Creative Developments (Cosmetics) Limited

Natural Ingredients 1996

 

Although a natural material may be animal, vegetable or mineral, in cosmetics it is assumed to mean ingredients of botanical origin. To be truly natural it must be extracted from the relevant part of the plant without undergoing any significant chemical change. In Europe these are defined as extractives and their physically modified derivatives such as tinctures, concretes, absolutes, essential oils, oleoresins, terpenes, terpene-free fractions, distillates, residues, etc., obtained from the parent plant. These now appear on ingredient lists as the Latin name of the parent plant according to the Linne’ system whereby the genus and species name of the plant appear but the type of extract is not defined, e.g. Prunus dulcis. In the U.S.A. cosmetic ingredients directly derived from plants that have not undergone significant chemical modification are listed by the CTFA as extracts, juices, waters, distillates, powders, oils, waxes, gels, saps, tars, gums, unsaponifiables, proteins, starches and resins. For more than twenty years these have appeared on American cosmetic ingredient lists as the common name for the plant followed by the type of preparation, e.g. Sweet Almond Oil. As a step towards harmonising the two systems the CTFA report that an acceptable combination would be to insert the Linne’ system name in parenthesis between the common plant name and the type of preparation, e.g. Sweet Almond (Prunus Amygdalus Dulcis) Oil. In this way different preparations such as meal, extract, protein, seed extract and oil are identified whereas under the EU system they all become one. Note also, as in this example, the Linneaen name adopted under the two systems is not necessarily identical!

 

Natural oils may be used for their skin feel and emolliency and ground nut shells and kernels as abrasives in skin exfoliants but many natural ingredients are used because of the marketing claims that may be made. Such claims have often been of the “according to folklore” variety but under the 6th Amendment claims for efficacy will have to be substantiated. If relying on folklore then a significant body of evidence will be required and the concentration of material used in the final product must equate to that used in folk medicine. Folklore may point the way but claims will have more substance if the supplier has performed a proper evaluation under recognised protocols to prove efficacy. Thus an extract from the Bearberry plant, Arctostaphylos uva-ursi, is known in folklore to act as a skin whitening agent. Creations Couleurs have prepared an extract of the plant and demonstrated. its action in inhibiting melanin production in human melanocytes by reducing tyrosinase activity The results show it to be more effective than either kojic acid or L-ascorbic acid and to be more effective as an antioxidant than hydroquinone. The combination of these properties and test results will support the use of the extract in skin whitening products.

 

Passionfruit (Passiflora Incarnata) Extract, Blackcurrant (Ribes Nigrum) Extract and Grapeleaf (Vitus Vinefera) Extracts are traditionally claimed to improve skin tone and elasticity. A composite mixture, AE Complex produced and evaluated by Solabia, is shown to inhibit elastase activity. Under certain circumstances such as pregnancy, exposure to UV radiation and through natural ageing processes this enzyme is responsible for breaking down elastin in the skin so inhibiting its action will improve skin tone. Citrus extracts have long been used as skin cleansing agents, their alpha hydroxy acid content is now known to be the reason that they have this traditional use. However not all traditional uses are substantiated by modern research; in a paper1 given at the 19th IFSCC Congress2 the antioxidant activity of some natural extracts were evaluated with the following results:

 

Henna (Lawsonia Inermis)                17.7 ± 0.9

Calendula (Calendulae Officinalis)         5.2 ± 0.6

Palan-Palan (Nicotiana Glauca)                 3.6 ± 0.2

Ginkgo (Ginkgo Biloba)                  2.8 ± 0.1

Hammamelis (Hammamelis Virginiana)         0.7 ± 0.1

Aloe Vera no significant antioxidant activity

Cucumber (Cucumis Sativus) no significant antioxidant activity.

The figures are expressed as the antioxidant capacity of the material which is determined by a chemiluminescence method using Luminol and an LKB Wallac1250 Luminometer and Trolox as the reference material.

