Sunday, 13 July 2014

Snail Gel - Whatever next?

Over the years, women have tried all sorts of treatments and remedies, some of which are downright bizarre, in order to stay looking young. Cleopatra was famed for her fondness for milk baths and more recently, we have spa treatments ranging from vampire face masks to bird poo facials and urine therapy. I have already written about the use of another new craze bee venom in an earlier post: http://yaso-shan.blogspot.co.uk/2013/07/the-latest-beauty-fad-bee-venom.html. Other strange rituals include caviar creams (the skincare manufacturer La Prairie make a fortune from this product) and solid gold facials. You can read more about other strange beauty treatments throughout history in this interesting post: http://blog.myskin.com/insights/strange-beauty-treatments-throughout-history/. However, whether any of these treatments actually work is another matter entirely yet, and without definitive proof, it is baffling that people flock to try the latest craze in the perpetual quest to stay young-looking. A relative 'newby' to the market is snail gel and whilst it is a far cry from the glamorous world of skincare, it does not seem to faze the hardy perennials who are more than willing to try this 'elixir of youth' no matter how unappealing and insane the prospect is regarding its origin. This was all on the basis of claims that a 'miraculous' product containing anti-oxidant and regenerating ingredients profoundly delayed skin ageing. The so-called magical product was in fact an extract from snails and was advertised as a panacea to eliminate wrinkles, scars, stretch marks, burns, acne and sunspots. So was there any basis to these claims?

Background
The properties of snail slime was in fact an accidental discovery in the 1960s, when a Spanish oncologist called Rafael Abad subjected snails to radiation therapy which was used to treat cancer and observed that they released a substance totally different from the slime that they normally use to move. Abad also noticed that the snails very rapidly cured small wounds on their skin caused by the radiation. Observing the repair capacity of the snails, Abad tested the effects of this substance on human skin. Snail slime is obtained by hand in specialised farms (in Chile, for example). The snail is stimulated with a wooden stick and, feeling attacked, it secretes this special substance to defend itself. Litres of this substance are sent to laboratories in Europe (at 1,000 euros per litre!) where it is analysed, purified and filtered to obtain the cosmetic ingredient (SSF). Due to the now widespread inclusion of SSF in a variety of skincare products, the substance even has an INCI code, which means it is registered – as Snail Secretion Filtrate (SSF) – on an international list of cosmetic ingredients. (INCI = International Nomenclature of Cosmetic Ingredients). Creams and serums on the market contain 10-15% SSF. The common snail (Cryptomphalus aspersa) secretes a substance which promotes skin regeneration and minimises the effect of the free radicals responsible for premature ageing of the skin.

But is snail slime really so miraculous?

History of Use
The slime produced by terrestrial molluscs (slugs and snails) has interesting properties which have been utilised for centuries for the treatment of minor wounds and other skin disorders such as warts. Both slugs and snails secrete visco-elastic slime or mucus which acts both as an adhesive and lubricant and enables the creatures to adhere to, and glide over, all types of surfaces including rough or potentially hostile terrain. Mucus also helps to prevent the creatures from drying out, renders them fairly unattractive as food for  predators and is also thought to help prevent infection and facilitate healing.For centuries snails, and to a lesser extent slugs, have been used both as a food and as a treatment for a variety of medical conditions. In southern Italy, the common garden slug, Arion hortensis, is sometimes swallowed whole as a treatment for gastritis or stomach ulcers.  In America slugs are not thought to be swallowed live in this way, but a recipe for ‘Slug Syrup’ instructs that a jar be filled with alternating layers of slugs and sugar. After about a day, when the sugar has ‘dissolved’ the slugs, the resulting mixture is run through a sieve, after which 1/3 grain alcohol is added by volume. The resulting syrup be used for the treatment  of ulcers, bronchitis, asthma,  claiming that it is able to ‘heal these conditions when nothing else will.’

Current Medical Use
Snail and slug slime have been used sporadically as skin treatments since the time of the Ancient Greeks; Hippocrates reportedly recommended the use of crushed snails to relieve inflamed skin and some 20 years ago, the potential of snail slime was noted by Chilean snail farmers who found that skin lesions healed quickly, with no scars, when they handled snails for the French food market. This observation resulted in the production of ‘Elicina’ a Chilean snail slime-based product. In 2010 ‘Missha’ then launched Super ‘Aqua Cell Renew Snail Cream’, claiming that its 70% snail extract ‘soothes regenerates and heals skin’. However, long before this, there was evidence of its use in wound healing and skin restoration completely discordant with its cosmetic and commercial appeal as an anti-ageing product. Snail slime based products are claimed to be the new miracle face-fixer in the US where they are used to treat acne, reduce pigmentation and scarring, and combat wrinkles.

Scientific evidence which provides some credible basis for the possible use of slime in wound management may be found in report published in 2008.  The authors found that slime from Cryptomphalus aspersa (also known as Helix aspersa or the common garden snail) contains antioxidant superoxide dismutase (SOD) and Glutathione-S-Transferase Activity (GST) activities. Antioxidants are substances that may protect cells from the damage caused by unstable molecules known as free radicals or reactive oxygen species. SODs act as antioxidants and protect cellular components from being oxidized by reactive oxygen species. The authors also reported that the snail slime stimulated fibroblast proliferation, extracellular matrix assembly and the regulation of metalloproteinase activities and concluded that these effects together provided an array of molecular mechanisms underlying the secretion’s induced cellular regeneration, thereby supporting its possible use in repair of wounded tissues.  In a subsequent study it was also demonstrated that the slime increased migration and increased the expression of cell-cell and cell-substrate adhesion molecules in mammalian fibroblast and keratinocyte cells. It should be noted that some of these properties are analogous to claims made for some modern wound management materials.

