α-Bisabolol

α-Bisabolol is a principal constituent of German chamomile and several wood oils. The compound is safe at practical use levels.

Skin. Non-phototoxic at 3 and 15 percent in guinea pigs. The compound increased 5-fluorouracil permeation through human skin 17-fold and triamcinolone acetonide 73-fold, suggesting a role as a skin penetration enhancer.

Oral. Acute oral LD50 is 15.25 mL/kg in rats, 15.1 mL/kg in mice. Rat oral LD50 also reported above 5 g/kg. Mouse intraperitoneal LD50 is 633 mg/kg.

Subchronic. Gavage at 2 mL/kg in rats for 28 days caused dose-dependent motor agitation and urinary ketone reaction. At 3 mL/kg, 20 percent mortality and liver dysfunction in female rats occurred. Dermal 1,000 mg/kg/day for 28 days reduced absolute liver weight in females and increased relative testes weight in males.

Reproductive. Gavage up to 1 mL/kg in rats and rabbits on gestation days 6–15 produced no teratogenic effects. At 3 mL/kg, fetal numbers were reduced in both species.

Mutagenicity. Non-mutagenic in the Ames test with and without S9. Protected against urethane-induced mutation in fruit flies.

α-Bisabolol is highly valued in sensitive, irritated and infant skin care. The compound has mild anti-inflammatory and antibacterial activity.

The (R)-α-bisabolol form has better biological activity than (S)-, though both are used commercially.