A novel physiologically active substance.

Detailed Description of the Invention

The present invention relates to a novel physiologically active substance which is extracted from a tissue activated by internal and external stressors.

Living organisms keep each of their lives as individuals by adjusting and maintaining their physical and chemical states to and within certain stable physiological conditions corresponding to the changes in internal and external circumstances.

In order to maintain and adjust such homeostasis, the living organism always produces various substances <i>in vivo</i> and, in case of an invasion of viruses, bacteria, etc. and of a generation of tumor cells, it also produces certain substances <i>in vivo</i> which are resistant to such external and internal invasions.

However, if the above-mentioned biofunctions are unbalanced for some reason and that becomes chronic, then so-called morbidity results causing various diseases.

The ideal way of curing the disease is that the function of the organism to maintain homeostasis is activated and adjusted so that the abnormal imbalance of the disordered biofunction recovers to a normal state. It is well known that the maintenance and the normalization of the biofunction are carried out especially by various receptors on cell surfaces and the ion channels such as sodium, potassium, calcium, etc.

It is known that, upon growing older, the recovering ability of DNA against damage lowers in mammalian cells and that the production of free radicals <i>in vivo</i> promotes ageing, collagen disease and generation of cancer. Incidentally, collagen is a noncellular substance widely present in skins, blood vessels, cartilages, eye balls, kidney, etc. and, with an advance in age, a crosslinking of collageneous materials proceeds whereby their elasticity reduces and they become hard. It is well known that, in patients suffering from diabetes, an excessive crosslinking of the collageneous materials proceeds as a result of a continuing high sugar level in the blood, whereby cataracts, atherosclerosis, renal diseases, peripheral nervous disorders, etc. particularly result.

By paying attention to the function of maintaining homeostasis of living organisms which adjusts and recovers the strain in nervous, immunological and endocrine systems caused by a disorder of cell functions <i>in vivo</i> as a result of diseases and ageing, the present inventors have conducted an extensive investigation into the substances which are produced at the resisting stage of the organisms against the internal and external stresses (i.e. at the activating stage of the living tissues) and promote the natural curing ability of the organisms to participate in the normalization of the biofunctions whereby the present invention has been achieved.

As one of the mechanisms for adjusting the complicated functions <i>in vivo</i>, an enzymatic system called a kallikrein-kinin system has been known. With respect to this plasma kallikrein-kinin system, it is believed that a blood coagulation factor XII is activated due to a stimulation by lesion or invasion of the tissues <i>in vivo</i> whereby a series of the enzymatic reactions is induced. Thus, the activated blood coagulation factor XII acts on the plasma prekallikrein existing in the same plasma to convert it to a plasma kallikrein of an activated enzyme type and then the plasma kallikrein acts on the high-molecular-weight kininogen in the plasma to liberate bradykinin.

The bradykinin which is a product of the plasma kallikrein-kinin system exhibits various physiological activities such as dilation of peripheral blood vessels, acceleration of permeation of blood vessels, induction of pain, generation of inflammation, migration of leucocytes, etc. and has been known as a mediator for induction of pain, inflammation and allergic reactions. Accordingly, when an excessive liberation and production of bradykinin is inhibited, it is possible to relieve pain, inflammation, allergic syndromes, etc. and to normalize such disorders.

As mentioned above, bradykinin is liberated and produced in the reaction of the plasma kallikrein with high molecular weight kininogen and, therefore, substances which inhibit the kallikrein production in the plasma kallikrein-kinin system and prevent an excessive production of bradykinin have the possibility of being used as analgesics, antiinflammatory agents, antiallergic drugs, etc. and are highly useful as pharmaceuticals.

In accordance with the present invention, various animals or animal tissues are inoculated with virus or tumor cells as a stressor to activate the tissues and then a novel physiologically active substance is extracted from those tissues, and the present invention relates to the biofunction-adjusting and maintaining substance which exhibits an activity of inhibiting the production of plasma kallikrein and of improving the peripheral blood flow and recovers and normalizes the abnormal function of the diseased state.

An object of the present invention is to provide a physiologically active substance which is extracted from activated tissues of animals and is to offer a substance which exhibits an improving action for peripheral blood flow as well as analgesic, antiinflammatory and antiallergic actions, etc.

The substance of the present invention is a physiologically active substance which is obtained in such a manner that the activated tissues of an animal are ground down, a solvent for extraction is added, tissue residues are removed therefrom, proteins are removed, then the remainder is adsorbed with an adsorbent and the substance adsorbed therewith is eluted.

The present invention will be further illustrated as hereunder.

