Bavachinin, a main compound of Psoraleae Fructus, facilitates GSDMD-mediated pyroptosis and causes hepatotoxicity in mice.

Psoraleae Fructus (PF, Psoralea corylifolia L.), a traditional medicine with a long history of application, is widely used clinically for the treatment of various diseases. However, the reports of PF-related adverse reactions, such as hepatotoxicity, phototoxic dermatitis, and allergy, are increasing year by year, with liver injury being the mostly common. Our previous studies have demonstrated that PF and its preparations can cause liver injury in lipopolysaccharide (LPS)-mediated susceptibility mouse model, but the mechanism of PF-related liver injury is unclear. In this study, we showed that PF and bavachinin, a major component of PF, can directly induce the expression of caspase-1 and interleukin-1ß (IL-1ß), indicating that PF and bavachinin can directly triggered the activation of inflammasome. Furthermore, pretreatment with NLR family pyrin domain-containing 3 (NLRP3), NLR family CARD domain containing 4 (NLRC4) or absent in melanoma 2 (AIM2) inflammasome inhibitors, containing MCC950, ODN TTAGGG (ODN) and carnosol, all significantly reversed bavachinin-induced inflammasome activation. Mechanistically, bavachinin dose-dependently promote Gasdermin D (GSDMD) post-shear activation and then induce mitochondrial reactive oxygen species (mtROS) production and this effect is markedly inhibited by pretreatment with N-Acetylcysteine amide (NAC). In addition, combination treatment of LPS and bavachinin significantly induced liver injury in mice, but not LPS or bavachinin alone, and transcriptome analysis further validated these results. Thus, PF and bavachinin can induce the activation of inflammasome by promoting GSDMD cleavage and cause hepatotoxicity in mice. Therefore, PF, bavachinin, and PF-related preparations should be avoided in patients with inflammasome activation-associated diseases.

Bavachinin protects the liver in NAFLD by promoting regeneration via targeting PCNA.

INTRODUCTION: Nonalcoholic fatty liver disease (NAFLD) is the most common liver disease all over the world, and no drug is approved for the treatment of NAFLD. Bavachinin (BVC) is proven to possess liver-protecting effect against NAFLD, but its mechanism is still blurry. OBJECTIVES: With the use of Click Chemistry-Activity-Based Protein Profiling (CC-ABPP) technology, this study aims to identify the target of BVC, and investigate the mechanism by which BVC exerts its liver-protecting effect. METHODS: The high fat diet induced hamster NAFLD model is introduced to investigate BVC's lipid-lowering and liver-protecting effects. Then, a small molecular probe ofBVC is designed and synthesized based on theCC-ABPP technology, and BVC's target is fished out. A series of experiments are performed to identify the target, including competitive inhibition assay, surface-plasmon resonance (SPR), cellular thermal shift assay (CETSA), drug affinity responsive target stability (DARTS) assay, and co-immunoprecipitation (Co-IP). Afterward, the pro-regeneration effects of BVC are validated in vitro and in vivo through flow cytometry, immunofluorescence, and the terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL). RESULT: In the hamster NAFLD model, BVC shows lipid-lowing effect and improvement on the histology. PCNA is identified as the target of BVC with the method mentioned above, and BVC facilitates the interaction between PCNA and DNA polymerase delta. BVC promotes HepG2 cells proliferation which is inhibited by T2AA, an inhibitor suppresses the interaction between PCNA and DNA polymerase delta. In NAFLD hamsters, BVC enhances PCNA expression and liver regeneration, reduces hepatocyte apoptosis. CONCLUSION: This study suggests that, besides the anti-lipemic effect, BVC binds to the pocket of PCNA facilitating its interaction with DNA polymerase delta and pro-regeneration effect, thereby exerts the protective effect against HFD induced liver injury.

Bavachinin selectively modulates PPAR γ and maintains bone homeostasis in Type 2 Diabetes.

