Safety studies of LAURESH^® a standardized Laurus nobilis leaf extract

Abstract

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.