1,3-DITHIO-2-YLIDENE MALONATES FOR CURING FAT NECROSIS

Abstract: A curing agent for fat necrosis which contains a dithia derivative represented by the general formula wherein R and R¹ may be either the same or different and denote a lower alkyl group; n denotes an integer of 0, 1 or 2; and A denotes -CH₂-,- M being H or a saltforming rest, -CH=CH-,-CH₂CH₂-,or --CH₂-, and a method for curing said disease using the said curing agent.

Description: This invention relates to the use of a dithia derivative represented by the general formula (I) wherein R and R¹ which may be the same or different represent a lower alkyl group; n represents an integer of 0, 1 or 2; and A represents -CH₂-, M being H or a salt-forming rest, -CH=CH-, -CH₂-CH₂- or for the manufacture of a medicament for treating fat necrosis. Fat necrosis of domestic animals has hitherto frequently occurred particularly in domesticated cattle such as breeding cattle and beef cattle, and very few cases have been reported for pigs and chickens. The disease of cattle presently called fat necrosis has been known in Japan as well as in foreign countries for some time. It is a disease in which fatty tissue mainly in the abdominal cavity forms a mass, causing trouble to a living body. The tissue is found to develop mainly in the kidney, the colon, the circumference of the rectum, and the circumference of the kidney. There are two types of the mass. In one type, the mass forms a hard lump ranging in size from a small finger to a volleyball. In the other type, the mass does not form a hard lump but appears in the form of yellowish white lesions of a poppy seed size not only in the intestinal cavity but nearly over the whole body including the thoracic cavity and subcutaneous and intermuscular sites. The former type is more commonly observed. The symptoms of this disease include loss of appetite, diarrhoea, bloody excrement, excretion of hard faeces, colic pain, and leanness. Cattle suffering the disease will have digestive trouble or a breeding disturbance and, in many cases, die or become useless. In Japan, the onset of fat necrosis of cattle was first reported in 1966 in Nagano Prefecture, and since then has frequently occurred mainly in breeding Japanese Cattle. However, the definite cause of the disease is as yet unknown. Since no specific medicine is known for fat necrosis, there have been hitherto conducted, as a tentative measure, confirmation of the disease by rectum inspection and early-stage slaughter of cattle suffering the disease, and cure or prevention by means of adlay or coix seed (an adlay constituent) preparations. However, these measures are not always satisfactory in their efficacy. Adlay is cultivated in Japan as a herb medicine in warm places and marshy ground in the Kanto district and westward, but not as a food crop. It is only produced worldwide in a limited quantity. For reasons mentioned above, feeding of adlay for the cure or prevention of fat necrosis is not easily conducted at present. It is the object of this invention to provide a curing agent for fat necrosis. Said object is achieved by the use defined in claims 1 to 3. Figs. 1 and 2 are graphs showing the change of serum components with time in Cure Test I. Fig. 1 shows the change of lipid components and Fig. 2 the change of the other components. The compounds of the general formula (I) are already known as a curative for liver disorders of men and animals from US-A-4,080,467, 4,080,466, 4,022,907, and 4,118,506, as a germicide for agricultural and horticultural use from JP-A-34,883/76 and 34,126/72, and as a livestock feed composition from US-A-4,564,627. The curing agent for liver disorders mentioned above shows pharmacologically (1) a liver protein synthesis promoting action and (2) a liver fibrosis suppressing action, and is used as a preventing or curing agent for various liver disorders including adiposis hepatica, hepatocirrhosis, toxic hepatic disorder, and congestion of blood. It is believed that its effect lies in transferring the fat present in the liver to other tissues thereby reducing the amount of fat in the liver. As to the use as a livestock feed composition, its object is to reduce the fat present in the abdominal cavity thereby preventing the lowering of meat utilization efficiency (carcass efficiency) which is caused by the cattle growing corpulent as the result of accumulation of excess fat in the visceral cavity. Thus, it has been believed that such fat present in excess in the liver or the abdominal cavity is utterly different from the morbidly denatured fat formed in the mass of fat necrosis described below, and hence reducing the fat accumulated in excess under such normal conditions has no relation with removing the morbidly denatured fat of mass thereby curing morbid animals and recovering their health. Accordingly, it was unexpected that the compound of the general formula (I) is effective for the present disease. Thus under microscopic inspection of the fat necrosis cells, lively historytic cells are present on the outside. These cells enclose the fat cells which have been necrosed nearly completely and the central portion thereof give an indistinct image on dyeing, and saturated solid fat is observed inside the fat cells. According to an example of analysis of the fat, the ratio of unsaturated fatty acid to saturated fatty acid is 0.691 on the average, which shows, as compared with the value of 0.987 of the fat in a normal part, that the proportion of saturated fatty acid is larger in the necrosed part. Accordingly, in view of such a state of extinction of mass tissue in fat necrosis and the marked difference of its fat composition from normal, it was utterly unanticipated that the compound of the general formula (I) acts effectively on the disease. The present inventors have made comparative tests between curing agents using the compound of the general formula (I) in combination with adlay, plant sterol, or vitamin E, most commonly employed hitherto, and using the compound of the general formula (I) alone, with the object of improving the efficacy of prior art drugs. The tests were conducted in an attempt to develop a curing agent