Full peroxisome proliferator-activated receptor (PPAR) γ agonists, Thiazolidinediones (TZDs), effectively prevent the process of Type 2 Diabetes Mellitus (T2DM), but their side effects have curtailed use in the clinic, including weight gain and bone loss. Here, we identified that a selective PPAR γ modulator, Bavachinin (BVC), isolated from the seeds of Psoralea Corylifolia L., could potently regulate bone homeostasis. MC3T3-E1 pre-osteoblast cells and C3H10T1/2 mesenchymal stem cells were assessed for osteogenic differentiation activities, and receptor activator of NF-κB ligand (RANKL)-induced RAW 264.7 cells were assessed osteoclasts formation. Leptin receptor-deficient mice and diet-induced obesity mice were applied to evaluate the effect of BVC on bone homeostasis in vivo. Compared to full PPAR γ agonist rosiglitazone, BVC significantly increased the osteogenesis differentiation activities under normal and high glucose conditions in MC3T3-E1 cells. Moreover, BVC could alleviate osteoclast differentiation in RANKL-induced RAW 264.7 cells. In vivo, synthesized BVC prodrug (BN) has been applied to improve water solubility, increase the extent of oral absorption of BVC and prolong its residence time in blood circulation. BN could prevent weight gain, ameliorate lipid metabolism disorders, improve insulin sensitivity, and maintain bone mass and bone biomechanical properties. BVC, a unique PPAR γ selective modulator, could maintain bone homeostasis, and its prodrug (BN) exhibits insulin sensitizer activity while circumventing the side effects of the TZDs, including bone loss and undesirable weight gain.

Bavachinin Ameliorates Rheumatoid Arthritis Inflammation via PPARG/PI3K/AKT Signaling Pathway.

Bavachinin (BVC) is a natural small molecule from the Chinese herb Fructus Psoraleae. It exhibits numerous pharmacological effects, including anti-cancer, anti-inflammation, anti-oxidation, anti-bacterial, anti-viral, and immunomodulatory properties. BVC may serve as a novel drug candidate for the treatment of rheumatoid arthritis (RA). Nevertheless, the effects and mechanisms of BVC against RA are still unknown. BVC targets were selected by Swiss Target Prediction and the PharmMapper database. RA-related targets were collected from the GeneCards, OMIM, DrugBank, TTD, and DisGeNET databases. PPI network construction and enrichment analysis were conducted by taking the intersection target of BVC targets and RA-related targets. Hub targets were further screened using Cytoscape and molecular docking. MH7A cell lines and collagen-induced arthritis (CIA) mice were used to confirm the preventive effect of BVC on RA and its potential mechanism. Fifty-six RA-related targets of BVC were identified through databases. These genes were primarily enriched in PI3K/AKT signaling pathway according to KEGG enrichment analysis. Molecular docking analysis suggested that BVC had the highest binding energy with PPARG. The qPCR and western blotting results showed that BVC promoted the expression of PPARG at both the mRNA level and protein level. Western blotting indicated that BVC might affect MH7A cell functions through the PI3K/AKT pathway. Furthermore, treatment with BVC inhibited the proliferation, migration, and production of inflammatory cytokines in MH7A cells and induced cell apoptosis to a certain extent. In vivo, BVC alleviated joint injury and inflammatory response in CIA mice. This study revealed that BVC may inhibit the proliferation, migration, and production of inflammatory cytokines in MH7A cells, as well as cell apoptosis through the PPARG/PI3K/AKT signaling pathway. These findings provide a theoretical foundation for RA therapy.

Progress on pharmacological activities and hepatotoxicity of bavachinin / 药学实践杂志

Bavachinin is a dihydroflavone isolated from dried ripe fruits of Psoralea corylifolia L.，which has various pharmacological activities, such as anti-tumor, anti-virus, anti-diabetes, anti-inflammatory and neuroprotective, and good potential in clinical applications. With the increasing concern about the safety of P. corylifolia applications in clinical, the bavachinin has been found to be one of the main components causing liver injury. In this paper, the pharmacological activities and hepatotoxicity of bavachinin in the recent 20 years were reviewed, in order to provide reference for the further study and clinical application.

