a secondary metabolite responsible for different kind of biological activities, such as the antioxidant, antimicrobial, cytotoxic and anti-inflammatory bioactivities. The purpose of this work was to evaluate spilanthol content in A. oleracea plants obtained from three different cultivation conditions - in vitro, acclimatized and in field - and compare two different extraction techniques: maceration and microwave assisted extraction (MAE). Therefore, A. oleracea nodal segments were cultured on Murashige and Skoog medium. After 30days, developed plants were transferred to ex vitro conditions and successfully acclimatized. From all types of culture, the whole plant as well as the flowers, leaves, stems and roots were used, separately, to obtain ethanolic extract (75%) but only the micropropagated whole plant was used on the factorial design 24–1 on the microwave-assisted extraction. All the samples were quantified by HPLC-DAD and analyzed by CG-MS. Results show that the different acclimatized plant parts are the richest in spilanthol content, followed by the in vitro culture and, finally, field material. The MAE was able to extract the highest amount of spilanthol from in vitro whole plant (3.09%) compared to the classical maceration extract (0.98%) and, furnished good crude extracts yields under an optimized study accurately explained by the mathematical model. The antibacterial assay presented a negative result using in vitro samples and bacteria inhibition with field samples against Staphylococcus aureus (ATCC 29213) and Staphylococcus epidermidis (ATCC 12228) standard strains.