Involvement of Heme Oxygenase-1 Participates in Anti-Inflammatory and Analgesic Effects of Aqueous Extract of Hibiscus taiwanensis

Abstract EN

Anti-inflammatory effects of the aqueous extract of Hibiscus taiwanensis (AHT) were used in lipopolysaccharide (LPS-)stimulated mouse macrophage RAW264.7 cells and carrageenan (Carr-)induced mouse paw edema model.

When RAW264.7 macrophages were treated with AHT together with LPS, a concentration-dependent inhibition of nitric oxide (NO), tumor necrosis factor (TNF-α), and prostaglandin E2 (PGE2) levels productions were detected.

Western blotting revealed that AHT blocked protein expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), and elevated heme oxygenase-1 (HO-1), significantly.

In the animal test, AHT decreased the paw edema at the 4th and the 5th h after Carr administration, and it increased the activities of catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx) in the paw tissue.

We also demonstrated AHT decreased the NO, TNF-α, and PGE2 levels on the serum level at the 5th h after the Carr injection.

Western blotting revealed that AHT decreased Carr-induced iNOS, and COX-2, and increased HO-1 expressions at the 5th h in the edema paw.

These findings demonstrated that AHT has excellent anti-inflammatory activities in vitro and in vivo and thus it has great potential to be used as a source for natural health products.