High-Throughput and Reliable Isotope Label-free Approach for Profiling 24 Metabolic Enzymes in FVB Mice and Sex Differences

Sulfonation of Capsaicin by sulfotransferases produces an anti-inflammatory metabolite with NF-κB pathway modulatory activity

Capsaicin (CAP), the principal bioactive component of chili peppers (Capsicum annuum L.), is widely recognized for its anti-inflammatory properties. However, its oral bioavailability is low, likely due to extensive sulfonation metabolism. Despite the well-known pharmacological benefits of CAP, the role of sulfotransferase (SULT)-mediated sulfonation in modulating its therapeutic effects remains poorly understood. This study aims to elucidate the sulfonate metabolic profile of CAP, investigate the anti-inflammatory role of its sulfonate metabolite (CAP-S), and uncover the mechanisms underlying CAP-S's anti-inflammatory effects. In our study, the mono-sulfonate metabolite of CAP, designated as CAP-S ((E)-N-[(4-sulfo-3-methoxyphenyl)methyl]-8-methylnon-6-enamide), is identified using ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) and proton nuclear magnetic resonance (1H-NMR). The metabolic profile of CAP was investigated in liver S9 fractions from human, rat, and mouse samples, with sulfonation of CAP examined using seven major recombinant SULT isoforms. The results demonstrate that CAP is primarily catalyzed by SULT1A subfamily and SULT1E1. The anti-inflammatory effects of CAP-S are evaluated in lipopolysaccharide (LPS)-stimulated RAW264.7 cells and an acute liver injury (ALI) mouse model. CAP-S significantly reduces inflammatory mediators and nitric oxide (NO) production in LPS-induced RAW264.7 cells. In vivo, CAP-S treatment alleviates hepatocyte necrosis, inflammatory cell infiltration, and reduces aspartate aminotransferase, alanine aminotransferase, and malondialdehyde levels, while enhancing superoxide dismutase activity and decreasing NO production. Additionally, CAP-S exerts comparable anti-inflammatory effects to CAP by suppressing NF-κB p65 phosphorylation and reducing pro-inflammatory cytokines, as evidenced by network pharmacology and western blot assays. These findings underscore the role of sulfonation in modulating CAP's therapeutic potential.

Integrated analysis revealing a novel stemness-metabolism-related gene signature for predicting prognosis and immunotherapy response in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a malignant lethal tumor and both cancer stem cells (CSCs) and metabolism reprogramming have been proven to play indispensable roles in HCC. This study aimed to reveal the connection between metabolism reprogramming and the stemness characteristics of HCC, established a new gene signature related to stemness and metabolism and utilized it to assess HCC prognosis and immunotherapy response. The clinical information and gene expression profiles (GEPs) of 478 HCC patients came from the Gene Expression Omnibus (GEO) and the Cancer Genome Atlas (TCGA). The one-class logistic regression (OCLR) algorithm was employed to calculate the messenger ribonucleic acid expression-based stemness index (mRNAsi), a new stemness index quantifying stemness features. Differentially expressed analyses were done between high- and low-mRNAsi groups and 74 differentially expressed metabolism-related genes (DEMRGs) were identified with the help of metabolism-related gene sets from Molecular Signatures Database (MSigDB). After integrated analysis, a risk score model based on the three most efficient prognostic DEMRGs, including Recombinant Phosphofructokinase Platelet (PFKP), phosphodiesterase 2A (PDE2A) and UDP-glucuronosyltransferase 1A5 (UGT1A5) was constructed and HCC patients were divided into high-risk and low-risk groups. Significant differences were found in pathway enrichment, immune cell infiltration patterns, and gene alterations between the two groups. High-risk group patients tended to have worse clinical outcomes and were more likely to respond to immunotherapy. A stemness-metabolism-related model composed of gender, age, the risk score model and tumor-node-metastasis (TNM) staging was generated and showed great discrimination and strong ability in predicting HCC prognosis and immunotherapy response.

