Investigation of bacterial neuraminidase inhibition of xanthones bearing geranyl and prenyl groups from Cratoxylum cochinchinense.

Introduction: The root of Cratoxylum cochinchinense has been widely used as Chinese folk medicine to cure fevers, burns, and abdominal complications because it contains various bioactive metabolites such as xanthones, triterpenes, and flavonoids. In this study, we estimated bacterial neuraminidase inhibition with a series of xanthones from C. cochinchinense. BNA has connected to various biological functions such as pathogenic bacteria infection inflammatory process after infection and biofilm formation. Methods: The identification of xanthones (1-6) bearing geranyl and prenyl groups was established by spectroscopic data using UV, IR, NMR, and HREIMS. BNA inhibitory modes of isolated xanthones were investigated by Double-reciprocal plots. Moreover, the competitive inhibitor was evaluated the additional kinetic modes determined by kinetic parameters (k 3, k 4, and K i app). The molecular docking (MD) and molecular dynamics simulations (MDS) studies also provided the critical information regarding the role of the geranyl and prenyl groups against BNA inhibition. Results: A series of xanthones (1-6) appended prenyl and geranyl groups on the A-ring were isolated, and compounds 1-3 were shown to be new xanthones. The analogues within this series were highly inhibited with excellent affinity against bacterial neuraminidase (BNA). A subtle change in the prenyl or geranyl motif affected the inhibitory potency and behavior significantly. For example, the inhibitory potency and binding affinity resulting from the geranyl group on C4: xanthone 1 (IC50 = 0.38 µM, KA = 2.4434 × 105 L·mol-1) were 100-fold different from those of xanthone 3 (IC50 = 35.8 µM, KA = 0.0002 × 105 L·mol-1). The most potent compound 1 was identified as a competitive inhibitor which interacted with BNA under reversible slow-binding inhibition: K i app = 0.1440 µM, k 3 = 0.1410 µM-1s-1, and k 4 = 0.0203 min-1. The inhibitory potencies (IC50) were doubly confirmed by the binding affinities (KA). Discussion: This study suggests the potential of xanthones derived from C. cochinchinense as promising candidates for developing novel BNA inhibitors. Further research and exploration of these xanthones may contribute to the development of effective treatments for bacterial infections and inflammatory processes associated with BNA activity.

[Effect of moxibustion combined with Guifu Yuhe decoction on the conversion score of idiopathic constitution, serum total lgE and blood EOS in the patients with allergic acne].

OBJECTIVE: To observe the therapeutic effect of moxibustion combined with Guifu Yuhe decoction on allergic acne and the influence on immunologic function in the patients. METHODS: A total of 60 patients with allergic acne were rando-mized into an observation group (30 cases) and a control group (30 cases).Thirty healthy employees were in the healthy group. In the control group, Guifu Yuhe decoction was prescribed for oral administration, while in the observation group, on the base of the treatment as the control group, moxibustion was exerted at Dazhui (GV14) and Shenque (GV8). The treatment duration was 8 weeks. Before and after treatment, serum IgE, blood EOS, CD4+T cell, CD8+ T cell and CD4+T/CD8+T, as well as the conversion score of idiopathic constitution and the symptom score were compared in the patients of two groups. The clinical therapeutic effect was observed in the two groups. RESULTS: Before treatment, compared with the healthy group, IgE and EOS, CD4+T cell and CD8+T cell all increased (P<0.05), and CD4+T/CD8+T decreased in the two groups (P<0.05). After treatment, IgE, EOS and CD4+T cell and CD8+T cell decreased (P<0.05), and CD4+T/CD8+T increased (P<0.05) in the intra-group comparison in the patients. The changes of IgE, EOS, CD4+T cell and CD8+T cell in the observation group were more larger than those in the control group (P<0.05). After treatment, the conversion score of body constitution and symptom score all decreased in either group (P<0.05) and the scores in the observation group were lower than those of the control group (P< 0.05). The total effective rate of the observation group (29/30, 96.7%) was higher than that of the control group (22/30, 73.3%, P<0.05). CONCLUSION: Moxibustion combined with Guifu Yuhe decoction can significantly improve immune function and body constitution of the patients with allergic acne, which may be related to rectifying idiopathic constitution, improving in lymphocyte subsets dysfunction and inhibiting allergic reaction.

