Mendelian randomization to evaluate the effect of folic acid supplement on the risk of Alzheimer disease.

We conducted a study to evaluate the impact of folic acid supplementation on the risk of Alzheimer disease (AD). A Mendelian randomization (MR) analysis model assessed the causal effects of folic acid supplementation on AD, utilizing data from recent genome-wide association studies. Effect estimates were scrutinized using various methods: inverse-variance weighted (IVW), simple mode, weighted mode, simple median, weighted median, penalized weighted median, and the MR-Egger method. The sensitivity analysis assessed heterogeneity and pleiotropy of individual single nucleotide polymorphisms (SNPs) using the IVW method with Cochran Q statistics and MR Egger intercept, respectively. Additionally, a leave-one-out sensitivity analysis determined potential SNP-driven associations. Both fixed-effect and random-effect IVW models in the MR analysis revealed a reduced risk of AD associated with folic acid supplementation (odds ratio, 0.930; 95% CI, 0.903-0.958, P < .001; odds ratio, 0.930; 95% CI, 0.910-0.950, P < .001) based on 7 SNPs as instrumental variables. The reverse MR analysis indicated no causal association between AD and folic acid supplementation. This study, utilizing genetic data, suggests that folic acid supplementation may potentially reduce the risk of AD and provides novel insights into its etiology and preventive measures.

Diosbulbin C, a novel active ingredient in Dioscorea bulbifera L. extract, inhibits lung cancer cell proliferation by inducing G0/G1 phase cell cycle arrest.

BACKGROUND: Despite the critical progress of non-small cell lung cancer (NSCLC) therapeutic approaches, the clinical outcomes remain considerably poor. The requirement of developing novel therapeutic interventions is still urgent. In this study, we showed for the first time that diosbulbin C, a natural diterpene lactone component extracted from traditional Chinese medicine Dioscorea bulbifera L., possesses high anticancer activity in NSCLC. METHODS: A549 and NCI-H1299 cells were used. The inhibitory effects of the diosbulbin C on NSCLC cell proliferation were evaluated using cytotoxicity, clone formation, EdU assay, and flow cytometry. Network pharmacology methods were used to explore the targets through which the diosbulbin C inhibited NSCLC cell proliferation. Molecular docking, qRT-PCR, and western blotting were used to validate the molecular targets and regulated molecules of diosbulbin C in NSCLC. RESULTS: Diosbulbin C treatment in NSCLC cells results in a remarkable reduction in cell proliferation and induces significant G0/G1 phase cell cycle arrest. AKT1, DHFR, and TYMS were identified as the potential targets of diosbulbin C. Diosbulbin C may inhibit NSCLC cell proliferation by downregulating the expression/activation of AKT, DHFR, and TYMS. In addition, diosbulbin C was predicted to exhibit high drug-likeness properties with good water solubility and intestinal absorption, highlighting its potential value in the discovery and development of anti-lung cancer drugs. CONCLUSIONS: Diosbulbin C induces cell cycle arrest and inhibits the proliferation of NSCLC cells, possibly by downregulating the expression/activation of AKT, DHFR, and TYMS.

Ergolide covalently binds NLRP3 and inhibits NLRP3 inflammasome-mediated pyroptosis.

BACKGROUND: NLR family pyrin domain-containing 3 (NLRP3)-mediated pyroptosis plays a key role in various acute and chronic inflammatory diseases. Targeted inhibition of NLRP3-mediated pyroptosis may be a potential therapeutic strategy for various inflammatory diseases. Ergolide (ERG) is a sesquiterpene lactone natural product derived from the traditional Chinese medicinal herb, Inula britannica. ERG has been shown to have anti-inflammatory and anti-cancer activities, but the target is remains unknown. HYPOTHESIS/PURPOSE: This study performed an in-depth investigation of the anti-inflammatory mechanism of ERG in NLRP3-mediated pyroptosis and NLPR3 inflammasome related sepsis and acute lung injury model. METHODS: ELISA and Western blot were used to determine the IL-1ß and P20 levels. Co-immunoprecipitation assays were used to detect the interaction between proteins. Drug affinity response target stability (DARTS) assays were used to explore the potential target of ERG. C57BL/6J mice were intraperitoneally injected with E. coli DH5α (2 × 109 CFU/mouse) to establish a sepsis model. Acute lung injury was induced by intratracheal administrationof lipopolysaccharide in wild-type mice and NLRP3 knockout mice with or without ERG treatment. RESULTS: We showed that ERG is an efficient inhibitor of NLRP3-mediated pyroptosis in the first and second signals of NLRP3 inflammasome activation. Furthermore, we demonstrated that ERG irreversibly bound to the NACHT domain of NLRP3 to prevent the assembly and activation of the NLRP3 inflammasome. ERG remarkably improved the survival rate of wild-type septic mice. In lipopolysaccharide-induced acute lung injury model, ERG alleviated acute lung injury of wild-type mice but not NLRP3 knockout mice. CONCLUSION: Our results revealed that the anti-pyroptosis effect of ERG are dependent on NLRP3 and NLRP3 NACHT domain is ERG's direct target. Therefore, ERG can serve as a precursor drug for the development of novel NLRP3 inhibitors to treat NLRP3 inflammasome mediated inflammatory diseases.

