Acaricidal activity of synthetic spilanthol derivative against ticks of medical and veterinary importance.

The ANESPSAT, a synthetic spilanthol derivative, and its nanoformulation were evaluated against Rhipicephalus microplus and Amblyomma sculptum ticks. ANESPSAT activity was compared with spilanthol and derivatives (ANESPE and others). The compound was synthesized in a gram-scale by a 2-step process, comprising a direct ester amidation and a Horner-Wadsworth- Emmons reaction. The nanoemulsions were produced by coarse homogenization followed by high-energy ultrasonication, in which hydrodynamic diameter, polydispersity index, and zeta potential remained stable. The spilanthol-eugenol hybrid derivatives did not show significant acaricidal activity. ANESPE killed 83% of the R. microplus larvae at 30 mg.mL-1, while ANESPSAT killed 97% at 0.5 mg.mL-1, showing to be the most active compound. Spilanthol and ANESPSAT had similar high mortality rates for tick larvae, with LC50 values of 0.10 and 0.14 mg.mL-1 for R. microplus larvae, and 0.04 and 0.48 mg.mL-1 for A. sculptum larvae, respectively. The efficacy of spilanthol was lower against R. microplus engorged females when compared with ANESPSAT, which was highly effective (>98%) against R. microplus engorged females. The nanoemulsion with ANESPSAT was effective against tick females, preventing egg laying and achieving 100% efficacy at 2.5 mg.mL-1. Spilanthol had only 59% efficacy at 10 mg.mL-1. The results suggest that ANESPSAT, a natural product derivative, could be used in novel formulations for tick management that might be safer and environmentally friendly.

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.

Jambu Flower Extract (Acmella oleracea) Increases the Antioxidant Potential of Beer with a Reduced Alcohol Content.

Craft beers with different sensory perceptions have received the attention of more demanding consumers. In this sense, the application of plant extracts as brewing adjuncts is being increasingly studied. Allied with these perspectives is the consumption of lower alcoholic beverages, which also represents the desire for a market niche that has been growing gradually. The present work aimed to produce craft lager beer with the addition of plant extract and reduced alcohol content by partial replacement of malt with malt bagasse. The physical-chemical analyzes of the beer produced showed that it was possible to reduce the alcohol content by 40.5% compared to the control sample. In addition, an extract of Acmella oleracea (Jambu) obtained by supercritical extraction was added to increase the beer's antioxidant capacity. The ABTS, DPPH, and ORAC methods evaluated the antioxidant capacity. These assays were performed again after six months of storage. The quantification and identification of the significant substance in the extract (spilanthol) were performed using Gas Chromatography (GC-FID), Thin Layer Chromatography (TLC), and Attenuated Total Reflectance Infrared Spectroscopy (FTIR-ATR). The results showed significant increases in antioxidant activity compared to the sample without extract. This positive aspect opens a perspective for using jambu flower extract as a prominent antioxidant adjunct in beer.

Clinical Safety of a Pharmaceutical Formulation Containing an Extract of Acmella oleracea (L.) in Patients With Premature Ejaculation: A Pilot Study.

Acmella oleracea (L.) R. K. Jansen (Asteraceae) is a plant species widely used in traditional Amazonian medicine to treat sexual dysfunction. The use of this plant has gained popularity because of its sensory properties, such as a tingling sensation. In this study on patients with premature ejaculation, we evaluated the clinical action of a nano-formulation containing an ethanolic extract of A. oleracea inflorescences. Major constituents in the extracts were identified based on gas chromatographic analysis. Participants used a spray preparation based on the A. oleracea extract for 12 weeks, during which they were instructed to apply the product 5 min prior to sexual intercourse. To assess therapeutic efficacy, participants were required to record the mean intravaginal latency time for ejaculation (IELT). During the period of spray treatment, the nano-formulation of A. oleracea increased participant IELT values (M = 293 s) compared with the baseline values (193 s). This nano-formulation reported clinical action in patients with premature ejaculation. It is accordingly considered to have potential application as a therapeutic alternative with benefits for both patients and their partners. Given the small number of participants in this study, further multicenter studies involving a larger number of participants are needed to confirm these observations.

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

Alkylamides are secondary metabolites in Acmella oleracea and display wide applications in treating several diseases. Since alkylamides can inhibit pain, this work aims to evaluate the antinociceptive profile of A. Oleracea methanolic extracts used in vivo and in silico assays. The extracts inhibited the neurogenic and inflammatory phases of the formalin test, ratifying the antinociceptive effect of alkylamides. Furthermore, the results from molecular docking demonstrated the interaction of A. oleracea alkylamides with the CB1/CB2 and TRPV1 receptors. Additionally, the crude methanolic extract of flowers did not induce potential side effects related to the classical cannabinoid tetrad: hypolocomotion and catalepsy. In conclusion, this work confirms the potential of the alkylamides of A. Oleracea as antinociceptive agents and, for the first time, correlates its effects with the endocannabinoid and vanilloid systems through in silico assays.

