37 research outputs found
Lebanese Plants and Plant-Derived Compounds Against Colon Cancer
Colorectal cancer (CRC) is a major health concern and demands long-term efforts in developing strategies for screening and prevention. CRC has become a preventable disease as a consequence of a better understanding of colorectal carcinogenesis. However, current therapy is unsatisfactory and necessitates the exploration of other approaches for the prevention and treatment of cancer. Plant based products have been recognized as preventive with regard to the development of colon cancer. Therefore, the potential chemopreventive use and mechanism of action of Lebanese natural product were evaluated.
Towards this aim the antitumor activity of Onopordum cynarocephalum and Centaurea ainetensis has been studied using in vitro and in vivo models. In vitro, both crude extracts were non cytotoxic to normal intestinal cells and inhibited the proliferation of colon cancer cells in a dose-dependent manner. In vivo, both crude extracts reduced the number of tumors by an average of 65% at weeks 20 (adenomas stage) and 30 (adenocarcinomas stage). The activity of the C. ainetensis extract was attributed to Salograviolide A, a guaianolide-type sesquiterpene lactone, which was isolated and identified through bio-guided fractionation. The mechanism of action of thymoquinone (TQ), the active component of Nigella sativa, was established in colon cancer cells using in vitro models. By the use of N-acetyl cysteine, a radical scavenger, the direct involvement of reactive oxygen species in TQ-induced apoptotic cells was established. The analytical detection of TQ from spiked serum and its protein binding were evaluated. The average recovery of TQ from spiked serum subjected to several extraction procedures was 2.5% proving the inability of conventional methods to analyze TQ from serum. This has been explained by the extensive binding (>98%) of TQ to serum and major serum components such as bovine serum albumin (BSA) and alpha-1-acid glycoprotein (AGP). Using mass spectrometry analysis, TQ was confirmed to bind covalently to the free cysteine in position 34 and 147 of the amino acid sequence of BSA and AGP, respectively.
The results of this work put at the disposal for future development new plants with anti-cancer activities and enhance the understanding of the pharmaceutical properties of TQ, a prerequisite for its future clinical development.Paksusuolen syöpä on merkittävä terveyttä uhkaava sairaus ja vaatii pitkäjänteisiä ponnisteluita kehitettäessä lähestymistapoja taudin toteamiseksi ja hoitamiseksi. Paksusuolen syövän hoito on parantunut ja paksusuolen syövän kehittymiseen vaikuttavat tekijät tunnetaan paremmin kuin aikaisemmin. Kuitenkin nykyiset hoitokäytännöt eivät ole täysin tyydyttäviä ja tekevät välttämättömäksi, että tutkitaan muita tapoja ennalta ehkäistä ja hoitaa syöpää. On havaittu kasviperäisten tuotteiden estävän paksusuolen syövän kehittymistä. Tämän johdosta tässä tutkimuksessa libanonilaisten luonnontuotteiden syöpää estävää vaikutusta ja vaikutusmekanismia tutkittiin.
Tutkittiin Onopordum cynarocephalum ja Centaurea ainetensis kasvien vaikutuksia paksusuolen syöpään käyttämällä in vitro and in vivo solu- ja eläinkoe malleja. In vitro, solukokeissa molemmat raakauutteet eivät olleet sytotoksisia suolistosoluille ja estivät paksusuolen syöpäsolujen lisääntymistä annosvasteisesti. In vivo, eläinkokeissa molemmat raakauutteet vähensivät kasvaimien määrää keskimäärin 65%:lla 20 viikkoa hoidon aloittamisesta (adenooma vaihe) and 30 viikkoa hoidon aloittamisesta (adenokarsinooma vaihe). C. ainetensis-uutteen aktiivisuus voitiin liittää Salograviolidi A:han, guaianolidi-tyyppinen seskviterpeenilaktoniin, mikä eristettiin ja tunnistettiin aktiivisuuden ohjaaman eristyksen avulla.
Nigella sativa-kasvin vaikuttavan aineen tymokinonin (TQ) vaikutusmekanismia tutkittiin käyttämällä paksusuolen syöpäsolumalleja in vitro. Käyttämälllä N-asetyylikysteiiniä, radikaalin sieppaajaa, reaktiivisen happimolekyylien suora osallistuminen TQ-indusoiduissa apoptoottisissa soluissa voitiin osoittaa.
TQ:n mittaamista seerumista ja TQ:n sitoutumista proteiineihin tutkittiin. Kun TQ oli lisätty seerumiin sen keskimääräinen saanto useiden uuttojen jälkeen oli vain 2.5%, mikä osoitti tavanomaisten menetelmien heikkouden analysoitaessa TQ:ta seerumista. Tämä selittyi TQ:n voimakkaalla sitoutumisella (>98%) seerumiin ja seerumin pääkomponentteihin kuten naudan seerumin albumiini (BSA) ja hapan glykoproteiini (alpha-1-acid glycoprotein, AGP). Käyttämällä massaspektrometri-analytiikkaa TQ:n voitiin osoittaa sitoutuvan kovalenttisesti vapaaseen kysteiiniin aminohappoissa 34 (BSA) ja 147 (AGP).
