Guizhi Fuling capsules can alleviate bortezomib-induced peripheral neuropathy by decreasing Interleukin-6 levels to regulate mTOR pathway-induced autophagy.

Objective: To investigate the therapeutic effect and underlying mechanism of Guizhi Fuling capsule (GZFL) on bortezomib-induced peripheral neuropathy (BiPN).

Materials And Methods: Interleukin-6 (IL-6) levels in the plasma of Multiple myeloma (MM) patients were measured by ELISA, and correlation analysis between IL-6 and clinical features of BiPNs was performed. Then, we assess the clinical therapeutic effects of GZFL on MM patients by detecting IL-6 level, PN grade, FACT score, VAS score, MVC and SCV before and after the treatment. A combination of LC/MS and network pharmacology analysis was used to investigate the components and targets of GZFL. Then, bioinformatics was carried out. After PC12 cells were treated with GZFL, a BiPN cell model was constructed to evaluate cell autophagy function by cell viability, IL-6 levels, ROS levels, immunofluorescence staining of LC3 puncta, electron transmission electron microscopy (TEM), and Western blotting (WB). C57BL/6 mice were administered bortezomib by intraperitoneal injection to establish a model of BiPN. Nerve injury in BiPN mice was observed by measuring ethology, motor nerve conduction velocity, and IL-6. ROS, HE staining. TEM, western blotting and IHC were used to detect the expression of autophagy-related indexes.

Results: In BiPN patients, IL-6 levels were positively correlated with the PN and FACT, VAS scores. Collectively, GZFL can alleviate BiPN by reducing the level of IL-6, which is mainly manifested in the decline of PN grade, FACT, VAS score and the improvement of MVC and SCV. Thirty-four components and 107 targets of GZFL for BiPN were obtained. IL-6, mTOR, and AKT1 showed high degree values, and the significantly enriched signaling pathways were closely related to inflammatory factors and autophagy pathways, such as TNF and the mTOR signaling pathway. GZFL significantly decreased IL-6 levels in cell and animal models of BiPN. For the autophagy test, GZFL increased PC12 cell ability and the numbers of LC3 puncta and autophagic vesicles after bortezomib treatment. In vivo experiments showed that GZFL effectively improved the behavior of mice with BiPN and alleviated sciatic nerve injury. WB and IHC showed that GZFL enhanced autophagy, as indicated by the alteration of autophagy-related protein levels in PC12 cells and sciatic nerve tissue.

Conclusion: The present study confirmed that GZFL significantly ameliorates peripheral neuropathy by regulating autophagy levels via alleviating high levels of IL-6 .

Trial Registration: The link to the registration: Chinese Clinical Trial Registry (https://www.chictr.org.cn/bin/project/edit?pid=214832). The name of the trial register is "The role of mitochondrial autophagy in multiple myeloma peripheral neuropathy and the application of traditional Chinese medicine for warming Yang and removing blood stasis". The clinical trial registration number is ChiCTR2400088065.