OBJECTIVES: Chronic obstructive pulmonary disease (COPD) is a major chronic respiratory condition with high morbidity and mortality, imposing a serious economic and public health burden. The World Health Organization ranks COPD among the top 4 chronic diseases worldwide. Zangsiwei Qingfei Mixture (ZSWQF), a novel Tibetan herbal formulation independently developed by our research team, has shown therapeutic potential for chronic respiratory diseases. This study aims to evaluate the effects of aerosolized ZSWQF on cigarette smoke-induced COPD in mice and explore its underlying mechanisms. METHODS: Thirty C57 mice were randomly divided into a Control group, a COPD group, and a ZSWQF group. The Control group received saline aerosol inhalation without cigarette smoke exposure; both the COPD group and the ZSWQF group were exposed to cigarette smoke, with the former receiving saline inhalation and the latter treated with ZSWQF aerosol. White blood cell (WBC) count was performed using a fully automatic blood cell analyzer. Serum, alanine transaminase (ALT), and serum creatinine (SCr), as well as interleukin (IL)-6, IL-8, and tumor necrosis factor (TNF)-α levels in serum and bronchoalveolar lavage fluid (BALF) were measured by enzyme-linked immunosorbent assay (ELISA). BALF cell classification was determined using a hematology analyzer. Lung function was assessed with a small animal pulmonary function system, including airway resistance (RI) and cyclic dynamic compliance (CyDN). Lung tissues were stained with hematoxylin and eosin (HE), and mean linear intercept (MLI) and destruction index (DI) were calculated to evaluate morphological changes. Network pharmacology was applied to identify disease-related and ZSWQF-related targets, followed by intersection and protein-protein interaction (PPI) network analysis, and enrichment analysis of biological functions and pathways. Primary type II alveolar epithelial cell (AEC II) from SD rats were isolated and divided into a Control group, a lipopolysaccharide (LPS) group, a normal serum group, a water extract of ZSWQF (W-ZSWQF) group, a ZSWQF containing serum group, and a MLN-4760 [angiotensin-converting enzyme (ACE) 2 inhibitor]. Western blotting was performed to assess protein expression of ACE, p38 [a mitogen-activated protein kinase (MAPK)], phospho (p)-p38, extracellular signal-regulated kinases 1 and 2 (ERK1/2), p-ERK1/2, c-Jun N-terminal kinase (JNK), p-JNK, inhibitor of nuclear factor-kappa B alpha (IκBα), p-IκBα, and p-p65 subunit of nuclear factor-kappa B (NF-κBp65). RESULTS: WBC counts were significantly higher in the COPD group than in controls (P<0.01) and decreased following ZSWQF treatment (P<0.05). No significant intergroup differences were found in organ weights, ALT, or SCr (all P>0.05). Serum and BALF levels of IL-6, IL-8, and TNF-α, as well as total BALF cells, neutrophils, and macrophages, were elevated in the COPD group compared with controls and reduced by ZSWQF treatment (P<0.05). COPD mice exhibited increased RI, decreased CyDN, marked alveolar congestion, inflammatory infiltration, thickened septa, and higher MLI and DI values versus controls (P<0.05); ZSWQF treatment significantly reduced MLI and DI (P<0.05). Network pharmacology identified 151 potential therapeutic targets for ZSWQF against COPD, with key nodes including TNF, IL-6, protein kinase B (Akt) 1, albumin (ALB), tumor protein p53 (TP53), non-receptor tyrosine kinase (SRC), epidermal growth factor receptor (EGFR), signal transducer and activator of transcription 3 (STAT) 3, matrix metalloproteinase (MMP)-9, and beta-catenin (CTNNB1). Enrichment analysis indicates involvement of cancer-related, phosphatidylinositol 3-kinase (PI3K)/Akt, hypoxia-inducible factor (HIF)-1, calcium, and MAPK signaling pathways. Western blotting results showed that compared with the LPS group, AEC II treated with ZSWQF-containing serum exhibited decreased expression of ACE, p-p38/p38, p-ERK1/2/ERK1/2, p-JNK/JNK, p-IκBα/IκBα, and p-NF-κBp65, while ACE2 expression was upregulated, consistent with the MAPK/nuclear factor-kappa B (NF-κB) pathway regulation predicted by network pharmacology. CONCLUSIONS Aerosolized ZSWQF provides protective effects in COPD mice by reducing airway inflammation and remodeling.
