Development of a sensitive and rapid UHPLC-MS/MS method for simultaneous quantification of nine compounds in rat plasma and application in a comparative pharmacokinetic study after oral administration of Xuefu Zhuyu Decoction and nimodipine

N6-methyladenosine profiling reveals that Xuefu Zhuyu decoction upregulates METTL14 and BDNF in a rat model of traumatic brain injury

ETHNOPHARMACOLOGICAL RELEVANCE

The traditional Chinese herbal formula Xuefu Zhuyu decoction (XFZYD) is a classic formula in the category of invigorating blood circulation and resolving blood stasis. It has been proven to improve the neurological and ethological prognosis of traumatic brain injury. XFZYD promotes synaptic and axonal regeneration after traumatic brain injury, which is functionally modulated by the N6-methyladenosine (m6A) modification of RNA. However, the epigenetic effects of XFZYD on m6A modification remain unknown.

AIM OF THE STUDY

To explore how XFZYD protects against traumatic brain injury induced by controlled cortical impact (CCI) injury by altering RNA m6A modification.

MATERIALS AND METHODS

The modified neurological severity scoring and Morris water maze were performed to evaluate the neuroprotective effects of XFZYD for 14 days and screen the dose. Then, dot blot, western blotting, and methylated RNA immunoprecipitation sequencing (MeRIP-Seq) were used to explore changes in RNA m6A modification in the perilesional cortex. The Metascape platform was used to analyze the Gene Ontology, Kyoto Encyclopedia of Genes and Genomes (KEGG), and Reactome pathway of the differential m6A-tagged genes. Furthermore, MeRIP-qPCR was conducted to quantify differences in the hub differential m6A modification gene brain-derived neurotrophic factor (Bdnf).

RESULTS

XFZYD significantly ameliorated the neurological deficits, spatial learning, and memory impairments in rats post-CCI on day 14. XFZYD enhanced the m6A level, and the expression of METTL14 and YTHDC2 in the perilesional cortex of CCI rats. In all three groups, the 3'-untranslated regions and coding sequence were primarily enriched for m6A peaks. XFZYD reversed the increased proportion of 3'-untranslated regions, and the decreased proportion of coding sequence and 5'-untranslated regions post-CCI. Moreover, XFZYD markedly downregulated 41 elevated m6A-tagged transcripts and upregulated 119 decreased m6A-tagged transcripts following CCI. Gene ontology and KEGG pathway analysis revealed that XFZYD-regulated m6A-tagged transcripts were predominantly enriched in synapse assembly, synaptic plasticity, learning or memory, and MAPK signaling pathway. Then, the hub-regulated m6A-tagged gene BDNF was identified. Both the m6A methylation level and the protein level of BDNF were ascended by XFZYD treatment.

CONCLUSION

XFZYD improves neurological deficits, spatial learning and memory impairments in rats post-TBI probably through increasing the expression of METTL14 and BDNF in the cortex. Our study highlights a novel post-transcriptional regulation mechanism mediated by herbal medicine for traumatic brain injury treatment.

Bioinformatics Analysis of miRNAs and mRNAs Network-Xuefu Zhuyu Decoction Exerts Neuroprotection of Traumatic Brain Injury Mice in the Subacute Phase

Xuefu Zhuyu decoction (XFZYD) is used to treat traumatic brain injury (TBI). XFZYD-based therapies have achieved good clinical outcomes in TBI. However, the underlying mechanisms of XFZYD in TBI remedy remains unclear. The study aimed to identify critical miRNAs and putative mechanisms associated with XFYZD through comprehensive bioinformatics analysis. We established a controlled cortical impact (CCI) mice model and treated the mice with XFZYD. The high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) confirmed the quality of XFZYD. The modified neurological severity score (mNSS) and Morris water maze (MWM) tests indicated that XFZYD improved the neurological deficit (p < 0.05) and cognitive function (p < 0.01). Histological analysis validated the establishment of the CCI model and the treatment effect of XFZYD. HE staining displayed that the pathological degree in the XFZYD-treated group was prominently reduced. The transcriptomic data was generated using microRNA sequencing (miRNA-seq) of the hippocampus. According to cluster analysis, the TBI group clustered together was distinct from the XFZYD group. Sixteen differentially expressed (5 upregulated; 11 downregulated) miRNAs were detected between TBI and XFZYD. The reliability of the sequencing data was confirmed by qRT-PCR. Three miRNAs (mmu-miR-142a-5p, mmu-miR-183-5p, mmu-miR-96-5p) were distinctively expressed in the XFZYD compared with the TBI and consisted of the sequencing results. Bioinformatics analysis suggested that the MAPK signaling pathway contributes to TBI pathophysiology and XFZYD treatment. Subsequently, the functions of miR-96-5p, miR-183-5p, and miR-142a-5p were validated in vitro. TBI significantly induces the down-expression of miR-96-5p, and up-expression of inflammatory cytokines, which were all inhibited by miR-96-5p mimics. The present research provides an adequate fundament for further knowing the pathologic and prognostic process of TBI and supplies deep insights into the therapeutic effects of XFZYD.

Metabolite profiling of Shuganzhi tablets in rats and pharmacokinetics study of four bioactive compounds with liquid chromatography combined with electrospray ionization tandem mass spectrometry

Shuganzhi Tablets (SGZT) is developed on the basis of a clinical empirical formula as a hospital preparation for the treatment of fatty liver. In this study, a rapid and highly sensitive LC-MS/MS method was established and validated for simultaneous determination of ginsenoside Re, ginsenoside Rg1, notoginsenoside R1, naringin, specnuezhenide, emodin, polydatin, hesperidin and saikosaponin A in rat plasma. Multiple reaction monitoring mode played an important role in simultaneous quantitative analysis of multiple components. The analytes were separated by the action of an ACQUITY UPLC® BEH C18 column (2.1 × 50 mm, 1.7 μm) in five minutes. The validated LC-MS/MS method was successfully applied to the pharmacokinetic analysis of hesperidin, emodin, polydatin and naringin of SGZT in rat plasma after administration. A UHPLC system couple with a quadrupole combined with time of flight mass spectrometer was used for qualitatively analyzing of the composition of SGZT and its metabolites in serum, urine, bile and feces of rats. The results showed that a total of 65 components were detected in rat biological samples, including 10 prototype components and 55 metabolites. It was speculated that the ingredients of SGZT experienced mainly the following reactions in rats: phase I reaction such as hydrolysis, oxidation, hydroxylation, carboxylation and dehydroxylation and phase Ⅱ reaction such as glucuronidation and sulfation. These results provide useful information for the further study of its active ingredients.