Molecular Docking and NMR Binding Studies to Identify Novel Inhibitors of Human Phosphomevalonate Kinase

Phosphomevalonate kinase (PMK) phosphorylates mevalonate-5-phosphate (M5P) in the mevalonate pathway, which is the sole source of isoprenoids and steroids in humans. We have identified new PMK inhibitors with virtual screening, using autodock. Promising hits were verified and their affinity measured using NMR-based 1H–15N heteronuclear single quantum coherence (HSQC) chemical shift perturbation and fluorescence titrations. Chemical shift changes were monitored, plotted, and fitted to obtain dissociation constants (Kd). Tight binding compounds with Kd’s ranging from 6–60 μM were identified. These compounds tended to have significant polarity and negative charge, similar to the natural substrates (M5P and ATP). HSQC cross peak changes suggest that binding induces a global conformational change, such as domain closure. Compounds identified in this study serve as chemical genetic probes of human PMK, to explore pharmacology of the mevalonate pathway, as well as starting points for further drug development

Anticancer Activities of Six Selected Natural Compounds of Some Cameroonian Medicinal Plants

BACKGROUND: Natural products are well recognized as sources of drugs in several human ailments. In the present work, we carried out a preliminary screening of six natural compounds, xanthone V(1) (1); 2-acetylfuro-1,4-naphthoquinone (2); physcion (3); bisvismiaquinone (4); vismiaquinone (5); 1,8-dihydroxy-3-geranyloxy-6-methylanthraquinone (6) against MiaPaCa-2 pancreatic and CCRF-CEM leukemia cells and their multidrug-resistant subline, CEM/ADR5000. Compounds 1 and 2 were then tested in several other cancer cells and their possible mode of action were investigated. METHODOLOGY/FINDINGS: The tested compounds were previously isolated from the Cameroonian medicinal plants Vismia laurentii (1, 3, 4, 5 and 6) and Newbouldia laevis (2). The preliminary cytotoxicity results allowed the selection of xanthone V(1) and 2-acetylfuro-1,4-naphthoquinone, which were then tested on a panel of cancer cell lines. The study was also extended to the analysis of cell cycle distribution, apoptosis induction, caspase 3/7 activation and the anti-angiogenic properties of xanthone V(1) and 2-acetylfuro-1,4-naphthoquinone. IC(50) values around or below 4 µg/ml were obtained on 64.29% and 78.57% of the tested cancer cell lines for xanthone V(1) and 2-acetylfuro-1,4-naphthoquinone, respectively. The most sensitive cell lines (IC(50)<1 µg/ml) were breast MCF-7 (to xanthone V(1)), cervix HeLa and Caski (to xanthone V(1) and 2-acetylfuro-1,4-naphthoquinone), leukemia PF-382 and melanoma colo-38 (to 2-acetylfuro-1,4-naphthoquinone). The two compounds showed respectively, 65.8% and 59.6% inhibition of the growth of blood capillaries on the chorioallantoic membrane of quail eggs in the anti-angiogenic assay. Upon treatment with two fold IC(50) and after 72 h, the two compounds induced cell cycle arrest in S-phase, and also significant apoptosis in CCRF-CEM leukemia cells. Caspase 3/7 was activated by xanthone V(1). CONCLUSIONS/SIGNIFICANCE: The overall results of the present study provided evidence for the cytotoxicity of compounds xanthone V(1) and 2-acetylfuro-1,4-naphthoquinone, and bring supportive data for future investigations that will lead to their use in cancer therapy

Early management of sepsis in medical patients in rural Thailand: a single-center prospective observational study

Background:The burden of sepsis is highest in low- and middle-income countries, though the management of sepsis in these settings is poorly characterized. Therefore, the objective of this study was to assess the early management of sepsis in Thailand. Methods:Pre-planned analysis of the Ubon-sepsis study, a single-center prospective cohort study of Thai adults admitted to the general medical wards and medical intensive care units (ICUs) of a regional referral hospital with community-acquired sepsis. Results:Between March 2013 and January 2017, 3,716 patients with sepsis were enrolled. The median age was 59 years (IQR 44-72, range 18-101), 58% were male, and 88% were transferred from other hospitals. Eighty-six percent of patients (N = 3,206) were evaluated in the Emergency Department (ED), where median length of stay was less than 1 hour. Within the first day of admission, most patients (83%, N = 3,089) were admitted to the general medical wards, while 17% were admitted to the ICUs. Patients admitted to the ICUs had similar age, gender, and comorbidities, but had more organ dysfunction and were more likely to receive measured sepsis management interventions. Overall, 84% (N = 3,136) had blood cultures ordered and 89% (N = 3,308) received antibiotics within the first day of hospital admission. Among the 3,089 patients admitted to the general medical wards, 38% (N = 1,165) received an adrenergic agent, and 21% (N = 650) received invasive mechanical ventilation. Overall mortality at 28 days was 21% (765/3,716), and 28-day mortality in patients admitted to the ICUs was higher than that in patients admitted to the general medical wards within the first day (42% [263/627] vs. 16% [502/3,089], p &lt; 0.001). Conclusions:Sepsis in a regional referral hospital in rural Thailand, where some critical care resources are limited, is commonly managed on general medical wards despite high rates of respiratory failure and shock. Enhancing sepsis care in the ED and general wards, as well as improving access to ICUs, may be beneficial in reducing mortality. Trial registration:The Ubon-sepsis study was registered on clinicaltrials.gov (NCT02217592)

Early management of sepsis in medical patients in rural Thailand: a single-center prospective observational study

Background:The burden of sepsis is highest in low- and middle-income countries, though the management of sepsis in these settings is poorly characterized. Therefore, the objective of this study was to assess the early management of sepsis in Thailand. Methods:Pre-planned analysis of the Ubon-sepsis study, a single-center prospective cohort study of Thai adults admitted to the general medical wards and medical intensive care units (ICUs) of a regional referral hospital with community-acquired sepsis. Results:Between March 2013 and January 2017, 3,716 patients with sepsis were enrolled. The median age was 59 years (IQR 44-72, range 18-101), 58% were male, and 88% were transferred from other hospitals. Eighty-six percent of patients (N = 3,206) were evaluated in the Emergency Department (ED), where median length of stay was less than 1 hour. Within the first day of admission, most patients (83%, N = 3,089) were admitted to the general medical wards, while 17% were admitted to the ICUs. Patients admitted to the ICUs had similar age, gender, and comorbidities, but had more organ dysfunction and were more likely to receive measured sepsis management interventions. Overall, 84% (N = 3,136) had blood cultures ordered and 89% (N = 3,308) received antibiotics within the first day of hospital admission. Among the 3,089 patients admitted to the general medical wards, 38% (N = 1,165) received an adrenergic agent, and 21% (N = 650) received invasive mechanical ventilation. Overall mortality at 28 days was 21% (765/3,716), and 28-day mortality in patients admitted to the ICUs was higher than that in patients admitted to the general medical wards within the first day (42% [263/627] vs. 16% [502/3,089], p < 0.001). Conclusions:Sepsis in a regional referral hospital in rural Thailand, where some critical care resources are limited, is commonly managed on general medical wards despite high rates of respiratory failure and shock. Enhancing sepsis care in the ED and general wards, as well as improving access to ICUs, may be beneficial in reducing mortality. Trial registration:The Ubon-sepsis study was registered on clinicaltrials.gov (NCT02217592)