 

Extracts from the roots of the South American plant Krameria triandra Ruiz have long been used by Peruvian people for the treatment of mouth and throat disorders. The plant is included in many Pharmacopoeias and is recommended for the treatment of inflammatory process of mouth and throat. This has been shown3 to be mainly due to its antibacterial activity against Gram positive bacteria and in particular against Propionibacterium acnes. Escin, the active saponin extracted from the seeds of Aesculus hippocastanum is widely used for its therapeutic effects as an anti-edema and vasoprotecting agent and recently its complex with b-sitosterol and phospholipid has been demonstrated to exert a strong topical anti-inflammatory action in the croton oil test. In a carefully conducted study3, the anti-acne effect of a formulation containing standardised extract from Krameria triandra Ruiz (0.5%), escin-b-sitosterol Phytosome (1%) and lauric acid (0.2%) were investigated. Clinical trails on twenty selected subjects showed a significant reduction of the sebum production in the cheeks and chin areas and a significant reduction in Propionibacterium acnes, Streptococcus pyogenes and Staphylococcus aureus when compared with a placebo.

 

In modern skin care the formulator and user are looking for more benefit than simple moisturising and a feel-good factor. Sun protection, free radical scavenging, anti-inflammatory and antioxidant activity are all benefits which will improve skin protection and delay the onset of visible ageing and such benefits are often conferred by natural materials. A poster presentation4 at the 19th IFSCC Congress investigated the inhibitory activity of 100 plant extracts on tyrosinase activity and DOPA auto oxidation. The results of this mammoth study showed that plant extracts such as Morus alba and Glycyrrhiza glabra exhibited inhibitory activity (>50%) against tyrosinase at a concentration of 333mg/ ml. and plant extracts including Morus alba and Bupleurum falcatum showed inhibitory activity (>50%) at 500 mg/ml against DOPA autooxidation. Many other extracts were shown to be effective and a second poster5 prepared by the same team described the antioxidative properties and free radical scavenging efficacy of 100 plant extracts, concluding that Eugenia caryophyllata, Alpinia offiicinarum, Rhus verniciflua, Curcuma longa, Rheum palmatvm and Evodia officinalis were potential sources of antioxidant, but only one plant, Cornus officinalis, showed significant free radical scavenging properties. In a study published by A&E Connock6 Coffee Oil was tested in-vivo for its sun screening properties and shown to provide a natural SPF value of approximately 3. J-J Ettiene studied the anti-inflammatory and antioxidant properties of some well known essential oils and absolutes7 and found that chamomile, rose, lavender and marjoram were effective free radical scavengers with anti-inflammatory activity. These studies are excellent examples of the supporting information that is now becoming available to cosmetic chemists. They also illustrate the basic essential of using the active material at a concentration sufficient to give the claimed effect.

 

Usage levels of natural ingredients are important if claims are made. In traditional medicine the plant extract could well be an infusion reduced to maximise concentration; using 0.50% of a 20% extract will not support a claim for effect. It is also often difficult to assess the strength of extracts as supplied; some suppliers base their claim on the weight of fresh herb used, others on dry material and others on final solids content. For the purpose of ingredient listing it is also important to know all other constituents present; it is often surprising to find a number of preservatives in an extract that also contains 25% or more propylene glycol. At least European suppliers are now providing such information but it is still difficult to convince many from the U.S.A. that it is a legal necessity.

 

The search for new sources of oils that have cosmetic application continues and although for the most part they are used as part of the oil phase to affect skin feel or add an exotic name to the label some are proving to have additional benefits. Blackcurrant (Ribes Nigrum) Oil is used in cases of dry, flaky skin and in post-sunburn products. It is known to be a rich source of the polyunsaturated fatty acid, stearidonic acid which the human body is unable to synthesise and has to obtain through ingestion. It is also known that under the stimulation of UVB radiation, cell enzymes release strongly inflammatory leukotriene B4 and prostaglandin E2. Work at Croda Chemicals8 shows however, that topical application of lipids rich in stearidonic acid reduces the release of prostaglandin E2 by 4- 50% with a corresponding reduction in inflammatory response. In searching for alternative natural sources of stearidonic acid Croda has identified Echium plantagineum, a member of the Boraginaceae family, and has found that the oil from seeds cultivated in the Northern hemisphere yield 12% stearidonic acid whilst those grown in New Zealand contain 15% compared to 2% in black currant seed oil.

