Zhang Zehua,Yan Mingqiang,Wang Meixia

Puen Biotech Shanghai Co.,Ltd.,China

Abstract Considering the present article and patents,this article means to show the study and application of Acmella Oleracea extract in cosmetic field.Now studies show that the main actives is Alkyl amide,especially Spilanthol.Spilanthol is widely recognized as the most important active ingredient.Patents about Acmella Oleracea Extract mainly focus on anti-wrinkle effects and the anti-wrinkle effects when combine with other famous ingredient.Study also point out that ethanol extract may contain more active ingredient.Give prospective views on the application of Acmella Oleracea extract.

Key words Acmella Oleracea;alkyl amide;spilanthol;anti-wrinkle

As the society is developing with science and technology progress,people’s living condition are better,now consumers care more about natural/green/healthy/safety when choose cosmetics.Functional and Green skin-care products become more and more popular.Along with the progress of extraction and analyzing technology,the effective ingredients and the working mechanisms of vegetal extracts are found and certified[1].

Vegetal extracts become more popular in cosmetic field because of the green background[1,2].As many synthetic ingredients are restricted,’Green’will be the trend of future cosmetics.The developing of natural and vegetal extracts with anti-aging effect will be trending[2].

On the background of green and natural needs,if more effective and less weakness vegetal extract may occur,the prospect will be promising.The extracts with anti-aging effects are mainly on traditional medicine or food materials with reports of effects and mechanisms.Reports may focus on the traditional application and mechanism of the materials and try to use them into skin-care field.We try to summarize the reports and articles about Acmella Oleracea Extract which is already known in the market,and try to give some prospects about the application of this vegetal extract.

1 Origin and extraction of Acmella Oleracea

Acmella Oleracea belongs to the composite family-an important family of the nine botany families.Acmella Oleracea is from South Africa at first.It is an annual herb and has appeared all over the world[3].Acmella oleracea L./ spilanthes acmella Linn[4,5]is a traditional food material with strong spicy and refreshing effect.It is famous for its strong anesthetic[3]effect and is also used to treat toothache and headache[6].In recent years,it has been gradually applied to cosmetics.

1.1 The plant and extraction part

Spilanthol is the main functional component in Acmella Oleracea.Rondanelli’s article[6]pointed out that spilanthol is the main compound isolated from Acmella Oleracea flowers.Spilanthol is also contained in the stem of the plant.

Gomes’ et al.compared the chemical composition and physicochemical properties of dry leaf powder with fresh blades of Acmella Oleracea.It was found that the parameters of total soluble solid,ash,protein,lipid of dry leaf powder were not different from those of fresh samples.So,it concludes that the physical and chemical components of Acmella Oleracea have not changed due to drying[7].

Therefore,it can be considered that the plants and leaves of Acmella Oleracea all contain the effective active components.Not only the fresh plants,but also the dried plants can be used as the extraction resource.

1.2 Extraction medium

Balieiro et al.[8]optimized the extraction method of Acmella Oleracea.They choose pure ethanol as the extraction medium to get higher spilanthol content.

1.3 Patents about the extraction

Natura cosmoticos S.A from Brazil,holds a patent “A process of preparing jambu extract,use of said extract,cosmetic compositions comprising thereof and cosmetic products comprising said cosmetic compositions”[9]which relates to a preparation process of Acmella Oleracea extract without chlorophyll and with spilanthol content 20.30% ～ 28.7%,and a cosmetic product containing the cosmetic ingredient (spilanthol content from 0.001% to 10.00%).

Narjara et al.[10]pointed out that the spilanthol level obtained from plants is very low,which is also the key point of developing products from the plant.

2 Key effective ingredients

Acmella Oleracea contains amino acids,triterpenes,stigmasterols,myricyl alcohol,and alkaloids,especially N-alkyl amides,which is a secondary metabolite[5].

Shama et al.pointed out that due to the existence of alkyl amide,Acmella Oleracea has a convergence effect,and the existence of alkyl amide makes it available for cosmetics[11].Doug Monroe pointed out that spilanthol is contained in the extracts of Acmella Oleracea flower,leaf and stem[12].

J.Boonen pointed out that in the amides of Acmella Oleracea extract,spilanthol[13]has the largest content level.The author has tested three kinds of materials,the extract of Acmella Oleracea,a gel containing Spilanthol and a gel containing the extract of Acmella Oleracea.The ethanol extract of Acmella Oleracea was purchased from supplier,the ethanol in the Acmella Oleracea extract is volatilized,then the same amount of propylene glycol 10% aqueous solution was added.Eight N-alkyl amides were identified in the extract of Acmella Oleracea.In the total amount of N-alkyl amides,88.4% was spilanthol.

