Mechanisms Underlying the Antinociceptive, Antiedematogenic, and Anti-Inflammatory Activity of the Main Flavonoid fromKalanchoe pinnata

Abstract

Kalanchoe pinnata(KP) is popularly used for treating inflammatory diseases. This study investigated the antinociceptive, antiedematogenic, and anti-inflammatory potential of the subcutaneous administration of KP flower aqueous extract (KPFE), its ethyl acetate (EtOAcF) and butanol (BuOHF) fractions, and the main KP flavonoid [quercetin 3-O-α-L-arabinopyranosyl (1→2)α-L-rhamnopyranoside] (KPFV) in mice, as well as its possible mechanisms of action. KPFE (30–300 mg/kg) and KPFV (1–10 mg/kg) inhibited the acetic acid-induced writhing (ID50= 164.8 and 9.4 mg/kg, resp.). KPFE (300 mg/kg), EtOAcF (12 mg/kg), BuOHF (15 mg/kg), or KPFV (0.3–3.0 mg/kg) reduced leukocyte migration on carrageenan-induced pleurisy (ID50= 2.0 mg/kg for KPFV). KPFE (3–30 mg/kg) and KPFV (0.3–3.0 mg/kg) reduced the croton oil-induced ear edema (ID50= 4.3 and 0.76 mg/kg, resp.). KPFE and KPFV reduced the TNF-αconcentration in the pleural exudates on carrageenan-induced pleurisy test. Moreover, KPFV inhibited COX-1 (IC50= 22.1 μg/mL) and COX-2 (IC50> 50 μg/mL). The selectivity index (COX-1IC50/COX-2IC50) was <0.44. These results indicate that KPFE and KPFV produced antinociceptive, antiedematogenic, and anti-inflammatory activities through COX inhibition and TNF-αreduction, revealing that the main flavonoid in KP flowers and leaves plays an important role in the ethnomedicinal use of the plant.