Tabersonine attenuates obesity-induced renal injury via inhibiting NF-κB-mediated inflammation.

Obesity-induced metabolic disorders can cause chronic inflammation in the whole body, activating the nuclear factor kappa B (NF-κB) pathway and inducing apoptosis. Therefore, anti-inflammatory strategies may be effective in preventing obesity-related renal injury. Tabersonine (Tab) has been used pharmacologically to alleviate inflammation-related symptoms. This study evaluated the therapeutic effect of Tab on obesity-related renal injury and explored the pharmacological mechanism. Tab (20 mg/kg) relieved HFD-induced renal structural disorder and alleviated renal functional decline in mice, including improvement of renal tissue fibrosis, reducing renal cell apoptosis and inflammation in renal tissues. Mechanistically, we demonstrated that Tab inhibited the activation of NF-κB signaling pathway both in vivo and in vitro, thereby improving the renal tissue lesions in the mice with obesity-related renal injury. In both the obese mouse model and the mouse glomerular mesangial cell model, the natural compound Tab ameliorated HFD- and saturated fatty acid-induced renal cell injury by inhibiting the activation of NF-κB signaling pathway. Our data suggest that Tab may become a potential candidate for the prevention and treatment of obesity-related renal injury.

Anti-Inflammatory Activities of Pentaherbs formula and Its Influence on Gut Microbiota in Allergic Asthma.

Allergic asthma is a highly prevalent airway inflammatory disease, which involves the interaction between the immune system, environmental and genetic factors. Co-relation between allergic asthma and gut microbiota upon the change of diet have been widely reported, implicating that oral intake of alternative medicines possess a potential in the management of allergic asthma. Previous clinical, in vivo, and in vitro studies have shown that the Pentaherbs formula (PHF) comprising five traditional Chinese herbal medicines Lonicerae Flos, Menthae Herba, Phellodendri Cortex, Moutan Cortex, and Atractylodis Rhizoma possesses an anti-allergic and anti-inflammatory potential through suppressing various immune effector cells. In the present study, to further investigate the anti-inflammatory activities of PHF in allergic asthma, intragastrical administration of PHF was found to reduce airway hyperresponsiveness, airway wall remodeling and goblet cells hyperplasia in an ovalbumin (OVA)-induced allergic asthma mice model. PHF also significantly suppressed pulmonary eosinophilia and asthma-related cytokines IL-4 and IL-33 in bronchoalveolar lavage (BAL) fluid. In addition, PHF modulated the splenic regulatory T cells population, up-regulated regulatory interleukin (IL)-10 in serum, altered the microbial community structure and the short chain fatty acids content in the gut of the asthmatic mice. This study sheds light on the anti-inflammatory activities of PHF on allergic asthma. It also provides novel in vivo evidence that herbal medicines can ameliorate symptoms of allergic diseases may potentially prevent the development of subsequent atopic disorder such as allergic asthma through the influence of the gut microbiota.

Home-Based Transcutaneous Neuromodulation Improved Constipation via Modulating Gastrointestinal Hormones and Bile Acids.

