Zeolites are naturally formed minerals, arising from the combined action of violent rain and intense volcanic activity from approximately 250,000 years ago. The water imprisoned therein, reaching a very high temperature (120 °C) transform the minerals into porous rock made up of bubbles and channels. Zeolites are from a family of minerals comprised of 52 different chemically defined mineral types: hydrated aluminium silicates of Ca, Na and K,and structurally, constituent with feldspars, feldspathoids and silica minerals in the class of tectosilicates. Mordant and Clinoptilolite are geologically young zeolites and possess different properties from the zeolites of an earlier formation (2 million years). Even if of a similar composition, the clay minerals (kaolinite, illite, montmorillonite and bentonite) and sepiolite structurally belong to the class of the phyllosilicates and as such, cannot be considered zeolites, moreover not possessing the same technological properties (1).
Its capacity for ion2 exchange in particular enables its use in many industries:
- Industry: as a catalyst and absorbent
- Construction: as thermal and acoustic insulation
- Water purification: to remove ammonia and heavy metals
- Agriculture: as a fertiliser
- Livestock Farming: as absorbent in stalls and stables
- Food processing: food additives
- Medical Instrumentation: filtration systems for anaesthesia and dialysis machines and as contrast media for diagnostic imaging
- Cosmetics Industry: used to make deodorants and anti-mycoses
- Medicine: the administration of zeolites is associated with beneficial phenomena in the digestive tract and the stimulation of the immune system.
In the appendices a detailed chart of the chemical-physical properties of this category of minerals is provided (Appendix 1).
Due to its particular structural and replacement properties, clinoptilolite, the crystals of which have a lamellar structure, has over the years proved to be most suitable for use both in human and veterinary medicine.
In Japan, zeolites have been approved as food additives since 1996. 39 patents relative to the application of zeolites in human beings have been registered all over the world since 1986.
Owing to their specific chemical-physical properties zeolites have taken on notable significance in animal feed. Their effects are primarily linked to the regulation of the digestive tract function. In particular they perform the work of:
Protection of the intestinal mucosa ( 3 )Adding zeolites brings about the formation of a protective barrier on the surface of the intestinal mucosa by way of its interaction with the parietal mucus produced by the organism.
Absorption of excess water( 4, 5, 6 )Their particular spatial conformation and extreme porosity enable them to absorb large quantities of water contributing to the formation of more solid and well shaped feces whilst inducing an important anti-diarrhoeic effect.
Absorption of toxic substances ( 6, 7, 8, 9 )Due to their ionic exchange properties, given the mineral's negative charge and its relative capacity for physical absorption zeolites are capable of absorbing toxic substances such as bacterial toxins, mycotoxins, ammonia, biliary acids, etc.
Absorption of faecal odours ( 7, 10, 11 )Still due to their capacity to bind with ammonia and other volatile substances zeolites are useful for reducing foul faecal odours.
In addition to this, some important experimental effects noted are:
- Increase of the growth index ( 12, 13, 14 )
- Increase of animal production ( 15, 16 )
- Increased absorption of Ca ( 17, 18, 19, 20, 21, 22 )
- Erythropoietic and immune system stimulation effect ( 6, 23, 24, 25, 26 )
- Anti-carcinogenic effect ( 26, 27, 28, 29, 30, 31 )
In domestic animals, at the moment, use of zeolites is mainly linked to their absorption capacity, which, working in the intestinal tract, provide an effective anti-diarrhoea effect as well as reduction of faecal odour, using the substance as is or mixed in the feed or as a supplement.
Generally what is meant by activation is the application of a chemical, chemical-physical or physical procedure, to a substance so that it may have a more effective action. In the case of particular solids characterised by the ability to bind toxic substances onto their surfaces such as carbon, there is an attempt to increase porosity and surface area through the reduction of the particle size. This enables a larger number of channels capable of binding toxic substances to be made available. The result is the increase of the number of particles with reduced size, an increase in their surface area and a structural activation enabling these to more quickly and more stably bind toxins, radicals and metals. Indeed, starting from a dimension of approximately 3 m2/g, after activation a size of 1000 m2/g is achieved. Products composed of activated zeolite clinoptilolite have been classified by the EU (code GMDN) as: “substances for oral use suitable for absorption/chelation and removal of harmful and toxic substances from the gastrointestinal tract (e.g. heavy metals, nitrosamines, ammonia, mycotoxins, cations (radioactive), pesticides) reducing their absorption by the organism. These may also act as antioxidants capturing free radicals and reducing the formation of ROS (reactive oxygen species).