A bavachinin analog, D36, induces cell death by targeting both autophagy and apoptosis pathway in acute myeloid leukemia cells.

PURPOSE: Acute myeloid leukemia (AML) is an aggressive hematologic malignancy with high mortality, and it is urgent to find new and optimized treatment strategies for AML. In this study, bavachinin, isolated from Psoralea corylifolia L. exhibiting extensive anti-tumor activity in many solid tumors and a series of its synthesized analogs, were screened for their anti-cancer activity on AML cell lines. METHODS: The cell viability of AML cells was measured using CCK-8 assays. Cell apoptosis and cell cycle were detected by flow cytometry. The expression of apoptosis-related protein and autophagy-related protein/gene was detected by western blot, immunofluorescence or RT-PCR. Subcutaneous mice tumor model was used to evaluate the anti-cancer activity of D36 in vivo. RESULTS: D36 robustly induced AML cells death in a dose-dependent manner with the IC50 value of 1.0 µM for HL-60 cells and 0.81 µM for MV4-11 cells at 24 h. D36 activated autophagy by inducing the accumulation of LC3B and promoting the autophagy flux. In addition, D36 triggered the extrinsic apoptosis by upregulating the protein level of FAS, cleaved-caspase 8, cleaved-caspase 3 and cleaved-PARP. D36 also blocked the cell cycle at S phase or G2/M phase in AML cells. In addition, we find that activation of caspase cascade induced apoptosis and meanwhile activated autophagy, autophagy activation in turns contributes to apoptosis. Furthermore, D36 suppressed the tumor growth in HL-60 AML-bearing mice without obvious side effects. CONCLUSION: This study suggests that D36 is a promising small-molecule for the treatment of acute myeloid leukemia.

Induction of G2/M Cell Cycle Arrest via p38/p21Waf1/Cip1-Dependent Signaling Pathway Activation by Bavachinin in Non-Small-Cell Lung Cancer Cells.

Lung cancer is the most commonly diagnosed malignant cancer in the world. Non-small-cell lung cancer (NSCLC) is the major category of lung cancer. Although effective therapies have been administered, for improving the NSCLC patient's survival, the incident rate is still high. Therefore, searching for a good strategy for preventing NSCLC is urgent. Traditional Chinese medicine (TCM) are brilliant materials for cancer chemoprevention, because of their high biological safety and low cost. Bavachinin, which is an active flavanone of Proralea corylifolia L., possesses anti-inflammation, anti-angiogenesis, and anti-cancer activities. The present study's aim was to evaluate the anti-cancer activity of bavachinin on NSCLC, and its regulating molecular mechanisms. The results exhibited that a dose-dependent decrease in the cell viability and colony formation capacity of three NSCLC cell lines, by bavachinin, were through G2/M cell cycle arrest induction. Meanwhile, the expression of the G2/M cell cycle regulators, such as cyclin B, p-cdc2Y15, p-cdc2T161, and p-wee1, was suppressed. With the dramatic up-regulation of the cyclin-dependent kinase inhibitor, p21Waf1/Cip1, the expression and association of p21Waf1/Cip1 with the cyclin B/cdc2 complex was observed. Silencing the p21Waf1/Cip1 expression significantly rescued bavachinin-induced G2/M cell accumulation. Furthermore, the expression of p21Waf1/Cip1 mRNA was up-regulated in bavachinin-treated NSCLC cells. In addition, MAPK and AKT signaling were activated in bavachinin-added NSCLC cells. Interestingly, bavachinin-induced p21Waf1/Cip1 expression was repressed after restraint p38 MAPK activation. The inhibition of p38 MAPK activation reversed bavachinin-induced p21Waf1/Cip1 mRNA expression and G2/M cell cycle arrest. Collectively, bavachinin-induced G2/M cell cycle arrest was through the p38 MAPK-mediated p21Waf1/Cip1-dependent signaling pathway in the NSCLC cells.

