Dietary administration of β-caryophyllene and its epoxide to Sprague-Dawley rats for 90 days

Two independent 90-day GLP-compliant studies were conducted in Sprague-Dawley rats with β-caryophyllene or β-caryophyllene epoxide, two common flavoring and fragrance materials. Dietary concentrations of β-caryophyllene were 3500; 7000; and 21,000 ppm for males and 3500; 14,000; and 56,000 ppm for females. Dietary concentrations of β-caryophyllene epoxide were 1750; 10,500; and 21,000 ppm. There were no deaths or clinical toxicity attributable to either substance administration. Statistically significant, dose-dependent reductions in body weight, body weight gain, food consumption, and food efficiency at the highest dietary concentrations of β-caryophyllene, but not of β-caryophyllene epoxide, were attributed to palatability issues. Neither β-caryophyllene nor β-caryophyllene epoxide influenced estrus cyclicity or sperm parameters. Macroscopic and microscopic findings were primarily related to changes in the kidneys of male rats, consistent with α2u-globulin nephropathy, and in the liver of male and female rats, including hepatocyte hypertrophy at the middle and high intake levels. These changes correlated with increased absolute and relative organ weights. Since the kidney findings were a species- and sex-specific effect, the NOAEL in each study was based on hepatocyte hypertrophy at the two highest dietary concentrations and were determined to be 222 mg/kg bw/day for β-caryophyllene and 109 mg/kg bw/day for β-caryophyllene epoxide.

2,4-Decadienal does not induce genotoxic effects in in vivo micronucleus studies

2,4-Decadienal (E,E-) occurs naturally in foods and is also used as a flavoring ingredient. In vivo micronucleus studies were used to evaluate the potential for 2,4-decadienal to cause genotoxic effects. Male Han Wistar rats were dosed either by intraperitoneal injection or by gavage in two independent studies. The animals (12/group) received 25, 50, or 100 mg/kg bw of 2,4-decadienal via intraperitoneal injection, or 350, 700, or 1400 mg/kg bw via gavage. Dose-dependent decreases in the percentages of peripheral blood reticulocytes were observed in both studies, indicating that the target tissue was exposed to toxic levels of 2,4-decadienal. No induction of micronuclei in the bone marrow polychromatic erythrocytes or the peripheral blood reticulocytes was observed in either study. These results, coupled with previous mutagenicity studies, support the overall conclusion that 2,4-decadienal does not present a concern for genotoxicity.

Absence of adverse effects following the gavage administration of methyl propyl trisulfide to Sprague-Dawley rats for 90 days

Methyl propyl trisulfide is a flavoring substance found in foods such as garlic and onions. At the request of the European Food Safety Authority (EFSA) for additional toxicological data on methyl propyl trisulfide, groups of Sprague-Dawley rats (10/sex/group) were gavaged with 0 (corn oil vehicle control), 0.5, 2, or 6 mg methyl propyl trisulfide/kg bw/day in a 90-day GLP-compliant study. No effects on clinical observations, hematology and clinical chemistry parameters, organ weights, or macroscopic and histopathological examinations were found attributable to ingestion of methyl propyl trisulfide. The oral no-observed-adverse-effect level (NOAEL) for rats of both sexes was the highest dose tested of 6 mg/kg bw/day.