Experimental Studies on Acute Oral Toxicity, Skin Irritation and Skin Allergy of Thuja Essential Oil / 中国药师

ABSTRACT

Objective:To evaluate the acute oral toxicity , skin irritation and skin allergy of Thuja essential oil ( TEO) , and pro-vide experimental basis for the clinical use of TEO .Methods:The acute oral toxicity was measured by Horn ’ s assay .Totally 40 KM mice were divided into four groups and intragastrically administered with TEO at different dose of 21.50, 10.00, 4.64 and 2.15 g · kg-1 .After the 14-day observation, the death number and toxic manifestations were recorded and observed , and LD50 was calculated by checking the Horn's form of LD50 .The skin irritation test was performed on healthy adult white rabbits .Totally 9 rabbits were divid-ed into 3 groups randomly , and TEO at the concentration of 100%, 50%and 25%was painted on the skin of the rabbits .Edible vege-table oil was used as the negative control .The erythema and edema of the treated skin were evaluated and scored .Delayed skin hyper-sensitivity reaction was used to investigate the allergy of TEO .Totally 30 white guinea pigs were randomly divided into 3 groupsTEO group, the negative control (edible vegetable oil) and the positive group (1%2, 4-dinitrochlorobenzene).After the intracutaneous in-duction stage and local induction stage , TEO was used to activate the hypersensitive reaction .The skin response was observed and scored after the 24-hour and 48-hour activation.Results:The mice in 21.50 g · kg-1 TEO treatment group were all dead , while only a part of the mice in 10.00 and 4.64 g · kg-1 TEO treatment groups were dead , and no mice died in 2.15 g · kg-1 TEO treatment group.According to the Horn's form of LD50 , LD50 of TEO was 9.26 g · kg -1 for male mice and 7.94 g · kg -1 for female mice.The results of skin irritation test indicated the strong irritation effects of TEO .However , the irritation of TEO was reduced after the dilution , and 25%TEO showed no irritation to the skin of rabbits .The results of delayed skin hypersensitivity reaction showed obvious erythema and edema induced by 2, 4-dinitrochlorobenzene , while no obvious erythema and edema were found in TEO treated guinea pigs , indi-cating non-allergic effect of TEO .Conclusion:TEO has strong skin irritation in rabbits , while no obvious oral toxicity in mice and skin allergy in guinea pigs .