Modulation of Angiotensin II-Induced Cellular Hypertrophy by Cannflavin-C: Unveiling the Impact on Cytochrome P450 1B1 and Arachidonic Acid Metabolites.

This research aimed to clarify the impacts of cannflavin-C on angiotensin II (Ang II)-induced cardiac hypertrophy and their potential role in modulating cytochrome P450 1B1 (CYP1B1) and arachidonic acid (AA) metabolites. Currently there is no evidence to suggest that cannflavin-C, a prenylated flavonoid, has any significant effects on the heart or cardiac hypertrophy. The metabolism of arachidonic acid (AA) into midchain hydroxyeicosatetraenoic acids (HETEs), facilitated by CYP1B1 enzyme, plays a role in the development of cardiac hypertrophy, which is marked by enlarged cardiac cells. Adult human ventricular cardiomyocyte (AC16) cell line was cultured and exposed to cannflavin-C in the presence and absence of Ang II. The assessment of mRNA expression pertaining to cardiac hypertrophic markers and cytochromes P450 (P450s) was conducted via real-time polymerase chain reaction (PCR), whereas the quantification of P450 protein levels was carried out through western blot analysis. Ang II induced hypertrophic markers myosin heavy chain (ß/α-MHC), atrial natriuretic peptide (ANP), and brain natriuretic peptide (BNP) and increased cell surface area, whereas cannflavin-C mitigated these effects. Gene and protein expression analysis revealed that cannflavin-C downregulated CYP1B1 gene expression, protein level, and enzyme activity assessed by 7-methoxyresorufin O-deethylase (MROD). Arachidonic acid metabolites analysis, using liquid chromatography-tandem mass spectrometry (LC-MS/MS), demonstrated that Ang II increased midchain (R/S)-HETE concentrations, which were attenuated by cannflavin-C. This study provides novel insights into the potential of cannflavin-C in modulating arachidonic acid metabolites and attenuating Ang II-induced cardiac hypertrophy, highlighting the importance of this compound as potential therapeutic agents for cardiac hypertrophy. SIGNIFICANCE STATEMENT: This study demonstrates that cannflavin-C offers protection against cellular hypertrophy induced by angiotensin II. The significance of this research lies in its novel discovery, which elucidates a mechanistic pathway involving the inhibition of CYP1B1 by cannflavin-C. This discovery opens up new avenues for leveraging this compound in the treatment of heart failure.

Di (2-ethyl hexyl) phthalate and its metabolite-induced metabolic syndrome: a review of molecular mechanisms.

OBJECTIVES: Metabolic disorders, as multifactorial disorders, are induced by genetic susceptibility and exposure to environmental chemicals. Di (2-ethyl hexyl) phthalate (DEHP), a ubiquitous plasticizer, is well known as an endocrine-disrupting chemical in living organisms. In recent decades, researchers have focused on the potential of DEHP and its main metabolite (Mono (2-ethylhexyl) phthalate) (MEHP) to induce metabolic disorders. In the present review, we aimed to summarize studies regarding DEHP and MEHP-induced Metabolic syndrome (MetS) as well as address the involved mechanisms. METHODS: A search has been carried out in Google Scholar, PubMed, Scopus, and Web of Science databases using appropriate keywords including 'Metabolic syndrome' or 'Metabolic disorder' or 'Obesity' or 'Hyperglycemia' or 'Hyperlipidemia' or 'Hypertension' or 'Non-alcoholic fatty liver disease' and 'DEHP' or 'Di (2-ethyl hexyl) phthalate' or 'Bis(2-ethylhexyl) phthalate' or 'MEHP' or 'Mono (2-ethylhexyl) phthalate'. Studies were chosen based on inclusion and exclusion criteria. Inclusion criteria are in vitro, in vivo, epidemiological studies, and English-written studies. Exclusion criteria are lack of access to the full text of studies, editorial articles, review articles, and conference articles. RESULTS: Animal studies indicate that DEHP and MEHP disrupt insulin hemostasis, increase glucose content, and induce hyperlipidemia and hypertension as well as obesity, which could lead to type 2 diabetes mellitus (T2DM) and cardiovascular disease (CVD). DEHP and its metabolite induce such effects directly through influence on nuclear receptors such as peroxisome proliferator-activated receptors (PPARs) or indirectly through reactive oxygen species (ROS) production. Both events led to the disruption of several molecular signaling pathways and subsequently metabolic syndrome (MetS). Furthermore, epidemiological studies showed that there was a correlation between DEHP metabolites levels and obesity, hyperglycemia, and hypertension. CONCLUSIONS: According to studies, DEHP and its main metabolite have the potential to induce MetS by involving various molecular mechanisms. Epidemiological studies concerning the association of DEHP and MetS in humans are not sufficient. Therefore, more studies are needed in this regard.