Animals ; Pulmonary Disease, Chronic Obstructive/etiology* ; Drugs, Chinese Herbal/therapeutic use* ; Mice ; Mice, Inbred C57BL ; Male ; Network Pharmacology ; Smoke/adverse effects* ; Bronchoalveolar Lavage Fluid ; Administration, Inhalation ; Inflammation/drug therapy* ; Tumor Necrosis Factor-alpha ; Lung/drug effects* ; Interleukin-6/blood*

OBJECTIVES: To investigate the therapeutic mechanism of Thesium chinense Turcz. (TCT) for antibiotic-associated diarrhea (AAD). METHODS: Network pharmacology, KEGG pathway enrichment analysis and molecular docking were used to identify the shared targets and genes of TCT and AAD, the key signaling pathways and the binding between the active components in TCT and the core protein targets. In a Kunming mouse model of AAD established by intragastric administration of lincomycin hydrochloride, the effects of daily gavage of 1% carboxymethyl cellulose sodium or TCT gel solutions at 1.5 g/kg and 3 g/kg (n=10) on body weight and diarrhea were observed. HE staining, ELISA, 16S rRNA sequencing, and Western blotting were used to examine pathologies, expression levels of IL-6 and TNF-α, changes in gut microbiota, and protein expressions of EGFR, p-EGFR, PI3K, p-PI3K, Akt, and p-Akt in the colon tissues of the mice. RESULTS: We identified a total of 66 active components of TCT and 68 core targets including EGFR, STAT3 and PIK3CA. KEGG pathway enrichment analysis suggested that the therapeutic effects of TCT was mediated primarily through the PI3K/Akt signaling pathway. Molecular docking showed that EGFR had the highest binding affinity with coniferin, and the EGFR-coniferin complex maintained a stable conformation at 10 ns, whose stability was also confirmed by Gibbs free energy analysis. In the mouse models of AAD, treatment with TCT significantly improved colonic tissue morphology, decreased colonic levels of TNF-α and IL-6, increased gut microbiota diversity, and modulated the relative abundances of the key genera including Lactobacillus and Bacteroides. TCT treatment also markedly reduced protein expressions of p-EGFR, p-PI3K and p-Akt in the colon tissues of the mice. CONCLUSIONS TCT can alleviate AAD in mice by modulating gut microbiota composition, regulating the EGFR/PI3K/Akt signaling pathway, and reducing TNF‑α and IL-6 expressions.
Animals ; Gastrointestinal Microbiome/drug effects* ; Signal Transduction/drug effects* ; Mice ; ErbB Receptors/metabolism* ; Proto-Oncogene Proteins c-akt/metabolism* ; Diarrhea/drug therapy* ; Phosphatidylinositol 3-Kinases/metabolism* ; Anti-Bacterial Agents/adverse effects* ; Drugs, Chinese Herbal/therapeutic use* ; Molecular Docking Simulation

OBJECTIVES: To explore the bioactive components in Jiawei Xiaoyao Pills (JWXYP) and their mechanisms for alleviating depression-like behaviors. METHODS: The active compounds, key targets, and pathways of JWXYP were identified using TCMSP and TCMIP databases. Thirty-six SD rats were randomized equally into 6 groups including a control group and 5 chronic unpredictable mild stress (CUMS)-induced depression groups. After modeling, the 5 model groups were treated with daily gavage of normal saline, 1.8 mg/kg fluoxetine hydrochloride (positive control drug), or JWXYP at 1.44, 2.88, and 4.32 g/kg. The depression-like behaviors of the rats were evaluated using behavioral tests, and pathological changes in the liver and hippocampus were examined with HE staining. The biochemical indicators in the serum and brain tissues were detected using ELISA. Serum metabolomics analysis was performed to identify the differential metabolites using OPLS-DA, and gut microbiota changes were analyzed using 16S rDNA sequencing. RESULTS: Network pharmacology revealed that menthone and paeonol in JWXYP were capable of penetrating the blood-brain barrier to regulate inflammatory pathways and protect the nervous system. In the rat models subjected to CUMS, treatment with JWXYP significantly improved body weight loss, sucrose preference and open field activities, reduced liver inflammation, alleviated structural changes in the hippocampal neurons, decreased serum levels of TNF‑α, IL-1β, IL-6 and LBP, and increased 5-HT and VIP concentrations in the serum and brain tissue, and these effects were the most pronounced in the high-dose group. Metabolomics analysis showed changes in such metabolites as indole-3-acetamide and acetyl-L-carnitine in JWXYP-treated rats, involving the pathways for bile acid biosynthesis and amino acid metabolism. 16S rDNA analysis demonstrated increased gut microbiota diversity and increased abundance of Lactobacillus species in JWXYP-treated rats. CONCLUSIONS JWXYP alleviates depression-like symptoms in rats by regulating the neurotransmitters, inhibiting inflammation and oxidation, and modulating gut microbiota.