Spilanthol as a promising antifungal alkylamide for the treatment of vulvovaginal candidiasis.

Spilanthol is a bioactive alkylamide from the native Amazon plant species, Acmella oleracea. However, antifungal activities of spilanthol and its application to the therapeutic treatment of candidiasis remain to be explored. This study sought to evaluate the in vitro and in vivo antifungal activity of spilanthol previously isolated from A. oleracea (spilanthol(AcO)) against Candida albicans ATCC® 10231™, a multidrug-resistant fungal strain. Microdilution methods were used to determine inhibitory and fungicidal concentrations of spilanthol(AcO). In planktonic cultures, the fungal growth kinetics, yeast cell metabolic activity, cell membrane permeability and cell wall integrity were investigated. The effect of spilanthol(AcO) on the proliferation and adhesion of fungal biofilms was evaluated by whole slide imaging and scanning electron microscopy. The biochemical composition of the biofilm matrix was also analyzed. In parallel, spilanthol(AcO) was tested in vivo in an experimental vulvovaginal candidiasis model. Our in vitro analyses in C. albicans planktonic cultures detected a significant inhibitory effect of spilanthol(AcO), which affects both yeast cell membrane and cell wall integrity, interfering with the fungus growth. C. albicans biofilm proliferation and adhesion, as well as, carbohydrates and DNA in biofilm matrix were reduced after spilanthol(AcO) treatment. Moreover, infected rats treated with spilanthol(AcO) showed consistent reduction of both fungal burden and inflammatory processes compared to the untreated animals. Altogether, our findings demonstrated that spilanthol(AcO) is an bioactive compound against planktonic and biofilm forms of a multidrug resistant C. albicans strain. Furthermore, spilanthol(AcO) can be potentially considered for therapeutical treatment of vulvovaginal candidiasis caused by C. albicans. LAY SUMMARY: This study sought to evaluate the antifungal activity of spilanthol against Candida albicans ATCC® 10 231™, a multidrug-resistant fungal strain. Our findings demonstrated that spilanthol(AcO) can be potentially considered for therapeutical treatment of vulvovaginal candidiasis caused by C. albicans.

Chymase inhibition: A key factor in the anti-inflammatory activity of ethanolic extracts and spilanthol isolated from Acmella oleracea.

ETHNOPHARMACOLOGICAL RELEVANCE: Acmella oleracea (L.) R. K. Jansen (Asteraceae), known as jambú in Brazil, is used in traditional medicine as analgesic and for inflammatory conditions, characterized by the presence of N-alkylamides, mainly spilanthol. This bioactive compound is responsible for the above-described pharmacological properties, including sialagogue and anesthetic. AIM OF THE STUDY: This study aimed to characterize the anti-inflammatory effects of A. oleracea leaves (AOEE-L) and flowers (AOEE-F) extracts, including an isolated alkylamide (spilanthol), using in vitro and in vivo models. The mechanism underlying this effect was also investigated. MATERIALS AND METHODS: Extracts were analyzed by HPLC-ESI-MS/MS in order to characterize the N-alkylamides content. AOEE-L, AOEE-F (25-100 µg/mL) and spilanthol (50-200 µM) were tested in vitro on VSMC after stimulation with hyperglycemic medium (25 mM glucose). Their effects over nitric oxide (NO) generation, chymase inhibition and expression, catalase (CAT), superoxide anion (SOD) radical activity were evaluated. After an acute administration of extracts (10-100 mg/mL) and spilanthol (6.2 mg/mL), the anti-inflammatory effects were evaluated by applying the formalin test in rats. Blood was collected to measure serum aminotransferases activities, NO activity, creatinine and urea. RESULTS: A number of distinct N-alkylamides were detected and quantified in AOEE-L and AOEE-F. Spilanthol was identified in both extracts and selected for experimental tests. Hyperglycemic stimulation in VSMC promoted the expression of inflammatory parameters, including chymase, NO, CAT and SOD activity and chymase expression, all of them attenuated by the presence of the extracts and spilanthol. The administration of extracts or spilanthol significantly inhibited edema formation, NO production and cell tissue infiltration in the formalin test, without causing kidney and liver toxicity. CONCLUSION: Taken together, these results provide evidence for the anti-inflammatory activity of leaves and flowers extracts of jambú associated distinctly with their chemical profile. The effects appear to be associated with the inhibition of chymase activity, suppression of the proinflammatory cytokine NO and antioxidant activities.

