Rosemary (Rosmarinus officinalis) is grown throughout the world and is widely used as a medicinal herb and to season and preserve food. Rosemary polyphenols and terpenoids have attracted great ...interest due to their potential health benefits. However, complete information regarding their absorption and bioavailability in Caco-2 cell model is scarce. The permeation properties of the bioactive compounds (flavonoids, diterpenes, triterpenes and phenylpropanoids) of a rosemary extract (RE), obtained by supercritical fluid extraction, was studied in Caco-2 cell monolayer model, both in a free form or liposomed. Compounds were identified and quantitated by liquid chromatography coupled to quadrupole time-of-flight with electrospray ionization mass spectrometry analysis (HPLC-ESI-QTOF-MS), and the apparent permeability values (Papp) were determined, for the first time in the extract, for 24 compounds in both directions across cell monolayer. For some compounds, such as triterpenoids and some flavonoids, Papp values found were reported for the first time in Caco-2 cells.Our results indicate that most compounds are scarcely absorbed, and passive diffusion is suggested to be the primary mechanism of absorption. The use of liposomes to vehiculize the extract resulted in reduced permeability for most compounds. Finally, the biopharmaceutical classification (BCS) of all the compounds was achieved according to their permeability and solubility data for bioequivalence purposes. BCS study reveal that most of the RE compounds could be classified as classes III and IV (low permeability); therefore, RE itself should also be classified into this category.
Colorectal cancer (CRC) is a highly prevalent form of neoplasm worldwide. Capecitabine, an oral antimetabolite, is widely used for CRC treatment; however, there exists substantial variation in ...individual therapy response. This may be due to genetic variations in genes involved in capecitabine pharmacodynamics (PD). In this study, we investigated the role of single-nucleotide polymorphisms (SNPs) related to capecitabine's PD on disease-free survival (DFS) in CRC patients under adjuvant treatment. Thirteen SNPs in the
,
,
,
/
, and
/
genes were genotyped in 142 CRC patients using real-time PCR with predesigned TaqMan
probes. A significant association was found between favorable DFS and the
rs2612091-T allele (
= 0.010; HR = 0.34; 95% CI = 0.14-0.83), as well as with the
/
region ACT haplotype (
= 0.012; HR = 0.37; 95% CI = 0.17-0.80). Other factors such as low histological grade (
= 0.009; HR = 0.34; 95% CI = 0.14-0.79) and a family history of cancer (
= 0.040; HR = 0.48; 95% CI = 0.23-0.99) were also linked to improved DFS. Therefore, the SNP
rs2612091 could be considered as a predictive genetic biomarker for survival in CRC patients receiving capecitabine-based adjuvant regimens.
An ever-growing number of preclinical studies have investigated the tumoricidal activity of the milk thistle flavonolignan silibinin. The clinical value of silibinin as a bona fide anti-cancer ...therapy, however, remains uncertain with respect to its bioavailability and blood⁻brain barrier (BBB) permeability. To shed some light on the absorption and bioavailability of silibinin, we utilized the Caco-2 cell monolayer model of human intestinal absorption to evaluate the permeation properties of three different formulations of silibinin: silibinin-meglumine, a water-soluble form of silibinin complexed with the amino-sugar meglumine; silibinin-phosphatidylcholine, the phytolipid delivery system Siliphos; and Eurosil
/Euromed, a milk thistle extract that is the active component of the nutraceutical Legasil with enhanced bioavailability. Our approach predicted differential mechanisms of transport and blood⁻brain barrier permeabilities between the silibinin formulations tested. Our assessment might provide valuable information about an idoneous silibinin formulation capable of reaching target cancer tissues and accounting for the observed clinical effects of silibinin, including a recently reported meaningful central nervous system activity against brain metastases.
Silibinin is a direct inhibitor of STAT3 Verdura, Sara; Cuyàs, Elisabet; Llorach-Parés, Laura ...
