Konjac Ceramide, emerging in recent years, is the active ingredient of a kind of functional food and cosmetics.It has the effect of immunity enhancement, cancer prevention and anticancer, especially its highly effective moisturizing special features makes the Konjac Ceramide likely become a main ingredient of skin-care product in the future.The clinical studies showed that the content of ceramide in body decreased with the increasement of age,especially the face and hands.We can significantly delay skin aging and maintain youthful vitality by adding konjac ceramide frequently.As people become more aware of konjac ceramide, its applied research has expanded from skin-care products, shampoo products and toiletries to physiologically functional foods and pharmaceuticals of potential application value.
1 Introduction of ceramide
Ceramide is a kind of sphingolipid composed of a sphingosine long chain base and a fatty acid.In 1844, German doctors Thudichum found that there was sphinganine in the human brain, and later they also found its distribution in animals, plants and some microorganisms.In 1906, Winterstein reported the presence of galactose ceramide in wheat and studied the presenceof glycolipids in plants.
The abundant ceramide was extracted mainly from the animal brain,such as bovine brain.But since the “mad cow disease” occured,animal derived ceramide products have been replaced by the plant ceramide.Plant ceramide mainly exists in soybeans,rice, wheat and etc,but the content of which is quite low,for example:the content of ceramide in rice bran and wheat is merely 0.01%~0.02%.However,according to the latest report,the China Biostract phytochem company has extracted ceramide from konjak successfully,and the content is 0.15%~0.2%,which is about ten times than the former.
2 Structure of ceramide
The structure of ceramide molecular has two long chain alkyl groups, one amide group and two hydroxyl groups,these groups render the ceramide molecules hydrophilic and hydrophobic,this nature is of great significance on its moisturizing function in the culticle of the epidermis and so on.
Ceramide is composed of long-chain sphingosine covalently bound by amide bond fatty acids,the carbon chain length,saturation and hydroxyl number of sphingosine and fatty acid can change.Fatty acids are classified as non-hydroxyfatty acids and hydroxyfatty acids based on whether they contain hydroxyl groups in the carbon chain.Sphingosine has three structures,the sphingosine containing an unsaturated double bond is called sphingosine,the saturated sphingosine is called as dihydrosphingosine,the one contains three hydroxy sphingosine is called phytosphingosine.
3 Functions of ceramide
3.1 Effects on skin
3.1.1 Barrier function
Grubauer et al reported that the skin of male hairless mice aged 1 to 3 months were treated with organic solvents such as acetone to study the relationship between skin barrier function and skin lipid,and the result showed that the skin barrier function decreased with the reduction of the skin lipid.Holleran et al used infiltration [3H]H2O methods to study the relationship between the function of the epidermal barrier and the synthesis of spingolipids,and the result showed that when the hairless mouse skin barrier dysfunctioned caused by acetone treatment of skin,the synthesis of sphingolipids increased,the synthesis of splhingolipids reached 170% after acetone treatment for 5~7h;After 24 hours,the skin barrier function and the synthesis of sphingolipids recovered to normal.Therefore,the ceramide plays a vital role in maintaining skin barrier function.
3.2.2 Adhesion function
Ceramide binds to cell surface proteins via an ester bond can adhesive cells,this interaction is called “lipid-cell protein” wrap.Smith et al has reported that keratinocyte adhesion intensity can be judged by measuring the content of the ceramide in the epidermal cuticle,the decrease of ceramide content in the epidermal cuticle can reduce the keratinocyte adhesion,causing the skin dry、scraping、appearing scales.Pawlings et al studied the desquamation mechanism of dry skin,and the result showed that the main reason of dry skin is the reduction of ceramide content in epidermal cuticle,the content of ceramide is directly related to the degree of dryness of the skin.The use of phthalazin can significantly enhance keratinocyte adhesive force,improve the degree of dry skin,reduce the phenomenon of skin desquamation.
