Chiara Barla & Joshua Barella
Introduction
Snails mucus has lots of hidden properties, many of them have been discovered even in early history and in recent years scientific researches have demonstrated that mucus-derivated drugs can be used in a large variety of therapies. For example it is used in creams to ease skin abrasions and scars, to cure respiratory diseases, heartburn and at last scientists discovered unexpected and previously unknown properties.
At the beginning of twentieth century, a new interest about gasteropodes has grown up for their possible employment in medicine and industries.
Scientists started paying attention to the ability of snails in crawling on rough surfaces without hurting themselves and being resistant to pollutants and bacteria.
In 1959 the scientist A.P. Williams analyzed the collagen taken from the body wall of the garden snail Helix Aspersa and discovered that it is composed by a large amount of mucopolysaccharides components rich in glycine, proline and glutamic acid. (The chemical composition of snail gelatin, 1960)
A recent study shows that the presence of glycine and proline is strictly linked to the disposition of hydrogen-bridge in elastin. (Proline and Glycine Control Protein Self-Organization into Elastomeric or Amyloid Fibrils, 2006)
As result, these two amino acids are used in treatments for ulcerations. (Effect of Topical Application of Glycine and Proline on Recalcitrant Leg Ulcers of Prolidase Deficiency, 1986; Tratamiento efectivo con un ungüento de glicina y prolina en un caso de úlceras recurrentes por déficit de prolidasa, 2006)
Considering the role of snail mucus in repairing ulcers and thinking about the role of human mucus to prevent or fight acidity, it has been developed Gastrokaluma syrup against stomach acidity and gastric-esophagus reflux. In recent past, people used to eat alive snails to ease heartburn: when snails reach stomach they produce mucus, contrasting acidity.
Snail mucus
J. M. Pawlicki et alii studied mucus composition distinguishing a non-adhesive trail mucus and an adhesive mucus. (The effect of molluscan glue proteins on gel mechanics, 2003)
They observed that trail mucus is composed in 95% of water, so it has a lubricant and protective function incompatible to the ability of snail to join firmly at every surfaces.
Taking adhesive mucus from snails' back they found that it is richer in specific proteins called glue proteins which have a very important role in adhesive properties.
Isolating them they demonstrate their concentration-dependent effect that helps the formation of a glue from a mucus-like secretion.
The ability of glue proteins to cross-link large ionic polymers in the gel is very important, suggesting a possible role of adhesive mucus in dermatology and other branch of medicine.
Composition
The knowledge of curative action of snail mucus is very old: Pliny the Elder (AD 23 – AD 79) wrote that snails were "a sovereign remedy to treat pain related to burns, abscesses and other wounds". (Helix and Drugs: Snails for Western Health Care From Antiquity to the Present, 2005)
In 1980, the Chilean family Bascuñan, which raised snail for French restaurant, noticed that their hands were smooth and cuts recovered rapidly without scars or infections. For that reason they started analyzing snail mucus. (Elicina)
In 2000, with the authorization of Coaniquem's ethics committee, a study protocol has been designed to evaluate Elicina cream, a product derived from snails mucus (Le proprieta' naturali della bava di lumaca: la scienza le spiega, 2012)
The extract of Helix Aspersa Muller contains:
* Alantoin or 5-Ureidohydantoin which derives from the uric acid transformation by the enzyme urycase. It is known for its desquamating action, its promotion of cell proliferation and wound healing;
* Collagen ;
* Elastin ;
* Natural antibiotics against the most commonly found bacterias in human skin infections, such as: Escherichia Coli, Staphylococcus Aureus and Pseudomona Aeruginosa;
* Glycolic acid or alfa-Hydroxyacetic acid which has an excellent capability to penetrate skin and is capable to increase collagen synthesis.