Mental Health and Other Factors Associated with COVID-19 Vaccination Intention toward Children of Military Parents in Lambayeque, Peru.

There is evidence that vaccine acceptability is strongly associated with mental health. However, no studies assessing intention to vaccinate (ITV) intention toward children of military parents have been documented. The current research aimed to establish the prevalence and factors of ITV children against COVID-19 in military parents in Lambayeque-Peru, 2021. Analysis was conducted with the dependent variable ITV children reported by military parents. The independent variables were history of mental health, searching for mental health support, food insecurity, resilience, anxiety, depression, burnout, posttraumatic stress, and suicidal risk. Prevalence ratios and 95% confidence intervals were estimated. Of 201 military personnel evaluated, 92.5% were male, 82.5% were of the Catholic faith, and the median age was 40.9% of respondents reported seeking mental health help during the COVID-19 pandemic. It was reported anxiety (20.3%), depression (6.5%), and posttraumatic stress disorder (6.5%). Most reported ITV in children against COVID-19 (93%). In the multiple models, we found that Catholics had a 23% higher prevalence of ITV in the children where PR = prevalence ratios and CI = confidence intervals (PR = 1.23; 95% CI: 1.01-1.50). Likewise, seeking mental health support increased the prevalence of ITV by 8% (PR = 1.08; 95% CI: 1.00-1.15). Seeking mental health support and belonging to the Catholic faith had a higher ITV of children of Peruvian military personnel. Finding mental health support, experiencing burnout syndrome, having a relative who suffers from mental health problems, and being part of the Catholic religion were associated with a higher willingness to immunize the children of Peruvian military members.

Novel First-Generation Dissolution Models to Investigate the Release and Uptake of Oral Lymphotropic Drug Products.

Conventional dissolution tests only assess the aqueous release of drugs to ensure quality and performance, without indicating whether absorption occurs through the portal or the lymphatic circulation. To address this issue, this study aimed to develop novel first-generation dissolution models that could investigate the release and uptake of oral lymphotropic drugs and examine relevant formulation issues. Dissolution of three commercial lymphotropic drug products (Terbinafina, Apo-terbinafine, and Lamisil) was done using modified versions of USP Apparatus II and IV. The developed models contained a lymphatic compartment filled with artificial chylomicrons to account for absorption through intestinal lymphatic pathway. The various products exhibited different release profiles into the aqueous media and the lymphatic media across the two tested models. The modified USP IV apparatus demonstrated greater distinction in aqueous release patterns. However, the release pattern into the lymphatic media remained similar in both models. This work represents a progress in meeting the challenges posed by the increasing complexity of pharmaceutical products containing lipophilic drugs or formulations, and has the potential to contribute towards the development of in-vitro bioequivalence standards for formulations targeting intestinal lymphatics.

Hepatic Stellate Cells in Liver Fibrosis and siRNA-Based Therapy.