Bavachinin Induces G2/M Cell Cycle Arrest and Apoptosis via the ATM/ATR Signaling Pathway in Human Small Cell Lung Cancer and Shows an Antitumor Effect in the Xenograft Model.

Lung cancer is grouped into small cell lung cancer (SCLC) and non-SCLC (NSCLC). SCLC exhibits a poor prognosis, and the current anticancer treatment remains unsatisfactory. Bavachinin, present in the seed of Psoralea corylifolia, shows anti-inflammatory effects, immune modulation, and anticancer potency. This study aims to investigate the antitumor effect of bavachinin on SCLC and its underlying mechanism. The SCLC cell line H1688 was treated with different concentrations of bavachinin and showed decreased viability with arrested G2/M and sub-G1 phase cell accumulation at a concentration as low as 25 µM. Expression levels of caspase-3, -8, and -9, as well as Fas, FasL, and Bax, increased with the concentration of bavachinin. The accumulated sub-G1 cells and annexin V confirmed increasing apoptotic cancer cells after treatment. The accumulated G2/M phase cells with increasing levels of phosphorylated CDC25C, CDC2, ATM/ATR, and CHK2/CHK1 confirmed the arrested cell cycle caused by bavachinin via a dose-dependent manner. This phenomenon can be reversed by an ATM/ATR inhibitor, caffeine. Following the administration of bavachinin to xenograft mice with SCLC, the tumor burden decreased without impairing hematologic or hepatorenal functions. Bavachinin induces SCLC apoptosis via intrinsic and extrinsic pathways and causes cancer cell cycle arrest via the ATM/ATR signaling pathway.

Bavachinin mitigates DMH induced colon cancer in rats by altering p53/Bcl2/BAX signaling associated with apoptosis.

Bavachinin is a flavanone obtained from the Chinese herb, Fructus Psoraleae. Flavonoids and flavanones are recognized as cancer preventive agents. We investigated the anticancer properties of bavachinin using a model of dimethylhydrazine (DMH and dextran sodium sulfate (DSS) induced rat colon cancer. We investigated aberrant crypt foci (ACF), hyperplastic lesions, catalase (CAT), superoxide dismutase (SOD) and glutathione (GST) levels in Wistar rats. Expression of cancer biomarkers including IL-6, p53, Bcl2 and BAX was investigated. We found that bavachinin administered to rats re-established the colonic crypts that were damaged by DMH and prevented progression of the cancer.

Preparation and pharmacokinetics of polydopamine-loaded bavachinin nanoparticles coated with erythrocyte membrane / 中国药科大学学报

@#Polydopamine (PDA) nanoparticles were prepared as a carrier, and bavachinin (BVA) was efficiently loaded by physical adsorption.The erythrocyte membrane was further utilized to modify and construct the erythrocyte membrane biomimetic nanoparticles (RBC-BP), the residence time in the body was extended and the in vivo analytical method was established to investigate their pharmacokinetics in mice.Polydopamine nanoparticles loaded with BVA (BP) were prepared by solvent replacement method, and the influencing factors of PDA loaded with BVA were investigated with the adsorption rate as the evaluation index.The erythrocyte membrane was extracted and separated, and RBC-BP was prepared by incubation coextrusion method. The effects of pH value on membrane coating and the extrusion times on the particle size and uniformity of RBC-BP were investigated.The particle size, potential, morphology, and cumulative release rate of RBC-BP were systematically characterized, and their pharmacokinetics in mice were preliminarily explored.The results showed that the adsorption rate of BP was as high as (92.08 ± 0.17) % and the drug loading rate was (42.05 ± 2.95) % at the PDA to BVA ratio of 1∶0.5, the solution pH value of 7, the incubation time of 6 h, and the incubation temperature of 20 °C, and that the erythrocyte membrane could be successfully oriented and coated on the surface of BP by the action of electric charge at the pH value of 4. The in vitro studies showed that RBC-BP has the apparent core-shell structure with the particle size of (308.63 ± 6.56) nm and good stability, and in vivo pharmacokinetic studies showed that RBC-BP can significantly extend the circulation time of nanoparticles in vivo.

