Evaluation of the analgesic potential and safety of Cinnamomum camphora chvar. Borneol essential oil.

ABSTRACT: Cinnamomum camphora chvar. Borneol essential oil (BEO, 18.2% v/v borneol) is a by-product of steam distillation to produce natural crystalline borneol (NCB, 98.4% v/v borneol). Given the known medicinal properties of borneol, the analgesic function and safety were studied. Horn's method and the Draize test revealed a gender difference in mice regarding acute oral LD₅₀, i.e., low-toxicity to female mice (2749 mg/kg), but practically nontoxic to male mice (5081 mg/kg). There was no acute and skin or eye irritation when BEO was applied directly, if the BEO concentration was less than 50%. The analgesic effect of BEO was evaluated by the glacial acetic acid-induced writhing pain model. Continuous topical application of BEO to the abdomen of mice for 6 d, significantly reduced observed writhing in mice (p < 0.001) with a strong dose-response relationship (r = -0.9006). Concomitantly, the levels of the serum pain-related mediators, prostaglandin E₂ (PGE₂) and transient receptor potential melastatin-8 (TRPM8) were significantly reduced (p < 0.001), and the latter showed a strong dose-response relationship (r = -0.9427). Therefore, BEO had similar analgesic functions to borneol and was demonstrated to be safe for medicinal use.

SUBMITTER: Xiao S 

PROVIDER: S-EPMC8810075 | biostudies-literature | 2021 Dec

REPOSITORIES: biostudies-literature