Hepatic fibrosis is a reversible wound-healing response to either acute or chronic liver injury caused by hepatitis B or C, alcohol, and toxic agents. Hepatic fibrosis is characterized by excessive accumulation and reduced degradation of extracellular matrix (ECM). Excessive accumulation of ECM alters the hepatic architecture leading to liver fibrosis and cirrhosis. Cirrhosis results in failure of common functions of the liver. Hepatic stellate cells (HSC) play a major role in the development of liver fibrosis as HSC are the main source of the excessive production of ECM in an injured liver. RNA interference (RNAi) is a recently discovered therapeutic tool that may provide a solution to manage multiple diseases including liver fibrosis through silencing of specific gene expression in diseased cells. However, gene silencing using small interfering RNA (siRNA) is encountering many challenges in the body after systemic administration. Efficient and stable siRNA delivery to the target cells is a key issue for the development of siRNA therapeutic. For that reason, various viral and non-viral carriers for liver-targeted siRNA delivery have been developed. This review will cover the current strategies for the treatment of liver fibrosis as well as discussing non-viral approaches such as cationic polymers and lipid-based nanoparticles for targeted delivery of siRNA to the liver.

Lymphatic Drug Absorption via the Enterocytes: Pharmacokinetic Simulation, Modeling, and Considerations for Optimal Drug Development.

Most orally administered drugs gain access to the systemic circulation by direct passage from the enterocyte layer of the intestinal tract to the mesenteric blood capillaries. Intestinal lymphatic absorption is another pathway that certain drugs may follow to gain access to the systemic circulation after oral administration. Once absorbed, drug diffuses into the intestinal enterocyte and while in transit may associate with fats as they are processed into chylomicrons within the cells. The chylomicron-associated drug is then secreted from the enterocyte into the lymphatic circulation, thus avoiding the hepatic first-pass liver metabolism, and ultimately entering to the systemic circulation for disposition and action. Due to the possibility of parallel and potentially alternative absorptive pathways, mesenteric blood capillary and lymphatic drug exposure are both potential pathways of systemic availability for any individual drug. In this report, an in silico modeling approach was adopted to delineate the salient pharmacokinetic features of lymphatic absorption, and provide further guidance for the rationale design of drugs and drug delivery systems for lymphatic drug transport. The importance of hepatic extraction ratio, absorption lag time, lipoprotein binding, and the influence of competing portal and lymphatic pathways for systemic drug availability were explored using simulations. The degree of hepatic extraction was found to be an essential consideration when examining the influence of lymphatic uptake to overall oral drug bioavailability. Lymphatic absorption could potentially contribute to multiple peaking phenomena and flip flop pharmacokinetics of orally administered drugs.

Application of in Silico Tools in Clinical Practice using Ketoconazole as a Model Drug.

Hypochlorhydria is a condition where the production of hydrochloric acid in the stomach is decreased. As a result, the intragastric pH is elevated. This condition can be due to a series of causes, such as disease (gastric mucosal infection caused by Helicobacter pylori and is prominent in AIDS patients), ethnicity, age and also the use of antisecretory agents. This may significantly impact the absorption of other drugs that have pH-dependent solubility, such as ketoconazole, a weak base. Within this context, the purpose of this study was to demonstrate how GastroPlusTM - a physiological based software program- can be used to predict clinical pharmacokinetics of ketoconazole in a normal physiological state vs. elevated gastric pH. A simple physiologically based pharmacokinetic model was built and validated to explore the impact that different physiologic conditions in the stomach (hypochlorhydria, drug administered with water and Coca Cola®) had on ketoconazole's bioavailability. The developed model was able to accurately predict the impact of increased pH and beverage co-administration on dissolution and absorption of the drug, and confirmed that complete gastric dissolution is essential. Particle size only mattered in hypochlorhydric conditions due to the incomplete gastric dissolution, as its absorption would depend on intestinal dissolution, which corroborates with previous studies. Therefore, in silico approaches are a potential tool to assess a pharmaceutical product's performance and efficacy under different physiological and pathophysiological states supporting the assessment of different dosing strategies in clinical practice.

The Antioxidant Activity of Recombinant Rat Hepatic Fatty Acid Binding Protein T94A Variant.