Sulfation and Its Effect on the Bioactivity of Magnolol, the Main Active Ingredient of Magnolia Officinalis

Magnolol, the main active ingredient of Magnolia officinalis, has been reported to display anti-inflammatory activity. Sulfation plays an important role in the metabolism of magnolol. The magnolol sulfated metabolite was identified by the ultra-performance liquid chromatography to quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS) and a proton nuclear magnetic resonance (1H-NMR). The magnolol sulfation activity of seven major recombinant sulfotransferases (SULTs) isoforms (SULT1A1*1, SULT1A1*2, SULT1A2, SULT1A3, SULT1B1, SULT1E1, and SULT2A1) was analyzed. The metabolic profile of magnolol was investigated in liver S9 fractions from human (HLS9), rat (RLS9), and mouse (MLS9). The anti-inflammatory effects of magnolol and its sulfated metabolite were evaluated in RAW264.7 cells stimulated by lipopolysaccharide (LPS). Magnolol was metabolized into a mono-sulfated metabolite by SULTs. Of the seven recombinant SULT isoforms examined, SULT1B1 exhibited the highest magnolol sulfation activity. In liver S9 fractions from different species, the CLint value of magnolol sulfation in HLS9 (0.96 µL/min/mg) was similar to that in RLS9 (0.99 µL/min/mg) but significantly higher than that in MLS9 (0.30 µL/min/mg). Magnolol and its sulfated metabolite both significantly downregulated the production of inflammatory mediators (IL-1β, IL-6 and TNF-α) stimulated by LPS (p < 0.001). These results indicated that SULT1B1 was the major enzyme responsible for the sulfation of magnolol and that the magnolol sulfated metabolite exhibited potential anti-inflammatory effects.

Changes and sex- and age-related differences in the expression of drug metabolizing enzymes in a KRAS-mutant mouse model of lung cancer

Background

This study aimed to systematically profile the alterations and sex- and age-related differences in the drug metabolizing enzymes (DMEs) in a KRAS-mutant mouse model of lung cancer (KRAS mice).

Methodology

In this study, the LC-MS/MS approach and a probe substrate method were used to detect the alterations in 21 isoforms of DMEs, as well as the enzymatic activities of five isoforms, respectively. Western blotting was applied to study the protein expression of four related receptors.

Results

The proteins contents of CYP2C29 and CYP3A11, were significantly downregulated in the livers of male KRAS mice at 26 weeks (3.7- and 4.4-fold, respectively, p < 0.05). SULT1A1 and SULT1D1 were upregulated by 1.8- to 7.0- fold at 20 (p = 0.015 and 0.017, respectively) and 26 weeks (p = 0.055 and 0.031, respectively). There were positive correlations between protein expression and enzyme activity for CYP2E1, UGT1A9, SULT1A1 and SULT1D1 (r² ≥ 0.5, p < 0.001). Western blotting analysis revealed the downregulation of AHR, FXR and PPARα protein expression in male KRAS mice at 26 weeks. For sex-related differences, CYP2E1 was male-predominant and UGT1A2 was female-predominant in the kidney. UGT1A1 and UGT1A5 expression was female-predominant, whereas UGT2B1 exhibited male-predominant expression in liver tissue. For the tissue distribution of DMEs, 21 subtypes of DMEs were all expressed in liver tissue. In the intestine, the expression levels of CYP2C29, CYP27A1, UGT1A2, 1A5, 1A6a, 1A9, 2B1, 2B5 and 2B36 were under the limitation of quantification. The subtypes of CYP7A1, 1B1, 2E1 and UGT1A1, 2A3, 2B34 were detected in kidney tissue.

Conclusions

This study, for the first time, unveils the variations and sex- and age-related differences in DMEs in C57 BL/6 (WT) mice and KRAS mice.

Singularities of nevirapine metabolism: from sex-dependent differences to idiosyncratic toxicity

Nevirapine (NVP) is a first-generation non-nucleoside reverse transcriptase inhibitor widely used for the treatment and prophylaxis of human immunodeficiency virus infection. The drug is taken throughout the patient's life and, due to the availability of an extended-release formulation, it is administered once daily. This antiretroviral is one of the scarce examples of drugs with prescription criteria based on sex, in order to prevent adverse reactions. The therapy with NVP has been associated with potentially life-threatening liver and idiosyncratic skin toxicity. Multiple evidence has emerged regarding the formation of electrophilic NVP metabolites as crucial for adverse idiosyncratic reactions. The formation of reactive metabolites that yield covalent adducts with proteins has been demonstrated in patients under NVP-based treatment. Interestingly, several pharmacogenetic- and sex-related factors associated with NVP toxicity can be mechanistically explained by an imbalance toward increased formation of NVP-derived reactive metabolites and/or impaired detoxification capability. Moreover, the haptenation of self-proteins by these reactive species provides a plausible link between NVP bioactivation and immunotoxicity, further supporting the relevance of this toxicokinetics hypothesis. In the current paper, we review the existing knowledge and recent developments on NVP metabolism and their relation to NVP toxicity.

