Acmella oleracea
Acmella oleracea is a species of flowering herb in the family Asteraceae. Common names include toothache plant, paracress, Sichuan buttons, buzz buttons, tingflowers and electric daisy. Its native distribution is unclear, but it is likely derived from a Brazilian Acmella species. It is grown as an ornamental and attracts fireflies when in bloom. It is used as a medicinal remedy in various parts of the world. A small, erect plant, it grows quickly and bears gold and red inflorescences. It is frost-sensitive but perennial in warmer climates.
Its specific epithet oleracea means "vegetable/herbal" in Latin and is a form of .
Culinary uses
For culinary purposes, small amounts of shredded fresh leaves are said to add a unique flavour to salads. Cooked leaves lose their strong flavour and may be used as leafy greens. Both fresh and cooked leaves are used in dishes such as stews in northern Brazil, especially in the state of Pará. They are combined with chilis and garlic to add flavor and vitamins to other foods.The flower bud has a grassy taste followed by a strong tingling or numbing sensation and often excessive salivation, with a cooling sensation in the throat. The buds are known as "buzz buttons", "Sichuan buttons", "sansho buttons", and "electric buttons". In India, they are used as flavoring in chewing tobacco.
A concentrated extract of the plant, sometimes called jambu oil or jambu extract, is used as a flavoring agent in foods, chewing gum, and chewing tobacco. The oil is traditionally extracted from all part of the plant. EFSA and JECFA reviewed a feeding study in rats conducted by Moore et al. and both authorities recognized that the no adverse effect level for spilanthol was 572 mg/kg b.w./day, yielding a safe dose of spilanthol of 1.9 mg/kg b.w./day, or 133.5 mg/70-kg-male/day, 111 mg/58-kg-female/day, or 38 mg/20-kg-child/day.
Jambu extract as a flavoring agent is described as having a citrus, herbal, tropical or musty odor, and its taste can be described as pungent, cooling, tingling, numbing, or effervescent. Thus, as described, the flavor use of jambu extract includes the ability induce a mouth-watering sensation and the ability to promote the production of saliva. Spilanthol, the major constituent of jambu extract, is responsible for the perception of a mouth-watering flavor sensation, as well as the ability to promote salivation as a sialogogue, perhaps through its astringent action or its pungent taste.
Jambu extract can also be used in cosmetics and shampoos.
Cultivation
This plant prefers well-drained, black soil. If starting outdoors, the seeds should not be exposed to cold weather, so start after last frost. Seeds need direct sunlight to germinate, so should not be buried.Medicinal uses
A decoction or infusion of the leaves and flowers is a traditional remedy for stammering, toothache, and stomatitis.An extract of the plant has been tested against various yeasts and bacteria and was essentially inactive. It has been shown to have a strong diuretic action in rats.
As a bush plant used for treating toothache, the analgesic effect of the Spilanthes plant has been attributed to the presence of constituents containing an N-isobutylamide moiety, such as spilanthol, a substance that has been found to be an effective sialogogue, an agent that promotes salivation. Spilanthol is absorbed trans-dermally and through the buccal mucosa. Spilanthol may activate TRPA1, a specific transient receptor potential ion channel in the oral cavity. In addition to capsaicin, allyl isothiocyanate, and cinnamaldehyde, spilanthol is also reported to affect the catecholamine nerve pathways present in the oral cavity that promote the production of saliva, which is responsible for its ability to induce a mouth-watering sensation when used as a flavor.
