A high-affinity fluorescent probe for human uridine-disphosphate glucuronosyltransferase 1A9 function monitoring under environmental pollutant exposure

Uridine-disphosphate glucuronosyltransferase 1A9 (UGT1A9), an important detoxification and inactivation enzyme for toxicants, regulates the exposure level of environmental pollutants in the human body and induces various toxicological consequences. However, an effective tool for high-throughput monitoring of UGT1A9 function under exposure to environmental pollutants is still lacking. In this study, 1,3-dichloro-7-hydroxy-9,9-dimethylacridin-2(9H)-one (DDAO) was found to exhibit excellent specificity and high affinity towards human UGT1A9. Remarkable changes in absorption and fluorescence signals after reacting with UGT1A9 were observed, due to the intramolecular charge transfer (ICT) mechanism. Importantly, DDAO was successfully applied to monitor the biological functions of UGT1A9 in response to environmental pollutant exposure not only in microsome samples, but also in living cells by using a high-throughput screening method. Meanwhile, the identified pollutants that disturb UGT1A9 functions were found to significantly influence the exposure level and retention time of bisphenol S/bisphenol A in living cells. Furthermore, the molecular mechanism underlying the inhibition of UGT1A9 by these pollutant-derived disruptors was elucidated by molecular docking and molecular dynamics simulations. Collectively, a fluorescent probe to characterize the responses of UGT1A9 towards environmental pollutants was developed, which was beneficial for elucidating the health hazards of environmental pollutants from a new perspective.

Genetic deletion or pharmacological inhibition of soluble epoxide hydrolase attenuated particulate matter 2.5 exposure mediated lung injury

Air pollution represented by particulate matter 2.5 (PM2.5) is closely related to diseases of the respiratory system. Although the understanding of its mechanism is limited, pulmonary inflammation is closely correlated with PM2.5-mediated lung injury. Soluble epoxide hydrolase (sEH) and epoxy fatty acids play a vital role in the inflammation. Herein, we attempted to use the metabolomics of oxidized lipids for analyzing the relationship of oxylipins with lung injury in a PM2.5-mediated mouse model, and found that the cytochrome P450 oxidases/sEH mediated metabolic pathway was involved in lung injury. Furthermore, the sEH overexpression was revealed in lung injury mice. Interestingly, sEH genetic deletion or the selective sEH inhibitor TPPU increased levels of epoxyeicosatrienoic acids (EETs) in lung injury mice, and inactivated pulmonary macrophages based on the MAPK/NF-κB pathway, resulting in protection against PM2.5-mediated lung injury. Additionally, a natural sEH inhibitor luteolin from Inula japonica displayed a pulmonary protective effect towards lung injury mediated by PM2.5 as well. Our results are consistent with the sEH message and protein being both a marker and mechanism for PM2.5-induced inflammation, which suggest its potential as a pharmaceutical target for treating diseases of the respiratory system.

Macrophage Inactivation by Small Molecule Wedelolactone via Targeting sEH for the Treatment of LPS-Induced Acute Lung Injury

Soluble epoxide hydrolase (sEH) plays a critical role in inflammation by modulating levels of epoxyeicosatrienoic acids (EETs) and other epoxy fatty acids (EpFAs). Here, we investigate the possible role of sEH in lipopolysaccharide (LPS)-mediated macrophage activation and acute lung injury (ALI). In this study, we found that a small molecule, wedelolactone (WED), targeted sEH and led to macrophage inactivation. Through the molecular interaction with amino acids Phe362 and Gln384, WED suppressed sEH activity to enhance levels of EETs, thus attenuating inflammation and oxidative stress by regulating glycogen synthase kinase 3beta (GSK3β)-mediated nuclear factor-kappa B (NF-κB) and nuclear factor E2-related factor 2 (Nrf2) pathways in vitro. In an LPS-stimulated ALI animal model, pharmacological sEH inhibition by WED or sEH knockout (KO) alleviated pulmonary damage, such as the increase in the alveolar wall thickness and collapse. Additionally, WED or sEH genetic KO both suppressed macrophage activation and attenuated inflammation and oxidative stress in vivo. These findings provided the broader prospects for ALI treatment by targeting sEH to alleviate inflammation and oxidative stress and suggested WED as a natural lead candidate for the development of novel synthetic sEH inhibitors.

Inula japonica ameliorated the inflammation and oxidative stress in LPS-induced acute lung injury through the MAPK/NF-κB and Keap1/Nrf2 signalling pathways

OBJECTIVES

To investigate the protective effect and underlying mechanism of Inula japonica (TEIJ) in the treatment of acute lung injury (ALI).

METHODS

Protective effects of TEIJ in the inflammation and oxidative stress were studied in lipopolysaccharide (LPS)-induced ALI mice. Meanwhile, Western blot and real-time qPCR were carried out to investigate the underlying mechanism of TEIJ for ALI as well as immunohistochemistry.

KEY FINDINGS

TEIJ significantly alleviated the course of ALI via suppressing the interstitial infiltrated inflammatory cells, the increase of inflammatory factors and the decrease of anti-oxidative factors. TEIJ inactivated the MAPK/NF-κB signalling pathway to suppress the transcription of its downstream target genes, such as TNF-α, IL-6, etc. Meanwhile, TEIJ activated the Keap1/Nrf2 signalling pathway to regulate expression levels of Nrf2 and its target proteins. The results of LC-QTOF-MS/MS indicated potential active constituents of I. japonica, terpenoids and flavonoids. Additionally, terpenoids and flavonoids synergistically alleviated LPS-induced ALI depending on MAPK/NF-κB and Keap1/Nrf2 signalling pathways.