Applications in medicine
Chelator of heavy metals
Activated Clinoptilolite is the only inorganic substance, characterised by a notable capacity for total exchange (0.64 – 0.98 mol/Kg), capable of releasing free cations (Na+, K+, Ca2+, Mg2+) and bind heavy metals, ammonia ions, radioisotopes or other cations (Cd2+, NH4+, Fe2+, Pb2+, Cu2+, Cs+, Sr2+), in their place, for which it manifests great selectivity. The advantage of activated clinoptilolite comes from the insolubility of the particles that move through the intestine unaltered and absorb the metals expelling them together with the faeces, without interfering with any physiological intestinal function. In addition this mechanism enables the existing balance between the intestine and the rest of the organism with consequent drawing of the metals to the intestinal lumen from the rest of the organism therefore bringing about systemic detoxification. One of the applications of activated clinoptilolite in human medicine has been in fact in the treatment of subjects exposed to the radiation from Chernobyl stricken with radioactive strontium and caesium with significant results.
Within the scope of cationic exchange activity of activated clinoptilolite, particularly significant is that relative to ammonia ions, making the clinoptilolite particularly useful for the reduction of levels of ammonia in the blood. Hyperammonaemia arising from an enzyme deficiency in the urea cycle or by liver damage causes dysfunctions of varying nature both in human and veterinary medicine. For this latter, in particular, typical pathological manifestations of renal or liver insufficiency take on notable significance (Changes in the CNS, gastric ulcers, stomatitis, kidney stones, etc.), which make up one of the most frequent occurrences in clinical visits. The therapy for hyperammonaemia includes a diet with reduced protein intake yet with values that do not damage muscle function, elimination of ammonia from the intestine using non-absorbable disaccharides (lactulose) or the use of antibiotics for the reduction of ammonia production in the intestine whilst experimentation with substances capable of stimulating hepatic urea synthesis or glutamate synthesis in the muscles is being carried out (34). The possibility of using clinoptilolite in hyperammonaemia therapy has therefore become particularly significant, confirmed by its demonstrated capacity to drastically reduce the quantity of ammonia in swine intestine. In human medicine, confirmation of its action is given by research that has showed clear improvement of lucidity and cognitive capabilities in all subjects treated but in particular in those affected by cerebral pathologies such as Alzheimer's or Parkinson's diseases.
Activated clinoptilolite's ability to normally regenerate function in several organs has proven to be particularly significant even on treatment of minor skin lesions, bed sores, reddening of the skin, acne and psoriasis with very interesting results being the subject of much currently on going research. Its capacity for absorption has often proven to be useful during cutaneous inflammation or as an aid to the disinfectant action of other substances (Chlorhexidine) in the treatment of infections of the skin and mucosa. In particular the effect of ionic exchange and its special properties make it a valid aid in the hygiene of cat and dog coats, absorbing humidity and toxins, preventing foul odours and making their fur dry and glossy.
Effects on faeces quality (conformation and volume)
Many scientific studies have shown that, thanks to Clinoptilolite's high water absorption capacity, due to the large exchange surface and high porosity of the mineral, faeces excreted by animals with clinoptilolite administered in their feed, showed better form, lower volume and greater consistency. Recent studies have shown the efficacy of these effects on the dog as well, with a statistically significant difference in the subjects that were administered clinoptilolite (both together with and far from meals) compared to the control group.
Nevertheless, the results of these studies indicate that clinoptilolite is a valid and effective aid in case of pathologies (uncontainable diarrhoea, flatulence, soft stools) improved quality faeces was a result that was found in all subjects tested, whether ill or healthy. This makes adding clinoptilolite to the diet a good suggestion, which may be recommended for the normal feeding of dogs aimed at generally improving the quality of their faeces and the dog's general well being.
Effects on faeces quality (odour)
In domestic species such as dogs or cats, where there is a close living relationship with human beings, at times taking the form of cohabitation of the same spaces, qualitative improvement of the faeces is necessarily to be valorised not just in terms of volume and conformation but also from the point of view of the smell. Many studies have demonstrated that clinoptilolite's capacity to bind the ammonia and other volatile substances in animal faeces makes this mineral extremely effective in the reduction of foul faecal odour.
No effect on the digestibility of the feed
Scientific studies performed on groups of dogs have shown that, at recommended dosages (2.5%), clinoptilolite does not interfere in any manner whatsoever with the digestibility of the feed, maintaining it constant compared to the control group. No statistically significant difference in the digestibility of the feed was indicated even in larger doses (5%) testifying to the ease of handling and the safety of this substance.
For dogs, the capacity of clinoptilolite to absorb water in the intestinal lumen, thus ensuring dryer, more solid better shaped faeces without side effects was demonstrated at a dosage of from 2.5% to 5% of added product to the feed. Based on this data an addition of 2.5% is the recommended initial dosage for healthy subjects, with the possibility of increasing the dosage up to double (5%) for more results in case of more or less severe cases of diarrhoea. Given, in addition, the undeniable difficulty in evaluating, with each administration, the dosage of clinoptilolite based on the quantity of feed, in a subsequent study, a valid empirical dosage method was established: set by way of an estimate of the feed requirements for an average dog, based on its weight and its relative nutritional needs.