A 90-day subchronic toxicity study of Myrrh in F344 rats
Tatsuya Mitsumoto1, Yuji Ishii2, Moeka Namiki2
1Division of Pathology, National Institute of Health Sciences, 3-25-26 Tonomachi, Kawasaki-ku, Kawasaki-shi, Kanagawa, 210-9501, Japan; Faculty of Animal Health Technology, Yamazaki University of Animal Health Technology, 4-7-2, Minami-osawa, Hachihoji, Tokyo, 192-0364, Japan.
Abstract:
Myrrh is a flavoring agent and food additive. Here, we performed a subchronic toxicity study of Myrrh in male and female F344 rats by feeding at 5,000, 15,000 and 50,000 ppm for 90 days. No deaths or clinical signs were observed. Suppression of body weight gain was observed from the early phase of administration in both males and females in the 50,000 ppm group. Because there were no obvious changes in food intake in any of the Myrrh groups compared with the control group, suppression of body weight gain was considered an adverse effect of Myrrh. Hematology and serum biochemistry parameters with significant changes observed in the Myrrh groups were considered to have no toxicological significance. We observed a significant increase in relative kidney weight in male rats treated with 50,000 ppm Myrrh; this effect was considered to be related to the appearance of hyaline droplets in the epithelium of the proximal tubules histopathologically observed in this group. Immunohistochemical staining with anti-α2u-globulin antibodies suggested that these hyaline droplets were caused by factors other than α2u-globulin deposition. Thus, the no-observed-adverse-effect level of Myrrh was determined to be 15,000 ppm (males: 0.85 g/kg/day, females: 0.95 g/kg/day).
Insights
Myrrh, a food additive, showed no deaths in a 90-day rat study. The no-observed-adverse-effect level was 15,000 ppm, with reduced weight gain at 50,000 ppm being the primary adverse effect.
Area of Science:
- Toxicology
- Food Science
- Pharmacology
Background:
- Myrrh is utilized as a flavoring agent and food additive.
- Understanding the toxicological profile of food additives is crucial for consumer safety.
Purpose of the Study:
- To evaluate the subchronic toxicity of Myrrh in a rodent model.
- To determine the no-observed-adverse-effect level (NOAEL) for Myrrh consumption.
Main Methods:
- A 90-day oral toxicity study was conducted using male and female F344 rats.
- Rats were administered Myrrh at concentrations of 5,000, 15,000, and 50,000 ppm.
- Comprehensive clinical observations, hematology, serum biochemistry, and histopathology were performed.
Main Results:
- Suppression of body weight gain was observed in the 50,000 ppm group, considered an adverse effect.
- Increased relative kidney weight and hyaline droplet formation in proximal tubules were noted in male rats at 50,000 ppm.
- Hematological and biochemical changes were deemed not to have toxicological significance.
Conclusions:
- The no-observed-adverse-effect level (NOAEL) for Myrrh was established at 15,000 ppm (0.85 g/kg/day for males, 0.95 g/kg/day for females).
- Myrrh is considered safe at levels up to 15,000 ppm under the conditions of this study.