CONCLUSION

I. japonica could be considered a potential agent to treat ALI via regulating the MAPK/NF-κB and Keap1/Nrf2 signalling pathways.

Direct targeting of sEH with alisol B alleviated the apoptosis, inflammation, and oxidative stress in cisplatin-induced acute kidney injury

Acute kidney injury (AKI) is a pathological condition characterized by a rapid decrease in glomerular filtration rate and nitrogenous waste accumulation during hemodynamic regulation. Alisol B, from Alisma orientale, displays anti-tumor, anti-complement, and anti-inflammatory effects. However, its effect and action mechanism on AKI is still unclear. Herein, alisol B significantly attenuated cisplatin (Cis)-induced renal tubular apoptosis through decreasing expressions levels of cleaved-caspase 3 and cleaved-PARP and the ratio of Bax/Bcl-2 depended on the p53 pathway. Alisol B also alleviated Cis-induced inflammatory response (e.g. the increase of ICAM-1, MCP-1, COX-2, iNOS, IL-6, and TNF-α) and oxidative stress (e.g. the decrease of SOD and GSH, the decrease of HO-1, GCLC, GCLM, and NQO-1) through the NF-κB and Nrf2 pathways. In a target fishing experiment, alisol B bound to soluble epoxide hydrolase (sEH) as a direct cellular target through the hydrogen bond with Gln384, which was further supported by inhibition kinetics and surface plasmon resonance (equilibrium dissociation constant, K _D = 1.32 μM). Notably, alisol B enhanced levels of epoxyeicosatrienoic acids and decreased levels of dihydroxyeicosatrienoic acids, indicating that alisol B reduced the sEH activity in vivo. In addition, sEH genetic deletion alleviated Cis-induced AKI and abolished the protective effect of alisol B in Cis-induced AKI as well. These findings indicated that alisol B targeted sEH to alleviate Cis-induced AKI via GSK3β-mediated p53, NF-κB, and Nrf2 signaling pathways and could be used as a potential therapeutic agent in the treatment of AKI.

Biotransformation of 18β-Glycyrrhetinic Acid by Human Intestinal Fungus Aspergillus niger RG13B1 and the Potential Anti-Inflammatory Mechanism of Its Metabolites

18β-Glycyrrhetinic acid (GA) is a triterpenoid possessing an anti-inflammatory activity in vivo, while the low bioavailability limits its application due to its intestinal accumulation. In order to investigate the metabolism of GA in intestinal microbes, it was incubated with human intestinal fungus Aspergillus niger RG13B1, finally leading to the isolation and identification of three new metabolites (1-3) and three known metabolites (4-6) based on 1D and 2D NMR and high-resolution electrospray ionization mass spectroscopy spectra. Metabolite 6 could target myeloid differentiation protein 2 (MD2) to suppress the activation of nuclear factor-kappa B (NF-κB) signaling pathway via inhibiting the nuclear translocation of p65 to downregulate its target proteins and genes in lipopolysaccharide (LPS)-mediated RAW264.7 cells. Molecular dynamics suggested that metabolite 6 interacted with MD2 through the hydrogen bond of amino acid residue Arg90. These findings demonstrated that metabolite 6 could serve as a potential candidate to develop the new inhibitors of MD2.

Total terpenoids of Inula japonica activated the Nrf2 receptor to alleviate the inflammation and oxidative stress in LPS-induced acute lung injury

BACKGROUND

Acute lung injury (ALI) is a life-threatening lung disease and characterized by pulmonary edema and atelectasis. Inula japonica Thunb. is a commonly used traditional Chinese medicine for the treatment of lung diseases. However, the potential effect and mechanism of total terpenoids of I. japonica (TTIJ) on ALI remain obscure.

PURPOSE

This study focused on the protective effect of TTIJ on lipopolysaccharide (LPS)-induced ALI in mice and its potential mechanism.

STUDY DESIGN AND METHODS

A mouse model of ALI was established by intratracheal instillation of LPS to investigate the protective effect of TTIJ. RNA-seq and bioinformatics were then performed to reveal the underlying mechanism. Finally, western blot and real-time qPCR were used to verify the effects of TTIJ on the inflammation and oxidative stress.

RESULTS

TTIJ notably attenuated LPS-induced histopathological changes of lung. The RNA-seq result suggested that the protective effect of TTIJ on LPS-induced ALI were associated with the Toll-like receptor 4 (TLR4) and nuclear factor-erythroid 2-related factor 2 (Nrf2) signaling pathways. Pretreatment with TTIJ significantly reduced the inflammation and oxidative stress via regulating levels of pro-inflammatory and anti-oxidative cytokines, such as tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), superoxide dismutase (SOD), and glutathione (GSH), in LPS-induced ALI mice. TTIJ treatment could suppress the cyclooxygenase-2 (COX-2) expression level and the phosphorylation of p65, p38, ERK, and JNK through the inactivation of the MAPK/NF-κB signaling pathway in a TLR4-independent manner. Meanwhile, TTIJ treatment upregulated expression levels of proteins involved in the Nrf2 signaling pathway, such as heme oxygenase-1 (HO-1), NAD(P)H: quinoneoxidoreductase-1 (NQO-1), glutamate-cysteine ligase catalytic subunit (GCLC), and glutamate-cysteine ligase modifier subunit (GCLM), via activating the Nrf2 receptor, which was confirmed by the luciferase assay.