This study aims to investigate the role of transcutaneous neuromodulation (TN) on the regulation of gastrointestinal hormones and bile acids in patients with functional constipation (FC). Twenty FC patients were treated with TN for four weeks. The effects of TN on symptoms were evaluated by questionnaires. Plasma levels of serotonin (5-HT), motilin, somatostatin, and vasoactive intestinal peptide (VIP) were measured by ELISA and 12 individual bile acids assayed by liquid chromatography tandem mass spectrometry. Results were as follows. (1) TN treatment increased the frequency of spontaneous bowel movement, improved the Bristol Stool Score, and reduced Patient Assessment of Constipation Symptom score and Patient Assessment of Constipation Quality of Life score. (2) FC patients showed decreased plasma levels of 5-HT, motilin, and VIP and an increased plasma level of somatostatin (P < 0.05). Four-week TN treatment increased plasma levels of 5-HT and motilin and decreased the plasma level of somatostatin in the FC patients (P < 0.05). (3) Taurocholic deoxycholate, taurocholic acid, and taurocholic lithocholic acid were increased in the FC patients (P < 0.005) but reduced by TN treatment (P < 0.05). This study has suggested that the therapy may improve the symptoms of FC by alleviating the disorders of gastrointestinal hormones and bile acids.

Everolimus-inhibited multiple isoforms of UDP-glucuronosyltransferases (UGTs).

1. Everolimus is an inhibitor of mammalian target of rapamycin (mTOR) and has been clinically utilized to prevent the rejection of organ transplants. This study aims to determine the inhibition of everolimus on the activity of phase-II drug-metabolizing enzymes UDP-glucuronosyltransferases (UGTs). 2. The results showed that 100 µM of everolimus exerted more than 80% inhibition toward UGT1A1, UGT-1A3 and UGT-2B7. UGT1A3 and UGT2B7 were selected to elucidate the inhibition mechanism, and in silico docking showed that hydrogen bonds and hydrophobic interactions mainly contributed to the strong binding of everolimus toward the activity cavity of UGT1A3 and UGT2B7. Inhibition kinetic-type analysis using Lineweaver-Burk plot showed competitive inhibition toward all these UGT isoforms. The inhibition kinetic parameters (Ki) were calculated to be 2.3, 0.07 and 4.4 µM for the inhibition of everolimus toward UGT1A1, UGT-1A3 and UGT-2B7, respectively. 3. In vitro-in vivo extrapolation (IVIVE) showed that [I]/Ki value was calculated to be 0.004, 0.14 and 0.002 for UGT1A1, UGT-1A3 and UGT-2B7, respectively. Therefore, high DDI potential existed between everolimus and clinical drugs mainly undergoing UGT1A3-catalyzed glucuronidation.

The triplet state of tanshinone I and its synergic effect on the phototherapy of cancer cells with curcumin.

The excited triplet state of tanshinone I (Tan I) extracted from the traditional Chinese medicine Salvia miltiorrhiza Bunge was characterized by laser flash photolysis. The synergic effect of Tan I on the phototherapy of cancer cells with curcumin (Cur) was also investigated by MTT assay because the excited energy transfer from the triplet state of Tan I ((3)Tan I(∗)) to Cur occurred. At the same time, the characteristic absorption spectra of (3)Tan I(∗) were recorded, and its molar absorption coefficient and rate constants for several excited energy transfers were obtained. The photo-therapeutic effect of Cur is enhanced by combination with Tan I.

Inhibition of UDP-Glucuronosyltransferases (UGTs) Activity by constituents of Schisandra chinensis.

Structure-activity relationship for the inhibition of Schisandra chinensis's ingredients toward (Uridine-Diphosphate) UDP-glucuronosyltransferases (UGTs) activity was performed in the present study. In vitro incubation system was employed to screen the inhibition capability of S. chinensis's ingredients, and in silico molecular docking method was carried out to explain possible mechanisms. At 100 µM of compounds, the activity of UGTs was inhibited by less than 90% by schisandrol A, schisandrol B, schisandrin, schisandrin C, schisantherin A, gomisin D, and gomisin G. Schisandrin A exerted strong inhibition toward UGT1A1 and UGT1A3, with the residual activity to be 7.9% and 0% of control activity. Schisanhenol exhibited strong inhibition toward UGT2B7, with the residual activity to be 7.9% of control activity. Gomisin J of 100 µM inhibited 91.8% and 93.1% of activity of UGT1A1 and UGT1A9, respectively. Molecular docking prediction indicated different hydrogen bonds interaction resulted in the different inhibition potential induced by subtle structure alteration among schisandrin A, schisandrin, and schisandrin C toward UGT1A1 and UGT1A3: schisandrin A > schisandrin > schisandrin C. The detailed inhibition kinetic evaluation showed the strong inhibition of gomisin J toward UGT1A9 with the inhibition kinetic parameter (Ki ) to be 0.7 µM. Based on the concentrations of gomisin J in the plasma of the rats given with S. chinensis, high herb-drug interaction existed between S. chinensis and drugs mainly undergoing UGT1A9-mediated metabolism. In conclusion, in silico-in vitro method was used to give the inhibition information and possible inhibition mechanism for S. chinensis's components toward UGTs, which guide the clinical application of S. chinensis.

