AU704517B2

AU704517B2 - Anti-piroplasmotic agent

Info

Publication number: AU704517B2
Application number: AU63699/96A
Authority: AU
Inventors: Ivan Havlik; Yutaro Kaneko; Tohru Mimura; G. E. Swan; J. H. Taylor
Original assignee: Ajinomoto Co Inc
Current assignee: Ajinomoto Co Inc
Priority date: 1995-07-13
Filing date: 1996-07-12
Publication date: 1999-04-22
Anticipated expiration: 2016-07-12
Also published as: BR9609606A; NZ312211A; AU6369996A; WO1997003095A1; ZA965962B

Description

SPECIFICATION

Anti-piroplasmotic Agent Detailed Description of the Invention Field of the Invention This invention relates to an anti-piroplasmotic agent for use in human or mammals other than human, which contains a sulfated polysaccharide as its active ingredient.

Prior Art Piroplasmosis is an infectious disease caused by Piroplasmida parasites carried by ticks, which is one of the important diseases in the field of veterinary science, because it broadly spreads in cattle, horses, dogs, cats, sheep, pigs, camels, water buffaloes, reindeer and the like domestic and wild animals. Cases of this disease have recently been reported even in human caused by Piroplasmida parasites through rodents and cattle.

The infected Piroplasmida parasites live upon erythrocytes or lymphocytes and cause strong hemolytic anemia in the host.

Mortality rate of this disease is 30 to Though trypan blue, diminazene, aminoquinoline and the like are known as its therapedtic drugs, their doses are limited due to strong side effects such as nervous disorder and the like, so that it is difficult to exterminate Piroplasmida parasites.

On the other hand, it is known that the sulfated polysaccharide

I,

to be used in the present invention has an anti-blood coagulation activity, antiviral activity (Japanese Patent Application Kokai No.

62-215529) and antimalarial activity (WO 95/08334).

Problems to be resolved by the Invention The object of the present invention is to provide a novel anti-piroplasmotic agent having low side effects and high therapeutic effects.

Means for resolving the Problems With the aim of resolving such problems, the inventors of the present invention have conducted intensive studies and found as the result that a sulfated polysaccharide has an anti-piroplasmotic activity and hardly shows side effects, hence resulting in the accomplishment of the present invention.

Accordingly, the present invention relates to an anti- :piroplasmotic agent which contains a sulfated polysaccharide or a pharmaceutically acceptable salt thereof as its active ingredient.

.oo *0* S' In one aspect the invention provides a use of sulfated polysaccharide for producing a pharmaceutical composition comprising a sulfated polysaccharide or a pharmaceutically acceptable salt thereof in an amount effective for treatment of piroplasmosis caused by Piroplasmida parasites, and a pharmaceutically acceptable carrier In another aspect the invention provides a method of treatment of piroplasmosis caused by Piroplasmida parasites comprising the step of administering to a mammal in need thereof a therapeutically effective amount of a sulfated polysaccharide or a pharmaceutically acceptable salt thereof.

V:.2 go) 2 ooC>,! b -2A- Mode of carrying out the Invention Examples of the sulfated polysaccharide to be used in the present invention include synthetic or natural sulfated polysaccharides such as sulfated curdlan, dextran sulfate, chondroitin sulfate A, B, C, D, E, H and K, heparin, keratan sulfate, keratan polysulfate, heparan sulfate, carrageenan and the like, of which curdlan sulfate is particularly preferred in view of the antipiroplasmotic effect. Also included in the sulfated polysaccharide of the present invention are chemically modified sulfated polysaccharides obtained by subjecting a sulfated *e o*.

o a *a *0 I polysaccharide to partial oxidation to effect rinq-op('ninq and then to reduction in order to increase water solubility of the sulfated polysaccharide or by subjecting a sulfated polysaccharide to carboxymethylation for the purpose of increasing its blood retentivity. A preferred sulfated polysaccharide to be used may have a sulfur content of from 5 to 25% by weight, preferably from 10 to by weight, most preferably from 12 to 17% by weight, and a weight average molecular weight, when calculated by a gel filtration method (GPC), of from 5,000 to 500,000, preferably from 20,000 to 200,000, most preferably from 50,000 to 120,000. The sulfated polysaccharide can be produced from a known polysaccharide in accordance with a known method described for example in Japanese Patent Application Kokai No. 61-130301, 61-130302 or 2-145601.

Examples of the pharmaceutically acceptable salt of sulfated polysaccharide include inorganic salts such as sodium salt, potassium salt, calcium salt, magnesium salt and the like.

Dosage form of the anti-piroplasmotic agent of the present invention is not particularly limited, and the agent can be made into optional dosage forms such as injections, drippings, suppositories, nasal sprays and the like.

