Metabolomics focuses on the comprehensive analysis of overall metabolites in biological samples, including known and unknown metabolites (Zhang et al., 2012; Liang et al., 2015; Li et al., 2018), and give more emphasis on the identification of unknown metabolites. Currently, metabolomics is often analyzed by mass spectrometry (MS) technology in the mode of multiple reaction monitoring (MRM) and parallel reaction monitor (Zhang et al., 2013a; Liang et al., 2016a; Nan et al., 2016). MS plays a dominant analytical platform in metabolomics for its quantitatively and qualitatively measuring metabolites with robustness and high-throughput properties (Zhang et al., 2015; Wang et al., 2019; Pareek et al., 2020). Liquid chromatography-mass spectrometry (LC-MS) is the most widely used metabolomics analysis platform because of its high resolution and sensitivity (Zhang et al., 2013b; Liang et al., 2016b; Zhang et al., 2018). The introduction of ultra-high performance LC improved the efficiency of the chromatographic column, peak resolution and sensitivity. In addition, with a variety of ion sources, UPLC can be associated with a variety of MS detectors, resulting in a broader metabolite coverage (Liang et al., 2017; Qiu et al., 2017; Zhang et al., 2019a). Other MS technologies, such as MS imaging, direct injection MS analysis, etc., can also be used for metabolomics analysis, which provides a variety and broad platforms for metabolomics research (Wang et al., 2016; Zhang et al., 2016; Ren et al., 2018). Metabolomics is a powerful approach to discovering the disease biomarkers, metabolic mechanisms and targets for drugs (Li et al., 2017; Xiong et al., 2020; Xiong et al., 2021).

Prostatitis is a common and multiple disease in middle-aged men, which inevitably affect physical and psychological health of the patients, however, the therapeutic drugs are still rare (Meng et al., 2018). Magnoflorine (Mag), a quaternary aporphine alkaloid, possesses a wide spectrum of pharmacological activities, such as anti-inflammatory, anti-diabetic, immunomodulatory, hypotensive, neuropsychopharmacological, antioxidant, and antifungal activities (Xu et al., 2020). Recently, magnoflorine has received attention due to its multiple pharmacological activities. It has a treatment of diseases including allergies, hypertension, inflammatory ones, osteoporosis, bacterial, fungal infections, and cancer, diabetes, obesity, dementia, or depression (Okon et al., 2020). Mag could prevent inflammatory osteolysis by suppressing MAPK and NF-κB signaling (Sun et al., 2020a). Mag can exert significant anti-inflammatory effects by Inducing Autophagy, Apoptosis and Cell Cycle Arrest (Sun et al., 2020b). Mag could protect against acute lung injury by inhibiting TLR4-mediated NF-κB and MAPK signaling pathways (Guo et al., 2018).

These researches have fully demonstrated the scientific value of Mag in treating prostatic disease. However, it is urgently required togain a better understanding of the molecular mechanisms and targets. We demonstrated the potential of meabolomics approaches to identify candidate biomarker of interest. However, the related material basis is still no sign of a breakthrough. Therefore, we selected the prostatitis model to explore the intervention effect of Mag from the perspective of metabolomics, and provide reliable experimental data for therapeutic material basis of Mag treating prostatitis.

In this study, capsaicin was used to prepare the rat model of prostatitis. We evaluated the prostatitis model by classical behavior and prostate protein exudation. The results of eye movement and activity, protein exudation and histopathological sections showed that the pain symptoms of prostatitis occurred after capsaicin injection into the prostatic tissue of the rats, which indicated that the rat model of prostatitis was replicated successfully. According to the relevant consequences, it can be seen that the Mag alkaloid could significantly improve the symptoms of prostatitis. The difference of metabolic profiles of endogenous molecules in vivo can bee analyzed by means of metabolomics method (Wang et al., 2013; Wang et al., 2014; Zhang et al., 2019b). They were grouped into two clusters distinctly, means that the replication of the model was successful at the metabolomics level. A total of 25 biomarkers related to the rat model of prostatitis were identified in positive and negative modes, and the metabolic pathways associated with the prostatitis model were discovered.

Based on analysis of contour characterization and pattern recognition, it was found that oral administration of Mag alkaloids could affect the potential biomarkers of the prostatitis model, and the content of them tends to be regulated to near the level of the control group. Among 18 potential biomarkers of prostatitis rat model, 11 potential biomarkers related to the prostatitis model were regulated, which may improve the situation of endogenous metabolites. Levels of 18-hydroxycortisol, 18-hydroxyarachidonic acid, uric acid and3-hydroxycapric acid were adjusted greatly. Uric acid has antioxidant property that prevents the development of inflammatory environments (Zhang et al., 2014b; Qiu et al., 2020; Zhang et al., 2020). The remarkable reversal of L-leucine and L-tyrosine may correct the abnormality of amino acid metabolism (Zhang et al., 2014a; Song et al., 2017; Zhang et al., 2017). Regulation of LysoPC(22:0) has an important effect on lipid metabolism. The above results indicated that alkaloids have an effective intervention therapy for prostatitis, and five types of metabolic pathways closely related to prostatitis model were obtained, including phenylalanine, tyrosine and tryptophan biosynthesis, phenylalanine metabolism, tyrosine metabolism, arginine and proline metabolism, glycine, serine and threonine metabolism, alanine, aspartate and glutamate metabolism.

Magnoflorine (Mag) has multiple pharmacological activities for the prevention and treatment of prostatitis. The promising metabolomics strategy has been used for reveling the metabolic biomarkers, ans efficacy mechanisms, as well as pharmacological targets for drugs (Qiu et al., 2021; Ren et al., 2021; Zhang et al., 2021). In this work, metabolomics method was used to clarify the intervention of Mag against prostatitis and the biological mechanism. The biomarkers associated with the prostatitis model were identified and a number of metabolic pathways closely related to the model were also obtained. It was found that Mag had regulative effects on potential biomarkers, which can regulate them to the control group and five types of metabolic pathways closely related to prostatitis model were obtained, including phenylalanine, tyrosine and tryptophan biosynthesis, phenylalanine metabolism, tyrosine metabolism, etc. This work has provided the experimental data for the development of Mag in the treatment of prostatitis.

This work used UPLC-MS/MS to explore the blood metabolomics and therapeutic effects of Mag against chronic non-bacterial prostatitis. Through the analysis of the metabolic profiles, there were 25 biomarkers have been defined, which were closely relevant to the occurrence and development of prostatitis. The results showed that Mag could regulate the expression abnormality of biomarkers, and adjust the abnormal metabolic profile close to the normal condition. Mag could inhibit the development of inflammatory symptom, and effectively intervene the treatment of prostatitis. It serves as a theoretical basis for further study of the therapeutic and preventive effects of Mag on chronic non-bacterial prostatitis.