20(S)-Ginsenoside Rg3 Inhibits Lung Cancer Cell Proliferation by Targeting EGFR-Mediated Ras/Raf/MEK/ERK Pathway.

Lung cancer is the leading cause of cancer death in the world and classified into non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC). As tyrosine kinase inhibitors (TKIs), several triterpenoid saponins can target to epidermal growth factor receptor (EGFR), a widely used molecular therapeutic target, to exhibit remarkable anti-proliferative activities in cancer cells. As one of triterpenoid saponins, 20([Formula: see text])-ginsenoside Rg3 [20([Formula: see text])-Rg3] was confirmed to be an EGFR-TKI in this work. According to the quantitative real-time reverse transcription-PCR (qRT-PCR) and immunoblotting analysis, 20([Formula: see text])-Rg3 was certified to play a key role on EGFR/Ras/Raf/MEK/ERK signal pathway regulation. Our data demonstrated that 20([Formula: see text])-Rg3 might block the cell cycle at the G0/G1 phase by downregulating CDK2, Cyclin A2, and Cyclin E1. Molecular docking suggested that the combination of both hydrophobic and hydrogen-bonding interactions may help stabilizing the 20([Formula: see text])-Rg3-EGFR binding. Furthermore, their binding stability was assessed by molecular dynamics simulation. Taken together, these data provide the evidence that 20([Formula: see text])-Rg3 could prohibit A549 cell proliferation, probably by arresting the cell cycle at the G0/G1 phase via the EGFR/Ras/Raf/MEK/ERK pathway.

Phytochemical analysis of aerial part of Ikonnikovia kaufmanniana and their protection of DNA damage.

Ikonnikovia kaufmanniana is an endemic plant of Kazakhstan of which phytochemical analysis has not been reported. The present study found out that this species enriched with antioxidant chemicals. Isolation and structural identification processes reveal twelve phenolic compounds (1-12) having dihydroflavanonol, flavonol, isoflavone and flavanol skeletons. The annotation of individual components in the extract was carried out by LC-ESI-MS/MS to represent a chemotaxonomic marker of the target plant. The antioxidant activities of all compounds were screened using three different radical sources (DPPH, ORAC, and hydroxyl radicals). Most compounds (1-11) had significant antioxidant activity against three radical sources, and their efficacies were found to differ by their functionality and skeleton. The potential of the isolated compounds in preventing oxidative damage of DNA was evaluated with pBR322 plasmid DNA. Compounds (1, 5, 7, and 8) had protective effects on DNA damaged with 80% efficacy at 60 µM concentration.

Xanthine Oxidase Inhibition and Anti-LDL Oxidation by Prenylated Isoflavones from Flemingia philippinensis Root.

Xanthine oxidase is a frontier enzyme to produce oxidants, which leads to inflammation in the blood. Prenylated isoflavones from Flemingia philippinensis were found to display potent inhibition against xanthine oxidase (XO). All isolates (1-9) inhibited XO enzyme with IC50 ranging 7.8~36.4 µM. The most active isoflavones (2-5, IC50 = 7.8~14.8 µM) have the structural feature of a catechol motif in B-ring. Inhibitory behaviors were disclosed as a mixed type I mode of inhibition with KI < KIS. Binding affinities to XO enzyme were evaluated. Fluorescence quenching effects agreed with inhibitory potencies (IC50s). The compounds (2-5) also showed potent anti-LDL oxidation effects in the thiobarbituric acid-reactive substances (TBARS) assay, the lag time of conjugated diene formation, relative electrophoretic mobility (REM), and fragmentation of apoB-100 on copper-mediated LDL oxidation. The compound 4 protected LDL oxidation with 0.7 µM in TBARS assay, which was 40-fold more active than genistein (IC50 = 30.4 µM).