Tämän työn tulokset mahdollistavat tulevaisuudessa uusien kasviperäisten syöpälääkkeiden kehittämisen ja edesauttavat TQ:n farmaseuttisten ominaisuuksien ymmärtämistä kehitettäessä sitä tulevaisuudessa lääkkeeksi kliiniseen käyttöön
Efficacy of Vancomycin and Meropenem in Central Nervous System Infections in Children and Adults: Current Update
The current antimicrobial therapy of bacterial infections of the central nervous system (CNS) in adults and pediatric patients is faced with many pitfalls as the drugs have to reach necessary levels in serum and cross the blood-brain barrier. Furthermore, several studies report that different factors such as the structure of the antimicrobial agent, the severity of disease, or the degree of inflammation play a significant role. Despite the available attempts to establish pharmacokinetic (PK) modeling to improve the required dosing regimen for adults and pediatric patients, conclusive recommendations for the best therapeutic strategies are still lacking. For instance, bacterial meningitis, the most common CNS infections, and ventriculitis, a severe complication of meningitis, are still associated with 10% and 30% mortality, respectively. Several studies report on the use of vancomycin and meropenem to manage meningitis and ventriculitis; therefore, this review aims to shed light on the current knowledge about their use in adults and pediatric patients. Consequently, studies published from 2015 until mid-July 2021 are included, and data about the study population, levels of drugs in serum and cerebrospinal fluid (CSF), and measured PK data in serum and CSF are provided. The overall aim is to provide the readers a recent reference that summarizes the pitfalls and success of the current therapy and emphasizes the importance of performing more studies to improve the clinical outcome of the current therapeutical approach
Repurposing of Chronically Used Drugs in Cancer Therapy: A Chance to Grasp
Despite the advancement in drug discovery for cancer therapy, drug repurposing remains an exceptional opportunistic strategy. This approach offers many advantages (faster, safer, and cheaper drugs) typically needed to overcome increased challenges, i.e., side effects, resistance, and costs associated with cancer therapy. However, not all drug classes suit a patient’s condition or long-time use. For that, repurposing chronically used medications is more appealing. This review highlights the importance of repurposing anti-diabetic and anti-hypertensive drugs in the global fight against human malignancies. Extensive searches of all available evidence (up to 30 March 2023) on the anti-cancer activities of anti-diabetic and anti-hypertensive agents are obtained from multiple resources (PubMed, Google Scholar, ClinicalTrials.gov, Drug Bank database, ReDo database, and the National Institutes of Health). Interestingly, more than 92 clinical trials are evaluating the anti-cancer activity of 14 anti-diabetic and anti-hypertensive drugs against more than 15 cancer types. Moreover, some of these agents have reached Phase IV evaluations, suggesting promising official release as anti-cancer medications. This comprehensive review provides current updates on different anti-diabetic and anti-hypertensive classes possessing anti-cancer activities with the available evidence about their mechanism(s) and stage of development and evaluation. Hence, it serves researchers and clinicians interested in anti-cancer drug discovery and cancer management
Paclitaxel, Imatinib and 5-Fluorouracil Increase the Unbound Fraction of Flucloxacillin In Vitro
Flucloxacillin (FLU), an isoxazolyl penicillin, is widely used for the treatment of different bacterial infections in intensive care units (ICU). Being highly bound to plasma proteins, FLU is prone to drug-drug interactions (DDI) when administered concurrently with other drugs. As FLU is binding to both Sudlow's site I and site II of human serum albumin (HSA), competitive and allosteric interactions with other drugs, highly bound to the same sites, seem conceivable. Knowledge about interaction(s) of FLU with the widely used anticancer agents paclitaxel (PAC), imatinib (IMA), and 5-fluorouracil (5-FU is scarce. The effects of the selected anticancer agents on the unbound fraction of FLU were evaluated in pooled plasma as well as in HSA and alpha-1-acid glycoprotein (AGP) samples, the second major drug carrier in plasma. FLU levels in spiked samples were analyzed by LC-MS/MS after ultrafiltration. Significant increase in FLU unbound fraction was observed when in combination with PAC and IMA and to a lesser extent with 5-FU. Furthermore, significant binding of FLU to AGP was observed. Collectively, this is the first study showing the binding of FLU to AGP as well as demonstrating a significant DDI between PAC/IMA/5-FU and FLU
Ceftazidime and cefepime antagonize 5-fluorouracil’s effect in colon cancer cells
Background
Drug-drug interaction (DDI), which can occur at the pharmacokinetics and/or the pharmacodynamics (PD) levels, can increase or decrease the therapeutic or adverse response of a drug itself or a combination of drugs. Cancer patients often receive, along their antineoplastic agents, antibiotics such as Ăź-lactams to treat or prevent infection. Despite the narrow therapeutic indices of antibiotics and antineoplastic agents, data about their potential interaction are insufficient. 5-fluorouracil (5-FU), widely used against colon cancer, is known for its toxicity and large intra- and inter- individual variability. Therefore, knowledge about its interaction with antibiotics is crucial.