Formulation of the agent also has no particular limitation, and, in the case of injections or drippings, the sulfated polysaccharide is used together with lactose, glucose, mannitol, maltose, amino acids, gelatin, distilled water, ethanol, Ringer solution, isotonic sodium chloride solution and the like. In the case of suppositories, the sulfated polysaccharide can be formulated

I

by mixing it with non-irritant fillers which areo solid at ordinary temperature but dissolve and release the drug at the body temp erature, such as cocoa butter, glyceride ester, polyethylene glycol and t h e like.

Dose of the anti-piroplasmotic agent of the present invention varies depending on the species, age, body weight, symptoms, physical condition, sex and feed of each animal to be administered, combination with other drugs, its administration method and the like, and is generally from 0.1 to 1,000 mg/kg body weight/day, preferably from 1 to 500 mg/kg/day, in terms of the active ingredient.

The anti-piroplasmotic agent of the present invention exerts its anti-piroplasmotic effect when it is administered before or after Piroplasmida infection.

In addition, the anti-piroplasmotic agent of the present invention can be used in combination with trypan blue, diminazene, aminoquinoline and the like conventional therapeutic drugs, and, in that case, the combined use exerts excellent therapeutic effect in comparison with their single use.

Examples Examples of the present invention are given below by way of illustration and not by way of limitation.

Test Example 1 (Effect of sulfated curdlan on babesiasis in dog) Two beagle dogs (18 to 24 months of age) which have been confirmed for the absence of anti-babesia antibody titer in advance were inoculated and infected with a Piroplasmida species, Babesia canis. After the infection, the number of babesia-infect ed erythrocytes in peripheral blood was counted, and, when the ratio reached sulfated curdlan sodium salts (CRDS; 79,500 in molecular weight and 12 to 13% in sulfation degree) was administered. CRDS was dissolved in physiological saline and administered by drip infusion in a dose of 5mg/kg spending 30 minutes. The administration was carried out every 6 hours for 2 days in a total of 8 times. Fig.

1 shows changes in the ratio of babesia-infected erythrocytes in peripheral blood until 11 days after inoculation of Babesia canis.

Also, conditions of the dogs were observed to obtain crisis scores based on the following criteria (Fig. 2).

(Crisis score) 0: death 1: coma 2: faint 3: serious fever, anemia 4: slight fever, anenia healthy As the results, sulfated curdlan excluded Babesia canis effectively and showed no side effects.

Formulation Example 1 (Dripping preparation) A 100 mg portion of sulfated curdlan sodium salts, 50 mg of mannitol and sodium hydrogenphosphate.12H,O were dissolved in 2 ml of distilled water for injection use, and the solution was adjusted to pH 6.5 with phosphoric acid and then freeze-dried to obtain a dripping preparation.

Effect of the Invention Since the anti-babesia agent of the present invention has excellent therapeutic effect and shows low side effects, it is markedly useful as a preventive or therapeutic agent for mammals.

Brief Description of the Drawings Fig. 1 is a graph showing changes in the ratio of babesia-infected erythrocytes in peripnural blood carried out in Test Example 1.

Fig. 2 is a graph showing changes in the crisis scores carried out in Test Example 1.

Throughout this specification and the claims which follow, unless the context requires otherwise, the word "comprise", and variations such as "comprises" and "comprising", will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps

C

a o 0

C

Claims

1. Use of sulfated polysaccharide for producing a pharmaceutical composition comprising a sulfated polysaccharide or a pharmaceutically acceptable salt thereof in an amount effective for treatment ofpiroplasmosis caused by Piroplasmida parasites, and a pharmaceutically acceptable carrier.

2. The use of claim 1, wherein the sulfated polysaccharide is sulfated curdlan.

3. Method of treatment ofpiroplasmosis caused by Piroplasmida parasites comprising the step of administering to a mammal in need thereof a therapeutically effective amount of a sulfated polysaccharide or a pharmaceutically acceptable salt thereof

4. The method of claim 3 wherein the sulfated polysaccharide is sulfated curdlan.

5. An anti-piroplasmotic agent substantially as hereinbefore described with reference to the Examples. 99*0 e. 0 9099 0* *9 0 0 0 0*e* 9 p 4 Dated this NINTH day of FEBRUARY, 1999 Ajinomoto Co., Inc. by its Patent Attorney Davies Collison Cave *0 9 *9oi [Object] To provide a novel anti-piroplasmotic agent having low side effects and high therapeutic effects. [Resolving Means] To contain a sulfated polysaccharide or a pharmaceutically acceptable salt thereof as an active ingredient. Sulfated curdlan sulfate is particularly desirable.