Animals ; Drugs, Chinese Herbal/therapeutic use* ; Gastrointestinal Microbiome/drug effects* ; Rats, Sprague-Dawley ; Depression/drug therapy* ; Neurotransmitter Agents/metabolism* ; Rats ; Inflammation ; Male ; Hippocampus ; Behavior, Animal/drug effects*

OBJECTIVES: To study the therapeutic mechanism of Tuihuang Mixture against cholestasis. METHODS: Forty-eight Wistar rats were randomized equally into blank group, model group, ursodeoxycholic acid group and Tuihuang Mixture group. Except for those in the blank group, all the rats were given α‑naphthylisothiocyanate (ANIT) to establish rat models of cholestasis, followed by treatments with indicated drugs or distilled water. Serum levels of ALT, AST, ALP, γ-GT, TBA and TBIL of the rats were determined, and hepatic expressions IL-1β, IL-18, FXR, NLRP3, ASC, Caspase-1 and GSDMD were detected using q-PCR, ELISA or Western blotting. Histopathological changes of the liver tissues were observed using HE staining. RESULTS: The rat models of cholestasis had significantly increased serum levels of ALT, AST, ALP, γ-GT, TBA and TBIL with increased mRNA and protein expressions of IL-1β and IL-18, decreased protein and mRNA expressions of FXR, and increased protein expressions of NLRP3 and Caspase-1 and mRNA expressions of NLRP3, ASC, Caspase-1 and GSDMD in the liver tissue, showing also irregular arrangement of liver cells, proliferation of bile duct epithelial cells and inflammatory cells infiltration. Treatment of the rat models with Tuihuang Mixture significantly decreased serum levels of ALT, AST, ALP, γ-GT, TBA and TBIL, lowered IL-1β and IL-18 and increased FXR protein and mRNA expressions, and reduced NLRP3, ASC, Caspase-1 and GSDMD proteins and NLRP3, ASC and Caspase-1 mRNA expressions in the liver tissue. Tuihuang Mixture also significantly alleviated hepatocyte injury, bile duct epithelial cell proliferation and inflammatory cell infiltration in the liver of the rat models. CONCLUSIONS Tuihuang Mixture can effectively improve cholestasis in rats possibly by inhibiting NLRP3 inflammatosome-mediated pyroptosis via regulating FXR.
Animals ; NLR Family, Pyrin Domain-Containing 3 Protein ; Rats ; Receptors, Cytoplasmic and Nuclear/metabolism* ; Cholestasis/drug therapy* ; Rats, Wistar ; Inflammasomes/metabolism* ; 1-Naphthylisothiocyanate ; Drugs, Chinese Herbal/therapeutic use* ; Male ; Interleukin-18/metabolism* ; Caspase 1/metabolism* ; Interleukin-1beta/metabolism* ; Liver/metabolism*

OBJECTIVES: To assess the efficacy and safety of Tiaozhou Ziyin (TZZY) recipe for treatment of premature ovarian insufficiency (POI) and explore the possible mechanisms. METHODS: We used bioinformatics analyses and network pharmacology to identify the main active ingredients in TZZY recipe and their core targets, which were verified by Western blotting. We tested the efficacy and safety of the recipe in 60 POI patients, who were randomized into control group (n=30) with Femoston treatment and TZZY group (n=30) with additional TZZY recipe treatment for 3 menstrual cycles. RESULTS: The core active ingredients of TZZY recipe included kaempferol, β-sitosterol, luteolin, and quercetin. The core targets included SRC, TP53, STAT3, PIK3CA, and MAPK3, which were involved in positive regulation of cell movement and protein phosphorylation, the cancer pathways and the PI3K-Akt signaling pathway. Molecular docking showed that the core active ingredients had good binding ability with the core targets. In female rat models of POI, TZZY recipe treatment significantly up-regulated ovarian expressions of p-PI3K and p-Akt proteins. In the clinical trial, treatment with Femoston and Femoston plus TZZY recipe both significantly increased E₂ levels and reduced FSH and LH levels and Kupperman scores of the patients, and the combined treatment produced significantly stronger effects. Both treatments increased the number of antral follicles of the patients, but the combined treatment also significantly increased the levels of AMH. CONCLUSIONS The therapeutic mechanism of TZZY recipe for POI involves multiple active ingredients, multiple therapeutic targets and multiple pathways, and activating the PI3K /Akt pathway is one of its main mechanisms of action, to improve ovarian reserve function, alleviate clinical symptoms, and enhance clinical efficacy in POI patients.
