Hinokitiol Attenuates LPS-Induced Arthritic Inflammation: A Preclinical Perspective

Abstract

The purpose of this research was to investigate the efficacy of the natural monoterpenoid hinokitiol in mitigating lipopolysaccharide (LPS)-induced arthritic inflammation in animal models. Arthritis was produced by intraplantar infusion of LPS (1 mg/Kg), and the effects of hinokitiol at doses of 0.2 mg/Kg (H-1) and 0.4 mg/Kg were evaluated. To test for an anti-arthritic effect, the animals’ paw volumes, arthritis indices, paw thicknesses, and percent changes, as well as their average body weights on days 0–7, 14–21, and 28, were measured. On day 28, we tested for changes in marker enzyme levels (serum glutamic-oxaloacetic transaminase (SGOT), alkaline phosphatase (ALP), and serum glutamic pyruvic transaminase (SGPT)), performed an antioxidant enzyme assay (superoxide dismutase (SOD), catalases (CAT), glutathione peroxidase (GPx)), tested for cartilage degrading enzymes (myeloperoxidase (MPO), cathepsin-D (CAT-D), elastase (ELA)), and examined red blood cells, white blood cells, and erythrocyte sedimentation rate (ESR). Paw volume, arthritic index, paw thickness, and percent change were all shown to be significantly reduced (P 0.05) in H-1, and H-2 treated rats, whereas body weight was found to be significantly restored. Animals treated with H-1 and H-2 had significantly lower levels of SGOT, ALP, SGPT, MPO, CAT-D, and ELA compared to controls (P 0.05). Lipoperoxidation inhibition and SOD activity were both significantly improved in H-1 and H-2 (P 0.05). Red blood cell (RBC) count increases significantly (P 0.05) in H-1 and H-2-treated animals, while white blood cell (WBC) and ESR drop significantly (P 0.05).