Food and chemical toxicology,
06/2018, Volume:
116, Issue:
Pt B
Journal Article
Peer reviewed
Open access
We herein combined experimental and computational efforts to delineate the mechanism of action through which the flavonolignan silibinin targets STAT3. Silibinin reduced IL-6 inducible, constitutive, ...and acquired feedback activation of STAT3 at tyrosine 705 (Y705). Silibinin attenuated the inducible phospho-activation of Y705 in GFP-STAT3 genetic fusions without drastically altering the kinase activity of the STAT3 upstream kinases JAK1 and JAK2. A comparative computational study based on docking and molecular dynamics simulation over 14 different STAT3 inhibitors (STAT3i) predicted that silibinin could directly bind with high affinity to both the Src homology-2 (SH2) domain and the DNA-binding domain (DBD) of STAT3. Silibinin partially overlapped with the cavity occupied by other STAT3i in the SH2 domain to indirectly prevent Y705 phosphorylation, yet showing a unique binding mode. Moreover, silibinin was the only STAT3i predicted to establish direct interactions with DNA in its targeting to the STAT3 DBD. The prevention of STAT3 nuclear translocation, the blockade of the binding of activated STAT3 to its consensus DNA sequence, and the suppression of STAT3-directed transcriptional activity confirmed silibinin as a direct STAT3i. The unique characteristics of silibinin as a bimodal SH2- and DBD-targeting STAT3i make silibinin a promising lead for designing new, more effective STAT3i.
Display omitted
•Silibinin directly binds the SH2 domain of STAT3 to prevent Y705 phosphorylation-related STAT3 activation and dimerization.•Silibinin establishes direct interactions with DNA in its targeting to the STAT3 DNA-binding domain (DBD).•Silibinin impedes the activation, dimerization, nuclear translocation, DNA-binding, and transcriptional activity of STAT3.•Silibinin functions as a bimodal SH2- and DBD-targeting STAT3i with proven therapeutic activity in brain metastasis.
The signal transducer and activator of transcription 3 (STAT3) has been suggested to play a prominent role in mediating non-small-cell lung cancer (NSCLC) resistance to some tyrosine kinase inhibitor ...(TKI)-mediated therapies. Using a model of anaplastic lymphoma kinase gene (ALK)-translocated NSCLC with acquired resistance to the ALK TKI crizotinib, but lacking amplifications or mutations in the kinase domain of ALK, we herein present evidence that STAT3 activation is a novel mechanism of crizotinib resistance that involves the upregulation of immune escape and epithelial to mesenchymal transition (EMT) signaling pathways. Taking advantage of the flavonolignan silibinin as a naturally occurring STAT3-targeted pharmacological inhibitor, we confirmed that STAT3 activation protects ALK-translocated NSCLC from crizotinib. Accordingly, silibinin-induced inhibition of STAT3 worked synergistically with crizotinib to reverse acquired resistance and restore sensitivity in crizotinib-resistant cells. Moreover, silibinin treatment significantly inhibited the upregulation of the immune checkpoint regulator PD-L1 and also EMT regulators (e.g., SLUG, VIM, CD44) in crizotinib-refractory cells. These findings provide a valuable strategy to potentially improve the efficacy of ALK inhibition by cotreatment with silibinin-based therapeutics, which merit clinical investigation for ALK TKI-resistant NSCLC patients.
The aim of this systematic review was to provide a comprehensive overview of the literature published in the last decade on the association of single-nucleotide polymorphisms in genes involved in the ...pharmacodynamic and pharmacokinetic pathways of capecitabine with treatment outcomes among colorectal cancer patients. A systematic search of the literature published in the last 10 years was carried out in two databases (Medline and Scopus) using keywords related to the objective. Quality assessment of the studies included was performed using an assessment tool derived from the Strengthening the Reporting of Genetic Association (STREGA) statement. Thirteen studies were included in this systematic review. Genes involved in bioactivation, metabolism, transport, mechanism of action of capecitabine, DNA repair, and folate cycle were associated with toxicity. Meanwhile, genes related to DNA repair were associated with therapy effectiveness. This systematic review reveals that several SNPs other than the four
variants that are screened in clinical practice could have an impact on treatment outcomes. These findings suggest the identification of future predictive biomarkers of effectiveness and toxicity in colorectal cancer patients treated with capecitabine. However, the evidence is sparse and requires further validation.