Bavachinin inhibits cholesterol synthesis enzyme FDFT1 expression via AKT/mTOR/SREBP-2 pathway.

Non-alcoholic fatty liver disease (NAFLD) is a progressive and chronic liver disease. No effective drug is currently approved for the treatment of NAFLD. Traditionally it is thought that pathogenesis of NAFLD develops from some imbalance in lipid control, thereby leading to hepatotoxicity and disease development. Squalene synthase (SQS), encoded by FDFT1, is a key regulator in cholesterol synthesis and thus a potential target for the treatment of NAFLD. Here we could identify bavachinin, a component from traditional Chinese medicine Fructus Psoraleae (FP), which apparently protects HepaRG cells from palmitic acid induced death, suppressing lipid accumulation and cholesterol synthesis through inhibition of FDFT1 through the AKT/mTOR/SREBP-2 pathway. Over-expression of FDFT1 abolished bavachinin (BVC) -induced inhibition of cholesterol synthesis. The data presented here suggest that bavachinin acts as a cholesterol synthesis enzyme inhibitor, and might serve as a drug for treating NAFLD in the future.

Bavachinin Induces Oxidative Damage in HepaRG Cells through p38/JNK MAPK Pathways.

Drug-induced liver injury is one of the main causes of drug non-approval and drug withdrawal by the Food and Drug Administration (FDA). Bavachinin (BVC) is a natural product derived from the fruit of the traditional Chinese herb Fructus Psoraleae (FP). There have been reports of acute liver injury following the administration of FP and its related proprietary medicines. To explore BVC hepatotoxicity and its mechanisms, we used the HepaRG cell line. In our recent research, we showed that BVC induces HepaRG cell death, mainly via BVC-induced oxidative damage. The formation of ROS is closely related to the activation of the stress-activated kinases, JNK and p38, while SP600125 (SP, JNK inhibitor) and SB203580 (SB, p38 inhibitor) pretreatment inhibited the generation of ROS. On the other hand, N-acetylcysteine (NAC) pretreatment prevented the phosphorylation of p38 but not that of JNK. Taken together, these data reveal that BVC induces HepaRG cell death via ROS and the JNK/p38 signaling pathways.

Multi-Target Anti-Alzheimer Activities of Four Prenylated Compounds from Psoralea Fructus.

Alzheimer's disease (AD) is an age-related neurodegenerative disease that is mediated by multiple signaling pathways. In recent years, the components of Psoralea Fructus (PF) have demonstrated some anti-Alzheimer effects both in vitro and in vivo. To further reveal the active compounds of PF and their mechanisms regulating key targets of AD, in this study, we identified four prenylated compounds from the 70% ethanolic aqueous extract of PF, namely bavachin, bavachinin, bavachalcone, and isobavachalcone. Multi-target bioactivity analysis showed that these compounds could differentially inhibit neuroinflammation, oxidative damage, and key AD-related protein targets, such as amyloid ß-peptide 42, ß-secretase, glycogen synthase kinase 3ß, and acetylcholinesterase. These compounds may generate beneficial effects in AD prevention and treatment.

Synthesis and biological evaluation of novel bavachinin analogs as anticancer agents.