CONCLUSION

TTIJ could activate the Nrf2 receptor to alleviate the inflammatory response and oxidative stress in LPS-induced ALI mice, which suggested that TTIJ could serve as the potential agent in the treatment of ALI.

Total flavonoids of Inula japonica alleviated the inflammatory response and oxidative stress in LPS-induced acute lung injury via inhibiting the sEH activity: Insights from lipid metabolomics

BACKGROUND

Acute lung injury (ALI) is a severe respiratory disease characterized by diffuse lung interstitial and respiratory distress and pulmonary edema with a mortality rate of 35%-40%. Inula japonica Thunb., known as "Xuan Fu Hua" in Chinese, is a traditional Chinese medicine Inulae Flos to use for relieving cough, eliminating expectorant, and preventing bacterial infections in the clinic, and possesses an anti-pulmonary fibrosis effect. However, the effect and action mechanism of I. japonica on ALI is still unclear.

PURPOSE

This study aimed to investigate the protective effect and underlying mechanism of total flavonoids of I. japonica (TFIJ) in the treatment of ALI.

STUDY DESIGN AND METHODS

A mouse ALI model was established through administration of LPS by the intratracheal instillation. Protective effects of TFIJ in the inflammation and oxidative stress were studied in LPS-induced ALI mice based on inflammatory and oxidative stress factors, including MDA, MPO, SOD, and TNF-α. Lipid metabolomics, bioinformatics, Western blot, quantitative real-time PCR, and immunohistochemistry were performed to reveal the potential mechanism of TFIJ in the treatment of ALI.

RESULTS

TFIJ significantly alleviated the interstitial infiltration of inflammatory cells and the collapse of the alveoli in LPS-induced ALI mice. Lipid metabolomics demonstrated that TFIJ could significantly affect the CYP2J/sEH-mediated arachidonic acid metabolism, such as 11,12-EET, 14,15-EET, 8,9-DHET, 11,12-DHET, and 14,15-DHET, revealing that sEH was the potential target of TFIJ, which was further supported by the recombinant sEH-mediated the substrate hydrolysis in vitro (IC₅₀ = 1.18 μg/ml). Inhibition of sEH by TFIJ alleviated the inflammatory response and oxidative stress via the MAPK, NF-κB, and Nrf2 signaling pathways.

CONCLUSION

These results demonstrated that TFIJ could suppress the sEH activity to stabilize the level of EETs, allowing the alleviation of the pathological course of lung injury in LPS-treated mice, which suggested that TFIJ could serve as the potential agents in the treatment of ALI.

Human cytochrome P450 3A-mediated two-step oxidation metabolism of dimethomorph: Implications in the mechanism-based enzyme inactivation

Dimethomorph (DMM), an effective and broad-spectrum fungicide applied in agriculture, is toxic to environments and living organisms due to the hazardous nature of its toxic residues. This study aims to investigate the human cytochrome P450 enzyme (CYP)-mediated oxidative metabolism of DMM by combining experimental and computational approaches. Dimethomorph was metabolized predominantly through a two-step oxidation process mediated by CYPs, and CYP3A was identified as the major contributor to DMM sequential oxidative metabolism. Meanwhile, DMM elicited the mechanism-based inactivation (MBI) of CYP3A in a suicide manner, and the iminium ion and epoxide reactive intermediates generated in DMM metabolism were identified as the culprits of MBI. Furthermore, three common pesticides, prochloraz (PCZ), difenoconazole (DFZ) and chlorothalonil (CTL), could significantly inhibit CYP3A-mediated DMM metabolism, and consequently trigger elevated exposure to DMM in vivo. Computational studies elucidated that the differentiation effects in charge distribution and the interaction pattern played crucial roles in DMM-induced MBI of CYP3A4 during sequential oxidative metabolism. Collectively, this study provided a global view of the two-step metabolic activation process of DMM mediated by CYP3A, which was beneficial for elucidating the environmental fate and toxicological mechanism of DMM in humans from a new perspective.

Inhibition of sEH via stabilizing the level of EETs alleviated Alzheimer's disease through GSK3β signaling pathway

Alzheimer's disease (AD) is the most common neurodegenerative disorder characterized by dementia. Inhibition of soluble epoxide hydrolase (sEH) regulates inflammation involving in central nervous system (CNS) diseases. However, the exactly mechanism of sEH in AD is still unclear. In this study, we evaluated the vital role of sEH in amyloid beta (Aβ)-induced AD mice, and revealed a possible molecular mechanism for inhibition of sEH in the treatment of AD. The results showed that the sEH expression and activity were remarkably increased in the hippocampus of Aβ-induced AD mice. Chemical inhibition of sEH by TPPU, a selective sEH inhibitor, alleviated spatial learning and memory deficits, and elevated levels of neurotransmitters in Aβ-induced AD mice. Furthermore, inhibition of sEH could ameliorate neuroinflammation, neuronal death, and oxidative stress via stabilizing the in vivo level of epoxyeicosatrienoic acids (EETs), especially 8,9-EET and 14,15-EET, further resulting in the anti-AD effect through the regulation of GSK3β-mediated NF-κB, p53, and Nrf2 signaling pathways. These findings revealed the underlying mechanism of sEH as a potential therapeutic target in treatment of AD.