The animal tissues used in the present invention are cultured tissues cultured cells or inflammatory tissues of human or animal origin which are infected with virus, or chorio-allantoic membranes of embryonated eggs infected with virus. Examples of the virus used for the activation of the animal tissues as a stressor are vaccinia virus, cowpox virus, variola virus, ectromelia virus, simian pox virus and other orthopox viruses, Orf virus, paravaccinia virus, bovine nopplelike stomatitis virus and other parapoxviruses, sheep pox virus, goatpox virus, lumpy skin disease virus and other goatpox viruses, avian pox virus, hare fibroma virus and other avian pox viruses, rabbit myxoma virus, rabbit fibroma virus and other rabbit pox viruses as well as swine pox virus, Yava monkey tumor virus, Tara pox virus and other viruses belonging to the family poxvirus. As to the tumor cells as a stressor, various tumor-cultured cell strains derived from human beings and animals may be used and anything that can be inoculated to the above animals and animal tissues will do.

With respect to the animals for preparing the activated tissues, domestic animals and fowl, such as rabbits, cows, horses, sheep, goat, swine, chickens, etc. and mammals such as monkeys, rats, mice, guinea pigs, hamsters, etc. may be used and they may be suitably selected depending upon the type of the stressors and the object. With respect to the cells for the culture, any cell will do so far as the stressor used is able to grow there. Examples of such cells for the culture include various tissues (e.g. human hemocytes and placentae) and the cells of various tissues, such as kidney, skin, lung, testis, muscle, adrenal gland, thyroid gland, brain, nerve cells, hemocytes, etc. of the above-mentioned animals and embryos thereof.

Those activated tissues are aseptically collected, ground and made into an emulsified suspension by adding 1 to 5 times as much extracting solvent thereto. Examples of the extracting solvent applicable are distilled water, physiologically saline solution, weakly acidic to weakly basic buffers, etc. If necessary, stabilizers such as glycerol, antibacterial/ antiseptic agents such as phenol, inorganic salts such as sodium chloride, potassium chloride, magnesium chloride, etc. may be added thereto. At that time, the extraction can be made easier by carrying out a freezing/melting treatment, subjecting to ultrasonic waves, or adding cell membrane dissolving enzymes or surface-active agents.

The resulting milky extract is filtered or centrifuged to remove the tissue residue and then proteins are removed therefrom. Removal of the proteins can be carried out by known methods and the treatments of heating, subjecting to ultrasonic waves, adding protein denaturating agents such as acids, bases, urea, guanidine, organic solvents, surface-active agents, etc., isoolectric precipitation, salting-out, and the like. Then the proteins separated out therefrom are filtered off by means of filtration using filter paper (cellulose, nitrocellulose, etc.), glass-filter, Celite, Seitz filter, etc. as well as ultrafiltration, gel filtration, ion exchange resin, centrifugation and the like.

The resulting extracted fraction is adjusted to be acidic, preferably, to pH 3.5-5.5, by an acid such as hydrochloric acid, sulphuric acid, hydrobromic acid, etc. and adsorbed with an adsorbent. Examples of the applicable adsorbent are activated charcoal, kaolin, ion exchange resins, etc. The adsorbent is added to the extract followed by stirring or the extract is passed through a column filled with the adsorbent whereby the effective component can be adsorbed.

In eluting the substance of the present invention from the adsorbent, an extracting solvent (e.g. a basic aqueous solution, a solution in a water-miscible solvent such as alcohol or a mixed solution thereof) is added, the mixture is preferably adjusted to pH 9-12, then eluted at room temperature or by beating to some extent or with stirring and the adsorbent is removed by conventional means such as filtration, whereby elution can be achieved. Then, if necessary, means such as chromatography, ultrafiltration, dialysis using reverse osmosis filtration etc. or removal of the salt therefrom are applied whereupon the physiologically active substance of the present invention can be prepared in a purer state.

The silicon contained in the physiologically active substance of the present invention is present as water-soluble silicic acids or silicates or polymers thereof. It may be present as silicic acids such as orthosilicic acid, metasilicic acid, mesodisilicic acid, mesotrisilicic acid, mesotetrasilicic acid, etc. or alkali salts (e.g. sodium and potassium salts) thereof, in a form of monomers, or in a polymerized form. The substance of the present invention contains 1-20 micrograms/mg (preferably 1.5-15 micrograms/mg) of it when calculated as silicon.

Examples of the method for manufacturing the substance of the present invention are given below.