S.J. Kim et alii demonstrated that glicolic acid is able to increase collagen synthesis in vivo by functional activation of fibroblasts proliferation and by a major expression of collagen mRNA. In high concentration it has an epydermolytic action and could have side effects not to be ignored. (Increased in vivo collagen synthesis and in vitro cell proliferative effect of glycolic acid, 1998) The effect of alpha hydroxy acid is basal cell activation with an increase of epidermal thickness, of dermal fibroblast count and densely arranged type I collagen fibers in the dermis. Desquamation was seen in the upper layer of the stratum corneum along with small intercellular disjunction and intracytoplasmic vacuolization in the keratinocytes. (Histopathological and ultrastructural effects of glycolic acid on rat skin, 2006 ; Glycolic Acid Treatment Increases Type I Collagen mRNA and Hyaluronic Acid Content of Human Skin, 2001)
It is demonstrated that the association of glycolic acid and exogenous collagen (as happens in snail mucus) has synergic effects on endogenous collagen synthesis. (Interaction between bovine collagen and glycolic acid peeling: a proposal of a new protocol, 1996)
Cream for burn scars and graft
A controlled and randomized double blind clinical trial compared the effect of Elicina to a Novobase cream application in patients with burn scars and graft.
Snail extract had a better effect in decreasing pigmentation and height of scars and texture of graft. (Snail Extract Cream in burn scars and grafts, 2000)
No side effects were observed.
Pollution tester
Helix Aspersa showed a particular resistance to freezing (Effects of a freezing event during hibernation on further survival, reproduction and growth in the partially freezing tolerant land snail Helix aspersa muller (Gastropoda: helicidae), 2002) and to pollutants such as heavy metals (after digestive and dermal exposure at Cd, Cu, Ni, Pb, and Zn, they were bioaccumulated in snail tissues without showing any effect on snail mortality or growth) (Transfer of Cd, Cu, Ni, Pb, and Zn in a soil-plant-invertebrate food chain: A microcosm study, 2009) and polycyclic aromatic compounds. (Effects and uptake of polycyclic aromatic compounds in snails (Helix aspersa), 2009) For their resistance snails are used for testing soil and vegetables pollution.
Cure of respiratory diseases
In past, Greeks handed down the use of snail mucus against respiratory obstructive diseases. This practice had been investigated throughout centuries.
In 1953 Quevauviller described the benefit in using this therapy for patients with chronic bronchitis. (Helix and Drugs: Snails for Western Health Care From Antiquity to the Present, 2005)
In 1999, Pons et alii demonstrated the broncho-relaxant effect of helicidine, extracted from the snail Helix Pomatia. (The bronchorelaxant effect of helicidine, a helix pomatia extract, involves prostaglandin e2 release, 1998)
They investigated a possible relaxant effect of helicidine on guinea-pig airway smooth muscle.
Tracheal segments were dissected out and pre-contracted with histamine. Applying H. Pomatia extract, they observed an immediate dose-dependent relaxation with significant increase in PGFa release.
No significant difference was observed between tracheal segments with and without epithelium.
In the presence of the cyclooxygenase inhibitor Indomethacin, there was a near total inhibition of the relaxing effect.
They concluded that helicidine relaxes airway smooth muscles either by acting directly on tracheal smooth muscle or by activating an intermediary cell other than the epithelial cells to release some broncho-relaxant agent. The relaxation is mediated by the relaxant prostanoid prostaglandin E2.
Also in Italy is commercialized Kalumax syrup against cough.
Anesthetic
The FDA has also shown interest in snails. In the 1980s, American investigators from the University of Utah evaluated hundreds of neurotoxins derived from sea snails. These are utilized as they attack their prey or their predators and induce a neuro-muscular blockage. As consequence, a synthetic peptide derived from snail venom named Ziconotide has been studied as powerful anesthetic. This peptide is currently used in the drug Prialt. (PRIALT, ziconotide intrathecal infusion; Characterization of Confusion, An Adverse Event Associated with Intrathecal Ziconotide Infusion in Chronic Pain Patients, 2001)
Ziconotide binds to N-type calcium channels located on the primary nociceptive (A-delta and C) afferent nerves in the superficial layers of the dorsal horn in the spinal cord.
Results in animals suggest that it blocks the excitatory neurotransmitter release from the primary afferent nerve terminals.
However, because of its serious neurological side effects (cognitive impairment, hallucinations, or changes in mood or consciousness), it is only used in terminal patients who are morphine no responders.
Breast cancer prognosis
A recent study (2001) investigated a possible role of the lectin Helix Pomatia agglutinin (HPA) in the prediction of breast cancer prognosis. (Helix pomatia agglutinin lectin-binding oligosaccharides of aggressive breast cancer, 2001)
Evidences suggest that HPA is able to bind oligosaccharides associated with poor-prognosis cancer.