Identification, semisynthesis, and anti-inflammatory evaluation of 2,3-seco-clavine-type ergot alkaloids from human intestinal fungus Aspergillus fumigatus CY018

Intestinal commensal fungi are vital to human health, and their secondary metabolites play a key role in the reciprocal relationship. In the present study, the first example of 2,3-seco ergot alkaloids belonging to clavine-type were isolated from the fermentation of human intestinal fungus Aspergillus fumigatus CY018, including two pairs of diastereoisomers, secofumigaclavines A (3) and B (4) and secofumigaclavines C (5) and D (6), one analogue features a highly unsaturated skeleton, secofumigaclavine E (7), along with two known ones, fumigaclavines C (1) and D (2). Their structures were identified based on extensive spectroscopic data in a combination of quantum chemical calculations. Moreover, a single-step operation of semi-synthetic reaction based on riboflavin (RF)-dependent photocatalysis was performed to obtain the novel 2,3-seco ergot alkaloids 3 and 5 from their biosynthetic precursors 1 and 2. All the isolated compounds were evaluated for their anti-inflammatory activity. Among them, secofumigaclavine B (4) could bind to MD2 with a low micromole level of the equilibrium dissociation constant measured by surface plasmon resonance (SPR), and suppress TLR4-mediated NF-κB signaling pathway in RAW264.7 cells, resulting in its anti-inflammatory effect. Molecular dynamics revealed that amino acid residue Tyr131 played a key role in the interaction of secofumigaclavine B (4) with MD2. These findings suggested that secofumigaclavine B (4) could be considered as a potential candidate for the development of MD2 inhibitors.

Natural soluble epoxide hydrolase inhibitors from Inula britanica and their potential interactions with soluble epoxide hydrolase: Insight from inhibition kinetics and molecular dynamics

Soluble epoxide hydrolase (sEH) is a potential drug target to treat inflammation and neurodegenerative diseases. In this study, we found that the extract of Inula britanica exhibited significantly inhibitory effects against sEH, therefore, we investigated its phytochemical constituents to obtain seven new compounds together with sixteen known ones (1-20), including two pairs of novel enantiomers, (2S,3S)-britanicafanin A (1a), (2R,3R)-britanicafanin A (1b), (2R,3S)-britanicafanin B (2a), and (2S,3R)-britanicafanin B (2b), and three new lignans britanicafanins C-E (3-5). Their structures were determined by HRESIMS, 1D and 2D NMR, and electronic circular dichroism (ECD) spectra as well as quantum chemical computations. All the isolates were evaluated for their inhibitory effects against sEH, compounds 1-3, 5-7, 9, 10, 13, 14, and 17-20 showed significant inhibitory effects against sEH with IC₅₀ values from 3.56 μM to 26.93 μM. The inhibition kinetics results indicated that compounds 9, 10, 13, and 19 were all uncompetitive inhibitors, and their inhibition constants (K_i) values were 7.11, 1.99, 4.06, and 8.78 μM, respectively. Their potential interactions were analyzed by molecular docking and molecular dynamics (MD), which suggested that amino acid residues Asp335 and Asn359, especially Gln384, played an important role in the inhibition of compounds 10 and 13 on sEH, and compounds 10 and 13 could be considered as the potential candidates for the development of sEH inhibitors.

Medicinal Inula Species: Phytochemistry, Biosynthesis, and Bioactivities

As a genus of the Asteraceae, Inula is widely distributed all over the world, and several of them are being used in traditional medicines. A number of metabolites were isolated from Inula species, and some of these have shown to possess ranges of pharmacological activities. The genus Inula contains abundant sesquiterpenoids, such as eudesmanes, xanthanes, and sesquiterpenoid dimers and trimers. In addition, other types of terpenoids, flavonoids, and lignins also exist in the genus Inula. Since 2010, more than 300 new secondary metabolites, including several known natural products that were isolated for the first time from the genus Inula. Most of them exhibited potential bioactivities in various diseases. The review aimed to summarize the advance of recent researches (2010-2020) on phytochemical constituents, biosynthesis, and pharmacological properties of the genus Inula for providing a scientific basis and supporting its application and exploitation for new drug development.

Investigation of the inhibitory effect of protostanes on human carboxylesterase 2 and their interaction: Inhibition kinetics and molecular stimulations

Carboxylesterase 2 (CES 2), plays a pivotal role in endobiotic homeostasis and xenobiotic metabolism. Protostanes, the major constituents of the genus Alisma, display a series of pharmacological activities. Despite the extensive studies of pharmacological activities, the investigation on inhibitory effects of protostanes against CES 2 is rarely reported. In this study, the inhibitory activities of a library of protostanes (1-25) against human CES 2 were investigated for the first time, using 6,8-dichloro-9,9-dimethyl-7-oxo-7,9-dihydroacridin-2-yl benzoate (DDAB) as the specific fluorescent probe for human CES 2. Compounds 1, 2, 7, 8, 12, 13, 18, 19, and 25 showed strong inhibitory effects towards CES 2. For the most potent compounds 1, 7, 13, and 25, the inhibition kinetics were further investigated, and these four protostanes were all uncompetitive inhibitors against human CES 2 with the inhibition constant (K_i) values ranging from 0.89 μM to 2.83 μM. In addition, molecular docking and molecular dynamics stimulation were employed to analyze the potential interactions between these protostanes and CES 2, and amino acid residue Gln422 was identified to play a crucial role in the strong inhibition of protostanes towards CES 2.

