Context Despite several pharmacological studies of volatile oils of Angelica sinensis (Oliv.) Diels (Umbelliferae) (VOAS), its anti-inflammatory mechanism remains unknown. Objective The study investigates the effects of VOAS on the lipopolysaccharide (LPS)-induced acute inflammation rat model and analyzes its possible anti-inflammatory mechanisms. Materials and methods Fourty rats were randomly divided into the control, model, VOAS and dexamethasone (Dex) groups. The VOAS and Dex groups were given VOAS (0.176 mL/kg) and Dex (40 μg/kg), respectively. Rats in all groups except the control group were intraperitoneally injected with LPS (100 μg/kg), their exterior behaviour and liver pathological changes were observed, and the level of white blood cell (WBC), the number of neutrophils (NE)%, glutamic oxalacetic transaminase (GOT), glutamic pyruvic transaminase (GPT), alkaline phosphatase (ALP), tumour necrosis factor (TNF-α), interleukin (IL)-1β, IL-6, IL-10, histamine (HIS), 5-hydroxytryptamine (5-HT), nitric oxide (NO), prostaglandin E2 (PGE2), inducible nitric oxide synthase (iNOS) and cyclooxygenase 2 (COX-2) were detected. Results Compared with the model group, VOAS and Dex significantly accelerated the recovery of the exterior behaviour, the liver pathological changes of rats, and increased the level of IL-10, but decreased the level of WBC, NE%, GOT, GPT, ALP, TNF-α, IL-1β, IL-6, HIS, 5-HT, NO, PGE2, iNOS and COX-2 (p < 0.05). Conclusion VOAS exhibits anti-inflammatory and liver protection effects by inhibiting the secretion of the pro-inflammatory cytokines (TNF-α, IL-1β and IL-6), the inflammatory mediators (HIS, 5-HT, PGE2 and NO), the inflammation-related enzymes (iNOS and COX-2), as well as promoting the production of the anti-inflammatory cytokines IL-10.
Keywords: Anti-inflammatory mechanism; inflammation reaction; lipopolysaccharide; metabolic pathways.