Albert N. Booth

Physiologic effects of three microbial polysaccharides on rats

Abstract Catharsis and reduced rates of growth were the only detectable effects produced in rats ingesting diets containing 15% phosphomannan Y-2448 or polysaccharide B-1459 during a 91-day period. A third microbial polysaccharide, dextran B-512F did not produce the same effects. Digestibility and caloric availability assays indicate that dextran was highly digestible and utilized as a source of energy for growth, whereas polysaccharide B-1459 was nondigestible, being completely accounted for in the feces. Phosphomannan Y-2448 was partially utilized. Data on gum guar, pectin, gum arabic, and agar are included for comparative purposes. Acute toxicity tests of phosphomannan and polysaccharide B-1459 and skin irritation and sensitization tests were negative.

Isolation of a toxic factor from jojoba meal.

Summary A new toxic glucoside from jojoba meal called simmondsin, has been isolated and identified as a 2-(cyanomethylene)-3-hydroxy-4,5-dimethoxycyclohexyl β-D-glucoside by application of conventional chemical fractionation and animal bioassay techniques. Preliminary rat and mouse toxicological data implicates the benzyl cyanide derivative of simmondsin as the toxicant.

The reversible nephrotoxic effects of biphenyl

Abstract Rats ingesting diets containing 0.5% biphenyl developed nephrotoxic effects including focal tubular dilation in approximately 60 days. Rats returned to control diet for 60 days after ingesting a dietary level of 0.5% biphenyl for 165 days showed a regression of kidney lesions with scar formation. A more sensitive criterion of the renal effects of biphenyl was polyuria, which is probably a defense mechanism response to the irritant action caused by the insoluble biphenyl metabolites passing through the kidney. No evidence of either polyuria or histopathologic damage was observed from the ingestion of 0.1% biphenyl in the diet for 120 days.

Comparative metabolic conversion of aflatoxin B1 to M1 and Q1 by monkey, rat and chicken liver

Abstract We studied the in vitro metabolish of flatoxin B1 by liver microsomal preparations from monkey, rat and chicken. With all these species, both the previously recognized metabolite aflatoxin M1 as well as the newly identified aflatoxin Q1 were produced from the aflatoxin B1 substrate. Aflatoxin Q1 is an isomer of aflatoxin M1 (with the hydroxyl on the carbon β to the carbonyl of the cyclopentenone ring) which we discovered recently in rat and monkey liver incubations with aflatoxin B1. In our incubations we did not detect aflatoxin P1 which has been reported as a major metabolite of aflatoxin B1 in vivo in the monkey. In general the conversion to aflatoxin M1 was comparable among the different species (1–3% of the substrate) except in the chicken in which it was lower (0.1–0.3%). Also the conversion to Q1 was comparable to or slightly higher than the conversion to M1 with rat and chicken liver but the conversion to Q1 with the monkey liver was outstandingly high, accounting for 19–52% of the substrate in three species of monkeys tested.

O-methylation in vitro of dihydroxy- and trihydroxy-phenolic compounds by liver slices

Abstract Several instances of O-methylation of dihydroxy- and trihydroxy-phenolic acids are shown in vitro with surviving rat or rabbit liver slices. Instances are shown where O-methylation affects the m-hydroxyl group specifically, the p-hydroxyl group specifically, or either one of the m- or p-Hydroxyl groups of the same phenolic acid indifferently. Some factors which influence the course of O-methylation are discussed.

Subacute toxicity study of a microbial polysaccharide fed to dogs

Abstract The potential utility of a new polysaccharide (B-1459) of microbial origin as a food thickening agent prompted the study of its subacute toxicity in young adult beagle dogs. The polysaccharide was fed at two levels, 1 and 2 g/kg body weight per day for 12 weeks. Another group of dogs received 2 g/kg of cellulose per day. All dogs, including controls, lost weight during the trial period, the weight loss being greater for the group fed the high level of polysaccharide, presumably because of persistent diarrhoea. Red blood cell counts, haemoglobin concentrations, and serum cholesterol values were lowered and adrenals were slightly enlarged in the group receiving the 2 g/kg level of polysaccharide. These effects might also be accounted for by the persistent diarrhoea observed in this group.

Protection by flavonoids against histamine shock.

Summary A slight protection of guinea pigs treated with rutin and subjected to an LD50 dose of histamine has been confirmed. The failure of certain other investigators to substantiate this finding may have been due to excessive histamine dosage or the use of inadequately standardized animals. Quercitrin, quercetin and methyl hesperidin chalcone also were found to afford protection against histamine. The protection is slight and is of theoretical rather than clinical interest.

Xanthurenic Acid Dehydroxylation by Fecal Microflora

Summary In vitro dehydroxylation of xanthurenic acid has been demonstrated in an artificial cecum charged with rabbit fecal fluid. The dehydroxylated product, 8-hy-droxyquinaldic acid, was isolated and crystallized. The results clearly indicate that intestinal microorganisms are responsible for the dehydroxylation reaction. Dehydroxylation of kynurenic acid to produce quinaldic acid was only qualitatively detectable in the same system.

Caloric requirements of rat intestinal microorganisms

Abstract A gain in weight equivalent to that produced by 0.5 gm. D-glucose was obtained when neomycin was added to the diet of rats on a restricted caloric intake. A decrease in moisture-free fecal output indicative of a reduction in the intestinal microflora was also observed. It was concluded that 10% of the dietary caloric intake of rats was required to support the population of intestinal microorganisms.