A library of 28 analogs of bavachinin including aliphatic and aromatic ethers, epoxide, chalcone, oxime, semicarbazide, oxime ether and triazole derivatives have been synthesized and evaluated for cytotoxicity against four different human cancer cell lines. Bio-evaluation studies exhibited better cytotoxic profile for many analogs compare to bavachinin. Best results were observed for a 1,2,3-triazole analog (17i) with IC50 values 7.72, 16.08, 7.13 and 11.67 µM against lung (A549), prostate (PC-3), colon (HCT-116) and breast (MCF-7) cancer cell lines respectively. This analog showed three and four fold improvement in cytotoxicity against HCT-116 and A549 cell lines than parent molecule (1). Structure activity relationship (SAR) study for all synthesized analogs was carried out. Further, mechanistic study of the lead molecule (17i) revealed that it inhibits colony formation and in vitro migration of human colon cancer cells (HCT-116). Also, it induced the morphological changes and mediated the apoptotic cell death of HCT-116 cells with perturbance in mitochondrial membrane potential (MMP) and PARP cleavage.

Study on mechanism of HepaRG cell injury induced by bavachinin / 中国药理学通报

Aim To probe into the bavachinin toxic mechanisms in HepaRG cells. Methods MTT assay was used to determine toxicity and dose. After treated with 6.25,12.5 and 25 μmol·L-1bavachinin for 24 h,the cell death was investigated by Hoechst 33342/PI,LDH,caspase-3 activity,and Bax,Bcl-2 expression levels. Mitochondrial damage was detected by mito-chondrial membrane potential,ATP content,openness of mitochondrial permeability transition pore and cyto-chrome C level. Results Bavachinin administration up-regulated Bax/Bcl-2 ratio and caspase-3 activity with increase of drug concentration after 24 h. Apop-totic rate increased in a dose-dependent manner be-tween 6.25 and 25 μmol·L-1,but when reached to 25 μmol·L-1,cells showed more necrosis. Mitochon-drial injury indicators significantly increased after 24h. Conclusion Bavachinin induces HepaRG cell apopto-sis and necrosis through mitochondria injury.

Design, Synthesis, and Structure-Activity Relationships of Bavachinin Analogues as Peroxisome Proliferator-Activated Receptor†γ Agonists.

Peroxisome proliferator-activated receptor γ (PPARγ) agonists have been used for the treatment of diabetes with the effect of lowering blood glucose levels and improving insulin sensitivity. Natural compounds such as flavones, flavanones, and isoflavones have shown excellent PPARγ agonist activity. In this study, analogues of bavachinin were designed, synthesized, and evaluated by reporter gene assays for PPARγ agonist activity. Preliminary structure-activity relationships for these bavachinin analogues have been summarized, and seven compounds were found to have higher PPARγ agonist activities than the parent flavanone bavachinin.

UGT1A10 Is a High Activity and Important Extrahepatic Enzyme: Why Has Its Role in Intestinal Glucuronidation Been Frequently Underestimated?

The aim of this work was to highlight a considerable and broad problem in UGT1A10 activity assessment that has led to underestimation of its role in intestinal glucuronidation of drugs and other xenobiotics. The reason appears to be poor activity of the commercial UGT1A10 that is used by many laboratories, and here we have tested it by comparison with our recombinant His-tagged UGT1A10 (designated as UGT1A10-H), both expressed in insect cells. The glucuronidation rates of morphine, estradiol, estrone, SN-38, diclofenac, 4-methylumbelliferone, 7-amino-4-methylcoumarin, N-(3-carboxypropyl)-4-hydroxy-1,8-naphthalimide, and bavachinin were assayed. The results revealed that the activity of commercial UGT1A10 was low, very low, and in the cases of morphine, estrone, 7-methyl-4-aminocoumarin, and bavachinin it was below the detection limit. On the other hand, under the same conditions, UGT1A10-H exhibited high glucuronidation rates toward all these compounds. Moreover, using estradiol, morphine, and estrone, in the presence and absence of suitable inhibitors, nilotinib or atractylenolide I, it was demonstrated that UGT1A10-H, but not the commercial UGT1A10, provides a good tool to study the role of native UGT1A10 in the human intestine. The results also suggest that much of the data in the literature on UGT1A10 activity may have to be re-evaluated.