Since 2000, there are several medicinal activities reported for Acmella oleracea:
| Pharmacological activity | Species | Part used | Type of extract | Models used |
| Antimalarial, larvicidal | S. acmella Murr. | Flowers | Ethanol | Anopheles, Aedes, Culex larvae |
| Antinociception, antihyperalgesic | S. acmella | Flowers | CWE | Formalin test of nociception and carrageenan-induced thermal hyperalgesia in rats |
| Antinociception, antihyperalgesic | Acmella uliginosa, Cass | Flowers | Methanol | Chemicals and thermal models of nociception in mice |
| Immunomodulatory | S. acmella Murr. | Leaves | Ethanol | Macrophage function in mice |
| Immunomodulatory | S. acmella | Leaves | Ethanol | Neutrophil adhesion test in rat |
| Antiviral | S. americana | Flowers | NA | NA |
| Insecticidal | S. calva | Leaves and flowers | Petroleum ether, ethyl acetate and methanol | Helopeltis theivora |
| Antimalarial, larvicidal | S. acmella, S. calva, S. paniculata | Flowers | Hexane | A. stephensi, A. culicifacies, C. quinquefasciatus larvae |
| Antioxidant | S. acmella | Leaves, stems | Methanol | DPPH, SOD assay |
| Antihepatoxic | S. ciliata | Whole plant | Ethanol | Paracetamol-induced hepatic damage in rats |
| Antimicrobial | S. calva | Roots | Methanol | Oral microflora: Streptococcus mutans, Lactobacillus acidophilus and Candida albicans |
| Anti-inflammatory | S. acmella | Aerial parts | Ethanol | Lipopolysaccharide-activated murine macrophage model |
| Antimalarial, larvicidal | S. mauritiana | Aerial parts | Methanol extract | Aedes aegypti larvae |
| Insecticidal | S. acmella Murr. | Leaves and flowers | Aqueous | Chilo partellus |
| Diuretic | S. acmella | Flowers | CWE | Hydrated rats |
| Antioxidant | S. acmella Murr. | Aerial parts | Chloroform, hexane, ethyl actate, methanol | 2,2-Diphenyl-1-picrylhydrazyl and superoxide dismutase assay |
| Antimicrobial | S. americana | Whole plant | Aqueous, ethanol and hexane | Staphylococcus aureus, Streptococcus hemolytic, Bacillus cereus, Pseudomonas aeruginosa and Escherichia coli |
| Antipyretic | S. acmella Murr. | NA | Aqueous | Aspirin-treated rats |
| Diuretic | S. acmella | Leaves | Petroleum ether, chloroform and ethanol | Hydrated Wistar albino rats |
| Antimicrobial | S. paniculata | Leaves | NA | Bacillus subtilis, Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, Pseudomonas aeruginosa, Candida albicans and Microsporum gypseum |
| Antimicrobial | S. mauritiana | Roots and flowers | NA | Staphylococcus, Enterococcus, Pseudomonas, Escherichia and Klebsiella, Salmonella |
| Antimicrobial | S. mauritiana | Roots and flowers | NA | Candida species and Aspergillus species |
| Antimicrobial | S. acmella Linn. | Flower heads | Petroleum ether | Fusarium oxysporium, F. moniliformis, Aspergillus Niger and A. paraciticus |
| Local anaesthetic | S. acmella Murr. | NA | Aqueous | Xylocaine-induced guinea pig and frog |
| Antimalarial, larvicidal | S. mauritiana | Leaves | Crude powder | A. gambiae, Culex larvae |
| Anti-inflammatory | S. acmella | Aerial parts | Aqueous | Carragenan-induced paw edema in rats |
| Aphrodisiac | S. acmella L. Murr. | Flowers | Ethanol | Nitric oxide release in human corpus cavernosum cell line and penile erection in rats |
| Insecticidal | S. acmella | NA | NA | Periplaneta Americana |
| HIV-1 protease inhibitor | S. acmella L. | Whole plant | Chloroform, methanol and water | In vitro HIV-1 protease solution assay method |
| Analgesic | S. acmella | Aerial parts | Aqueous | Acetic acid-induced writhing response in albino mice |
| Pancreatic lipase-inhibitory | S. acmella | Flowers | Ethanol | In vitro test |
| Vasorelaxant | S. acmella Murr. | Aerial parts | Chloroform, hexane, ethyl acetate, methanol | Phenethylephrine-induced rat |
| Antimutagenic | S. calva | NA | Chloroform | Ames Salmonella/microsome assay |
| Convulsant | S. acmella | Whole plant | Hexane | Electroencephalograph response of rats |