6-gingerol attenuates pulmonary inflammation and oxidative stress in mice model of house dust mite-induced asthma

Asthma is a chronic non-communicable inflammatory disease of the lung that affects over 300 million people worldwide. 6-Gingerol (6-G) is a phytocompound found in ginger rhizome that has been reported to exhibit anti-inflammatory effects. However, there is paucity of information regarding the effect of 6-G on asthma. This study was designed to evaluate the effect of 6-G on house dust mite (HDM) -induced asthma. Male mice were divided into 5 groups of 10 mice each. Group 1 served as control; group 2 received 6-G (10 mg/kg/day) for 5 weeks. Group 3 received HDM (10 µg/kg/day) for 4 weeks. Group 4 received 6-G (10 mg/kg/day) for 1 week prior to co-exposure with HDM (10 µg/kg/day) for 4 weeks, and group 5 received Dexamethasone (DEX) (1 mg/kg/day) and HDM (10 µg/kg/day) for 4 weeks. Administration of HDM significantly increased lymphocytes, leukocytes, neutrophils, eosinophils, myeloperoxidase (MPO), nitric oxide (•NO), malondialdehyde, tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and decreased the activities of superoxide dismutase (SOD), catalase, glutathione S-transferase (GST), glutathione peroxidase (GPx), glutathione (GSH) and ascorbic acid (AA) levels relative to control. Administration of 6-G and DEX prior to HDM exposure significantly decreased lymphocytes, leukocytes, neutrophils, eosinophils, MPO, •NO, malondialdehyde, TNF-α, IL-6 and increased the activities of SOD, catalase, GST, GPx, and levels of GSH and AA relative to HDM group. Histopathological examination of the lungs of HDM-treated mice showed the presence of oedema and inflammation of the bronchi and alveoli. Administration of 6-G and DEX reversed these lesions. 6-G ameliorated House dust mite-induced asthma via anti-inflammatory and anti-oxidant mechanism.