[Examples]

Example 1

The skin of a healthy adult rabbit was inoculated with vaccinia virus in order to activate it, then the activated skin was aseptically taken off, finely cut, water was added thereto and the mixture was ground using a homogenizer to prepare an emulsion. This was filtered with pressure, the resulting filtrate was adjusted to pH 5.0 with hydrochloric acid and heated at 100°C with a steam flow. Proteins were removed by filtration, the filtrate was adjusted to pH 9.1 with sodium hydroxide, heated at 100°C and filtered. The filtrate was adjusted to pH 4.1, stirred after adding 2% of activated charcoal and the mixture was filtered. To the filtrate was added 5.5% of activated charcoal and the mixture was stirred for two hours and filtered. The activated charcoal which was obtained from the first filtration was mixed with water, adjusted to pH 9.9 with sodium hydroxide, stirred at 6O°C for 1.5 hours and filtered. Water was added to the first quantity of activated charcoal and the second one, adjusted to pH 10.9 with sodium hydroxide, stirred at 6O°C for 1.5 hours and filtered. The filtrates were combined, neutralized with hydrochloric acid, desalted using a reverse osmotic filter membrane (molecular weight: 100) and dried <i>in vacuo</i>. The yield from 1 kg of the activated skin was 3 g. The physiologically active substance prepared as such exhibited the following properties. <ul id="ul0001" list-style="none"><li>(1) Characteristic: an amorphous and hygroscopic powder with pale yellowish brown color containing 2-10 micrograms/mg of silicon which is calculated as silicon;</li><li>(2) Solubility: it is soluble in water, methanol and ethanol and is insoluble in benzene and ether;</li><li>(3) pH; 6.0-8.3;</li><li>(4) Ultraviolet absorption: λ_max = 265-275 nm;</li><li>(5) Color reactions: amino acids (positive to the ninhydrin reaction), sugars (positive to the orcinol-iron(III) chloride-hydrochloric acid method), phosphorus (positive to the molybdenum blue method), proteins (negative to the trichloroacetic acid method) and phenols (negative to the ferric chloride method).</li></ul>

Example 2.

L cells (sarcoma cells of mice) were hypodermically transplanted to C3H mice, vaccinia virus was inoculated in the same place after ten days and, five days after that, the areas of tumor inflammation were excised. The excised tissue (100 g) was finely cut, a 70% glycerol solution buffered to pH 7.0 was added, ground down using a Waring blender and an operation of freezing/melting was repeated three times. The milky ground liquid was centrifuged at 2,000 x g for one hour, the precipitates wore removed, the pH of the supernatant fluid was adjusted to 5.0, heated at 100°C and filtered. The filtrate was adjusted to pH 9.0, heated at 100°C again and filtered to remove the insoluble matter. After cooling, the filtrate was adjusted to pH 4.5, passed through a column filled with activated charcoal and the column was washed with distilled water and eluted with N/25 aqueous ammonia. Neutralization and desalting were carried out in the same manner as in Example 1 followed by drying <i>in vacuo</i> whereupon a powdery product was obtained. The physiologically-active substance of the present invention prepared as such contained a larger amount of silicic acids and the amount contained in 1 mg of the hygroscopic powder was 5-14 micrograms calculated as silicon.

The pharmacological activity of the physiologically-active substance of the present invention is as follows.

(1) The action of inhibiting the production of plasma kallikrein.

The inhibitory action of the physiologically-active substance against the production of plasma kallikrein was measured according to a method mentioned in the literature [<i>Kiso to Rinsho</i>, vol.20. no.17, pages 399-405(1986)].

Thus, a suspension of kaolin was added to the normal human plasma diluted with a physiologically saline solution, a lima bean trypsin inhibitor was added thereto after certain period to stop the reaction of the kallikrein production and then the resulting kallikrein was determined by a synthetic substrate (D-Pro-Phe-Arg-p-nitroaniline). The substance to be tested was made copresent in the above system whereby the inhibitory action of the substance to be tested against the production of kallikrein was determined.

One example of the result is given in Table 1. The potency of the activity is given in terms of a concentration (IC₅₀) whereby the production of the plasma kallikrein was inhibited to an extent of 50%. <tables id="tabl0001" num="0001"><table frame="all"><title>Table 1</title><tgroup cols="2" colsep="1" rowsep="0"><colspec colnum="1" colname="col1" colwidth="78.75mm" /><colspec colnum="2" colname="col2" colwidth="78.75mm" /><thead valign="top"><row><entry namest="col1" nameend="col1" align="left">Substance Tested</entry><entry namest="col2" nameend="col2" align="center">IC₅₀(micrograms/ml)</entry></row></thead><tbody valign="top"><row><entry namest="col1" nameend="col1" align="left">The substance of this invention</entry><entry namest="col2" nameend="col2" align="left">35</entry></row><row><entry namest="col1" nameend="col1" align="left">Indomethacin</entry><entry namest="col2" nameend="col2" align="left">370</entry></row><row><entry namest="col1" nameend="col1" align="left">Ketoprofen</entry><entry namest="col2" nameend="col2" align="left">400</entry></row><row><entry namest="col1" nameend="col1" align="left">Ibuprofen</entry><entry namest="col2" nameend="col2" align="left">700</entry></row><row rowsep="1"><entry namest="col1" nameend="col1" align="left">Pentazocine</entry><entry namest="col2" nameend="col2" align="left">1,600</entry></row></tbody></tgroup></table></tables>

(2) The action of improving the peripheral circulation disturbance.