Female ; Primary Ovarian Insufficiency/drug therapy* ; Humans ; Drugs, Chinese Herbal/therapeutic use* ; Animals ; Rats ; Molecular Docking Simulation ; Signal Transduction ; Sitosterols/therapeutic use* ; Kaempferols/therapeutic use*

OBJECTIVES: To explore the mechanism of Shenqi Buzhong (SQBZ) Formula for alleviating mitochondrial dysfunction in a rat model of chronic obstructive pulmonary disease (COPD) in light of the AMPK/SIRT1/PGC-1α pathway. METHODS: Fifty male SD rat models of COPD, established by intratracheal lipopolysaccharide (LPS) instillation, exposure to cigarette smoke, and gavage of Senna leaf infusion, were randomized into 5 groups (n=10) for treatment with saline (model group), SQBZ Formula at low, moderate and high doses (3.08, 6.16 and 12.32 g/kg, respectively), or aminophylline (0.024 g/kg) by gavage for 4 weeks, with another 10 untreated rats as the control group. Pulmonary function of the rats were tested, and pathologies and ultrastructural changes of the lung tissues were examined using HE staining and transmission electron microscopy. The levels of SOD, ATP, MDA, and mitochondrial membrane potential in the lungs were detected using WST-1, colorimetric assay, TBA, and JC-1 methods. Flow cytometry was used to analyze ROS level in the lung tissues, and the protein expression levels of P-AMPKα, AMPKα, SIRTI, and PGC-1α were detected using Western blotting. RESULTS: The rat models of COPD showed significantly decreased lung function, severe histopathological injuries of the lungs, decreased pulmonary levels of SOD activity, ATP and mitochondrial membrane potential, increased levels of MDA and ROS, and decreased pulmonary expressions of P-AMPKα, SIRTI, and PGC-1α proteins. All these changes were significantly alleviated by treatment with SQBZ Formula and aminophylline, and the efficacy was comparable between high-dose SQBZ Formula group and aminophylline group. CONCLUSIONS SQBZ Formula ameliorates mitochondrial dysfunction in COPD rats possibly by activating the AMPK/SIRT1/PGC-1α pathway.
Animals ; Pulmonary Disease, Chronic Obstructive/drug therapy* ; Drugs, Chinese Herbal/therapeutic use* ; Sirtuin 1/metabolism* ; Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha ; Rats, Sprague-Dawley ; Male ; Rats ; AMP-Activated Protein Kinases/metabolism* ; Mitochondria/metabolism* ; Disease Models, Animal ; Signal Transduction/drug effects*

OBJECTIVES: To investigate the therapeutic mechanism of Huoxue Shufeng Granules (HXSFG) for alleviating central sensitization in a mouse model of chronic migraine (CM). METHODS: We analyzed the main chemical components of HXSFG through literature review and explored their pharmacological mechanisms by bioinformatics analyses. In a male C57BL/6J mouse model of CM established by intraperitoneal injections of nitroglycerin (10 mg/kg) every other day (5 injections), the effects of gavage with low, and high doses of HXSFG or intraperitoneal injections of topiramate for ameliorating central sensitization were evaluated using Von Frey test and a hot plate apparatus; the changes in expressions of inflammatory factors, the proteins in the TLR4/NF‑κB signaling pathway, and activation of c-Fos and CGRP were detected using RT-qPCR, Western blotting and immunofluorescence staining. RESULTS: Network pharmacology analysis suggested that the main active components in HXSFG for alleviating CM included formononetin, paeoniflorin, quercetin, and tanshinone. Gene Ontology (GO) enrichment analysis identified 492 GO entries, comprising 366 biological processes, 46 cellular components, and 80 molecular functions. KEGG pathway enrichment analysis indicated that the Toll-like receptor and NF‑κB signaling pathways were crucial in mediating the therapeutic effects of HXSFG on CM. In the mouse models of CM, both topiramate and HXSFG treatments alleviated the symptoms of central sensitization, evidenced by improved mechanical and thermal pain thresholds in the mice. HXSFG significantly reduced the expression of c-Fos and CGRP, improved inflammatory markers, and downregulated the expressions of TLR4, p-NF‑κB, IL-1β, and TNF‑α proteins in the mouse models. CONCLUSIONS HXSFG effectively alleviates central sensitization in CM mice by modulating the inflammatory pathways and inhibiting the TLR4/ NF-κB signaling pathway, suggesting its potential as a therapeutic option for CM.