PURPOSE: Liver fatty acid binding protein (FABP1) is a cytoplasmic polypeptide that transports substrates throughout the cytosol and functions as an antioxidant. A common polymorphic variant, FABP1 T94A has a minor allele frequency of 26-38%, 8.3±1.9% homozygous in the human population. The purpose of this study was to mutate and isolate recombinant rat FABP1 to the T94A variant to evaluate the mutant's antioxidant activity using in vitro studies. METHODS: Site-directed mutagenesis was used to generate a mutation in rat cDNA within a pGEX-6p-2 vector. This plasmid was transformed into competent cells and cultured for expression of FABP1 T94A mutant. The mutated protein was purified using GSTrap Fastflow columns within an ÄKTA FPLC system. A 2,7-dichlorofluorescein (DCF) assay was used to screen the T94A variant antioxidant activity. Additionally, Thiobarbituric Acid Reactive Substances (TBARS) assay was used in determining T94A mutant antioxidant activity in hydrophilic and lipophilic environments through the use of the azo compounds AAPH and MeO-AMVN, respectively and in the presence and absence of the long-chain fatty acid palmitate and α-bromo palmitate. RESULTS: Although the FABP1 T94A (20 µM) mutant significantly reduced DCF fluorescence compared to control (no protein; P< 0.001), there were no significant difference when compared to the wild-type (WT) FABP1. T94A was able to diminish the formation of malondialdehyde (MDA) in both lipophilic and hydrophilic systems. There were significant differences between T94A mutant and WT FABP1 at concentrations 1 and 10 µM (P< 0.05) in the hydrophilic milieu, however, this was not seen at 20 µM and also not seen in the lipophilic milieu at all concentrations. When T94A was pre-incubated with the long-chain fatty acids palmitate or α -bromo palmitate, MDA formation was decreased in both lipid peroxidation systems. There were no statistical differences between the WT FABP1 and T94A bound with fatty acids in both lipid peroxidation systems, however, there was a slight statistical difference when the T94A and WT FABP1 bound α-Br-PA in the AAPH lipid peroxidation system only. CONCLUSIONS: The T94A has antioxidant activity in both hydrophilic and lipophilic environments. The T94A variant of FABP1 does not have a loss of function in regard to acting as an antioxidant but the extent of function may be influenced by ligand binding. We conclude that populations having the minor T94A allele frequency would have similar ROS scavenging potential as those with nascent FABP1.

Pharmaceutical Characterization of MyoNovin, a Novel Skeletal Muscle Regenerator: in silico, in vitro and in vivo Studies.

PURPOSE: MyoNovin is a novel skeletal muscle-regenerating compound developed through synthesis of two nitro groups onto a guaifenesin backbone to deliver nitric oxide to skeletal muscle with a potential to treat muscle atrophy. The purpose of this study was to utilize in silico, in vitro, and in vivo approaches to characterize MyoNovin and examine its safety, biodistribution, and feasibility for drug delivery. METHODS: In silico software packages were used to predict the physicochemical and biopharmaceutical properties of MyoNovin. In vitro cardiotoxicity was assessed using human cardiomyocytes (RL-14) while effects on CYP3A4 metabolic enzyme and antioxidant activity were examined using commercial kits. A novel HPLC assay was developed to measure MyoNovin concentration in serum, and delineate initial pharmacokinetic and acute toxicity after intravenous administration (20 mg/kg) to male Sprague-Dawley rats. RESULTS: MyoNovin showed relatively high lipophilicity with a LogP value of 3.49, a 20-fold higher skin permeability (19.89 cm/s*107) compared to guaifenesin (0.66 cm/s*107), and ~10-fold higher effective jejunal permeability (2.24 cm/s*104) compared to guaifenesin (0.26 cm/s*104). In vitro, MyoNovinwas not cytotoxic to cardiomyocytes at concentrations below 8 µM and did not inhibit CYP3A4 or show antioxidant activity. In vivo, MyoNovin had a short half-life (t1/2) of 0.16 h, and a volume of distribution Vss of 0.62 L/kg. Biomarkers of MyoNovincardiac and renal toxicity did not differ significantly from baseline control levels. CONCLUSIONS: The predicted high lipophilicity and skin permeability of MyoNovin render it a potential candidate for transdermal administration while its favourable intestinal permeation suggests it may be suitable for oral administration. Pharmacokinetics following IV administration of MyoNovin were delineated for the first time in a rat model. Preliminary single 20 mg/kg dose assessment of MyoNovin suggest no influenceon cardiac troponin or ß-N-Acetylglucosaminidase. This article is open to POST-PUBLICATION REVIEW. Registered readers (see "For Readers") may comment by clicking on ABSTRACT on the issue's contents page.