3.1.3 Moisturizing function
Skin moisture content takes up 18%~20% of body weight,skin moisturizing and elasticity are closely related to the moisture contained in epidermis.Excessive loss of moisture in the skin can cause skin dry or even chapped.Imokawa et al used organic solvents to remove cuticle lipid, found that the skin continued chapped(>4days),appeared scaly and the skin conductivity decreased significantly.The extracted epidermal cuticle lipids component was performed the topical skin test under the same condition to discuss which lipid component has what effect on skin moisture recovery.The result showed that the topical application of ceramide can lead the skin electrical conductivity increase significantly,followed by cholesterol,whereas the effect of free fatty acid and cholesteryl ester is not obvious.Ceramides have a strong ability to associate water molecules and maintain the skin moisture by forming network structures in the cuticle.
Therefore, ceramide has the function of maintaining the skin moisture.
3.1.4 Anti-aging function
In the aging process of the skin, the lipid synthesis decreases, the ceramide content in cuticle decreased.The characteristic features of skin aging are:(1)The skin becomes dry, scaling, rough and tarnished;(2)Skin cuticle becomes thin,wrinkles increase,elasticity decreased.The use of ceramide can increase the content of ceramide in epidermal cuticle,improve the condition of skin becoming dry,scaling,rough,etc.Meanwhile,ceramide can increase the thickness of epidermal cuticle,improve the water-holding capacity of skin,reduce wrinkles,enhance skin elasticity,delay skin aging process.
3.2 Ceramide biological function
3.2.1 Participate in cell function
Ceramide exists in the tissue cell membrane of animals and plants,its molecules expose monosaccharides or oligosaccharide residues to the extracellular space,it participates in the glycolipid head group reaction with other cells, antibodies, bacterial toxins, viral envelope proteins.Therefore, ceramide plays a very important role in cell adhesion, regulation of cellular immunity, determination of blood type and as a tumor antigen.Sphingosine directly involves in cell recognition through GSL-GSL interaction, GSL-lectin interaction.Neurophagosides, such as gangliosides(GM3), regulate the function of integrin receptors. In the process of transmembrane signaling, some specific gangliosides directly regulate the activity of receptor, tyrosine kinase and protein kinase C(PKC).Ceramides act as membrane antigens of some tumors and also act as viruses, bacteria and their toxin receptors. They are related cell-cell, cell-microbe, cell-binding protein interaction regulators.
3.2.2 Regulates cell growth variation function
Treatment of HL-60 leukemia cells with C2-ceramide or other water-soluble derivatives can induce these cell variations.Exogenous ceramide has the same effect on HL-60 cells as TNFα, 1,2 dihydroxy VD3, and γ-interferon. Ceramide and homologues have a special function of anti HL-60 cell proliferation,and they have activity of anti-other-leukemia cells and malignant cells in tissue culture . Ceramide can regulate growth and variation of nerve cells.
3.2.3 Induce cell apoptosis
Ceramides are intracellular cytotoxins modulators.In bone marrow and lymphocytes, ceramide derivatives cause early special interchromosome DNA fragmentation, which is an extrinsic feature of apoptosis.Ceramide can regulate the apoptosis of TNFα cells and participate in other processes of apoptotic cells.Transcription factor AP-1 is the key to apoptosis of HL-60 cells. Ceramide regulates signal transcription by activating AP-1 and induces cell apoptosis.
3.2.4 The role of inflammation
Ceramide regulates the secretion of PGE2 and enhances the secretion of IL-2 in lymphocytes. In addition, ceramide regulates the action of TNFα, indicating that it can modulate the immune function and inflammatory response.
3.3 Pharmacological function
3.3.1 Anti-tumor effect
Ceramide is closely related to the tumor.Ceramide trisaccharide found in many tissues has been identified as P-bloodtype PK antigen and is cell-surface receptor.It is associated with lymphoma, human teratoma, human embryonal tumor and other types of tumor cells.It is also closely related to Fabry’s disease,this kind of patient lacks α-D lactase.GB3 isoform is associated with breast cancer in rats.