As an index for the action of the substance of the present invention for improving the abnormal sensation, the action of improving the peripheral blood circulation disturbance by chinoform was measured. Thus, chinoform was intraperitoneally administered to rats for 27 days with gradually increasing doses to cause a peripheral circulation disturbance, then the hind paws were dipped in water of 5°C for two minutes to give a low temperature load and the progress in the recovery of the paw temperature was subjected to a picture analysis by means of a thermography to evaluate the improving action against the peripheral circulation disturbance. The substance of the present invention was intraveously administered for a continuing seven days from the 21st day after the administration of chinoform.

An example of the results to given in Table 2. <tables id="tabl0002" num="0002"><table frame="all"><title>Table 2</title><tgroup cols="2" colsep="1" rowsep="0"><colspec colnum="1" colname="col1" colwidth="78.75mm" /><colspec colnum="2" colname="col2" colwidth="78.75mm" /><thead valign="top"><row><entry namest="col1" nameend="col1" align="center"> </entry><entry namest="col2" nameend="col2" align="center">Average Skin Temp of the Hind Paws (°C)15 Minutes after Releasing the Low Temp Load</entry></row></thead><tbody valign="top"><row><entry namest="col1" nameend="col1" align="left">Non-treated group</entry><entry namest="col2" nameend="col2" align="char" char=".">27.3 ± 0.8</entry></row><row><entry namest="col1" nameend="col1" align="left">Control group (treated with chinoform)</entry><entry namest="col2" nameend="col2" align="char" char=".">24.1 ± 0.3</entry></row></tbody></tgroup><tgroup cols="2" colsep="1" rowsep="0"><colspec colnum="1" colname="col1" colwidth="78.75mm" /><colspec colnum="2" colname="col2" colwidth="78.75mm" /><thead valign="top"><row><entry namest="col1" nameend="col1" align="center">Groups treated with the substance of the invention</entry><entry namest="col2" nameend="col2" /></row></thead><tbody valign="top"><row><entry namest="col1" nameend="col1" align="right">50 mg/kg</entry><entry namest="col2" nameend="col2" align="char" char=".">25.7 ± 0.3</entry></row><row rowsep="1"><entry namest="col1" nameend="col1" align="right">100 mg/kg</entry><entry namest="col2" nameend="col2" align="char" char=".">28.2 ± 0.7</entry></row></tbody></tgroup></table></tables>

It is clear from the result of Table 1 that the physiologically active substance of the present invention exhibits an extremely excellent inhibitory action against the production of plasma kallikrein. As mentioned already, the plasma kallikrein acts on a high-molecular-weight kininogen whereby bradykinin is liberated and produced. Said bradykinin is known as a mediator for inducing peripheral blood vessel dilation, pain, inflammation and allergic reactions. Thus, when production of the plasma kallikrein is inhibited, the liberation of bradykinin can be inhibited and, accordingly, the substance of the present invention exhibiting an excellent inhibitory action against the plasma kallikrein production is very highly useful as a pharmaceutical such as, for example, an analgesic, antiinflammatory and antiallergic drug. Further, the pharmacological activity of the physiologically-active substance of the present invention was tested in various systems both <i>in vitro</i> and <i>in vivo</i> whereupon it was found that the substance of the present invention exhibits excellent pharmacological activities such as a peripheral blood flow improving action, and antiinflamatory and antiallergic actions.

The physiologically active substance of the present invention can be made into various pharmaceutical preparations by a suitable combination with various pharmaceutical carriers or diluents by conventional means whereby solid, semisolid, liquid or aerosol preparations for oral or parenteral use are obtained in the formulation, the substance of the present invention may be used solely or together with other pharmaceutically active components.

In the case of injections, a solution or a suspension may be prepared using an aqueous or nonaqueous solvent such as distilled water for injections, physiologically saline solution. Ringer's solution, plant oil, synthetic fatty acid glycerides, higher fatty acid esters, propylene glycol, etc. followed by adjusting the pH and isotonization.

In the case of preparations for oral administration, the substance of the invention <i>per se</i> or its mixture with suitable additives such as fillers (e.g. lactose, mannitol, corn starch, crystalline cellulose, etc.) may be combined together with binders (e.g. gum arabicum, corn starch, gelatin, etc.), disintegrating agents (e.g. corn starch, potato starch, carmerose, carmerose calcium, etc.), lubricants (e.g. talc, magnesium stearate, etc.), bulking agents, moisturizers, buffers, preservatives, perfumes and the like to give tablets, diluted powders, granules or capsules. Depending upon the state of the patient and on the type of the disease, the preparation forms which are other than the above-given ones and are suitable as a therapy therefore such as suppositories, inhalating agents, aerosols, ointments, cataplasms, eye drops, etc. may be prepared.