Animals ; Toll-Like Receptor 4/metabolism* ; NF-kappa B/metabolism* ; Drugs, Chinese Herbal/therapeutic use* ; Mice ; Male ; Mice, Inbred C57BL ; Signal Transduction/drug effects* ; Migraine Disorders/metabolism* ; Disease Models, Animal ; Inflammation

OBJECTIVES: To explore the mechanism by which Tougu Xiaotong Capsule (TXC) promotes chondrogenic differentiation and cartilage repair in mice with osteoarthritis (OA). METHODS: Fifty 8-week-old male C57BL mice were randomly divided into normal control group, cartilage damage (induced by subchondral ring-shaped drilling) model group and TXC treatment groups at low, moderate and high doses (184, 368 and 736 mg/kg, respectively). Saline (in normal control and model groups) and TXC were administered after modeling by daily gavage for 6 consecutive weeks. The changes of cartilage damage in the mice were assessed by measuring thermal withdrawal latency (TWL) and mechanical withdrawal threshold (MWT) and using micro-CT, modified safranine O and fast green staining, HE staining, and qPCR. Primary cultures of mouse synovial mesenchymal stem cells (SMSCs) with lentivirus vector transfection for interfering CXCL12, TXC treatment, or both for 24 h were examined for chondrogenic differentiation using immunofluorescence staining, scratch assay, immunocytochemistry, and Western blotting. RESULTS: In mouse models with cartilage damage, TXC treatment at the moderate dose significantly alleviated joint pain, promoted cartilage repair, and upregulated the mRNA expression levels of CXCL12, GDF5, collagen II, aggrecan, Comp and Sox9 in the cartilage tissue. In primary mouse SMSCs, CXCL12 knockdown resulted in significant reduction of GDF5 protein expression, migration ability and Sox9 protein expression, and these changes were obviously reversed by TXC treatment. CONCLUSIONS TXC promotes chondrogenic differentiation of mouse SMSCs to promote repair of cartilage damage in mice by activating the CXCL12/GDF5 pathway.
