Effects of Qingre Huoxue Jiedu Formula on Nerve Growth Factor-Induced Psoriasis

Objective To elucidate the mechanisms of 4 effective components from a Chinese medicine formula, namely Qingre Huoxue Jiedu Formula (QHJ heat- and toxin-clearing and blood-activating formula), in the treatment of nerve growth factor (NGF)-induced psoriasis. Methods Keratinocyte proliferation and T cell proliferation models were developed using NGF. An NGF solution (NGF+DMEM, 100 ng/mL) was added to all induced groups and treated groups and were cultured for 24 h, while a solution with NTRK1 antagonist (K252a+DEME, 300 nmol/L) was added and cultured for 1 h. The models were used to evaluate the effects of the treatment with each of the 4 components of QHJ, namely shikonin, paeonol, astilbin and ursolic acid. Cell apoptosis and proliferation were measured by flow cytometry analysis and CCK8 assay, respectively. The mRNA expression levels of Bax, Bcl-xl, and NGF receptor (NGFR) were assessed by quantitative real-time PCR (qRT-PCR) and Western blot analysis, respectively. Results (1) All QHJ-treated groups showed significantly increased cell apoptosis and inhibition of cell proliferation compared with the NGF-induced groups (P<0.05). In addition, treatment with QHJ plus NTRK1 significantly enhanced cell apoptosis and inhibition of cell proliferation compared with cells treated with QHJ only (P<0.05), particularly in cells treated with ursolic acid. (2) QHJ-treated groups showed higher protein expression levels of Bax, Bcl-xl compared with other groups (P<0.05). Additionally, treatment with QHJ plus NTRK1 significantly increased the protein expression levels of Bax, Bcl-xl and NGFR compared with those treated with QHJ only (all P<0.05), especially in those treated with shikonin. Conclusion The action mechanism of QHJ on psoriasis might be through enhancing cell apoptosis and inhibition of cell proliferation, and upregulating the expression level of Bax, Bcl-xl and NGFR.