Alkylamides from Acmella oleracea: antinociceptive effect and molecular docking with cannabinoid and TRPV1 receptors

Cytotoxic and molecular evaluation of spilanthol obtained from Acmella oleracea (L.) R. K. Jansen (jambu) in human gastric cancer cells

Acmella oleracea (L.) is a plant popularly known as jambu in the Brazilian Amazon. This species has several biological properties, such as anaesthetic, antioxidant and anti-inflammatory activities, among others. However, there is limited information on its anticancer activity. In this context, this study aims to evaluate the effects of the hydroethanolic extract of jambu and its active compound (spilanthol) on gastric cancer cells. Hydroethanolic jambu inflorescence extract was obtained, and spilanthol was isolated by HPLC. Biological cytotoxicity assays were determined using MTT tests. In addition, an in silico study using molecular docking evaluated the inhibitory properties of spilanthol against JAK1 and JAK2 proteins. The results showed that the hydroethanolic extract and the isolated compound spilanthol exhibited cytotoxicity against cancer cells. Molecular docking revealed that spilanthol has inhibitory potential for JAK1 and JAK2 proteins. Thus, extract of jambu and spilanthol can be a possible candidate for the treatment of gastric carcinoma.

Affinin, Isolated from Heliopsis longipes, Induces an Antihypertensive Effect That Involves CB1 Cannabinoid Receptors and TRPA1 and TRPV1 Channel Activation

In previous studies, we demonstrated that the ethanolic extract of Heliopsis longipes roots and its main alkamide, affinin, elicit a vasorelaxant effect through a mechanism involving activation of the gasotransmitter pathways and stimulation of cannabinoid type 1 receptors and transient receptor potential ankyrin 1 and transient receptor potential vanilloid 1 channels. However, it has not yet been demonstrated whether the EEH and affinin are capable of lowering high blood pressure. Therefore, the aim of the present study was to determine the effect of the oral administration of the EEH and affinin on the systolic blood pressure of NG-nitro-L-arginine methyl ester-induced hypertensive rats and to explore the participation of cannabinoid receptors and transient receptor potential channels in the mechanism of action of this alkamide. Our results showed that the ethanolic extract of H. longipes and affinin significantly lowered systolic blood pressure and induced an improvement in endothelial function, which is associated with increased serum nitric oxide levels. Inhibition of cannabinoid type 1 receptors by rimonabant (3 mg/kg), transient receptor potential ankyrin 1 channels by HC-030031 (8 mg/kg), and transient receptor potential vanilloid 1 channels by capsazepine (5 mg/kg) significantly decreased the antihypertensive effect induced by affinin, suggesting that the blood pressure-lowering effect of this alkamide involves activation of cannabinoid type 1 receptors and transient receptor potential ankyrin 1 and transient receptor potential vanilloid 1 channels.

Natural Deep Eutectic Solvents for the Extraction of Spilanthol from Acmella oleracea (L.) R.K.Jansen

With a growing focus on green chemistry, the extraction of natural products with natural deep eutectic solvents (NADES), which are eutectic mixtures of hydrogen bond donors and acceptors, has become an ever-expanding field of research. However, the use of NADES for the extraction of spilanthol from Acmella oleracea (L.) R.K.Jansen has not yet been investigated. Therefore, in this study, 20 choline chloride-based NADES, and for comparison, ethanol, were used as green extraction agents for spilanthol from Acmella oleracea flower heads. The effects of time, water addition, and temperature on NADES extractions were investigated and analysed by HPLC-DAD quantification. Additionally, UHPLC-DAD-ESI-MSn results for dichloromethane extracts, as well as the isolation of spilanthol and other main constituents as reference compounds, are reported. The best green extraction results were achieved by choline chloride (ChCl) with 1,2-propanediol (P, 1:2 molar ratio, +20% water) at 244.58 µg/mL, comparable to yields with ethanol (245.93 µg/mL). Methylurea (MeU, 1:2, +20% water) also showed promising results as a hydrogen bond donor in combination with choline chloride (208.12 µg/mL). In further experiments with NADES ChCl/P (1:2) and ChCl/MeU (1:2), extraction time had the least effect on spilanthol extraction with NADES, while yield decreased with water addition over 20% and increased with extraction temperature up to 80 °C. NADES are promising extraction agents for the extraction of spilanthol, and these findings could lead to applicable extracts for medicinal purposes, due to their non-toxic constituents.

Study of Mono and Di-O-caffeoylquinic Acid Isomers in Acmella oleracea Extracts by HPLC-MS/MS and Application of Linear Equation of Deconvolution Analysis Algorithm for Their Characterization

Chlorogenic acids, the esters of caffeic and quinic acids, are the main phenolic acids detected in Acmella oleracea extracts and have gained increasing interest in recent years due to their important biological activities. Given their structural similarity and instability, the correct analysis and identification of these compounds in plants is challenging. This study aimed to propose a simple and rapid determination of the A. oleracea caffeoylquinic isomers, applying an HPLC-MS/MS method supported by a mathematical algorithm (Linear Equation of Deconvolution Analysis (LEDA)). The three mono- and the three di-caffeoylquinic acids in roots of Acmella plants were studied by an ion trap MS analyzer. A separation by a conventional chromatographic method was firstly performed and an MS/MS characterization by energetic dimension of collision-induced dissociation mechanism was carried out. The analyses were then replicated using a short HPLC column and a fast elution gradient (ten minutes). Each acquired MS/MS data were processed by LEDA algorithm which allowed to assign a relative abundance in the reference ion signal to each isomer present. Quantitative results showed no significant differences between the two chromatographic systems proposed, proving that the use of LEDA algorithm allowed the distinction of the six isomers in a quarter of the time.