Animals ; Drugs, Chinese Herbal/therapeutic use* ; Osteoarthritis/metabolism* ; Male ; Growth Differentiation Factor 5/metabolism* ; Mice, Inbred C57BL ; Mice ; Chemokine CXCL12/metabolism* ; Signal Transduction/drug effects* ; Cell Differentiation/drug effects* ; Cartilage, Articular/drug effects* ; Mesenchymal Stem Cells/cytology*

OBJECTIVES: To explore the mechanism of Pingchuanning Formula (PCN) for inhibiting airway inflammation in rats with asthmatic cold syndrome. METHODS: A total of 105 SD rats were randomized equally into 7 groups, including a control group, an asthmatic cold syndrome model group, 3 PCN treatment groups at high, medium and low doses, a Guilong Kechuanning (GLCKN) treatment group, and a dexamethasone (DEX) treatment group. In all but the control rats, asthma cold syndrome models were established and daily gavage of saline, PCN, GLCKN or DEX was administered 29 days after the start of modeling. The changes in general condition, lung function and lung histopathology of the rats were observed, and inflammatory factors in the alveolar lavage fluid (BALF), oxidative stress, lung tissue ultrastructure, cytokine levels, and expressions of the genes related to the HMGB1/Beclin-1 axis and autophagy were analyzed. RESULTS: The rat models had obvious manifestations of asthmatic cold syndrome with significantly decreased body mass, food intake, and water intake, reduced FEV_0.3, FVC, and FEV_0.3/FVC, obvious inflammatory cell infiltration in the lung tissue, and increased alveolar inflammation score and counts of neutrophils, eosinophils, lymphocytes, macrophages, and leukocytes in the BALF. The rat models also had significantly increased MDA level and decreased SOD level and exhibited obvious ultrastructural changes in the lung tissues, where the expressions of HMGB1, Beclin-1, ATG5, TNF-α, IL-6,IL-1β, and IL-13 and the LC3II/I ratio were increased, while the levels of Bcl-2 and IFN-γ were decreased. PCN treatment significantly improved these pathological changes in the rat models, and its therapeutic effect was better than that of GLKCN and similar to that of DEX. CONCLUSIONS PCN can effectively alleviate airway inflammation in rat models of asthmatic cold syndrome possibly by modulating the HMGB1/Beclin-1 signaling axis to suppress cell autophagy, thereby attenuating airway inflammatory damages.
Animals ; Rats ; Autophagy/drug effects* ; Rats, Sprague-Dawley ; Asthma/pathology* ; Beclin-1 ; HMGB1 Protein/metabolism* ; Drugs, Chinese Herbal/therapeutic use* ; Disease Models, Animal ; Male ; Lung/pathology* ; Inflammation

OBJECTIVES: To investigate the therapeutic mechanism of Wendan Decoction for phlegm syndrome in rats with metabolic syndrome (MS). METHODS: Forty Wistar rats were randomly divided into normal control group (n=8) and 3 phlegm syndrome model groups (induced by high-fat, high-sugar, and high-salt feeding and a single-dose intraperitoneal STZ injection; n=24) treated with daily gavage of saline, Wendan Decoction (3.6 g/kg), or metformin (0.1 g/kg) for 4 weeks. General conditions and glucose and lipid metabolism parameters of the rats were monitored, and serum LPS, liver histopathology, hepatic expressions of FXR, CYP7A1 and FGFR4 and ileal expressions of FXR and FGF15 were examined. Gut microbiota structure was analyzed using 16S rDNA sequencing, and serum bile acids were quantified with UHPLC-MS/MS. RESULTS: The rat models of phlegm syndrome exhibited severe hepatic steatosis and necrosis, increased body weight, abdominal circumference, Lee's index, FBG, FINS, HOMA-IR, TG, TC, LDL and LPS, and decreased HDL level. The abundance of Bacteroidetes, Megamonas, and Bacteroides in gut microbiota increased while Firmicutes, Lachnospiraceae_NK4A136_group, isohyodeoxycholic acid, and glycohyodeoxycholic acid decreased significantly; hepatic FXR and FGFR4 expressions and ileal FXR and FGF15 expressions decreased while hepatic CYP7A1 expression increased significantly in the rat models. Treatment with Wendan Decoction effectively alleviated hepatic pathology, reduced body weight and abdominal circumference, improved glucose and lipid metabolic profiles and gut microbiota structure, and reversed the changes in hepatic and ileal protein expressions. Correlation analysis revealed that Firmicutes and Lachnospiraceae_NK4A136_group were positively correlated while Bacteroidetes, Megamonas and Bacteroides were negative correlated with the levels of isohyodeoxycholic acid and hyodeoxycholic acid. CONCLUSIONS Wendan Decoction can significantly improve metabolic profiles in rats with phlegm syndrome of MS possibly by regulating the intestinal flora-bile acid axis to modulate the intestinal flora structure and maintain bile acid homeostasis via the FXR signaling pathway.
Animals ; Gastrointestinal Microbiome/drug effects* ; Metabolic Syndrome/microbiology* ; Bile Acids and Salts/metabolism* ; Rats, Wistar ; Drugs, Chinese Herbal/therapeutic use* ; Rats ; Male ; Fibroblast Growth Factors/metabolism* ; Liver/metabolism* ; Cholesterol 7-alpha-Hydroxylase/metabolism* ; Receptors, Cytoplasmic and Nuclear/metabolism*