3.3.2 Anti-virus effect
Ceramide isolated from green algae has in vivo and in vitro anti-EMCvirus effects,the anti-virus concentration in vitro is 1.6 μg/well;Each mouse was administered 0.5mg and administered 3 times, which can play a 50% protective effect.
3.3.3 Anti-liver-toxicity effect
Two ceramides were isolated from the wolfberries,they can significantly block the release of GPT and SDH in primary cultured rats liver cells from CCl4 toxicity,they also have the effect of anti-liver-toxicity induced by CCl4.The ceramide isolated from the northeast star Arisaema amurense is of high anti-liver-toxicity as well as.
3.3.4 Other effects
The ceramide obtained from sponges has the effect of inhibiting histidine decarboxylase,in addition,it has the effect of reducing pressure in anesthetized rats. Soyacerebroside II is the ceramide isolated from soybean,it was used to measure the activity of ion transport and ion blocking by adapting the new liquid membrane instrument W-08,and the human red cell membrane was used to test its ionic permeability.These tests showed that Soyacerebroside II has Ca2+ ion carrier activity.In addition, the antibacterial and anti-inflammatory ceramide was isolated from great ferns and algae.
4 Ceramide application
Ceramide is naturally present in the mesenchymal intercellular mass and plays a key role in the physiological function of the stratum corneum.It keeps the skin smooth and delicate, prevents the skin from drying out due to water loss, and contains antioxidant functions.Meanwhile, ceramide is involved in many physiological and pathological processes of cell differentiation. Ceramide is widely used in medicine, food and cosmetic industry as physiologic active substances and Interfacial active agent.
4.1 Application in food industry
Many health food products have been developed with some physiological functions of ceramide. Functions include these:inhibiting the rise of blood pressure, activating immunity, inhibiting lipase activity, inhibiting the proliferation of cancer cells and so on.Plant ceramide products have also been commercialized to markets since 1998.So far, its products mainly include functional drinks, tablets and other nutritional supplements and health food, but actually there are not many effective products.
It was reported that in the trial production including ceramide flavor jelly,each product adds ceramide in accordance with daily recommended intake to produce several kinds of jelly products,which has received rave reviews in the product tasting sessions held in the industry, some flavors and scents of ceramides are entirely appropriate.It was also reported that every loaf of trial-produced bread added daily recommended intake ceramide, the flavor and manufacturing of bread did not appear any problems,after the bread was baked on 160 degrees for about 15 minutes,the confirmed amount of ceramide residue was more than 80%.In addition, there were no problems in the study of the trial-production of such foods as ceramide yogurt, casserole confectionery, salad dressing and etc.Therefore, a series of health food products can be developed according to the physiological functions of ceramide, such as soft capsules, enhanced tablets and so on.
4.2 Application in cosmetic industry
Using the live skin essence cosmetics that contain ceramide, can strengthen anti-aging function of skin, make skin stay elastic, smooth and meticulous, and reduce facial wrinkles formation. Ceramide is an effective moisturizer that is easily absorbed by the skin and can promote the penetration of other nutrients.In particular,the moisturizing efficiency of elderly skin can reach 80%.Some foreign famous cosmetics company has been launching new senior cosmetics containing ceramide, such as skin-care products containing ceramide, hair-care products, moisturizing lipstick, lip gloss, powdery cake, eye shadow and soap, etc.
4.3 Application in medical industry
Ceramide plays an important messenger role in the biological effects of various cytokines, vitamins D3,Fas and CD28 ligands, and its role in mediated cell apoptosis is increasingly concerned.Meanwhile, ceramide is involved in many physiological and pathological processes of cell differentiation.Ceramide can induce apoptosis in the process of formation of cell culture in epidermis.Ceramide is the second recognized messenger, which is a bilayer phospholipid decomposition product of biofilm. Ceramide plays a wide and important role in the process of cell growth, proliferation, differentiation, apoptosis and injury.