Influence of Addition and Subtraction Therapy of Zhenwutang to Residual Renal Function and Nutritional Status of Patients with Maintenance Hemodialysis / 中国实验方剂学杂志

Objective:To discuss influence of addition and subtraction therapy of Zhenwutang to residual renal function （RRF）， nutritional status， dialysis adequacy and quality of life of patients with maintenance hemodialysis （MHD）. Method:One hundred and thirty-six patients were randomly divided into control group （68 cases） and observation group （68 cases） by random number table. Patients in two group got MHD， 3 times/week， 4 h/time， levocarnitine injection （1 g dissolved in 5-10 mL water for injection） after the dialysis， 2-3 min/time， recombinant human erythropoietin injection with subcutaneous injection for 4 weeks， 3 000 U， 3 times/day， valsartan capsules for 3 months， 80 mg/time， 1 time/day. The control group took Manshenning mixture， 35 mL / time， 3 times / day.Patients in observation group added addition and subtraction therapy of Zhenwutang for 3 months， 1 dose/day. Before and after treatment， urea nitrogen （BUN）， creatinine （CR） and 24 hours' urine volume were recorded. And RRF， rate of decrease of RRF and rate of decrease in urine volume were also calculated. Levels of hemoglobin （HB）， albumin （ALB）， prealbumin （PA） and transferrin （TRF） were detected. After treatment， standardized protein metabolism rate （nPCR）， urea clearance index （Kt / V） and glomerular filtration rate （EGFR） were discussed. And improved subjective comprehensive nutrition assessment （SGA）， dialysis related quality of life （kdta） and health survey summary （SF-36） were graded. Six months' follow-up， primary end point event （24 h urine volume ≤ 400 mL） and no residual renal function （24 h urine volume ≤ 400 mL） were recorded. Result:Levels of RRF， Kt/V， nPCR， eGFR， Hb， Alb， PA， TRF and total scores of KDTA and SF-36 in observation group were higher than those in control group （P<0.01）. And score of SGA， rate of decrease of RRF and rate of decrease in urine volume were less than those in control group （P<0.01）.Incidence rate of primary end point event was 27.94%（19/68） lower than 47.06%（32/68） in control group （χ2=5.302， P<0.05）， incidence rate of no residual renal functionwas 17.65%（11/68） lower than 36.76%（25/68） in control group （χ2=6.274， P<0.05）. And BUN and Cr were lower than those in control group （P<0.01）， 24 h urine volume was more than that in control group （P<0.01）. Conclusion:Addition and subtraction therapy of Zhenwutang can maintenance of RRF， improvement of nutritional status， improvement of dialysis adequacy and quality of life of patients .

Human neutrophil elastase (HNE) inhibitory polyprenylated acylphloroglucinols from the flowers of Hypericum ascyron.

In the course of an investigation of human neutrophil elastase (HNE) associated with inflammation, the extract of the flower parts of Hypericum ascyron showed a significant influence to HNE. The responsible metabolites to HNE inhibition were found to be eight polyprenylated acylphloroglucinols, PPAPs (1-8) which showed IC50 ranges between 2.4 and 19.9 µM. This is the first report to demonstrate that PPAP skeleton exhibits potent HNE inhibition. The compounds 1-3 were characterized and newly named as ascyronone E (IC50 = 4.3 µM), ascyronone F (IC50 = 19.9 µM), ascyronone G (IC50 = 4.5 µM) based on 2D-NMR spectroscopic data. In the kinetic analysis of double reciprocal plots, all the compounds showed noncompetitive behaviors to HNE enzyme with the remaining of Km and the increase of Vmax. The binding affinity levels (KSV) by using fluorescence were sufficient to be able to prove that PPAPs (1-8) had compliant interaction with inhibitory potencies.

Tyrosinase inhibitory study of flavonolignans from the seeds of Silybum marianum (Milk thistle).