Disparate Effects of Stilbenoid Polyphenols on Hypertrophic Cardiomyocytes In Vitro vs. in the Spontaneously Hypertensive Heart Failure Rat.

Stilbenoids are bioactive polyphenols, and resveratrol (trans-3,5,40-trihydroxystilbene) is a representative stilbenoid that reportedly exerts cardioprotective actions. As resveratrol exhibits low oral bioavailability, we turned our attention to other stilbenoid compounds with a history of medicinal use and/or improved bioavailability. We determined the effects of gnetol (trans-3,5,20,60-tetrahydroxystilbene) and pterostilbene (trans-3,5-dimethoxy-40-hydroxystilbene) on cardiac hypertrophy. In vitro, gnetol and pterostilbene prevented endothelin-1-induced indicators of cardiomyocyte hypertrophy including cell enlargement and protein synthesis. Gnetol and pterostilbene stimulated AMP-activated protein kinase (AMPK), and inhibition of AMPK, using compound C or shRNA knockdown,abolished these anti-hypertrophiceffects. In contrast,resveratrol, gnetol, nor pterostilbene reduced blood pressure or hypertrophy in the spontaneously hypertensive heart failure (SHHF) rat. In fact, AMPK levels were similar between Sprague-Dawley and SHHF rats whether treated by stilbenoids or not. These data suggest that the anti-hypertrophic actions of resveratrol (and other stilbenoids?) do not extend to the SHHF rat, which models heart failure superimposed on hypertension. Notably, SHHF rat hearts exhibited prolonged isovolumic relaxationtime(an indicator of diastolicdys function),and this was improved by stilbenoid treatment.In conclusion, stilbenoid-based treatment as a viable strategy to prevent pathological cardiac hypertrophy,a major risk factor for heart failure,may be context-dependent and requires furtherstudy.

Hyaluronic Acid Molecular Weight Determines Lung Clearance and Biodistribution after Instillation.

Hyaluronic acid (HA) has emerged as a versatile polymer for drug delivery. Multiple commercial products utilize HA, it can be obtained in a variety of molecular weights, and it offers chemical handles for cross-linkers, drugs, or imaging agents. Previous studies have investigated multiple administration routes, but the absorption, biodistribution, and pharmacokinetics of HA after delivery to the lung is relatively unknown. Here, pharmacokinetic parameters were investigated by delivering different molecular weights of HA (between 7 and 741 kDa) to the lungs of mice. HA was labeled with either a near-infrared dye or with iodine-125 conjugated to HA using a tyrosine linker. In initial studies, dye-labeled HA was instilled into the lungs and fluorescent images of organs were collected at 1, 8, and 24 h post administration. Data suggested longer lung persistence of higher molecular weight HA, but signal diminished for all molecular weights at 8 h. To better quantitate pharmacokinetic parameters, different molecular weights of iodine-125 labeled HA were instilled and organ radioactivity was determined after 1, 2, 4, 6, and 8 h. The data showed that, after instillation, the lungs contained the highest levels of HA, as expected, followed by the gastrointestinal tract. Smaller molecular weights of HA showed more rapid systemic distribution, while 67 and 215 kDa HA showed longer persistence in the lungs. Lung exposure appeared to be optimum in this size range due to the rapid absorption of <67 kDa HA and the poor lung penetration and mucociliary clearance of viscous solutions of HA > 215 kDa. The versatility of HA molecular weight and conjugation chemistries may, therefore, provide new opportunities to extend pulmonary drug exposure and potentially facilitate access to lymph nodes draining the pulmonary bed.