Phytochemical profile of different anatomical parts of jambu (Acmella oleracea (L.) R.K. Jansen): A comparison between hydroponic and conventional cultivation using PCA and cluster analysis.

Jambu [Acmella oleracea (L.) R.K. Jansen] is an edible plant with a wide range of constituents of biological interest. In this study, the chemical composition of leaves, flowers and stems of jambu cultivated in hydroponic and conventional systems was investigated. In both crop systems, the leaves showed the highest total phenolic content, total flavonoid content and in vitro antioxidant capacity. The extracts were characterized by determining 45 compounds, including phenolic acids, glycosylated flavonoids, alkamides and fatty acids, by LC-MS analysis. Of these compounds, 31 are described for the first time in this species, five of which are reported for the first time in the literature. The PCA and cluster analysis results distinguished different anatomical parts (PC1 and PC2) and cultivation systems (PC3) into well-defined groups.

Reproductive toxicity of the hydroethanolic extract of the flowers of Acmella oleracea and spilanthol in zebrafish: In vivo and in silico evaluation.

Hydroethanolic preparations of Acmella oleracea is used in the north of Brazil as a female aphrodisiac. Thus, the objective of this study was to evaluate the action of the hydroethanolic extract of Acmella oleracea (EHFAo) flowers (21.873 and 44.457 mg/kg) and spilanthol (3 mg/kg) administered orally on reproductive performance and effects on the embryonic development of zebrafish F1 generation. It was observed that in the groups in which males and females received EHFAo and spilanthol, the spawning was interrupted, whereas in the groups in which only the females were treated, spawning occurred during the 21 days. Thus, in the histopathological evaluation of the gonads, it was possible to observe that the percentage of mature cells in the spermatozoa and females was significantly reduced. Only the embryo groups in which parental generation was treated with EHFAo showed lethal and teratogenic effects. On the other hand, the parental groups treated with the spilanthol presented only the lethality. Spilanthol and some metabolites showed good oral availability and important toxicological properties. Thus, it is suggested that the treatment of parental generation of zebrafish with EHFAo and spilanthol caused severe changes in the gonads and on fertility. However, on the embryo, the most striking effects in the development were recorded in the groups in which the parental generation was treated with the EHFAo, while the spilanthol influenced the lethality of the embryos.

Heliopsis longipes: anti-arthritic activity evaluated in a Freund's adjuvant-induced model in rodents

ABSTRACT This study assesses the anti-arthritic effect of the affinin-enriched (spilanthol, main alkamide) hexane extract from the roots of Heliopsis longipes (A. Gray) S.F. Blake, Asteraceae, on a Freund adjuvant-induced arthritis model in rodents. The extract was orally administered at a dose of 2, 6.6, or 20 mg/kg; a significant edema-inhibitory activity in the acute and chronic phases was observed with a dose of 2 and 20 mg/kg, respectively. The extract showed higher anti-inflammatory and anti-arthritic effects than the reference drug phenylbutazone (80 mg/kg). Moreover, the extract prevented the occurrence of secondary lesions associated to this pharmacological model.

Effects of Acmella oleracea methanolic extract and fractions on the tyrosinase enzyme

Abstract The aim of the current study is to evaluate the effect of Acmella oleracea (L.) R.K. Jansen, Asteraceae, methanolic extract, hexane (84.28% spilanthol) and dichloromethane (approximately 100% spilanthol) fractions on the tyrosinase enzyme. The dehydrated jambu extract was obtained through maceration using methanol. The extract residue was solubilized in MeOH/H2O (8:2) and subjected to liq.–liq. partition in organic solvents. Both the extraction and the partition procedures were conducted with three replicates. The analyses were performed using GC–MS, 1H and 13C NMR. The hexane fraction provided samples containing 84.28, 82.91 and 62.83% spilanthol in repetitions 1, 2 and 3, respectively. The dichloromethane fraction showed 88.55% spilanthol in repetition 1, and approximately 100% spilanthol in repetitions 2 and 3. The jambu extract as well as the hexane fraction (84.28% spilanthol) were able to activate the oxidizing activity of the tyrosinase enzyme for L-DOPA. The dichloromethane fraction (approximately 100% spilanthol) showed stronger inhibition effect on the tyrosinase enzyme in the first 10 min. The results raise the interest in study in spilanthol formulations for topical use, since it may prevent and/or slow skin hyperpigmentation or depigmentation processes. Furthermore, spilanthol may be used to control the enzymatic browning in fruits and vegetables.

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

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.