Quantitative investigation of the hippuric acid formation in the rat after administration of some possible aromatic and hydroaromatic precursors

The FEMA GRAS assessment of phenethyl alcohol, aldehyde, acid, and related acetals and esters used as flavor ingredients

This publication is the ninth in a series of safety evaluations performed by the Expert Panel of the Flavor and Extract Manufacturers Association (FEMA). In 1993, the Panel initiated a comprehensive program to re-evaluate the safety of more than 1700 GRAS flavoring substances under conditions of intended use. Elements that are fundamental to the safety evaluation of flavor ingredients include exposure, structural analogy, metabolism, pharmacokinetics and toxicology. Flavor ingredients are evaluated individually and in the context of the available scientific information on the group of structurally related substances. Scientific data relevant to the safety evaluation of the use of phenethyl alcohol, aldehyde, acid, and related acetals and esters as flavoring ingredients is evaluated. The group of phenethylalcohol, aldehyde, acid, and related acetals and esters was reaffirmed as GRAS (GRASr) based, in part, on their self-limiting properties as flavoring substances in food, their rapid absorption, metabolic detoxication, and excretion in humans and other animals, their low level of flavor use, the wide margins of safety between the conservative estimates of intake and the no-observed-adverse effect levels determined from subchronic and chronic studies and the lack of significant genotoxic and mutagenic potential. This evidence of safety is supported by the fact that the intake of phenethyl alcohol, aldehyde, acid, and related acetals and esters as natural components of traditional foods is greater than their intake as intentionally added flavoring substances.

Fragrance material review on cinnamic acid

A toxicologic and dermatologic review of cinnamic acid when used as a fragrance ingredient is presented.

Fragrance material review on cinnamyl alcohol

A toxicologic and dermatologic review of cinnamyl alcohol when used as a fragrance ingredient is presented.

Fragrance material review on cinnamaldehyde

A toxicologic and dermatologic review of cinnamaldehyde when used as a fragrance ingredient is presented.

The FEMA GRAS assessment of hydroxy- and alkoxy-substituted benzyl derivatives used as flavor ingredients

This publication is the ninth in a series of safety evaluations performed by the Expert Panel of the Flavor and Extract Manufacturers Association (FEMA). In 1993, the Panel initiated a comprehensive program to re-evaluate the safety of more than 1700 GRAS flavoring substances under conditions of intended use. Elements that are fundamental to the safety evaluation of flavor ingredients include exposure, structural analogy, metabolism, pharmacokinetics and toxicology. Flavor ingredients are evaluated individually and in the context of the available scientific information on the group of structurally related substances. Scientific data relevant to the safety evaluation of the use of hydroxy- and alkoxy-substituted benzyl derivatives as flavoring ingredients is evaluated. The group of hydroxy- and alkoxy-benzyl derivatives was reaffirmed as GRAS (GRASr) based, in part, on their self-limiting properties as flavoring substances in food; their rapid absorption, metabolic detoxication, and excretion in humans and other animals; their low level of flavor use; the wide margins of safety between the conservative estimates of intake and the no-observed-adverse effect levels determined from subchronic and chronic studies and the lack of significant genotoxic and mutagenic potential. This evidence of safety is supported by the fact that the intake of hydroxy- and alkoxy-substituted benzyl derivatives as natural components of traditional foods is greater than their intake as intentionally added flavoring substances.

The FEMA GRAS assessment of cinnamyl derivatives used as flavor ingredients

This publication is the seventh in a series of safety evaluations performed by the Expert Panel of the Flavor and Extract Manufacturers Association (FEMA). In 1993, the Panel initiated a comprehensive program to re-evaluate the safety of more than 1700 GRAS flavoring substances under conditions of intended use. Elements that are fundamental to the safety evaluation of flavor ingredients include exposure, structural analogy, metabolism, pharmacokinetics and toxicology. Flavor ingredients are evaluated individually and in the context of the available scientific information on the group of structurally related substances. Scientific data relevant to the safety evaluation of the use of cinnamyl derivatives as flavoring ingredients is evaluated.

Metabolism of n-butyl benzyl phthalate in the female Wistar rat. Identification of new metabolites

n-Butyl benzyl phthalate (BBP), a plasticizer used in polyvinylchloride (PVC) and other polymers, has been orally administered to female Wistar rats with four doses (150, 475, 780 and 1500 mg/kg body weight/day) for 3 consecutive days. Metabolites recovered in urines were analysed by gas chromatography-mass spectrometry (GC-MS) after 24, 48 and 72 hours. Six metabolites were identified. Mono-n-butyl phthalate (MBuP) and mono-n-benzyl phthalate (MBeP) represented respectively 29-34% and 7-12% of the total recovered metabolites. Hippuric acid, the main metabolite of benzoic acid, represented the second major metabolite (51-56%). Phthalic acid, benzoic acid and an omega-oxidized metabolite of MBuP were also recovered in urine but in small quantities. BBP was never identified in urines. Total urinary metabolites recovery represented 56% of the dose administered in the first 24 hours. However, total recovery decreased when the dose increases (43% at 780 mg/kg body weight/day, only 30% at 1500 mg/kg body weight/day). Whatever the time was, BBP metabolites recovered in urines were all present and in the same proportions for the two lowest doses. Discrepancy in metabolites quantities expressed as percentages of the dose observed in urine of rat treated with the highest BBP dose disappeared with time as MBuP, MBeP and hippuric acid recovery has significantly increased at day 3. Metabolic profile of BBP in female rats has been established. The aim of the present study is to identify further the active(s) agent(s) involved in the BBP malformations and teratogenic effects.

