Study of extracts of barley grain infected with Fusarium sporotrichioides No. 63*

Brief communications/Notes Study of extracts of barley grain infected with Fusarium sporotrichioides No. 63 * M. A. AKHMETELI, A. B. LINNIK, K. S. CERNOV, V. M. VORONIN, & L. M. SABAD Abstract Experiments with mice showed that an aqueous extract of barley grain attacked by by Fusarium sporotrichioides is blastomogenic, but only mildly so. The discovery at the end of the 1930s, by a group of Soviet research workers headed by Professor B. G. Drobotko, of the etiology of stachybotryo- toxicosis was the beginning of a new stage in the understanding of the role played by mycotoxins in the etiology of a number of chronic noncommunic- able diseases. The pathogenic effects of mycotoxins on human health became particularly important after it was established in the post-war years by A. H. Sarkisov, E. S. Kvasnina, and Ju. I. Rubinstejn that the mould Fusarium sporotrichioides was the cause of a severe disease known at that time as " septic sore throat ". After careful study of the clinical course of the disease and the establishment of its etiology it was renamed " alimentary toxic aleukia" (ATA). A further development in this type of research was the discovery by British workers of the etiology of " turkey X-disease" and the discovery in animal experiments of the carcinogenic properties of meta- bolites of the mould Aspergillusflavus which became known as " aflatoxins ". However, while there is no doubt that aflatoxins do have a carcinogenic effect on experimental animals, their significance in human pathology is still to be proved. In connexion with the data on aflatoxins, the ques- tion naturally arose of the blastomogenicity of the metabolites of moulds of another genus, Fusarium, which attack cereals when they are not properly stored. These metabolites undoubtedly play a part in human pathology. Trials were carried out on mice to discover the blastomogenic properties of an aqueous extract of * From the Gamaleya Institute of Epidemiology and Microbiology of the Academy of Medical Sciences of the USSR and the Institute of Experimental and Clinical On- cology of the Academy of Medical Sciences of the USSR. barley grain infected with F. sporotrichioides No. 63.1 Ninety-seven F1 hybrid mice (C57 x CBA), both male and female, were used in the experiment at the age of about 21/2 months. To prepare the extract, 150 ml of water were poured on to 25 g of autoclaved grain and mechani- cally shaken for 3 hours. The solution was then filtered off. A preliminary experiment had shown that the maximum tolerated dose of this extract in chronic experiments on mice was 0.5 ml. At doses of 1.0 and 0.8 ml the animals quickly died with symptoms of toxicosis. In the main experiment the mice were each given 0.5 ml of the extract through a gastric sonde five times a week for a year. Altogether during the year the mice were given about 125 ml of the extract. Twelve mice died in the early stages and were not included when the results were summarized. Six months after completion of the experiment (i.e., 18 months after it had begun) all the surviving animals were sacrificed and a microscopic exami- nation was made of the liver and lungs and also of other macroscopically altered organs and tissues. The results of the experiment are given in Table 1. As will be seen from the data in the table, the extract caused a statistically significant increase in lung adenomas in general, and particularly inthe males. Lung adenomas occurred in 4 (11.4 Y.) of the 35 controls and in 18 (36.0%) of the 50 experimental animals. In males the respective percentages were 5.8 and 36.8. Although a statistically significant increase in lung adenomas was not found in females they were nevertheless more frequent than in the con- trols (35.4% as against 16.6%) and the only adeno- carcinoma of the lungs was found in this group. It should also be noted that in the experimental group the number of tumour nodules per mouse was higher than in the controls (1.7 as against 1.0). 1 The culture of the toxic mould F. sporotrichioides No. 63 was kindly supplied by Professor A. H. Sarkisov, to whom we are extremely grateful. 2880A - 123 - BRIEF COMMUNICATIONS Table 1. Numbers of tumours in experimental and control mice No. of mice Sex surviving to1 year of age a Animals with tumours Total tumours Hepatomas Adenomas No. % No. % No. % Experimental mice Female 31 14b 45.2 7C 22.6 11 d 35.5 1.7 Male 19 8 42.1 4 21.1 7 36.8 1.1 Total 50 22 44.0 11 22.0 18 36.0 1.5 Control mice Female 18 5e 27.8 1 5.6 3 16.7 1.0 Male 17 6 35.3 6 35.3 1 5.9 1.0 Total 35 11 31.4 7 20.0 4 11.4 1.0 a In animals that died before 1 year of age no tumours were found. b Including 1 undifferentiated carcinoma of unknown localization and 1 mammary-gland carcinoma. c One malignant hepatoma. d One lung adenocarcinoma with metastases to other lobes. e One mammary-gland carcinoma. As for hepatomas no statistically significant dif- ference was found between the experimental and con- trol groups, although in the group of females tumours occurred in greater numbers (22.5%) than in the controls (5.5 %). In the males, hepatomas occurred less frequently in the experimental animals (21.0%) than in the controls (35.0 %). As with lung adenomas, only one malignant hepatoma was discovered among the experimental animals and this showed infiltrative growth. In summarizing the results of the experiments it may be concluded that an aqueous extract of barley grain attacked by F. sporotrichioides is blastomogenic but only mildly so. It should be emphasized that we used aqueous extracts. On the one hand this type of extract is undoubtedly closer to actual conditions but on the other hand it may not provide complete results because of incomplete extraction of some blastomogenic components. The identification of the blastomogenic principle in the extract we examined required further investigations. The data already obtained, however, should be taken into account in analysing the results of a number of epidemiological investigations. No. per mouse 124