Fundamental Toxicological Sciences
Online ISSN : 2189-115X
ISSN-L : 2189-115X
Data Report
Safety studies of LAURESH® a standardized Laurus nobilis leaf extract
Chin Piow WongYukiko KobayashiJinwei Yang
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2023 Volume 10 Issue 4 Pages 143-156


The erroneous assumption that herbal products is generally safe for consumption, is a major factor leading to the increased of herb-induced liver injury (HILI). Even though Laurus nobilis or laurel is a commonly used spice, the safety aspect for its consumption is under-studied. To bridge this gap of knowledge, the mutagenicity, acute toxicity, and subacute toxicity of LAURESH®, which is a standardized laurel leaf extract were evaluated. Mutagenicity study using two S. typhimurium strains, TA100 and TA98 indicated that LAURESH® does not cause base substitution and frameshift mutation, thus suggesting that LAURESH® is non-mutagenic. While acute oral toxicity on mice established the LD50 at no less than 2,000 mg/kg of body weight, and a 28-day subacute toxicity test on rat revealed the NOAEL to be 1,000 mg/kg/day. Furthermore, blood chemistry, urinalysis, necropsy, and histopathological data from subacute toxicity study on rats does not show adverse event that could be attributed to LAURESH®, thus indicating that LAURESH® is unlikely to cause HILI. Taken together, the findings from this study and previous clinical study on LAURESH®, in combination with the historic use of laurel and previous toxicity studies conducted on laurel leaves extract, strongly suggest that LAURESH® is safe for human consumption.

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© 2023 The Japanese Society of Toxicology
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