Methods
In this study, we evaluated at the PD levels, against HCT-116 colon cancer cells, DDI between 5-FU and several Ăź-lactams (ampicillin, benzypenicillin, piperacillin, meropenem, flucloxacillin, ceftazidime (CFT), and cefepime (CFP)), widely used in intensive care units. All drugs were tested at clinically achieved concentrations. MTT assay was used to measure the metabolic activity of the cells. Cell cycle profile and apoptosis induction were monitored, in HCT-116 and DLD-1 cells, using propidium iodide staining and Caspase-3/7 activity assay. The uptake of CFT and CFP by the cells was measured using LC-MS/MS method.
Results
Our data indicate that despite their limited uptake by the cells, CFT and CFP (two cephalosporins) antagonized significantly 5-FU-induced S-phase arrest (DLD-1 cells) and apoptosis induction (HCT-116 cells). Remarkably, while CFP did not affect the proliferation of colon cancer cells, CFT inhibited, at clinically relevant concentrations, the proliferation of DLD-1 cells via apoptosis induction, as evidenced by an increase in caspase 3/7 activation. Unexpectedly, 5-FU also antagonized CFT’s induced cell death in DLD-1 cells.
Conclusion
This study shows that CFP and CFT have adverse effects on 5-FU’s action while CFT is a potent anticancer agent that inhibits DLD-1 cells by inducing apoptotic cell death. Further studies are needed to decipher the mechanism(s) responsible for CFT’s effects against colon cancer as well as the observed antagonism between CFT, CFP, and 5-FU with the ultimate aim of translating the findings to the clinical settings
Evidence for conserved function of γ–glutamyltranspeptidase in Helicobacter genus
The confounding consequences of Helicobacter bilis infection in experimental mice populations are well recognized, but the role of this bacterium in human diseases is less known. Limited data are available on virulence determinants of this species. In Helicobacter pylori, Îł-glutamyltranspeptidase (ÎłGT) contributes to the colonization of the gastric mucosa and to the pathogenesis of peptic ulcer. The role of ÎłGT in H. bilis infections remains unknown. The annotated genome sequence of H. bilis revealed two putative ggt genes and our aim was to characterize these H. bilis ÎłGT paralogues. We performed a phylogenetic analysis to understand the evolution of Helicobacter ÎłGTs and to predict functional activities of these two genes. In addition, both copies of H. bilis ÎłGTs were expressed as recombinant proteins and their biochemical characteristics were analysed. Functional complementation of Escherichia coli deficient in ÎłGT activity and deletion of ÎłGT in H. bilis were performed. Finally, the inhibitory effect of T-cell and gastric cell proliferation by H. bilis ÎłGT was assessed. Our results indicated that one gene is responsible for ÎłGT activity, while the other showed no ÎłGT activity due to lack of autoprocessing. Although both H. bilis and H. pylori ÎłGTs exhibited a similar affinity to L-Glutamine and Îł-Glutamyl-p-nitroanilide, the H. bilis ÎłGT was significantly less active. Nevertheless, H. bilis ÎłGT inhibited T-cell proliferation at a similar level to that observed for H. pylori. Finally, we showed a similar suppressive influence of both H. bilis and H. pylori ÎłGTs on AGS cell proliferation mediated by an apoptosis-independent mechanism. Our data suggest a conserved function of ÎłGT in the Helicobacter genus. Since ÎłGT is present only in a few enterohepatic Helicobacter species, its expression appears not to be essential for colonization of the lower gastrointestinal tract, but it could provide metabolic advantages in colonization capability of different niches.Peer reviewe
A rapid liquid chromatography-tandem mass spectrometry for the quantification of Fosfomycin in plasma, urine, and aqueous fluids
A simple and fast ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method for the analysis of Fosfomycin in different matrices (human plasma/urine, and aqueous fluid) has been established and validated. Sample cleanup consists, depending on the matrix used, on protein precipitation or dilution with methanol containing isotopically labeled Fosfomycin as internal standard. Compounds, separated on a Luna Omega PS C-18 column, were detected in multiple reactions monitoring in negative ion mode using API4000 system. With a total run time of 2 min and using low volume of samples (plasma: 10 mu l, urine: 2 mu l, and aqueous fluid: 5 mu l), the covered ranges were: plasma (12.5-800 mu g/mL), urine (62.5-4000 mu g/mL), and aqueous fluid (1-160 mu g/mL). The method proved to be precise and accurate. The inaccuracy and imprecision in each matrix at the four tested quality controls including the lower limit of quantification were:: plasma (<= 6.5%, <= 8%), urine (<= 5.8%, <= 6.3%), and aqueous fluid (<= 10.6%, <= 12%). The method is fast and robust which makes it relevant for pharmacolcinetic studies and therapeutic drug monitoring. The appropriateness of the developed method in clinical application is also confirmed
