432 Natural products NATURAL PRODUCTS 2707. Concanavalin A, the jack bean and the quail ,layne-Williams, D. J. (1973). Influence of dietary .jack beans (Ccmacalia ens!lbrmis) and of concanavalin A on the growth of conventional and gnotobiotic Japanese quail (CotmwHx eotlu'nix japonicai. Nature New Bioloqy 243, 150. The toxic effects of the raw navy bean to rats are well known (Cited iH F.C.T. 1966, 4, 356). Diets containing 50'!0 raw navy beans (Phaseolus culgaris) have also been found to induce progressive loss of weight and hypothermia followed by death in the Japanese quail (Cotm'ni.\ coturnixiaponica) (Jayne-Williams & Hewitt, J. appl. Bact. 1972. 35, 33 l). Germ- fi'ce quail given the same diet maintained a normal body temperature and did not show any increased mortality compared with controls. It has been suggested that phytohae- magglutinins (PHA) in beans may inhibit the birds" natural resistance to normally inno- cuous intestinal bacteria, which pass from the gut lumen into the lymph, blood and liver. Feeding experiments in quail were carried out using the PHA (concanavalin A) prepared ['tom jack bean {Canat~alia ens(formis), since this PHA was more readily obtainable in bulk than that from the navy bean. Jack beans are known to cause the death of young rats when fed raw but not when cooked. The same difference was found in the quail, a 50".,; raw bean diet causing 100"t; mortality in 3 days. while a diet containing 50<!i; autoclaved bean meal caused no deaths in 14 days. Neither diet was lethal to germ-free birds. In further studies, concanavalin A in sutticient volume to provide tin appropriate amount of agglutinating activity was added to autoclaved jack-bean meal and another diet was prepared with a similar amount of autoclaved concanavalin A. The diet containing native concanavalin A killed eight out of ten conventional quail but none of a group of ten gnotobiotic birds. Autoclaved concanavalin A produced no deaths in either group. The evidence indicates therefore that the oral toxicity of the jack bean is present in the same fraction as its hae- magglutinating activity, and that it does depend upon the presence of the intestinal flora. [P. Cooper] 2708. Effect of ochratoxin on glycogen storage Suzuki, S. & Satoh, Y. (1973). Effects of ochratoxin A on tissue glycogen levels in rats..lap. J. Pharmac. 23, 415. In common with aflatoxin, the fungal metabolite ochratoxin A has been isolated from strains of both Aspergillus and Penicillium, but the mechanism of its hepatotoxicity has not been investigated as extensively as has that of its notorious associate. In a previous isstie (Cited in F.C.T. 1969, 7, 401) evidence was presented suggesting that the toxin may compete with cyclic AMP for the enzyme phosphorylase h kinase, to elicit an observed cytoplasmic accumulation of glycogen. The present study was designed to investigate it1 rico this aspect of ochratoxin A hepatotoxicity in the rat. A single do se of 15 mg ochratoxin A/kg body weight given orally to either nor real or adrenalectomized rats resulted in a marked depletion of hepatic glycogen within 4 hr and an ele- vation of cardiac glycogen levels within 4-6 hr. In intact rats, the liver glycogen returned to normal in about 5 days, but in the adrenalectomized rats, a dramatic fall ended with death about 7 hr after dosing. In adrenalectomized rats pretreated with hydrocortisonc, the effect of the ochratoxin dose paralleled that in the intact rat.

2707. Concanavalin A, the jack bean and the quail: Jayne-Williams, D. J. (1973). Influence of dietary jack beans (Canavalia ensiformis) and of concanavalin A on the growth of conventional

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Page 1: 2707. Concanavalin A, the jack bean and the quail: Jayne-Williams, D. J. (1973). Influence of dietary jack beans (Canavalia ensiformis) and of concanavalin A on the growth of conventional

432 Natural products

NATURAL P R O D U C T S

2707. Concanavalin A, the jack bean and the quail

,layne-Williams, D. J. (1973). Influence of dietary .jack beans (Ccmacalia ens!lbrmis) and of concanavalin A on the growth of conventional and gnotobiotic Japanese quail (CotmwHx eotlu'nix japonicai. Nature New Bioloqy 243, 150.

The toxic effects of the raw navy bean to rats are well known (Cited iH F.C.T. 1966, 4, 356). Diets containing 50'!0 raw navy beans (Phaseolus culgaris) have also been found to induce progressive loss of weight and hypothermia followed by death in the Japanese quail (Cotm'ni.\ coturnixiaponica) (Jayne-Williams & Hewitt, J. appl. Bact. 1972. 35, 33 l). Germ- fi'ce quail given the same diet maintained a normal body temperature and did not show any increased mortality compared with controls. It has been suggested that phytohae- magglutinins (PHA) in beans may inhibit the birds" natural resistance to normally inno- cuous intestinal bacteria, which pass from the gut lumen into the lymph, blood and liver.

Feeding experiments in quail were carried out using the PHA (concanavalin A) prepared ['tom jack bean {Canat~alia ens(formis), since this PHA was more readily obtainable in bulk than that from the navy bean. Jack beans are known to cause the death of young rats when fed raw but not when cooked. The same difference was found in the quail, a 50".,; raw bean diet causing 100"t; mortality in 3 days. while a diet containing 50<!i; autoclaved bean meal caused no deaths in 14 days. Neither diet was lethal to germ-free birds. In further studies, concanavalin A in sutticient volume to provide tin appropriate amount of agglutinating activity was added to autoclaved jack-bean meal and another diet was prepared with a similar amount of autoclaved concanavalin A. The diet containing native concanavalin A killed eight out of ten conventional quail but none of a group of ten gnotobiotic birds. Autoclaved concanavalin A produced no deaths in either group. The evidence indicates therefore that the oral toxicity of the jack bean is present in the same fraction as its hae- magglutinating activity, and that it does depend upon the presence of the intestinal flora.

[P. Cooper]

2708. Effect of ochratoxin on glycogen storage

Suzuki, S. & Satoh, Y. (1973). Effects of ochratoxin A on tissue glycogen levels in rats..lap. J. Pharmac. 23, 415.

In common with aflatoxin, the fungal metabolite ochratoxin A has been isolated from strains of both Aspergillus and Penicillium, but the mechanism of its hepatotoxicity has not been investigated as extensively as has that of its notorious associate. In a previous isstie (Cited in F.C.T. 1969, 7, 401) evidence was presented suggesting that the toxin may compete with cyclic AMP for the enzyme phosphorylase h kinase, to elicit an observed cytoplasmic accumulation of glycogen. The present study was designed to investigate it1 rico this aspect of ochratoxin A hepatotoxicity in the rat.

A single do se of 15 mg ochratoxin A/kg body weight given orally to either nor real or adrenalectomized rats resulted in a marked depletion of hepatic glycogen within 4 hr and an ele- vation of cardiac glycogen levels within 4-6 hr. In intact rats, the liver glycogen returned to normal in about 5 days, but in the adrenalectomized rats, a dramatic fall ended with death about 7 hr after dosing. In adrenalectomized rats pretreated with hydrocortisonc, the effect of the ochratoxin dose paralleled that in the intact rat.