Qinzhuliangxue mixture ameliorates psoriasis by restraining apoptosis in psoriasis via downregulating the MDA-5 pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Psoriasis is characterized by hyperkeratosis that produces the classic silvery scales, and the pathogenesis of psoriasis involves abnormal proliferation of keratinocytes. Emerging evidence supports that apoptosis regulates keratinocyte proliferation and formation of stratum corneum, which maintains the homeostasis of the skin. Qinzhuliangxue mixture (QZLX) is a representative formula for the treatment of psoriasis, which was earliest recorded in the classic Chinese medicine book Xia's Surgery. In our previous clinical studies, QZLX demonstrated 83.33% efficacy with few side effects in the treatment of psoriasis. Furthermore, our published basic research has also proved that the QZLX mixture effectively inhibits the hyperproliferation of keratinocytes, thus exerting therapeutic effects on psoriasis. However, whether QZLX mixture can regulate keratinocytes apoptosis requires further clarification.

OBJECTIVE OF THE STUDY

To investigate the mechanism of QZLX in the treatment of psoriasis from the perspective of keratinocyte apoptosis.

MATERIALS AND METHODS

First, psoriasis-like mice with imiquimod (IMQ)-induced were given QZLX intragastric administration and Psoriasis Area Severity Index (PASI) scores were recored for 11 consecutive days to appraise the efficacy. Then, tissue samples were collected for transcriptome analysis. The DEseq2 method detected significantly differentially expressed genes (DEGs), Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) Pathway databases were used to analyze the functions and pathway enrichment of DEGs. After that, the therapeutic mechanisms of QZLX in intervening with psoriasis were explored using TUNEL, immunohistochemical staining, and western blotting.

RESULTS

QZLX ameliorated the symptoms and pathological characteristics of IMQ-induced psoriasis in mice. The epidermal cell hyperplasia in the skin was inhibited, in accordance with the suppressed expression of PCNA and Ki67 after treatment. Transcriptome sequencing showed that melanoma differentiation associated gene-5 (MDA-5) was downregulated. GO and KEGG enrichment analysis of the signaling pathways indicated that the differentially expressed genes were significantly enriched in apoptosis pathways. Besides, QZLX treatment decreased the apoptosis of keratinocyte as shown by reduced TUNEL-positive cells. As MDA-5 protein levels decreased, so did the expression of the downstream protein Caspase-8, which indicates that the apoptotic pathway was triggered. Furthermore, QZLX therapy might also help to balance the apoptotic Bcl-2 family expression.

CONCLUSION

QZLX restrains the apoptosis of keratinocyte in psoriasis-like mice by downregulating the MDA-5 pathway. The restoration of the balance between cell apoptosis and proliferation in the skin may lead to considerable psoriasis relief. Our study reveals the possible molecular processes behind the effects of QZLX therapy on the skin lesions of psoriasis, and lends support to its clinical efficacy.

Qinzhuliangxue mixture alleviates psoriasis-like skin lesions via inhibiting the IL6/STAT3 axis

ETHNOPHARMACOLOGICAL RELEVANCE

Psoriasis is a chronic inflammatory skin disease mediated by immunity. Our pre-clinical studies have proved that QZLX mixture can improve patients' clinical symptoms with psoriasis without noticeable adverse reactions. In a psoriasis-like mouse model induced by imiquimod, QZLX mixture has been shown to alleviate epidermal inflammation and inhibit the hyperproliferation of keratinocytes. However, its related molecular mechanism remains to be elucidated.

AIM OF THE STUDY

To assess the mechanism of QZLX mixture against psoriasis.

MATERIALS AND METHODS

This study combines network pharmacology and experiments to study the mechanism of QZLX against psoriasis. First, construct the active compound-target network and PPI network. Secondly, determine possible drug targets through Molecular docking and KEGG. Thirdly, high-performance liquid chromatography (HPLC) was used for the quality control of QZLX. Finally, use a mouse model of psoriasis to further confirm the role of QZLX.

RESULTS

(1) Network pharmacology analysis shows that QZLX alleviates psoriasis's epidermal inflammation, and neovascularization may be achieved by inhibiting the IL6/STAT3 signaling pathway. (2) QZLX improves the pathological characteristics of IMQ-induced skin damage in psoriasis-like mice. (3) QZLX inhibits the IL6/STAT3 signaling pathway and reduces the expression of IL-17, IL-23, and TNF-α related to inflammation in peripheral blood, as well as the expression of S100A7 in the lesion area. QZLX is better than MTX in inhibiting neovascularization by down-regulating the expression of HIF-1 and CD31 in the lesion area. Finally, inhibition of Ki67 alleviates the excessive proliferation of keratinocytes.

CONCLUSION

In sum, this study clarifies the mechanism of QZLX against psoriasis and provides evidence to support its clinical use.