Liquid chromatography-tandem mass spectrometry for the quantification of moxifloxacin, ciprofloxacin, daptomycin, caspofungin, and isavuconazole in human plasma
A simple and precise ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed for the simultaneous analysis of five anti-infective agents used to treat severe infections [three antibiotics (daptomycin, moxifioxacin, ciprofloxacin) and two antifungals (isavuconazole, caspofungin)] in human plasma. Sample preparation was based on protein precipitation with ice cold methanol. All five agents were analyzed with the corresponding isotopically labeled internal standards. All analytes were detected in multiple reactions monitoring (MRM) using API 4000 triple-quadrupole mass spectrometer with electrospray (ESI) source operating in positive mode. The calibration curves were linear over the selected ranges (r > 0.99). The method is precise and accurate with a total run time of 5.5 min. Accuracy of all target analytes ranged between 95.9-116.6%, measured with an imprecision of less than 10.8%. The lower limit of quantification was 1.25 mg/L for caspofungin, 0.3125 mg/L for isavuconazole, 3.125 mg/L for daptomycin, 0.075 mg/L for ciprofloxacin, and 0.1875 mg/L for moxifioxacin. The successful application of the method in patient samples proved its suitability for the medical surveillance of antimicrobial therapy in intensive care units as well as to other pharmacokinetic studies. (C) 2018 Published by Elsevier B.V
Repurposing of Chronically Used Drugs in Cancer Therapy: A Chance to Grasp
Despite the advancement in drug discovery for cancer therapy, drug repurposing remains an exceptional opportunistic strategy. This approach offers many advantages (faster, safer, and cheaper drugs) typically needed to overcome increased challenges, i.e., side effects, resistance, and costs associated with cancer therapy. However, not all drug classes suit a patient’s condition or long-time use. For that, repurposing chronically used medications is more appealing. This review highlights the importance of repurposing anti-diabetic and anti-hypertensive drugs in the global fight against human malignancies. Extensive searches of all available evidence (up to 30 March 2023) on the anti-cancer activities of anti-diabetic and anti-hypertensive agents are obtained from multiple resources (PubMed, Google Scholar, ClinicalTrials.gov, Drug Bank database, ReDo database, and the National Institutes of Health). Interestingly, more than 92 clinical trials are evaluating the anti-cancer activity of 14 anti-diabetic and anti-hypertensive drugs against more than 15 cancer types. Moreover, some of these agents have reached Phase IV evaluations, suggesting promising official release as anti-cancer medications. This comprehensive review provides current updates on different anti-diabetic and anti-hypertensive classes possessing anti-cancer activities with the available evidence about their mechanism(s) and stage of development and evaluation. Hence, it serves researchers and clinicians interested in anti-cancer drug discovery and cancer management
Inflammation induced ER stress affects absorptive intestinal epithelial cells function and integrity
Recent studies have linked impairment of intestinal epithelial function in inflammatory bowel disease to the disturbance of endoplasmic reticulum homeostasis (ER) in response to stress. Most studies are on goblet and Paneth cells, which are considered more susceptible to stress due to their role in the protection of intestinal epithelium against microbes and harmful substances. However, studies on the role of inflammation-induced ER stress in absorptive intestinal cells are scarce. In this study, we show, using Caco-2 cells as a model of intestinal epithelial barrier, that inducing ER stress using a cocktail mixture of pro-inflammatory mediators [TNF alpha (50 ng/ml), MCP1 (50 ng/ml), and IL-1 beta (25 ng/ml)] as observed in IBD patients induces ER stress and leads to significant changes in key proteins of the apical (sucrase-isomaltase (SI), dipeptidyl-peptidase (DPPIV), and ezrin) and basolateral (E-cadherin, zonula occludens (ZO-1), and connexin-43) membranes. Aberrant trafficking of SI, DPPIV was observed as early as 8 h post-inflammation-induced ER stress and even in the absence of loss of intestinal cell integrity. The observed effect was associated with a re-localization of ezrin, ZO-1, and connexin-43, key differentiation and junction proteins. Collectively, this study shows that disruption of the trafficking of key digestive enzymes of the intestinal epithelium occur in response to inflammation induced ER stress before the loss of monolayer integrity