Pharmacologic Activities of 3'-Hydroxypterostilbene: Cytotoxic, Anti-Oxidant, Anti-Adipogenic, Anti-Inflammatory, Histone Deacetylase and Sirtuin 1 Inhibitory Activity.

PURPOSE: Delineate the selected pharmacodynamics of a naturally occurring stilbene 3'-Hydroxypterostilbene. OBJECTIVE: Characterize for the first time the pharmacodynamics bioactivity in several in-vitro assays with relevant roles in heart disease, inflammation, cancer, and diabetes etiology and pathophysiology. METHODS: 3'-Hydroxypterostilbene was studied in in-vitro assays to identify possible bioactivity. RESULTS: 3'-Hydroxypterostilbene demonstrated anti-oxidant, anti-inflammatory, cytotoxic, anti-adipogenic, histone deacetylase, and sirtuin-1 inhibitory activity. CONCLUSIONS: The importance of understanding individual stilbene pharmacologic activities were delineated. Small changes in chemical structure of stilbene compounds result in significant pharmacodynamic differences. This article is open to POST-PUBLICATION REVIEW. Registered readers (see "For Readers") may comment by clicking on ABSTRACT on the issue's contents page.

Pre-Clinical Pharmacokinetic and Pharmacodynamic Characterization of Selected Chiral Flavonoids: Pinocembrin and Pinostrobin.

PURPOSE: Delineate the stereospecific pharmacokinetics and pharmacodynamics of the chiral flavonoids pinocembrin and pinostrobin. OBJECTIVE: Characterize for the first time the stereoselective pharmacokinetics of two flavonoids, pinocembrin and pinostrobin and their bioactivity in several in vitro assays with relevant roles in heart disease, colon cancer, and diabetes etiology and pathophysiology. METHODS: Chiral flavonoids were intravenously and orally administered to male Sprague-Dawley rats. Concentrations in serum and urine were characterized via stereospecific HPLC or LC/MS. Pure enantiomeric forms of each flavonoid were tested, where possible, to identify the stereospecific contribution to bioactivity in comparison to their racemates. RESULTS: Short half-lives (0.2-6 h) in serum were observed, while a better estimation of half-life (3-26 h) and other pharmacokinetic parameters were observed using urinary data. The flavonoids are predominantly excreted via non-renal routes (fe values of 0.3-4.6 %), and undergo rapid and extensive phase II metabolism. Chiral differences in the chemical structure of these compounds result in significant pharmacodynamic differences. CONCLUSION: The importance of understanding the stereospecific pharmacokinetics and pharmacodynamics of two chiral flavonoids were delineated.This article is open to POST-PUBLICATION REVIEW. Registered readers (see "For Readers") may comment by clicking on ABSTRACT on the issue's contents page.

Calebin A: Analytical Development for Pharmacokinetics Study, Elucidation of Pharmacological Activities and Content Analysis of Natural Health Products.

PURPOSE: To develop a bioanalytical assay using RP-HPLC to quantify the curcuminoid calebin A, to characterize its pharmacokinetics in rats after intravenous (IV) and oral (PO) administration, to identify its pharmacological activities and to evaluate its content in natural health products. METHODS: An RP-HPLC method was developed for the detection of calebin A. Separation was carried out using a Phenomenex® Kinetex® C18 column with UV detection at 339 nm. An isocratic mobile phase consisting of acetonitrile and water with 10 mM ammonium formate (pH 7.0) (40:60, v/v) at a flow rate of 0.8 mL/min was employed. Linear standard curves were established and applied in the pharmacokinetic study. Calebin A was administered to male Sprague-Dawley (CD) rats IV (20 mg/kg) or PO (500 mg/kg) (n=4/route of administration). Serum and urine samples were collected for 72 h post dose. In vitro antioxidant activity, anti-inflammatory activity (cyclooxygenase and lipoxygenase inhibition), dipeptidyl peptidase-4 (DPP-4) inhibition and cytochrome P450 inhibitory activties of calebin A were examined using commercial assay kits. Content analysis of calebin A in 14 natural health products advertised to contain turmeric were carried out using methanolic extraction. RESULTS: The HPLC method was successfully applied to a pharmacokinetic study of calebin A in rats. After IV and PO administration of calebin A, the compound was detected as the aglycone and a glucuronidated metabolite. Oral bioavailabitily was found to be ~0.5%, serum half-life was ~1-3 h. Calebin A appears to be primarily excreted via non-renal routes. Calebin A possessed concentration-dependent antioxidant activity and DPP-4 inhibition. Calebin A appears to be a non-selective cyclooxygenase inhibitor and also a poor lipoxygenase inhibitor. The curcuminoid displayed in vitro interactions with CYP2D6 and CYP1A2. Content analysis of 14 natural health products that claimed to contain turmeric showed that concentration of calebin A was inconsistent among the products. CONCLUSION: A successful assay was developed for the detection of calebin A using RP-HPLC. Preliminary pharmacokinetic studies indicate that an unoptimised formulation of calebin A has poor oral bioavailability. Calebin A exhibits various pharmacological activities. This article is open to POST-PUBLICATION REVIEW. Registered readers (see "For Readers") may comment by clicking on ABSTRACT on the issue's contents page.