Alisma genus: Phytochemical constituents, biosynthesis, and biological activities

The genus Alisma contains 11 species distributed worldwide, of which at least two species (A. orientale [Sam.] Juzep. and A. plantago-aquatica Linn.) have been used as common herbal medicines. Secondary metabolites obtained from the genus Alisma are considered to be the material basis for the various biological functions and medicinal applications. In this review, we mainly focused on the recent investigations of secondary metabolites from plants of the genus Alisma and their biological activities, with the highlighting on the diversity of the chemical structures, the biosynthesis of interesting secondary metabolites, the biological activities, and the relationships between structures and bioactivities.

The genus Uncaria: A review on phytochemical metabolites and biological aspects

The genus Uncaira (Rubiaceae) comprises of 34 species, many of which are usually used as traditional Chinese medicines (TCMs) to treat hypertension, fever, headache, gastrointestinal illness, and fungal infection. Over the past twenty years, Uncaira species have been paid the considerable attentions in phytochemical and biological aspects, and about 100 new secondary metabolites, including alkaloids, triterpenes, and flavonoids, have been elucidated. This review aims to present a comprehensive and up-to date overview of the biological source, structures and their biosynthetic pathways, as well as the pharmacological of the compounds reported in the genus Uncaria for the past two decades. It would provide an insight into the emerging pharmacological applications of the genus Uncaria.

Uncarialins A-I, Monoterpenoid Indole Alkaloids from Uncaria rhynchophylla as Natural Agonists of the 5-HT1A Receptor

Nine new monoterpenoid indole alkaloids, uncarialins A-I (1-9), were isolated from Uncaria rhynchophylla as well as 14 known analogues (10-23). Their structures were determined by HRESIMS, 1D and 2D NMR, and experimental and calculated electronic circular dichroism data. Compounds 5, 7, 15, and 22 displayed significant agonistic effects against the 5-HT_1A receptor with EC₅₀ values of 2.2 ± 0.1, 0.1 ± 0.1, 1.6 ± 0.3, and 2.0 ± 0.5 μM, respectively. The mechanisms of action of these four compounds with the 5-HT_1A receptor were investigated by molecular docking, and the results suggested that amino acid residues Asp116, Thr196, Asn386, and Tyr390 played critical roles in the observed activity of the above-mentioned compounds.

Phytochemical constituents from Uncaria rhynchophylla in human carboxylesterase 2 inhibition: Kinetics and interaction mechanism merged with docking simulations

BACKGROUND

Carboxylesterases (CEs) belong to the serine hydrolase family, and are in charge of hydrolyzing chemicals with carboxylic acid ester and amide functional groups via Ser-His-Glu. Uncaria rhynchophylla (Miq.) Miq. ex Havil. is a famous traditional Chinese medicine used in managing hyperpyrexia, epilepsy, preeclampsia, and hypertension in China.

HYPOTHESIS/PURPOSE

To discover the potential natural human carboxylesterase 2 (hCE 2) inhibitors from U. rhynchophylla.

METHODS

Compounds were obtained from the hooks of U. rhynchophylla by silica gel and preparative HPLC. Their structures were elucidated by using HRESIMS, 1D and 2D NMR spectra. Their inhibitory activeties and inhibition kinetics against hCE 2 were assayed by the fluorescent probe, and potential mechanisms were also investigated by molecular docking.

RESULTS

Twenty-three compounds, including a new phenolic acid uncariarhyine A (1), eight known triterpenoids (2-9), and ten known aromatic derivatives (10, 13-16, and 19-23), were isolated from U. rhynchophylla. Compounds 1-5, 7, 9, and 15 showed significant inhibitory activities against hCE 2 with IC₅₀ values from 4.01  ± 0.61 µM to 18.60 ± 0.21 µM, and their inhibition kinetic analysis results revealed that compounds 1, 5, 9, and 15 were non-competitive; compounds 3 and 4 were mixed-type, and compounds 2 and 7 were uncompetitive. Molecular docking studies indicated inhibition mechanisms of compounds 1-5, 7, 9, and 15 against hCE 2.

CONCLUSION

Our present findings highlight potential natural hCE 2 inhibitors from U. rhynchophylla.

Chemical characteristics of the fungus Ganoderma lucidum and their inhibitory effects on acetylcholinesterase

The chemical characteristic of a well-known folk medicine Ganoderma lucidum has been investigated by a series of chromatographic technologies, which displayed the presences of 45 lanostane type triterpenoids, including two new nor-lanostane triterpenoids (40, 41). Their structures were identified on the basis of spectroscopic data analysis (UV, IR, HRESIMS, 1D, and 2D NMR). Notably, some triterpenoids displayed moderate inhibitory effects against AChE (acetylcholinesterase) by an in vitro screened experiment. Triterpenoid 2 displayed the potent inhibitory effect with IC₅₀ 10.8 and K_i 14.95 μM (inhibition kinetic). The preliminary SAR has been discussed by the docking analyses between ganoderic acids (1, 2) and AChE.

Diterpenoids from the roots of Euphorbia fischeriana and their inhibitory effects on α-glucosidase

Chemical investigation has been performed on the roots of Euphorbia fischeriana, a traditional Chinese medicine. Three diterpenoids were obtained using various chromatographic techniques, and their structures were determined by spectroscopic data including HRESIMS, 1D NMR, 2D NMR, ECD, and calculated ECD, which gave two new diterpenoids, daphnane type (1) and ent-pimarene type (3). Additionally, the isolated compounds (1-3) displayed moderate inhibitory effects against α-glucosidase in an in vitro bioassay.