Rondanelli et al.[6]pointed out when chewing the leaves and flowers of Acmella Oleracea,the lips and tongue feel tingling.This feeling is because of the presence spilanthol.A variety of compounds can be extracted from Acmella Oleracea,including spilanthol[14].Spilanthol is the main compound isolated from many parts of the plant,especially flowers.At the same time,the stem of Acmella Oleracea also contains Spilanthol.Spilanthol is an N-alkyl amide (C14H23NO) with isobutyl side chain.Like other alkali amides,it is an amphiphilic compound with polar amides and low polarity fatty acyls.It can be extracted from plants with methanol,ethanol,supercritical carbon dioxide or N-hexane.It can be purified by preparative thin layer chromatography and HPLC[6].

S.Savic et al.[5]identified the presence of 9 N-alkyl amides in the extract of Acmella Oleracea by UHPLC-DAD-ESI-MS/MS.The test results show that spilanthol and homospilanthol are the most stable N-alkyl amides in the Acmella Oleracea extract.Through the analysis of degradation outcomes,it is concluded that Spilanthol is the most stable amide in Acmella Oleracea extract.The article predicts that Acmella Oleracea extract,as an active,have huge possibility in the cosmetics field with anti-wrinkle and anti-aging effects.

3 Acmella Oleracea extract in cosmetics

3.1 Pantents about cosmetics

Narjara et al.[10]said that with regard to cosmetic patents,Natura Cosmeticos SA from Brazil,Gattefossé SAS from France,Dr.Belfer William from America have patents claiming the anti-aging effects,because spilanthol can relax facial muscles then avoid/reduce wrinkles.The Gattefossé SAS invention entitled “use of spilanthol,e.g.in the form of an Acmella oleracea extract,to make a cosmetic antiwrinkle composition” has been publishedin eight different territories.

Gattefossé SAS has a patent ‘use of an acmella oleracea extract for the botulinum toxin-like effect thereof in an anti-wrinkle cosmetic composition’[15].The patent is to develop a product that has the effect similar to botulinum toxin (inhibiting muscle contraction and reducing expression lines),and safe as well.It is found that spilanthol,especially in the form of Acmella Oleracea extract,can effectively inhibit the muscle contraction of the skin.They found Spilanthol in the form of acmella oleracea extract had better inhibiting effect on muscle contraction than spilanthol alone.The patent claims the right to produce anti-wrinkle ingredients for cosmetics in the form of pure spilanthol or acmella oleracea extract.

Belfer Cosmetics LLC has a patent[16],combines peptide and acmella oleracea extract,which reduces skin deformation by limiting the muscle contraction of facial skin.The extract can help the effect of the peptides on expression line reducing.

3.2 Skin care explore

M.Savic produced an emulsion containing 15% lipid and 1% emulsifier,while adding acmella oleracea extract then apply an in-vivo test.The TEWL,SCH and Erythema Index (EI) of the tested skin were marked.After the emulsion was used for 2 hours,silicone gel was used to cover the skin.TEWL,SCH and pH value were measured.It was found that the test parameters did not change significantly and no Erythema was observed.Therefore,it is considered that the formula has no irritation,well skin tolerance and safe to use.The volunteers accepted a two week test.The parallel and testing emulsion was applied to the periocular and perioral areas respectively.Make a silicone replica of the skin,the total area,number,length and depth of skin wrinkles were obtained by analyzing the data of the replica.The result shows that there is obvious reduction and improvement of wrinkles,suggesting that the product has a good effect of rapid improvement of expression lines,periocular and perioral wrinkles[17].

Alan F B’s article[18]studied the activation/inhibition of tyrosinase by spilanthol(from acmella oleracea)in different solvents,suggesting that it may inhibit or slow down pigmentation of the skin.

4 Prospects

In the food industry,Acmella Oleracea has been recognized by FEMA (Flavor and Extract Manufacturers Association) (2000)[19]And the European Food Safety Agency (EFSA) (2015)[20]as safe food (GRAS #3783).It has low toxicity[21,22]and wide application.As a reference for the safety of acmella oleracea in skin care products,M.Savic’s testing reports provides helpful information[17].

At present,the main opinion is that the active components of acmella oleracea are the amides,especially spilanthol.However,the spilanthol content in the extract needs to be clarified and optimized.

At present,there have been many studies on the application of acmella oleracea extract in skin care products.Studies mainly focus on the botulinum toxin like effect and relaxation of muscle contraction to reduce expression lines.Although there are patents and some results supporting its’ anti-wrinkle effect,direct action mod,effect improvement/ mechanism discussion are still needed.

In the green background,a plant extract may have multiple effects.Based on the research results in the existing literature,acmella oleracea extract shall be more and widely used in skin care products.