Structure-inhibition relationship of podophyllotoxin (PT) analogues towards UDP-glucuronosyltransferase (UGT) isoforms.

UDP-glucuronosyltransferases (UGTs) are involved in the clearance of many important drugs and endogenous substances, and inhibition of UGTs' activity by herbal components might induce severe herb-drug interactions or metabolic disturbances of endogenous substances. The present study aims to determine the inhibition of UGTs' activity by podophyllotoxin derivatives, trying to indicate the potential herb-drug interaction or metabolic influence towards endogenous substances' metabolism. Recombinant UGT isoforms (except UGT1A4)-catalyzed 4-methylumbelliferone (4-MU) glucuronidation reaction and UGT1A4-catalyzed trifluoperazine (TFP) glucuronidation were employed to firstly screen the podophyllotoxin derivatives' inhibition potential. Structure-dependent inhibition behavior of podophyllotoxin derivatives towards UGT isoforms was detected. Inhibition kinetic type and parameter (Ki) were determined for the inhi- bition of podophyllotoxin towards UGT1A1, and competitive inhibition of podophyllotoxin towards UGT1A1 was observed with the inhibition kinetic parameter (Ki) to be 4.0 µM. Furthermore, podophyllotoxin was demonstrated to exert medium and weak inhibition potential towards human liver microsomes (HLMs)-catalyzed SN-38 glucuronidation and estradiol-3-glucuronidation. In conclusion, podophyllotoxin inhibited UGT1A1 activity, indicating potential herb-drug interactions between podophyllotoxin-containing herbs and drugs mainly undergoing UGT1A1-mediated metabolism.

The Inhibition of the Components from Shengmai Injection towards UDP-Glucuronosyltransferase.

The mechanism of shengmai injection- (SMI-) related drug-drug interaction remains unclear. Evaluation of the inhibition potential of SMI's ingredients towards UDP-glucuronosyltransferases (UGTs) activity will provide a new insight to understand SMI-related drug-drug interaction. In vitro incubation system to model UGT reaction was used. Recombinant UGT isoforms-catalyzed 4-methylumbelliferone (4-MU) glucuronidation and UGT1A4-catalyzed trifluoperazine (TFP) glucuronidation reactions were employed to phenotype the inhibition profile of maidong's components towards the activity of UGT isoforms. Different inhibition potential of maidong's components towards various UGT isoforms was observed. Based on the inhibition kinetic investigation results, ophiopogonin D (OD) noncompetitively inhibited UGT1A6 and competitively inhibited UGT1A8, ophiopogonin D' (OD') noncompetitively inhibited UGT1A6 and UGT1A10, and ruscorectal (RU) exhibited competitive inhibition towards UGT1A4. The inhibition kinetic parameters were calculated to be 20.6, 40.1, 5.3, 9.0, and 0.02 µM, respectively. In combination with our previous results obtained for the inhibition of UGT isoforms by ginsenosides and wuweizi components, the important SMI ingredients exhibiting strong inhibition towards UGT isoforms were highlighted. All the results obtained in the present study provide a new insight to understand SMI-related drug-drug interaction.

Herb-drug interaction prediction based on the high specific inhibition of andrographolide derivatives towards UDP-glucuronosyltransferase (UGT) 2B7.