Biotransformation of furanocoumarins by fungi: preparation of imperation analogs

Imperation analogs have the furanocoumarin skeleton, with the isopentenyl group, which displayed significant bioactivities. The biotransformation of furanocoumarins imperation, isoimperation and phellopterin (1-3) by fungi has been proved to be an efficient method for the structural modification. Ten transformed furanocoumarin analogs were obtained by fungal biotransformation, including one new highly oxygenated furanocoumarin (4c). Aspergillus niger AS 3.739 displayed selectively transformed capability toward furanocouamrins (1-3) with one or two major products. So, seven hydroxylation and hydrolysis derivatives have been prepared efficiently. Additionally, the biotransformation of phellopterin gave multiple products (4a, 4b, 4c) by Cunninghamella blakesleana AS 3.970. The biotransformation time-courses of furanocoumarins have been established, which suggested the preferred incubation time. The bioactivities of furanocoumarin analogs have been investigated in an in vitro bioassay. And, furanocoumarins 1-3, 2a, and 2c displayed moderate anti-osteoporosis activities using MCET3-E1 cell line at the concentrations of 1, 10, and 100 μM.

Uncaria rhynchophylla Ameliorates Parkinson's Disease by Inhibiting HSP90 Expression: Insights from Quantitative Proteomics

BACKGROUND/AIMS

Uncaria rhynchophylla, known as "Gou-teng", is a traditional Chinese medicine (TCM) used to extinguish wind, clear heat, arrest convulsions, and pacify the liver. Although U. rhynchophylla has a long history of being often used to treat central nervous system (CNS) diseases, its efficacy and potential mechanism are still uncertain. This study investigated neuroprotective effect and the underlying mechanism of U. rhynchophylla extract (URE) in MPP+-induced SH-SY5Y cells and MPTP-induced mice.

METHODS

MPP+-induced SH-SY5Y cells and MPTP-induced mice were used to established Parkinson's disease (PD) models. Quantitative proteomics and bioinformatics were used to uncover proteomics changes of URE. Western blotting was used to validate main differentially expressed proteins and test HSP90 client proteins (apoptosis-related, autophagy-related, MAPKs, PI3K, and AKT proteins). Flow cytometry and JC-1 staining assay were further used to confirm the effect of URE on MPP+-induced apoptosis in SH-SY5Y cells. Gait analysis was used to detect the behavioral changes in MPTP-induced mice. The levels of dopamine (DA) and their metabolites were examined in striatum (STR) by HPLC-EC. The positive expression of tyrosine hydroxylase (TH) was detected by immunohischemical staining and Western blotting.

RESULTS

URE dose-dependently increased the cell viability in MPP+-induced SH-SY5Y cells. Quantitative proteomics and bioinformatics results confirmed that HSP90 was an important differentially expressed protein of URE. URE inhibited the expression of HSP90, which further reversed MPP+-induced cell apoptosis and autophagy by increasing the expressions of Bcl-2, Cyclin D1, p-ERK, p-PI3K p85, PI3K p110α, p-AKT, and LC3-I and decreasing cleaved caspase 3, Bax, p-JNK, p-p38, and LC3-II. URE also markedly decreased the apoptotic ratio and elevated mitochondrial transmembrane potential (DΨm). Furthermore, URE treatment ameliorated behavioral impairments, increased the contents of DA and its metabolites and elevated the positive expressions of TH in SN and STR as well as the TH protein.

CONCLUSIONS

URE possessed the neuroprotective effect in vivo and in vitro, regulated MAPK and PI3K-AKT signal pathways, and inhibited the expression of HSP90. U. rhynchophylla has potentials as therapeutic agent in PD treatment.

Alisma orientale extract exerts the reversing cholestasis effect by activation of farnesoid X receptor

BACKGROUND

Cholestasis is a clinical syndrome of liver damage that is caused by accumulation of bile acids in the liver and systemic circulation. Farnesoid X receptor (FXR) can regulate synthesis, metabolism, and excretion of bile acids. The rhizomes of Alisma orientale is a well-known traditional Chinese medicine to treat edema, obesity, gonorrhea, leukorrhea, diarrhea, hyperlipidemia, and diabetes in China.

HYPOTHESIS/PURPOSE

We hypothesized Alisma orientale extract (AOE) to exert hepatoprotective effect against α-naphthylisothiocyanate (ANIT) induced cholestasis in rat. We aimed to investigate the mechanism of AOE.

STUDY DESIGN

Male Sprague Dawley rats with intrahepatic cholestasis induced by ANIT were treated with AOE (150, 300, or 600 mg/kg). Rats receiving vehicle (0.5% CMC-Na) served as control.

METHODS

48 h after ANIT administration, rats were sacrificed. Blood was collected to obtain serum and livers were removed for histopathology and protein preparation. Biochemical indicators in serum were determined using commercial kits and triterpenoids were determined by liquid chromatography tandem Qtrap mass spectrometry. Proteomics was analyzed by liquid chromatography tandem ion-trap mass spectrometry. The differently expressed proteins were analyzed via the network database and verified by western blotting. The interaction between triterpenoids and FXR were evaluated by luciferase assay and molecular docking.

RESULTS

AOE treatment significantly decreased the serum AST, ALT, TBIL, and intrahepatic TBA and improved the liver pathologic change induced by ANIT. Proteomics analysis indicated that AOE regulated proteins related to bile acid homeostasis via activating farnesoid X receptor (FXR) signaling pathway. Luciferase assay and molecular docking results indicated that triterpenoids could activate FXR, which resulting in ameliorative accumulation of bile acids in the liver by increase of metabolism and transportation for bile acids, and decrease of synthesis for bile acids.