Preclinical Pharmacokinetics and Pharmacodynamics and Content Analysis of Gnetol in Foodstuffs.

Studies were undertaken to evaluate the bioavailability in rats and content analysis of gnetol in Gnetum gnemon products reported to contain gnetol and to examine the pharmacological properties of gnetol in in vitro models including anti-inflammatory/analgesic, antidiabetic, anti-adipogenesis, and anticancer activity. Male Sprague-Dawley rats were cannulated and dosed either intravenously with gnetol (10 mg/kg) or orally (100 mg/kg). Various methanolic extractions of G. gnemon products were quantified. Gnetol's effect on cell viability in selected cell lines with or without inflammatory stimulus was assessed. α-Amylase and α-glucosidase inhibition was evaluated. Cyclooxygenase (COX)-1, COX-2, and histone deacetylase inhibition and adipogenesis inhibition were examined. After oral and intravenous administration, gnetol was detected in both serum and urine as the parent compound and as a glucuronidated metabolite. The bioavailability of gnetol was determined to be 6%. Gnetol is rapidly glucuronidated and is excreted in urine and via nonrenal routes. Gnetol was found to exist as an aglycone and as a glycoside in G. gnemon products. Gnetol showed concentration-dependent reductions in cell viability in cancer cell lines with greatest activity in colorectal cancer and potent COX-1, histone deacetylase, and weak COX-2 activities along with limited reduction in inflammation. Gnetol also possessed concentration-dependent alpha-amylase, alpha-glucosidase, and adipogenesis activities. Pretreatment of mice with gnetol was able to increase the latency period to response in analgesia models.

Student perspectives of an online module for teaching physical assessment skills for dentistry, dental hygiene, and pharmacy students.

The integration of web-based learning into the curriculum of healthcare education has significantly increased over the past decade. This article aims to describe the student perspectives of an online module to teach physical assessment skills for pharmacy, dentistry, and dental hygiene students. A total of 103 students completed the online module: 48 third-year pharmacy students, 29 first-year dentistry students, and 26 first-year dental hygiene students. Students were asked to rate a list of 10 statements on a 5-point Likert scale on the relevance, impact, and overall satisfaction of the online module. Eighty-four of the 103 students (81.6% response rate) completed the questionnaire. While most students responded positively to the online content, pharmacy students responded more favorably compared with students from Dentistry and Dental Hygiene. These findings provide useful information to identify areas in which the web-based module can be improved for teaching skills in physical assessment across multiple healthcare programs.

Understanding the hysteresis loop conundrum in pharmacokinetic/pharmacodynamic relationships.

