Abstract:

Objective To investigate the effects of 13-hexyl-berberine hydrochloride （HB-13） and 13-hexyl-palmatine hydrochloride （HP-13） on the activation of nuclear factor-kappa B （NF-κB） and phosphorylation of p38 mitogen-activated protein kinase （MAPK） in a human keratinocyte cell line, HaCaT stimulated by tumor necrosis factor alpha （TNF-α）. Methods HaCaT cells were cultured in the presence of various concentrations （0.39, 0.78, 1.56 μg/mL） of HB-13 or HP-13 for 120 minutes followed by the stimulation with recombinant human TNF-α for 120 minutes （in phosphorylated-IκB-α test） or 15 minutes （in phosphorylated-p38 test）. Then, HaCaT cells were disrupted, total protein was extracted, and the expressions of phosphorylated I B-α and phosphorylated p38 were detected with Western blot. HaCaT cells receiving neither pretreatment nor stimulation served as blank control, untreated HaCaT cells stimulated by rhTNF-α as stimulator control, and HaCaT cells pretreated with turmeric root tuber and stimulated by rhTNF-α as positive control. Results From 0.39 to 1.56 μg/mL, both HB-13 and HP-13 significantly inhibited the expression of p-IκB-α in HaCaT cells stimulated by rhTNF-α, and a nonsignificant dose-dependent trend was observed for their inhibitory effect, with the IC50 value being 0.441 μg/mL for HB-13 （r = -0.990, n = 3, P > 0.05） and 0.832 μg/mL for HP-13 （r = -0.992, n = 3, P > 0.05）. In contrast, neither HB-13 nor HP-13 within the experiment concentration range had a significant effect on the expression of p-p38 in HaCaT cells stimulated by rhTNF-α （P > 0.05）. Conclusions Within the experimental concentration range, both HB-13 and HP-13 can inhibit the activation of NF-κB in HaCaT cells induced by TNF-α signal, but neither of them suppress the phosphorylation of p38MAPK induced by TNF-α signal in HaCaT cells.