Age-related changes in hepatic expression and activity of drug metabolizing enzymes in male wild-type and breast cancer resistance protein knockout mice

This study aimed to reveal age-related changes in the expression and activity of seven hepatic drug metabolizing enzymes (DMEs) in male wild-type and breast cancer resistance protein knockout (Bcrp1^-/- ) FVB mice. The protein expression of four cytochrome P450 (Cyps) (Cyp3a11, 2d22, 2e1, and 1a2), and three UDP-glucuronosyltransferases (Ugts) (Ugt1a1, 1a6a, and 1a9) in liver microsomes of wild-type and Bcrp1^-/- FVB mice at different ages were determined using a validated ultra high performance liquid chromatography with tandem mass spectrometry (UHPLC-MS/MS) method. The activities and mRNA levels of these DMEs were measured using the probe substrates method and real-time PCR, respectively. In the liver of wild-type FVB mice, Cyp3a11, 2d22, 2e1, 1a2, Ugt1a1, and 1a6a displayed maximum protein levels at 6-9 weeks of age. Cyp1a2, Ugt1a1, 1a6a, and 1a9 showed maximum activities at 6-9 weeks of age, whereas Cyp3a11, 2d22, and 2e1 showed maximum activities in 1-3-week-old mice. Additionally, most of the DMEs showed maximum mRNA levels in 17-week-old mice liver. Compared with wild-type FVB mice, the protein levels of these DMEs showed no significant changes in Bcrp1^-/- FVB mice liver. However, the activity of Cyp2e1 was increased and that of Cyp2d22 was decreased. In conclusion, the seven hepatic DMEs in FVB mice liver showed significant alterations in an isoform-specific manner with increased age. Although the protein levels of these DMEs showed no significant changes, the activities of Cyp2e1 and 2d22 were changed in Bcrp1^-/- mice.

Profiles and Gender-Specifics of UDP-Glucuronosyltransferases and Sulfotransferases Expressions in the Major Metabolic Organs of Wild-Type and Efflux Transporter Knockout FVB Mice

Hepatic and extrahepatic tissues participate in xenobiotic detoxication, carcinogen activation, prodrug processing, and estrogen regulation through UDP-glucuronosyltransferases (UGTs/Ugts) and sulfotransferases (SULTs/Sults). Wild-type (WT) and efflux transporter knockout (KO) FVB mice have been commonly used to perform the studies of pharmacokinetics, metabolism, and toxicity. We employed the developed UHPLC-MS/MS approach to gain systematic insight on gender-specific of Ugts and Sults in major metabolic organs. Results showed that the liver was the most abundant with Ugts/Sults, followed by the small intestine and the kidney. In the liver, Ugt2b5, Ugt2b1, Ugt1a6a, Ugt1a1, Sult1a1, and Sult1d1 were the major isoforms. The protein amounts of Ugt1a9 were significantly higher in male efflux transporter KO mice than in WT mice, whereas Ugt1a5 and Sult1a1 severely decreased in female efflux transporter KO mice. In WT and efflux transporter KO mice, the expression levels of Ugt1a1, Ugt1a5, Sult1a1, Sult1d1, and Sult3a1 were female-specific, whereas those of Ugt2b1, Ugt2b5, and Ugt2b36 were male-specific. In the small intestine, Ugt1a1, Sult1b1, and Sult2b1 were the major isoforms. The protein levels and gender differences of Ugts/Sults were obviously affected when KO of Mdr1a, and Bcrp1, Mrp1, Mrp2, and Mdr1a, respectively. The KO of efflux transporter affected the protein amounts of Ugts/Sults in the kidney, heart, and spleen. Therefore, a better understanding of the expression profiles and gender-specific of Ugts and Sults in major metabolic organs of WT and efflux transporter KO mice is useful for the evaluation of potential efficacy, and toxicity of corresponding substrates.