that is more effective for the mass by combined use of the two types of drugs, and the compound of the general formula (I) used as an adjuvant and was not expected to play the principal role in curing the mass. Unexpectedly, it has been found that the compound of the general formula (I) is effective in improving the condition of mass and/or curing the mass when used alone. Thus, it has been found that the compound of the general formula (I) has a marked effect in curing the denatured fat of the lesion of mass. Specific examples of the various compounds usable in this invention are shown in Table 1. The compounds shown in Table 1 have very low toxicity to warm-blooded animals, and are classified as substances of low toxicity in regulations for the control of deleterious or poisonous substances in various nations. Accordingly, they can usually be used, in oral administration, in a range of 0.01 to 100 mg per 1 kg of body weight. When mixed into livestock feed, they can be used in a range of 10 to 2000 ppm. For the purpose of curing the present disease in domesticated cattle, the dosage is preferably increased or decreased in accordance with the body weight, centering around 25 g per day per animal. The curing agent of the general formula (I) may be administered in any desired form including tablets, injections, particles, granules, and powders. Although oral administration is generally convenient, this invention is not limited thereto. Some embodiments of this invention will be described below in comparison with examples of cure by means of the prior art. EXAMPLE Fat necrosis cure test 1. Material and method (1) Cure Test I Cure Test I comprised treating test animals by oral administration mainly of soy sterol, which is a byproduct of soybean oil production and contains 20% of plant sterol and 4% of vitamin E, and partly of a combination thereof with adlay. The animals tested were nine head of cattle at the age of 3 to 8 years suffering from fat necrosis (body weight: 400 to 520 kg) and were divided into three groups of A, B and C each consisting of 3 animals. The A group was administered 50 g of soy sterol and 30 g of pulverized adlay, the B group 150 g of soy sterol, and the C group 200 g of soy sterol, respectively per day per animal continuously for 175 days from September 9, 1982 to February 21, 1983. During the period, rectum inspection for confirmation of necrosis lump was conducted 6 times (before administration and on the 37th, 70th, 97th, 144th and 174th day), and also phospholipid (PL), triglyceride (TG) in serum were determined. The results of determination for respective test items are shown in Figs. 1 and 2. (2) Cure Test II Cure Test II was conducted by treating 4 head of cattle suffering from fat necrosis (body weight: 450 to 530 kg) by oral administration, in the same manner as in Cure Test I, mainly with the compound No. 6 of Table 1, namely isoprothiolane. Cattle No. 1 was given for 91 days starting from October 29, 1983, and Cattle Nos. 2, 3 and 4 were given for 48 days starting from June 21, 1984, respectively 25 g of isoprothiolane per day per animal, Cattle No. 4 alone being additionally given 100 g of adlay. The test items were approximately the same as in Cure Test I. Cattle No. 1 was subjected 8 times in total (before administration and on the 8th, 12nd, 19th, 26th, 57th, 72nd, and 91st day) to blood sample collection and 6 times (before administration and on the 18th, 48th, 57th, 72nd, and 91st day) to rectum inspection. Cattle Nos. 2, 3 and 4 were subjected 3 times (before administration and on the 18th and 48th day) to the inspection. 2. Result (1) Changes in necrosis lump Tables 2 and 3 give a schematical representation of the state of necrosis lumps before administration and in the course of curing treatment, showing respectively the size of necrosis lumps and the development of wrinkles and constrictions. In Test I, in which the size of necrosis lumps of tested cattle before administration varied widely from a diameter of 3 cm to a case wherein the colon was strictured and the necrosis lump could not be confirmed, the reduction of size of necrosis lumps could be observed from the 37th day after administration in an early case, and begun in 70 days after administration even in a late case. In mild cases wherein the necrosis lump was small, the reduction of size proceeded smoothly, sometimes leading to complete cure and stoppage of administration. In serious cases, however, the necrosis lumps reduced their size to a certain extent but not further thereafter. Further, though depending on the conditions of the necrosis lumps of treated cattle, groups B and C, wherein the amount of soy sterol administered was larger, showed a tendency to reduce the size of necrosis lumps faster, among groups A, B and C. In Test II, the necrosis lumps began to reduce their size approximately after 18 days from administration in each of fat necrosis cattle. In cattle No. 1, the necrosis lump became almost unperceivable by touch in 91 days. Also in 3 other heads of cattle, the necrosis lumps reduced their size respectively. Thus, the above-mentioned compound No. 6 showed a curative effect of faster size reduction of necrosis lumps after initiation of administration as compared with the control tests of groups A, B and C. Tables 2 and 3 are shown below.

Claims: Use of a dithia derivative represented by the general formula (I) wherein R and R¹ which may be the same or different represent a lower alkyl group; n represents an integer of 0, 1 or 2; and A represents -CH₂-, M being H or a salt-forming rest, -CH=CH-, -CH₂CH₂-, or for the manufacture of a medicament for treating fat necrosis. The use according to claim 1 wherein the content of the compound represented by the general formula (I) is 10 to 2,000 ppm. The use according to claim 1 or 2 wherein the compound represented by the general formula (I) is diisopropyl 1,3-dithiolan-2-ylidenemalonate or diispropyl 1,3-dithiol-2-ylidenemalonate.

Inventors: KIMURA, HARUTAKA, NISHINO, ISAO, SHIBAYAMA, MASAKAZU, UCHIDA, MATAZAEMON
Applicants: NIHON NOHYAKU CO., LTD.
Application year: 1986
Main classification: A61K31
IPC codes: A61K31, C07D339, A61P3