Composition of Snail Slime

The composition of slime is thought to vary according to species, and it is believed that it is possible that each may also be able to vary its formulation. Mucus consists of a complex mix of proteoglycans, glycosaminoglycans, glycoprotein enzymes, hyaluronic acid, copper peptides, antimicrobial peptides, and metal ions including substantial quantities of zinc, iron, copper and manganese. The presence within the slime of these complex polymers, may have particular relevance for wound healing as many of the acdemic literature contains numerous references to the importance of these materials in the healing cascade.

Current Cosmetic Use
Each laboratory has its own formulas, but the final product usually contains the following ingredients:
  • allantoin: regenerates skin tissue and smoothes irritated skin.
  • collagen and elastin: proteins that form the 'backbone' of the skin.
  • glycolic acid: an exfoliant that eliminates dead cells and that helps other ingredients penetrate hair follicles to repair damaged tissues.
  • hyaluronic acid: A moisturising and regenerating ingredient that lubricates and softens the skin.
Scientific Studies
An study performed in 2004 showed that intensive treatment over 90 days with snail secretion filtrate (SSF) significantly reduced the number of wrinkles: fine lines by 26.7% and coarse wrinkles by 45.5%. In more recent research (December 2012) into skin samples artificially kept alive, it was found that SSF enabled cells to multiply more easily and increased collagen production. Both studies were conducted in animal models.

Studies have also shown that mucus contains peptides such as mucin which possess antibacterial activity against both gram positive and gram negative bacteria. These antimicrobial peptides not only act as natural antibiotics, but also stimulate many elements of the immune system, including barrier repair and inflammatory cell recruitment. The antibacterial factor from the body surface of the giant East African snail, Achatina fulica, for example, exhibited highly positive antibacterial activity both for the gram-positive bacteria, Bacillus subtilis and Staphylococcus aureus and for the gram-negative bacteria, Escherichia coli and Pseudomonas aeruginosa, but this activity was lost  when the material was heated at 75ยบ C for 5 min. The antibacterial factor of the snail mucus was shown to be a glycoprotein.These local anaesthetic properties (if confirmed) coupled with the antimicrobial properties and hygroscopic nature of the slime might offer significant benefits in the treatment of minor but painful wounds such as superficial burns in humans, hence its use in skincare.

Efficacy, no miracles
When purchasing snail slime-based cosmetics, be sure to ask for a brand that offers guarantees that the product’s SSF comes from snail extract obtained through stimulation. Hundreds of poor-quality imitations are offered nowadays, usually through the internet. Nonetheless, the effects of snail slime extract, even of the best quality, are not as spectacular as announced originally: it softens skin wrinkles because it hydrates them, but it does not eliminate the wrinkles entirely. It also fails to make stretch and scar marks disappear completely, although dermatologists do recommend it to patients undergoing radiotherapy, as it helps to heal wounds and burns.

Conclusions
The use of slugs and snail is not without risk, however, as these can sometimes act as vectors of disease. E.coli and other bacteria present in their faeces have a relatively long external and internal survival time. Slugs and snails can also become a vector of rat lungworm a disease caused by a parasitic worm Angiostrongylus cantonensis. Normally carried by rats, the molluscs become infected by consuming the infected faeces of carrier rats. The parasite develops further in the slugs and snails and if the infected molluscs are consumed in turn by rats the life cycle is completed.

A. cantonensis generally poses relatively little threat to humans as infections are very rare, although they can occur from consumption of undercooked or raw infected slugs and snails either by design or by consuming produce that has not been adequately washed and therefore contains a small slug or a snail. The fresh slime of snails and slugs can also have lungworms, which may be passed on to humans and other animals, although the risks are probably lower with dry slime as outside of hosts the lungworm dies quickly.

Lungworms are dangerous because once ingested they first head to the brain where they can cause meningitis type symptoms, with damage to brain tissue and swelling of the brain before the lungworm dies. Many people show no symptoms at all before the lungworm dies but others are greatly affected. In Sydney in 2011 one baby girl died due to lungworm infection and adults have had severe brain injuries after eating slugs. This small number of cases suggests that the risk of infection is possibly low, although the consequences can be disastrous.

Clearly there are some intriguing possibilities concerning the potential value of snail secretions in the treatment of wounds. These findings, together with the positive results of a simple study involving the treatment of a wart, provide some support for empirical observations made in different parts of the world which led to the use of these materials for medical purposes. Whilst it is true that in some instances these treatments also involve a degree of magic or superstitious ritual, this does not of itself mean that they have no scientific merit. Indeed, a direct parallel exists to the use of maggots, leeches, bees and bee products, all of which were used for centuries before the actual mechanisms of action were clearly defined or understood. However, the use of snail slime in cosmetics and skincare as an anti-ageing ingredient is more questionable and requires substantial clinical proof before many of the claims can be taken seriously..... well, for me at least!

References:
  1. http://www.worldwidewounds.com/2013/July/Thomas/slug-steve-thomas.html
  2. http://www.thehealthyskinblog.org/snail-slime-scam-or-panacea/
  3. http://www.cosmeticsdesign-europe.com/Formulation-Science/Scientists-develop-appetite-for-escargot-due-to-its-skin-regeneration-properties
  4. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1062150/
  5. http://www.ncbi.nlm.nih.gov/pubmed/22171745