Effects of gavage versus dosed feed administration on the toxicokinetics of benzyl acetate in rats and mice

Effects of gavage versus dosed feed administration on the toxicokinetics of benzyl acetate were studied in male F344 rats and B6C3F1 mice. Benzyl acetate was rapidly hydrolysed to benzyl alcohol and then oxidized to benzoic acid. After gavage administration of benzyl acetate in corn oil at 500 mg/kg (rats) and 1000 mg/kg (mice), high benzoic acid plasma concentrations were observed. In contrast, much lower benzoic acid plasma concentrations were found after dosed feed administration at about 615 mg/kg/day for rats and about 850 mg/kg/day for mice. Results show that although the daily doses of benzyl acetate are comparable, bolus gavage administration effectively saturated the benzoic acid elimination pathway whereas dosed feed administration did not. In contrast, hippuric acid plasma concentrations were similar after both gavage and dosed feed administration due to the depletion of the glycine supply pool. Study results could explain the different toxicity and carcinogenicity responses of benzyl acetate observed in 2-yr chronic gavage and dosed feed studies.

Tissue distribution and excretion of 14C-labelled cinnamic aldehyde following single and multiple oral administration in male Fischer 344 rats

14C-labelled cinnamic aldehyde (CNMA) was given as a single oral dose, or 24 hr after multiple oral administration of non-radioactive CNMA for 7 days at 24-hr intervals, to male Fischer 344 rats at dose levels of 5, 50 or 500 mg/kg body weight. Residues of radioactive CNMA were measured. After the single dose radioactivity was distributed primarily in the gastro-intestinal tract, the kidneys and the liver of the rats. The radiolabel was excreted mainly in the urine, and at 24 hr 85.1, 84.2 and 81.2% of the administered radiolabel was recovered in the urine at the 5, 50 and 500 mg/kg dose levels, respectively. Faecal excretion of radiolabel at 24 hr for the 5, 50 and 500 mg/kg doses was 5.1, 4.0 and 3.2% of the administered dose, respectively. At all dose levels, a small amount of the dose was distributed to the fat and was easily measured in animals killed 3 days after dosing at the 50 or 500 mg/kg dose levels. Following multiple oral administration, similar tissue distribution and excretion patterns of radiolabel were found at the three dose levels. After 24 hr the administered radiolabel was distributed mainly to the fat, liver and gastro-intestinal tract. At 24 hr, recoveries of the radiolabel in the urine were 80.4, 80.6 and 81.9% of the dose for the 5, 50 and 500 mg/kg dose levels, respectively. Faecal excretion of radiolabel after multiple dosing at 24 hr accounted for 6.3, 6.9 and 4.5% of the administered radioactivity at the 5, 50 and 500 mg/kg dose levels, respectively. The major metabolic pathway of CNMA for all single and the 5 and 50 mg/kg multiple dose levels in this species of rat was found to be degradation to benzoic acid through beta-oxidation and excretion in the urine mainly as hippuric acid, with much smaller amounts of benzoic and cinnamic acids. At the multiple dose level of 500 mg/kg, benzoic acid was the major urinary metabolite, indicating that in the Fischer 344 male rat at this relatively high oral dose level the detoxification of CNMA proceeds differently and an alternative metabolic pathway is proposed.

Toxicokinetics of cinnamaldehyde in F344 rats

The toxicokinetic profile of cinnamaldehyde (CNMA) was investigated in Fischer 344 rats. CNMA was found to be unstable in blood. After iv administration, a large fraction of CNMA was immediately oxidized to cinnamic acid. The biological half-life of CNMA after iv administration was found to be 1.7 hr. After administration by gavage of CNMA at 250 or 500 mg/kg body weight using corn oil as vehicle, the maximum blood concentrations of CNMA were in the order of 1 microgram/ml. These low blood concentrations were maintained over a 24-hr period after a dose of 500 mg/kg, which is relatively long considering the short (1.7 hr) biological half-life of CNMA. The estimated oral bioavailability of CNMA was less than 20% for both the 250 and 500 mg/kg doses. No CNMA was present in blood at any time in rats dosed with 50 mg CNMA/kg body weight. Only a small amount of the administered CNMA was excreted in rat urine as free cinnamic acid or beta-glucuronide-conjugated cinnamic acid. The majority of CNMA administered orally was excreted in urine as hippuric acid within 24 hr. The maximum excretion rate occurred at 8 hr after gavage. Hippuric acid recovered in 50-hr urine samples was found to be directly proportional to the oral dose of CNMA.

Metabolism of the cinnamon constituent o-methoxycinnamaldehyde in the rat

The metabolism of o-methoxycinnamaldehyde (1.3 mmol/kg, intragastrically) was studied in rats. Identification of the urinary metabolites by g.l.c.-mass spectrometry and quantification by h.p.l.c. showed that the major metabolic pathway (approx. two-thirds of the dose) was oxidation to the corresponding cinnamic and phenylpropionic acids (C6-C3 acids) which were largely excreted as glycine conjugates. Intermediate amounts (approx. 10% of the dose) of the O-demethylated C6-C3 acids were excreted. Relatively large amounts of the beta-hydroxylated phenylpropionic acid derivative were found, however only traces of the further products of beta-oxidation (2-methoxylated derivatives of benzoic and hippuric acid) were excreted. No evidence was obtained for conjugation of o-methoxycinnamaldehyde with glutathione. Urinary excretion of metabolites was rapid (91% in 24 h and 98% in 48 h).