Herb-drug interaction strongly limits the clinical application of herbs and drugs, and the inhibition of herbal components towards important drug-metabolizing enzymes (DMEs) has been regarded as one of the most important reasons. The present study aims to investigate the inhibition potential of andrographolide derivatives towards one of the most important phase II DMEs UDP-glucuronosyltransferases (UGTs). Recombinant UGT isoforms (except UGT1A4)-catalyzed 4-methylumbelliferone (4-MU) glucuronidation reaction and UGT1A4-catalyzed trifluoperazine (TFP) glucuronidation were employed to firstly screen the andrographolide derivatives' inhibition potential. High specific inhibition of andrographolide derivatives towards UGT2B7 was observed. The inhibition type and parameters (Ki) were determined for the compounds exhibiting strong inhibition capability towards UGT2B7, and human liver microsome (HLMs)-catalyzed zidovudine (AZT) glucuronidation probe reaction was used to furtherly confirm the inhibition behavior. In combination of inhibition parameters (Ki) and in vivo concentration of andrographolide and dehydroandrographolide, the potential in vivo inhibition magnitude was predicted. Additionally, both the in vitro inhibition data and computational modeling results provide important information for the modification of andrographolide derivatives as selective inhibitors of UGT2B7. Taken together, data obtained from the present study indicated the potential herb-drug interaction between Andrographis paniculata and the drugs mainly undergoing UGT2B7-catalyzed metabolic elimination, and the andrographolide derivatives as potential candidates for the selective inhibitors of UGT2B7.

Comparison of inhibition capability of scutellarein and scutellarin towards important liver UDP-glucuronosyltransferase (UGT) isoforms.

Scutellarin is an important bioactive flavonoid extracted from Erigeron breviscapus (Vant.) Hand-Mazz, and scutellarein is the corresponding aglycone of scutellarin. The present study aims to compare the inhibition potential of scutellarin and scutellarein towards several important UDP-glucuronosyltransferase (UGT) isoforms, including UGT1A1, UGT1A6, UGT1A9 and UGT2B7. It was demonstrated that scutellarein exerted stronger inhibition towards the tested UGT isoforms than scutellarin. Furthermore, the inhibition kinetic type and parameters (Ki ) were determined for the scutellarein's inhibition towards these UGT isoforms. Competitive inhibition of scutellarein towards all these UGT isoforms was demonstrated, and the Ki values were calculated to be 0.02, 5.0, 5.8 and 35.9 µM for UGT1A1, 1A6, 1A9 and 2B7, respectively. Using in vivo maximum plasma concentration of scutellarein in rat, the in vitro-in vivo extrapolation was performed to predict in vivo situation, indicating the most possible in vivo adverse effects due to the inhibition of scutellarein towards UGT1A1. All these results remind us to monitor the utilization of scutellarin and scutellarein, and the herbs containing these two components.

The enhanced immune response of hepatitis B virus DNA vaccine using SiO2@LDH nanoparticles as an adjuvant.

Various approaches have been used to improve systemic immune response to infectious disease or virus, and DNA vaccination has been demonstrated to be one of these effective ways to elicit protective immunity against pathogens. Our previous studies showed that layered double hydroxides (LDH) nanoparticles could be efficiently taken up by the MDDCs and had an adjuvant activity for DC maturation. To further enhance the immune adjuvant activity of LDH, core-shell structure SiO2@LDH nanoparticles were synthesized with an average diameter of about 210 nm. And its high transfection efficiency in vitro was demonstrated by using GFP expression plasmid as model DNA. Exposing SiO2@LDH nanoparticles to macrophages caused a higher dose-dependent expression of IFN-γ, IL-6, CD86 and MHC II, compared with SiO2 and LDH respectively. Furthermore, in vivo immunization of BALB/c mice indicated that, DNA vaccine loaded-SiO2@LDH nanoparticles not only induced much higher serum antibody response than naked DNA vaccine and plain nanoparticles, but also obviously promoted T-cell proliferation and skewed T helper to Th1 polarization. Additionally, it was proved that the caveolae-mediated uptake of SiO2@LDH nanoparticles by macrophage lead to macrophages activation via NF-κB signaling pathway. Our results indicate that SiO2@LDH nanoparticles could serve as a potential non-viral gene delivery system.

Structure-inhibition relationship of ginsenosides towards UDP-glucuronosyltransferases (UGTs).

