Integrative analysis of metabolomics and proteomics reveals mechanism of berberrubine-induced nephrotoxicity.

Berberrubine (BRB), a main metabolite of berberine, has stronger hypoglycemic and lipid-lowering activity than its parent form. We previously found that BRB could cause obvious nephrotoxicity, but the molecular mechanism involved remains unknown. In this study, we systematically integrated metabolomics and quantitative proteomics to reveal the potential mechanism of nephrotoxicity caused by BRB. Metabolomic analysis revealed that 103 significant- differentially metabolites were changed. Among the mentioned compounds, significantly upregulated metabolites were observed for phosphorylcholine, sn-glycerol-3-phosphoethanolamine, and phosphatidylcholine. The top three enriched KEGG pathways were the mTOR signaling pathway, central carbon metabolism in cancer, and choline metabolism in cancer. ERK1/2 plays key roles in all three metabolic pathways. To further confirm the main signaling pathways involved, a proteomic analysis was conducted to screen for key proteins (such as Mapk1, Mapk14, and Caspase), indicating the potential involvement of cellular growth and apoptosis. Moreover, combined metabolomics and proteomics analyses revealed the participation of ERK1/2 in multiple metabolic pathways. These findings indicated that ERK1/2 regulated the significant- differentially abundant metabolites determined via metabolomics analysis. Notably, through a cellular thermal shift assay (CETSA) and molecular docking, ERK1/2 were revealed to be the direct binding target involved in BRB-induced nephrotoxicity. To summarize, this study sheds light on the understanding of severe nephrotoxicity caused by BRB and provides scientific basis for its safe use and rational development.

Unraveling the enigma: Molecular mechanisms of berberrubine-induced nephrotoxicity reversed by its parent form berberine.

BACKGROUND: Berberine is an isoquinoline alkaloid that is extensively applied in the clinic due to its potential therapeutic effects on dysentery and infectious diarrhoea. Its main metabolite, berberrubine, a promising candidate for ameliorating hyperlipidaemia, has garnered more attention than berberine. However, our study revealed that berberrubine induces severe kidney damage, while berberine was proven to be safe. PURPOSE: Herein, we explored the opposite biological effects of these two compounds on the kidney and elucidated their underlying mechanisms. METHODS: First, integrated metabolomic and proteomic analyses were conducted to identify relevant signalling pathways. Second, a click chemistry method combined with a cellular thermal shiftassay, a drug affinity responsive target stability assay, and microscale thermophoresis were used to identify the direct target proteins. Moreover, a mutation experiment was performed to study the specific binding sites. RESULTS: Animal studies showed that berberrubine, but not berberine, induced severe chronic, subchronic, and acute nephrotoxicity. More importantly, berberine reversed the berberrubine-reduced nephrotoxicity. The results indicated that the cPLA2 signalling pathway was highly involved in the nephrotoxicity induced by berberrubine. We further confirmed that the direct target of berberrubine is the BASP1 protein (an upstream factor of cPLA2 signalling). Moreover, berberine alleviated nephrotoxicity by binding cPLA2 and inhibiting cPLA2 activation. CONCLUSION: This study is the first to revel the opposite biological effects of berberine and its metabolite berberrubine in inducing kidney injury. Berberrubine, but not berberine, shows strong nephrotoxicity. The cPLA2 signalling pathway can be activated by berberrubine through targeting of BASP1, while berberine inhibits this pathway by directly binding with cPLA2. Our study paves the way for studies on the exact molecular targets of herbal ingredients. We also demonstrated that natural small molecules and their active metabolites can have opposite regulatory roles in vivo through the same signalling pathway.

Chemometrics-based Chemical Analysis of Myrrh and Its Vinegar-processed Products by UPLC-MS/MS.

Myrrh is widely used in clinical practice but accompanied by obvious toxicity. According to traditional Chinese medicines theory, processing with vinegar can effectively reduce its toxicity. However, the detoxification processing technology of Myrrh and the corresponding mechanism have been unclear. The objective of this study is to systematically analyze the variation in chemical composition of raw Myrrh and its processed products using UPLC-Q-TOF-MS/MS coupled with chemometrics. A total of 75 compounds including 56 sesquiterpenoids, 2 diterpenoids, 15 triterpenoids and 2 other types were identified. Raw Myrrh and its processed products were divided into two major groups, and 14 chemical markers were selected out by principal component analysis and partial least square discriminant analysis. Additionally, the exact content of 5 representative chemical markers was determined to be significantly reduced after vinegar-processing by UPLC-QQQ-MS/MS. Moreover, multivariate statistical analysis and the quantitative results comprehensively indicated that the optimized processing method was processing at a ratio of 200 : 5 (Myrrh:vinegar). This research provides not only a reliable foundation for the study of Myrrh, but also a scientific reference for clinical use of this herb.

Combined analysis of inorganic elements and flavonoid metabolites reveals the relationship between flower quality and maturity of Sophora japonica L.

Flos Sophorae (FS), or the dried flower buds of Sophora japonica L., is widely used as a food and medicinal material in China. The quality of S. japonica flowers varies with the developmental stages (S1-S5) of the plant. However, the relationship between FS quality and maturity remains unclear. Inductively coupled plasma optical emission spectrometry (ICP-OES) and ultra-high performance liquid chromatography coupled with electrospray ionization-triple quadrupole-linear ion trap mass spectrometry (UPLC-ESI-Q TRAP-MS/MS) were used to analyze inorganic elements and flavonoid metabolites, respectively. A combined analysis of the inorganic elements and flavonoid metabolites in FS was conducted to determine the patterns of FS quality formation. Sixteen inorganic elements and 173 flavonoid metabolites that accumulated at different developmental stages were identified. Notably, 54 flavonoid metabolites associated with the amelioration of major human diseases were identified, and Ca, P, K, Fe, and Cu were postulated to influence flavonoid metabolism and synthesis. This study offers a novel perspective and foundation for the further exploration of the rules governing the quality of plant materials.