Determination of 10 components in stir-frying Psoralea Fructus with salt solution by different processing time / 中草药

Objective: To establish UPLC method for the simultaneous determination of 10 components, such as psoralen, isopsoralen, psoralidin, bavachinin, isobavaenin, corylifolin, isobavachalcone, corylin, neobavaisoflavone, and bakuchiol in Psoralea Fructus, and to study the effect of processing time on 10 components in stir-frying Psoralea Fructus with salt solution. Methods: The chromatographic separation was achieved on a C18 column (50 mm×4.6 mm, 1.8 μm) with acetonitrile (A)-water (B) as mobile phase at the flow rate of 1.0 mL/min for gradient elution; The column temperature was 30℃. The determination wavelength was 250 nm. Results: The 10 components were well separated within 15 min. The RSD values of reproducibility were less than 3%. The stability was good in 24 h. The linear relationship between the concentration and peak areas of the 10 components was good (r≥0.9970). The average recoveries were 96%-105% and the RSD values were all less than 3%. Conclusion: The method is simple, reliable and accurate, could be used for the quality control of Psoralea Fructus. With processing time prolonged, the content of coumarins showed first decreased, then increased and last decreased. Flavonoids, bakuchiol and the total content of 10 components above were decreased.

Bavachinin, as a novel natural pan-PPAR agonist, exhibits unique synergistic effects with synthetic PPAR-γ and PPAR-α agonists on carbohydrate and lipid metabolism in db/db and diet-induced obese mice.

AIMS/HYPOTHESIS: Pan-peroxisome proliferator-activated receptor (PPAR) agonists have long been sought as therapeutics against the metabolic syndrome, but current PPAR agonists show limited efficacy and adverse effects. Natural herbs provide a structurally untapped resource to prevent and treat complicated metabolic syndrome. METHODS: Natural PPAR agonists were screened using reporter gene, competitive binding and 3T3-L1 pre-adipocyte differentiation assays in vitro. The effects on metabolic phenotypes were verified in db/db and diet-induced obese mice. In addition, potentially synergistic actions of bavachinin (BVC, a novel natural pan-PPAR agonist from the fruit of the traditional Chinese glucose-lowering herb malaytea scurfpea) and synthetic PPAR agonists were studied through nuclear magnetic resonance, molecular docking, reporter gene assays and mouse studies. RESULTS: BVC exhibited glucose-lowering properties without inducing weight gain and hepatotoxicity. Importantly, BVC synergised with thiazolidinediones, which are synthetic PPAR-γ agonists, and fibrates, which are PPAR-α agonists, to induce PPAR transcriptional activity, as well as to lower glucose and triacylglycerol levels in db/db mice. We further found that BVC occupies a novel alternative binding site in addition to the canonical site of synthetic agonists of PPAR, and that the synthetic PPAR-γ agonist rosiglitazone can block BVC binding to this canonical site but not to the alternative site. CONCLUSIONS/INTERPRETATION: This is the first report of a synergistic glucose- and lipid-lowering effect of BVC and synthetic agonists induced by unique binding with PPAR-γ or -α. This combination may improve the efficacy and decrease the toxicity of marketed drugs for use as adjunctive therapy to treat the metabolic syndrome.

Structural elucidation of in vitro metabolites of bavachinin in rat liver microsomes by LC-ESI-MSn and chemical synthesis.

1. Bavachinin isolated from Psoralea corylifolia has various activities, such as antimicrobial, antiallergic, antitumor and so on. Our previous study showed that natural bavachinin exhibits peroxisome proliferator-activated receptor γ-agonist activity. 2. In vitro studies on bavachinin metabolism were conducted using rat liver microsomes incubated at 37 °C for 60 min. 3. Structures of eight metabolites of the incubation mixtures were cautiously characterized using electrospray tandem mass spectra and three synthetic compounds. The results indicated that eight metabolites of bavachinin were biotransformed mainly through oxidation. 4. The metabolic pathways of bavachinin were elucidated in vitro. These results contribute to the understanding of bavachinin's in vivo metabolism.