CONCLUSION

AOE protected against rat liver injury and cholestasis induced by ANIT by activation of farnesoid X receptor, suggesting that A. orientale could be regarded as a potential hepatoprotective drug.

Diterpenoids from the roots of Euphorbia ebracteolata and their inhibitory effects on human carboxylesterase 2

A chemical investigation of the roots of Euphorbia ebracteolata identified eighteen diterpenoids and glycosides. On the basis of spectroscopic data, they were determined to be ent-kauranes, ent-atisanes, tigliane derivatives, ingenane, and ent-abietanes, among which were eleven previously undescribed diterpenoids. The inhibitory effects of the isolated compounds against human carboxylesterase 2 (hCE-2) were evaluated in vitro, which revealed moderate inhibitory effects with IC₅₀ values < 50 μM. Next, the inhibitory kinetics were evaluated for the putative hCE-2 inhibitor 4β,9α,16,20-tetrahydroxy-14(13 → 12)-abeo-12αH-1,6-tigliadiene-3,13-dione (IC₅₀ 3.88 μM), and results indicated competitive inhibition with K_i 4.94 μM. Additionally, none of the diterpenoids showed cytotoxic effects against five human tumor cell lines as determined by MTT assays.

Evaluation of the stability of tyrosol esters during in vitro gastrointestinal digestion

Lipophenols such as tea polyphenol palmitate derivatives (palmitoyl esters of tea polyphenols) have been classified as non-toxic food additives due to their better protective effects on lipidic food matrices from oxidation, but their digestion and absorption have remained unexplored.

Afatinib Decreases P-Glycoprotein Expression to Promote Adriamycin Toxicity of A549T Cells

We investigated the reversal effect of afatinib (AFT) on activity of adriamycin (ADR) in A549T cells and clarified the related molecular mechanisms. A549T cells overexpressing P-glycoprotein (P-gp) were resistant to anticancer drug ADR. AFT significantly increased the antitumor activity of ADR in A549T cells. AFT increased the intracellular concentration of ADR by inhibiting the function and expression of P-gp at mRNA and protein levels in A549T cells. Additionally, the reversal effect of AFT on P-gp mediated multidrug resistance (MDR) might be related to the inhibition of PI3K/Akt pathway. Cotreatment with AFT and ADR could enhance ADR-induced apoptosis and autophagy in A549T cells. Meanwhile, the co-treatment significantly induced cell apoptosis and autophagy accompanied by increased expression of cleaved caspase-3, PARP, LC3B-II, and beclin 1. Apoptosis inhibitors had no significant effect on cell activity, while autophagy inhibitors decreased cell viability, suggesting that autophagy may be a self protective mechanism of cell survival in the absence of chemotherapy drugs. Interestingly, when combined with AFT and ADR, inhibition of apoptosis and/or autophagy could enhance cell viability. These results indicated that in addition to inhibit P-gp, ADR-induced apoptosis, and autophagy promoted by AFT contributed to the antiproliferation effect of combined AFT and ADR on A549T cells. These findings provide evidence that AFT combined ADR may achieve a better therapeutic effect to lung cancer in clinic. J. Cell. Biochem. 119: 414-423, 2018. © 2017 Wiley Periodicals, Inc.

Comparative pharmacokinetic study of baicalin and its metabolites after oral administration of baicalin and Chaiqin Qingning capsule in normal and febrile rats

An accurate, precise, selective, and sensitive high performance liquid chromatography coupled to tandem mass spectrometry (HPLC-MS/MS) method was developed for the simultaneous determination of baicalin and its metabolite, baicalein 6-O-glucopyranuronoside, in normal and febrile rats plasma. Two analytes, along with hesperidin as an internal standard, were determined by multiple reactions monitoring (MRM) operated in the positive electrospray ionization (ESI) mode. Chromatographic separation was performed on an Agilent ZORBAX Extend-C18 column (100mm×2.10mm, 3.5μm) with a mobile phase of 0.1% formic acid solution and acetonitrile at a flow rate of 0.6mL/min. The calibration curves showed good linearity (r≥0.9974) with the concentration ranges of 2.000-2000ngmL^-1 for baicalin and baicalein 6-O-glucopyranuronoside. The inter- and intra-day accuracies (relative error, RE%) were between -6.62% and 6.75%, and the precisions (relative standard deviation, RSD%) were less than 9.09% for quality control samples (QCs). The method also possessed good selectivity, recovery and stability, and was successfully applied to a comparative pharmacokinetic study of baicalin and baicalein 6-O-glucopyranuronoside in normal and febrile rats after oral administration of baicalin and Chaiqin Qingning capsule.

Novel protostane-type triterpenoids with inhibitory human carboxylesterase 2 activities

Ten new triterpenoids, including two novel nor-protostanes, were isolated from A. orientalis and biotransformation of alisols A and B 23-acetate.

Alismanoid A, an unprecedented 1,2-seco bisabolene from Alisma orientale, and its protective activity against H2O2-induced damage in SH-SY5Y cells

A pair of unprecedented 1,2-seco bisabolenes, (8R)-alismanoid A (1a) and (8S)-alismanoid A (1b), were isolated from A. orientale.