The wide utilization of ginseng provides the high risk of herb-drug interaction (HDI) with many clinical drugs. The inhibition of ginsenosides towards drug-metabolizing enzymes (DMEs) has been regarded as an important reason for herb-drug interaction (HDI). Compared with the deep studies on the ginsenosides' inhibition towards cytochrome P450 (CYP), the inhibition of ginsenosides towards the important phase II enzymes UDP-glucuronosyltransferases (UGTs) remains to be unclear. The present study aims to evaluate the inhibition behavior of ginsenosides towards important UGT isoforms located in the liver and intestine using in vitro methods. The recombinant UGT isoform-catalyzed 4-methylumbelliferone (4-MU) glucuronidation reaction was employed as in vitro probe reaction. The results showed that structure-dependent inhibition existed for the inhibition of ginsenosides towards UGT isoforms. To clarify the possibility of in vivo herb-drug interaction induced by this kind of inhibition, the ginsenoside Rg(3) was selected as an example, and the inhibition kinetic type and parameters (K(i)) were determined. Rg(3) competitively inhibited UGT1A7, 2B7 and 2B15-catalyzed 4-MU glucuronidation reaction, and exerted noncompetitive inhibition towards UGT1A8-catalyzed 4-MU glucuronidation. The inhibition parameters (K(i) values) were calculated to be 22.6, 7.9, 1.9, and 2.0µM for UGT1A7, 1A8, 2B7 and 2B15. Using human maximum plasma concentration of Rg(3) (400ng/ml (0.5µM)) after intramuscular injection of 60mg Rg(3), the area under the plasma concentration-time curve (AUC) was extrapolated to increase by 2.2%, 6.3%, 26.3%, and 25% for the co-administered drugs completely undergoing the metabolism catalyzed by UGT1A7, 1A8, 2B7 and 2B15, respectively. All these results indicated that the ginsenosides' inhibition towards UGT isoforms might be an important reason for ginseng-drug interaction.

Investigation of the in vitro metabolism of evodiamine: characterization of metabolites and involved cytochrome p450 isoforms.

Evodiamine is the main active alkaloid of Evodia rutaecarpa (E. rutaecarpa) and has been demonstrated to exhibit many pharmacological activities including vasorelaxation, uterotonic action, anoxia and control of body temperature. The present study focused on the metabolism of evodiamine. Human and phenobarbital-induced rat liver microsomal incubation of evodiamine in the presence of NADPH resulted in the formation of five major metabolites (M-1, M-2, M-3, M-4, M-5). Four metabolites (M-1, M-2, M-3 and M-5) were identified to mono-hydroxylated evodiamine and one metabolite (M-4) was identified to be N-demethylated evodiamine. CYP3A4, CYP2C9 and CYP1A2 were identified to be the main CYP isoforms involved in the metabolism of evodiamine in human liver microsomes. Finding new metabolites can help us decipher novel substance basis of efficiency and toxicity. Elucidation of drug metabolizing enzymes will facilitate explaining the individual difference for response to the same drugs or herbs and the potential drug-drug interaction or herb-drug interaction. Taken together, these results are of significance for better understanding the pharmacokinetic behaviour of evodiamine and helpful for clinical application of evodiamine and E. rutaecarpa.

Deglycosylation of liquiritin strongly enhances its inhibitory potential towards UDP-glucuronosyltransferase (UGT) isoforms.

The detailed mechanisms on licorice-drug interaction remain to be unclear. The aim of the present study is to investigate the inhibition of important UGT isoforms by two important ingredients of licorice, liquiritin, and liquiritigenin. The results showed that liquiritigenin exhibited stronger inhibition towards all the tested UGT isoforms than liquiritin. Data fitting using Dixon and Lineweaver-Burk plots demonstrated the competitive inhibition of liquiritigenin towards UGT1A1 and UGT1A9-mediated 4-MU glucuronidation reaction. The inhibition kinetic parameters (Ki ) were calculated to be 9.1 and 3.2 µM for UGT1A1 and UGT1A9, respectively. Substrate-dependent inhibition behaviour was also observed for UGT1A1 in the present study. All these results will be helpful for understanding the deep mechanism of licorice-drug interaction. However, when translating these in vitro parameters into in vivo situations, more complex factors should be considered, such as substrate-dependent inhibition of UGT isoforms, the contribution of UGT1A1 and UGT1A9 towards the metabolism of drugs, and many factors affecting the abundance of ingredients in the licorice.

Rhizome of Anemarrhena asphodeloides counteracts diabetic ophthalmopathy progression in streptozotocin-induced diabetic rats.