Anti-melanogenesis effects of silymarin from milk thistle have been reported recently, but detailed tyrosinase inhibition properties of individual components have not been investigated. This study purported to substantiate tyrosinase inhibition and its mechanism based on a single metabolite. The responsible components for tyrosinase inhibition of target source were found out as flavonolignans which consist of isosilybin A (1), isosilybin B (2), silydianin (3), 2,3-dihydrosilychristin (4), silychristin A (5), silychristin B (6) and silybin (7), respectively. The isolated flavonolignans (1-7) inhibited both monophenolase (IC50 = 1.7-7.6 µM) and diphenolase (IC50 = 12.1-44.9 µM) of tyrosinase significantly. Their inhibitions were 10-fold effective in comparison with their mother skeletons (8-10). Inhibitory functions were also proved by HPLC analysis using N-acetyl-l-tyrosine as substrate. The predominant formation of Emet·I was confirmed from a long prolongation of lag time and a decrease of the static state activity of the enzyme. All tested compounds had a significant binding affinity to tyrosinase with KSV values of 0.06-0.27 × 104 L·mol-1, which are well correlated with IC50s. In kinetic study, all flavonolignan (1-7) were mixed type I (KI < KIS) inhibitors, whereas their mother skeletons (8-10) were competitive ones. The UPLC-ESI-TOF/MS analysis showed that the isolated inhibitors are the most abundant metabolites in the target plant.

Effectiveness of Prenyl Group on Flavonoids from Epimedium koreanum Nakai on Bacterial Neuraminidase Inhibition.

In this study, the inhibitory potential of bacterial neuraminidase (NA) was observed on the leaves of Epimedium koreanum Nakai, which is a popular ingredient in traditional herbal medicine. This study attempted to isolate the relevant, responsible metabolites and elucidate their inhibition mechanism. The methanol extraction process yielded eight flavonoids (1⁻8), of which compounds 7 and 8 were new compounds named koreanoside F and koreanoside G, respectively. All the compounds (1⁻8) showed a significant inhibition to bacterial NA with IC50 values of 0.17⁻106.3 µM. In particular, the prenyl group on the flavonoids played a critical role in bacterial NA inhibition. Epimedokoreanin B (compound 1, IC50 = 0.17 µM) with two prenyl groups on C8 and C5' of luteolin was 500 times more effective than luteolin (IC50 = 85.6 µM). A similar trend was observed on compound 2 (IC50 = 0.68 µM) versus dihydrokaempferol (IC50 = 500.4 µM) and compound 3 (IC50 = 12.6 µM) versus apigenin (IC50 = 107.5 µM). Kinetic parameters (Km, Vmax, and Kik/Kiv) evaluated that all the compounds apart from compound 5 showed noncompetitive inhibition. Compound 5 was proven to be a mixed type inhibitor. In an enzyme binding affinity experiment using fluorescence, affinity constants (KSV) were tightly related to inhibitory activities.

Antioxidant Activities of Phenolic Metabolites from Flemingia philippinensis Merr. et Rolfe and Their Application to DNA Damage Protection.

F. philippinensis Merr. et Rolfe has been cultivated on a large scale and is widely consumed by local inhabitants as an important nutraceutical, especially against rheumatism which has a deep connection with antioxidants. In this study, a total of 18 different phenolic metabolite compounds in F. philippinensis were isolated and identified, and evaluated for their antioxidant and DNA damage protection potential. The antioxidant activity of the 18 identified compounds was screened using DPPH, ORAC, hydroxyl and superoxide radical scavenging assays. The antioxidant potential of the compounds was found to differ by functionality and skeleton. However, most compounds showed a good antioxidant potential. In particular, seven of the identified compounds, namely, compounds 2, 3, 6, 10, 11, 15 and 16, showed significant protective effects on pBR322 plasmid DNA against the mutagenic and toxic effects of Fenton's reaction. The most active compound, compound 2, displayed a dose-dependent DNA damage protection potential in the range of 7.5~60.0 µM. The DNA damage protective effect of the identified compounds was significantly correlated with the hydroxyl radical scavenging activity. Compounds that exhibited effective (IC50 = 5.4~12.5 µg/mL) hydroxyl radical scavenging activity were found to be the ones with higher DNA damage protection potential.

[On authors of Lingnan Weisheng Fang (Lingnan Hygiene Prescription)].

By applying philological methods, the authors of different chapters of Lingnan Weisheng Fang (Lingnan Hygiene Prescription) were investigated based on historical materials and epitaphs. The date of compilation of the book was also approximately investigated.