Allicin Inhibits Keratinocytes Proliferation in HaCaT and
psoriatic lesions
Sustained abnormal proliferation is the hallmark of keratinocytes in
psoriatic lesions; thus, we investigated whether allicin inhibits the
proliferation of keratinocytes in IMQ-induced psoriatic skin. HaCaT
cells were treated with different concentrations of allicin (3.2, 6.4,
9.6, 12.8, 25.6, 51.2 μg/mL), and the cell viability was assessed by
CCK8 assays after 48h (figure 3A). The effect of allicin treatment was
concentration-dependent and significantly reduced cell viability. We
next analyzed the influence of allicin on the cell distribution in the
different cell cycle phases with flow cytometry. Allicin significantly
decreased the HaCaT cell numbers in the G0/G1 phase, whereas the number
of cells in the G2/M phase was increased compared with the control group
(Figure 3B). The percentage of cells in the G2/M increased from 21.62%
to 58.33%, indicating that allicin inhibited
the proliferation of keratinocytes
by inducing G2/M cell cycle arrest
(Figure 3C). We used immunohistochemistry analysis to examine the
expression of Ki67 in skin lesions, which is a marker expressed in
proliferating cells. Figure 3D showed that the Ki67 expression of
allicin-treatment was significantly fewer than with the IMQ-treated
group. These results demonstrate that allicin reduced epidermal
thickness by inhibiting keratinocyte hyperproliferation.