 

Black (Salix Nigra ) Willow is known as a source of salicylates and salicylic acid, a b-hydroxy acid, is currently receiving much attention because of its skin exfoliating and cell renewal properties. Research by Brooks Laboratories compared the cosmetic efficacy of Willow bark Extract and the extract in liposomal form against a 10% solution of salicylic acid in butylene glycol. Both forms of the extracts were shown to be more effective against staphylococcus aureus and Propionibacterium acnes than the acid and were slightly more efficacious at promoting cell renewal while toxicity studies showed the extracts to be considerably less irritating to both eyes and skin9

 

Many of the natural ingredients described come from China, Korea and the Asean region; Alchemy International specialise in providing herbs from the Orient and currently offers 40 extracts selected for their usage according to the Chinese Materia Medica and known ethnobotanical use. East-West Herbs of Kingham, Oxon supplies herbal materials selected for their use in traditional Chinese medicine10 and Campo Research of Singapore offers an extensive range of herbal extracts and naturally derived materials. A&E Connock has extended its range of oils from Africa with Ngali (Canarium Spp) Nut Oil which is high in oleic and linoleic acids and Ootanga Oil. Ootanga oil is used by the people of Northern Namibia to add sheen and lustre to hair, to soften and smooth skin and as a baby oil. The Ootanga is a species of water melon that grows wild in arid regions of Namibia; its fatty acid profile shows 16.5% oleic acid and 63% linoleic with 45ppm of b-carotene. Australia is also a rich source of essential oils and botanical materials; Blue Cypress (Callitrus intratropica) Oil has been used by the Aboriginal people of Australia to help soothe and heal skin irritations and Blue Cypress Holdings are able to offer a full safety toxicological profile and support its use as a natural antiseptic while Medi Herb, also of Australia, supplies a number of herbal extracts with full supporting documentation. Finally, and partially under the stimulus of the 6th Amendment and its demand for proof of efficacy, natural materials in Western cosmetics are being increasingly selected for their ethnobotanical usefulness rather than for the attractive appearance of the plant on the label; I hope this article helps fellow formulators find the evidence

 

1.      Evaluation of the potential use of natural materials as free radical scavengers in anti age cosmetics. Diego G. Fano. 19th IFSCC Congress, Sydney, Australia 1996

 

2.      19th IFSCC Congress, Sydney, Australia 1996

 

3.      Natural products in the management of acne. Bombardelli E et al 19th IFSCC Congress, Sydney, Australia 1996

 

4.      Biological screening of 100 plant extracts for cosmetic use (II) Inhibitory activities of tyrosinase and DOPA auto oxidation. Chang Hyun Seok l et al, 19th IFSCC Congress, Sydney, Australia 1996

 

5.      Biological screening of 100 plant extracts for cosmetic use (1) Anti oxidative activity and free radical scavenging activity Jeong Ha et al. 19th IFSCC Congress, Sydney, Australia 1996

 

6.      To evaluate the efficacy of Coffee Oil as a Sunscreen Product. A&E Connock Ltd.

 

7.      Anti-inflammatory Activity of some Classical Essential Oils through their Antioxidant and Anti-elsatase Properties. Etienne Jean-Jacques; 19th IFSCC Congress, Sydney, Australia 1996

 

8.      Moderation of Ultraviolet Induced Inflammation in skin by (n-3) and (n-6) Lipids; Coupland K., Packer C.E., 19th IFSCC Congress, Sydney, Australia 1996

 

9.      An Extract of Salix nigra: an Efficacious, Safe Remedy for Problem Skin. S. Bennet, The Active Ingredients Conference, Paris, 13-14 November.

 

10.  Applications of Traditional Chinese Medicine in Cosmetics and Toiletries, Dr Shouming Zhong,. The Active Ingredients Conference, Paris, 13-14 November.