Diabetic ophthalmopathy (DO) impairs patients' eyesight and even causes blindness. Here, we investigated the effect of 60% ethanol extract of the rhizome of Anemarrhenae asphodeloides (ERA), which is commonly used in Chinese medicine formulae in treating diabetes, on DO progression. Blood glucose, insulin, advanced glycation end products (AGE), super oxygen dehydrogenises (SOD), malondialdehyde (MDA) and glutathione peroxidase (GSH-Px) levels in serum and sorbitol concentration in the lens were measured. Retinal endothelium/pericyte (E/P) ratio was evaluated, and structural changes of the retina and lens were observed. Effects of mangiferin and neomangiferin, the two major components of ERA, on subnormal growth of pericytes induced by high glucose were also detected. It was found that the activities of SOD and GSH-Px in serum were increased, whereas MDA and AGE levels in serum and sorbitol concentration in the lens were decreased in ERA-treated DO rats. E/P ratio was decreased, and the pathological changes of the lens and retina were alleviated by ERA treatment. Moreover, the subnormal growth of pericytes induced by high glucose was ameliorated by mangiferin and neomangiferin. These results indicated that ERA could effectively prevent DO progression in streptozotocin-induced diabetic rats, and mangiferin and neomangiferin may be the main effective components.

Glycyrrhetinic acid exhibits strong inhibitory effects towards UDP-glucuronosyltransferase (UGT) 1A3 and 2B7.

The aim of the present study is to evaluate the inhibitory effects of liver UDP-glucuronosyltransferases (UGTs) by glycyrrhizic acid and glycyrrhetinic acid, which are the bioactive ingredients isolated from licorice. The results showed that glycyrrhetinic acid exhibited stronger inhibition towards all the tested UGT isoforms, indicating that the deglycosylation process played an important role in the inhibitory potential towards UGT isoforms. Furthermore, the inhibition kinetic type and parameters were determined for the inhibition of glycyrrhetinic acid towards UGT1A3 and UGT2B7. Data fitting using Dixon and Lineweaver-Burk plots demonstrated that the inhibition of UGT1A3 and UGT2B7 by glycyrrhetinic acid was best fit to competitive and noncompetitive type, respectively. The second plot using the slopes from Lineweaver-Burk plots versus glycyrrhetinic acid concentrations was employed to calculate the inhibition kinetic parameters (K(i)), and the values were calculated to be 0.2 and 1.7 µM for UGT1A3 and UGT2B7, respectively. All these results remind us the possibility of UGT inhibition-based herb-drug interaction. However, the explanation of these in vitro parameters should be paid more caution due to complicated factors, including the probe substrate-dependent UGT inhibition behaviour, environmental factors affecting the abundance of herbs' ingredients, and individual difference of pharmacokinetic factors.

Isoliquiritigenin showed strong inhibitory effects towards multiple UDP-glucuronosyltransferase (UGT) isoform-catalyzed 4-methylumbelliferone (4-MU) glucuronidation.

Isoliquiritigenin, a herbal ingredient with chalcone structure, has been speculated to be able to inhibit one of the most drug-metabolizing enzymes (DMEs) UDP-glucuronosyltransferase (UGT). Therefore, the aim of the present study was to investigate the inhibition of isoliquiritigenin towards important UGT isoforms in the liver and intestine, including UGT1A1, 1A3, 1A6, 1A7, 1A8, 1A9 and 1A10. The recombinant UGT-catalyzed 4-methylumbelliferone (4-MU) glucuronidation was used as probe reactions. The results showed that 100µM of isoliquiritigenin inhibited the activity of UGT1A1, UGT1A3, UGT1A6, UGT1A7, UGT1A8, UGT1A9, and UGT1A10 by 95.2%, 76.1%, 78.9%, 87.2%, 67.2%, 94.8%, and 91.7%, respectively. The data fitting using Dixon plot and Lineweaver-Burk plot showed that the inhibition of UGT1A1, UGT1A9 and UGT1A10 by isoliquiritigenin was all best fit to the competitive inhibition, and the second plot using the slopes from the Lineweaver-Burk plot versus isoliquiritigenin concentrations was used to calculate the inhibition kinetic parameter (K(i)) to be 0.7µM, 0.3µM, and 18.3µM for UGT1A1, UGT1A9, and UGT1A10, respectively. All these results indicated the risk of clinical application of isoliquiritigenin on the drug-drug interaction and other possible diseases induced by the inhibition of isoliquiritigenin towards these UGT isoforms.