Hysteresis loops are phenomena that sometimes are encountered in the analysis of pharmacokinetic and pharmacodynamic relationships spanning from pre-clinical to clinical studies. When hysteresis occurs it provides insight into the complexity of drug action and disposition that can be encountered. Hysteresis loops suggest that the relationship between drug concentration and the effect being measured is not a simple direct relationship, but may have an inherent time delay and disequilibrium, which may be the result of metabolites, the consequence of changes in pharmacodynamics or the use of a non-specific assay or may involve an indirect relationship. Counter-clockwise hysteresis has been generally defined as the process in which effect can increase with time for a given drug concentration, while in the case of clockwise hysteresis the measured effect decreases with time for a given drug concentration. Hysteresis loops can occur as a consequence of a number of different pharmacokinetic and pharmacodynamic mechanisms including tolerance, distributional delay, feedback regulation, input and output rate changes, agonistic or antagonistic active metabolites, uptake into active site, slow receptor kinetics, delayed or modified activity, time-dependent protein binding and the use of racemic drugs among other factors. In this review, each of these various causes of hysteresis loops are discussed, with incorporation of relevant examples of drugs demonstrating these relationships for illustrative purposes. Furthermore, the effect that pharmaceutical formulation has on the occurrence and potential change in direction of the hysteresis loop, and the major pharmacokinetic / pharmacodynamic modeling approaches utilized to collapse and model hysteresis are detailed.

Enantiospecific analysis of 8-prenylnaringenin in biological fluids by liquid-chromatography-electrospray ionization mass spectrometry: application to preclinical pharmacokinetic investigations.

8-Prenylnaringenin (8PN) is a naturally occurring bioactive chiral prenylflavonoid found most commonly in the female flowers of hops (Humulus lupulus L.). A stereospecific method of analysis for 8PN in biological fluids is necessary to study the pharmacokinetic disposition of each enantiomer. A novel and simple liquid chromatographic-electrospray ionization-mass spectrometry (LC-ESI-MS) method was developed for the simultaneous determination of R- and S-8PN in rat serum and urine. Carbamazepine was used as the internal standard (IS). Enantiomeric resolution of 8PN was achieved on a Chiralpak(®) AD-RH column with an isocratic mobile phase consisting of 2-propanol and 10 mM ammonium formate (pH 8.5) (40:60, v/v) and a flow rate of 0.7 mL/min. Detection was achieved using negative selective ion monitoring (SIM) of 8PN at m/z 339.15 for both enantiomers and positive SIM m/z at 237.15 for the IS. The calibration curves for urine were linear over a range of 0.01-75 µg/mL and 0.05-75 µg/mL for serum with a limit of quantification of 0.05 µg/mL in serum and 0.01 µg/mL in urine. The method was successfully validated showing that it was sensitive, reproducible, and accurate for enantiospecific quantification of 8PN in biological matrices. The assay was successfully applied to a preliminary study of 8PN enantiomers in rat.

CD44-tropic polymeric nanocarrier for breast cancer targeted rapamycin chemotherapy.

In contrast with the conventional targeting of nanoparticles to cancer cells with antibody or peptide conjugates, a hyaluronic acid (HA) matrix nanoparticle with intrinsic-CD44-tropism was developed to deliver rapamycin for localized CD44-positive breast cancer treatment. Rapamycin was chemically conjugated to the particle surface via a novel sustained-release linker, 3-amino-4-methoxy-benzoic acid. The release of the drug from the HA nanoparticle was improved by 42-fold compared to HA-temsirolimus in buffered saline. In CD44-positive MDA-MB-468 cells, using HA as drug delivery carrier, the cell viability was significantly decreased compared to free rapamycin and CD44-blocked controls. Rat pharmacokinetics showed that the area under the curve of HA nanoparticle formulation was 2.96-fold greater than that of the free drug, and the concomitant total body clearance was 8.82-fold slower. Moreover, in immunocompetent BALB/c mice bearing CD44-positive 4T1.2neu breast cancer, the rapamycin-loaded HA particles significantly improved animal survival, suppressed tumor growth and reduced the prevalence of lung metastasis. FROM THE CLINICAL EDITOR: This study demonstrates increased efficiency of rapamycin delivery and consequential treatment effects in a breast cancer model by hyaluronic acid - L-rapamycin conjugates with intrinsic tropism for CD44-positive cells.