Dietary polyphenols may exert their pharmacological effect via synergistic interactions with multiple targets. Putative effects of polyphenols in the management of obesity should be primarily ...evaluated in adipose tissue and consequently in well-documented cell model. We used Hibiscus sabdariffa (HS), a widely recognised medicinal plant, as a source of polyphenols with a number of salutary effects previously reported. We present here the full characterisation of bioactive components of HS aqueous extracts and document their effects in a model of adipogenesis from 3T3-L1 cells and in hypertrophic and insulin-resistant adipocytes. Aqueous extracts were up to 100 times more efficient in inhibiting triglyceride accumulation when devoid of fibre and polysaccharides. Significant differences were also observed in reactive oxygen species generation and adipokine secretion. We also found that, when polyphenols were fractionated and isolated, the benefits of the whole extract were greater than the sum of its parts, which indicated a previously unnoticed synergism. In conclusion, polyphenols have interactive and complementary effects, which suggest a possible application in the management of complex diseases and efforts to isolate individual components might be irrelevant for clinical medicine and/or human nutrition.
•Rosemary extracts show cytotoxic effects in cancer cell models but their active compounds are yet to be discovered.•Bioguided fractionation of rosemary extract was achieved by preparative HPLC and ...fractions characterized by HPLC-ESI-QTOF-MS.•Carnosic acid, carnosol, 12-methoxycarnosic acid, taxodione, hinokione and betulinic acid are the most active compounds.•Comparative antiproliferative study on the fractions and the whole extract revealed potential synergistic effects.•The antiproliferative or cytotoxic mechanism deserves further attention.
Rosemary extracts have exhibited potential cytostatic or cytotoxic effects in several cancer cell models but their bioactive compounds are yet to be discovered. In this work, the anticancer activity of a rosemary-leaf extract and its fractions were assayed to identify the phenolic compounds responsible for their antiproliferative/cytotoxic effects on a panel of human colon cancer cell lines. Bioguided fractionation of the rosemary-leaf extract was achieved by semi-preparative chromatography. The rosemary extract and the compounds in the fractions were characterized and quantified by HPLC-ESI-QTOF-MS. Cellular viability in the presence of these fractions and the whole extract was determined after 24 or 48 h incubations by using an MTT assay. Fractions containing diterpenes or triterpenes were the most active but not as much as the whole extract. In conclusion, carnosic acid, carnosol, 12-methoxycarnosic acid, taxodione, hinokione and betulinic acid were the putative candidates that contributed to the observed antiproliferative activity of rosemary in human colon cancer cells. Whether the effects of the extract and fractions are only cytostatic or cytotoxic needs to be elucidated. Nevertheless, the comparative antiproliferative study on the fractions and whole extract revealed potential synergistic effects between several components in the extract that may deserve further attention.
Background
Wilson disease is an autosomal recessive disorder of copper metabolism caused by mutations in the
ATP7B
gene. An early diagnosis is crucial to prevent evolution of the disease, as ...implantation of early therapeutic measures fully prevents its symptoms. As population genetics data predict a higher than initially expected prevalence, it was important to define the basic diagnostic tools to approach population screening.
Methods
A highly genetically homogeneous cohort of 70 patients, belonging to 50 unrelated families, has been selected as a framework to analyze all their clinical, biochemical and genetic characteristics, to define the disease in our population, with an estimated prevalence of 1 in 12,369, and determine the most useful features that reach diagnostic value.
Results
Serum ceruloplasmin below 11.5 mg/dL and cupremia below 60 μg/mL, were the best analytical predictors of the disease in asymptomatic individuals, while cupruria or hepatic copper determination were less powerful. Genetic analysis reached a conclusive diagnosis in all 65 patients available for complete testing. Of them, 48 were carriers of at least one p.Leu708Pro mutant allele, with 24 homozygotes. Nine patients carried a promoter deletion mutation, revealing that extended sequencing beyond the
ATP7B
gene-coding region is essential. All mutations caused hepatic damage since early ages, increasing its severity as diagnosis was delayed, and neurological symptoms appear.
Conclusion
Serum ceruloplasmin determination followed by genetic screening would reduce costs and favor the prioritization of non-invasive procedures to reach a definitive diagnosis, even for asymptomatic cases.
PDF
