Proliferation and migration of airway smooth muscle cells are key processes in the airway remodeling in asthma. This study was performed to identify an anti-asthmatic effect of fresh raw garlic extracts (FRGE) that have strong anti-inflammatory and anti-oxidant effects on airway remodeling processes using human asthmatic bronchial smooth muscle cells (HABSMC).
Methods:
Water extract of fresh raw garlic(FRG) and human asthmatic bronchial smooth muscle cells were used in this study. Cell viability and proliferation were determined using the 3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) reagent and BrdU, respectively. Cell migration was performed using three-dimensional migration assay kit. Two-dimensional wound healing assay was also used to identify cell proliferation and migration. The contraction assay was performed using a cell contraction assay kit.
Results:
Treatment of HABSMCs with LPS (1 μg/mL) and histamine (100 μM) significantly increased cell proliferation and migration compared to control (p < 0.05). The concentrations of LPS and histamine used in this study showed no cytotoxic effects. Wound healing assays showed that the effect of histamine on cell proliferation and migration was higher than produced by LPS in a time-dependent manner (10.6±4.7% and 35.8±6.2% at 12 h and 24 h treatment, respectively). Combination with FRGE significantly reduced LPS- and histamine-induced wound healing by 40.6±7.6% and 71.2±2.0%, respectively, at 24 h after treatment. LPS and histamine showed similar effect in separate 3D migration and BrdU cell proliferation assays as the effect shown in wound healing assay. Pretreatment with FRGE suppressed histamine-induced proliferation and migration by 50.1±3.7% and 45.8±6.9%, respectively. In addition, the FRGE pretreatment reduced the contractile ability of HABSMCs enhanced by histamine.
Conclusions:
These results show that FRGE pretreatment reduces histamine-induced cell proliferation, migration and contraction in HABSMCs. We suggest that FRGE could be used as a medicinal food for treatment of asthma to prevent airway remodeling processes.