Identification of the hydroxylated derivatives of bufalin: phase I metabolites in rats

Bufalin was a typical bioactive bufadienolide, existed in the traditional Chinese medicine Chan Su with the high content of 1-5%. The in vivo metabolites (1-5) of bufalin were prepared by various chromatographic techniques from the bile samples of SD rats, which were administrated with bufalin orally. Their structures were determined on the basis of the widely spectroscopic data, including HRESIMS, 1D-, and 2D NMR. And 1-3, 5 were new compounds. In the in vitro cytotoxicity assay, metabolites (1-5) showed weaker cytotoxic effects than bufalin against human cancer cell lines A549 and H1299, which indicated that the metabolism was a significant pathway for the detoxification of bufalin. Structures analyses indicated that metabolites 1-5 were hydroxylated derivatives of bufalin. This study suggested that Phase I metabolism catalyzed by CYP450 enzymes was one of the metabolic ways of bufalin, which may promote the excretion of bufalin.

Protostane Triterpenoids from the Rhizome of Alisma orientale Exhibit Inhibitory Effects on Human Carboxylesterase 2

Twelve new and 10 known protostane triterpenoids were isolated from the rhizome of Alisma orientale. Their structures were elucidated based on physical data analyses, including UV, HRESIMS, NMR experiments ((1)H, (13)C NMR, (1)H-(1)H COSY, HSQC, HMBC, and NOESY), and induced electronic circular dichroism. New compounds 1-12 were classified as protostanes (1-10), 29-norprotostane (11), and 24-norprotostane (12) by structure analyses. Furthermore, the inhibitory effects on human carboxylesterases (hCE-1, hCE-2) of compounds 1-22 were evaluated. Compounds 2, 6, 9, and 11 showed moderate inhibitory activities and were selective toward hCE-2 enzymes, with IC50 values of 8.68, 4.72, 4.58, and 2.02 μM, respectively. The inhibition kinetics of compound 11 toward hCE-2 were established, and the Ki value was determined as 1.76 μM using a mixed inhibition model. The interaction of bioactive compound 11 with hCE-2 was shown using molecular docking.

Diagnostic accuracy of three-dimensional CT reconstruction and cephalometry for lateral skull base tumors

OBJECTIVE

To explore the diagnostic accuracy of three-dimensional CT reconstruction and cephalometry in lateral skull base tumors.

PATIENTS AND METHODS

Fifty-eight patients with lateral skull base tumors were randomly divided into control group (n = 29, examined with conventional diagnostic technique) or study group (n = 29, examined with three-dimensional CT reconstruction and cephalometry). The diagnostic accuracy, tumor distribution and image characteristics were compared between both patient groups.

RESULTS

In control group, preoperative tumor diagnosis was consistent with intraoperative diagnosis in 20 patients, similar in 7 patients and discrepant in 2 patients. In study group, there were 24 consistent, 4 similar, and 1 discrepant diagnoses (p < 0.05 vs. control group). Frequency of individual tumor types, as revealed by either diagnostic method, was comparable. The images obtained with three-dimensional CT reconstruction were clearer, facilitating an accurate demonstration of the tumor, including tumor size and location.

CONCLUSIONS

Three-dimensional CT reconstruction and cephalometry provides accurate diagnosis of lateral skull base tumors, which is helpful for subsequent surgical treatment.

Identifying and applying a highly selective probe to simultaneously determine the O-glucuronidation activity of human UGT1A3 and UGT1A4

Glucuronidation mediated by uridine 5′-diphospho (UDP)-glucuronosyltransferase is an important detoxification pathway. However, identifying a selective probe of UDP- glucuronosyltransferase is complicated because of the significant overlapping substrate specificity displayed by the enzyme. In this paper, desacetylcinobufagin (DACB) 3-O- and 16-O-glucuronidation were found to be isoform-specific probe reactions for UGT1A4 and UGT1A3, respectively. DACB was well characterized as a probe for simultaneously determining the catalytic activities of O-glucuronidation mediated by UGT1A3 and UGT1A4 from various enzyme sources, through a sensitive analysis method.

Alisol B 23-acetate protects against ANIT-induced hepatotoxity and cholestasis, due to FXR-mediated regulation of transporters and enzymes involved in bile acid homeostasis

Intrahepatic cholestasis is a clinical syndrome with systemic and intrahepatic accumulation of excessive toxic bile acids that ultimately cause hepatobiliary injury. Appropriate regulation of bile acids in hepatocytes is critically important for protection against liver injury. In the present study, we characterized the protective effect of alisol B 23-acetate (AB23A), a natural triterpenoid, on alpha-naphthylisothiocyanate (ANIT)-induced liver injury and intrahepatic cholestasis in mice and further elucidated the mechanisms in vivo and in vitro. AB23A treatment dose-dependently protected against liver injury induced by ANIT through reducing hepatic uptake and increasing efflux of bile acid via down-regulation of hepatic uptake transporters (Ntcp) and up-regulation of efflux transporter (Bsep, Mrp2 and Mdr2) expression. Furthermore, AB23A reduced bile acid synthesis through repressing Cyp7a1 and Cyp8b1, increased bile acid conjugation through inducing Bal, Baat and bile acid metabolism through an induction in gene expression of Sult2a1. We further demonstrate the involvement of farnesoid X receptor (FXR) in the hepatoprotective effect of AB23A. The changes in transporters and enzymes, as well as ameliorative liver histology in AB23A-treated mice were abrogated by FXR antagonist guggulsterone in vivo. In vitro evidences also directly demonstrated the effect of AB23A on FXR activation in a dose-dependent manner using luciferase reporter assay in HepG2 cells. In conclusion, AB23A produces protective effect against ANIT-induced hepatotoxity and cholestasis, due to FXR-mediated regulation of transporters and enzymes.