Qisheng wan decoction alleviates the inflammation of CCI rats via TRP channels.

Ethnopharmacological relevance: Qisheng wan decoction (QWD), a traditional Chinese medicine, has promising potential anti-inflammatory effects against neuropathic pain (NP). However, its valid ingredients and specific anti-inflammatory mechanisms are still unclear.

Aim of the study: This study aimed to identify the active ingredients of QWD responsible for its anti- inflammatory effect by combining liquid chromatography with network pharmacology, and to explore its anti- inflammatory mechanism by chronic constriction injury (CCI) model rats.

Materials and methods: The UHPLC-Q Exactive Orbitrap-MS technique was used to identify the active ingredients of QWD. The potential ingredients of QWD, which targeted to the pathways of treating NP, were performed by network pharmacology, molecular docking and molecular dynamics simulations. After CCI rats-induced NP model operation, QWD (5.6 g/kg/d, 11.2 g/kg/d, 22.4 g/kg/d) and Pregabalin (10g/kg/d) as positive controls, were administered to the rats for 7 days. The behaviors of the different groups were tested at 0, 1, 3, 5, 7, 12 days, respectively. And the inflammatory factor including tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) was detected by ELISA. Meantime, the inflammation of the sciatic nerve was evaluated by the hematoxylin-eosin staining. Ionized calcium-binding adapter molecule-1 (Iba-1) and glial fibrillary acidic protein (GFAP) were detected by immunohistochemistry. Moreover, the expressions of TRPA1, TRPV1, TRPV2, TRPV3, TRPV4, TRPM8, and P38 mitogen-activated protein kinase (MAPK) were tested by RT-PCR, western blot, and immunohistochemistry.

Results: After screening by the liquid chromatography and network pharmacology approach, seventy ingredients of QWD were identified, and seven core targets including oncogene tyrosine-protein kinase (SRC), mitogen-activated protein kinase 3 (MAPK3), signal transducer and activator of transcription 1 (STAT1), protein-serine-threonine kinase 1 (AKT1), mitogen-activated protein kinase 1 (MAPK1), TNF-α, and IL-6 were confirmed. Six active ingredients exhibited binding energies less than -5 kcal/mol, and the complexes were structurally stable within 50 ns. Pathway analysis indicated that transient receptor potential (TRP) channels were mainly responsible for anti-inflammatory mediator regulation. Compared with the CCI group, the behavioral tests showed that QWD-L, QWD-M, and QWD-H group alleviated mechanical, thermal and cold hyperalgesia (p<0.05). HE staining results found out QWD-L, QWD-M, and QWD-H group decreased the inflammation of the sciatic nerve (p<0.05). Similarly, compared with the CCI group, the serum level of TNF-α and IL-6 of QWD groups decreased conformably (p<0.05). This reduction was downtrend with the inhibition of Iba-1, GFAP, and the TRP channel signaling pathway and p38 MAPK.

Conclusions: This study provides a primary investigation of the composition of QWD for its anti- inflammation effect and its molecular mechanism in CCI model rats. And this therapeutic efficacy of QWD was achieved by decreasing the inflammation. QWD also inhibited the level TNF-α and IL-6 and decreasing the activation of Iba-1 and GFAP in glia. And this anti-inflammation mechanism involved in inhibiting the TRPA1, TRPV1, TRPV2, TRPV4, and TRPM8 and p38 MAPK signaling pathways. These findings provide a scientific and theoretical basis for the prevention and treatment of NP with QWD.