ABSTRACT
Acute atrial fibrillation is defined as atrial fibrillation detected in the setting of acute care or acute illness; atrial fibrillation may be detected or managed for the first time during acute hospitalization for another condition. Atrial fibrillation after cardiothoracic surgery is a distinct type of acute atrial fibrillation. Acute atrial fibrillation is associated with high risk of long-term atrial fibrillation recurrence, warranting clinical attention during acute hospitalization and over long-term follow-up. A framework of substrates and triggers can be useful for evaluating and managing acute atrial fibrillation. Acute management requires a multipronged approach with interdisciplinary care collaboration, tailoring treatments to the patient's underlying substrate and acute condition. Key components of acute management include identification and treatment of triggers, selection and implementation of rate/rhythm control, and management of anticoagulation. Acute rate or rhythm control strategy should be individualized with consideration of the patient's capacity to tolerate rapid rates or atrioventricular dyssynchrony, and the patient's ability to tolerate the risk of the therapeutic strategy. Given the high risks of atrial fibrillation recurrence in patients with acute atrial fibrillation, clinical follow-up and heart rhythm monitoring are warranted. Long-term management is guided by patient substrate, with implications for intensity of heart rhythm monitoring, anticoagulation, and considerations for rhythm management strategies. Overall management of acute atrial fibrillation addresses substrates and triggers. The 3As of acute management are acute triggers, atrial fibrillation rate/rhythm management, and anticoagulation. The 2As and 2Ms of long-term management include monitoring of heart rhythm and modification of lifestyle and risk factors, in addition to considerations for atrial fibrillation rate/rhythm management and anticoagulation. Several gaps in knowledge related to acute atrial fibrillation exist and warrant future research.
Subject(s)
Atrial Fibrillation , Humans , Atrial Fibrillation/diagnosis , Atrial Fibrillation/epidemiology , Atrial Fibrillation/therapy , American Heart Association , Anti-Arrhythmia Agents/therapeutic use , Anticoagulants/therapeutic use , Anticoagulants/pharmacology , Hospitalization , Heart RateABSTRACT
The 2019-2020 Professional Affairs Committee was charged to (1) Describe the leadership role of schools of pharmacy in advancing interprofessional practice, with an emphasis on physician-pharmacist collaborative relationships; (2) Establish an inventory of resources that can support school efforts to grow collaborative partnerships between pharmacists and physicians; (3) Determine gaps that exist in the resources required to support schools in efforts to facilitate expansion of interprofessional partnerships; and (4) Define strategies and draft an action plan for AACP's role in facilitating member school efforts to accelerate the development of interprofessional practices within their geography of influence. This report provides information on the committee's process to address the committee charges as well as background and resources pertaining to the charges, describes the rationale for and the results from the focus groups conducted at the 2020 AACP Interim Meeting, communicates the results of an initial inventory of models that integrate pharmacists with primary care practices, and provides an overview on issues to continue the work to integrate pharmacists with primary care practices. The committee offered several revisions to current association policy statements and provided a proposed policy statement and several recommendations to AACP pertaining to the committee charges.
Subject(s)
Advisory Committees , Delivery of Health Care, Integrated , Pharmacists , Pharmacy and Therapeutics Committee , Primary Health Care , Professional Role , Schools, Pharmacy , Societies, Pharmaceutical , Cooperative Behavior , Humans , Interdisciplinary Communication , Leadership , Patient Care Team , Policy Making , United StatesABSTRACT
OBJECTIVES: To assess patients' knowledge of blood pressure (BP) and their comfort level with using technology, including a Bluetooth-enabled BP device and pharmacist telemonitoring. The secondary objective was to discover if pharmacist interventions improved BP readings. SETTING: The study took place in Pharmacy Plus and the Family Medicine Department at the University of South Florida in Tampa, FL. PRACTICE DESCRIPTION: The pharmacists within Pharmacy Plus and the Family Medicine Department are part of the interdisciplinary team providing care to patients and seeking to achieve optimal patient outcomes. Pharmacy Plus breaks away from the traditional behind-the-counter model using innovative technology to create a personalized experience for patients. PRACTICE INNOVATION: During this pilot study, the patients received a Bluetooth-enabled BP monitor and were asked to obtain their BP readings at least once daily for 6 weeks. The patients' electronic health records automatically captured the BP readings, which were reviewed by the study pharmacists. The patients had an appointment with the pharmacists once weekly via a telehealth platform through which they were counseled on their weekly average BP, BP goals, lifestyle modifications, and proper use of the devices. EVALUATION: The patients completed a prestudy survey assessing their baseline knowledge of BP, comfort level when using technology, and ease in working with pharmacists. Reliability and satisfaction in using the BP device and telehealth communication with pharmacists were also assessed poststudy. RESULTS: Twelve patients enrolled, with 9 completing the study. There was a statistically significant increase in patients' knowledge of BP and an improvement in the recommended lifestyle modifications. In addition, comfort level regarding communication with the pharmacist was statistically significantly improved. The patients responded positively to using the Bluetooth-enabled BP monitor and telehealth for receiving health care services. CONCLUSION: Using Bluetooth-enabled BP monitors that report results in real time into electronic health records, along with pharmacist interventions within a team-based care model, may result in improved BP control and patient outcomes.
Subject(s)
Pharmacists , Telemedicine , Blood Pressure , Florida , Humans , Pilot Projects , Reproducibility of Results , TechnologyABSTRACT
The burgeoning field of nanotechnology aims to create and deploy nanoscale structures, devices, and systems with novel, size-dependent properties and functions. The nanotechnology revolution has sparked radically new technologies and strategies across all scientific disciplines, with nanotechnology now applied to virtually every area of research and development in the US and globally. NanoFlorida was founded to create a forum for scientific exchange, promote networking among nanoscientists, encourage collaborative research efforts across institutions, forge strong industry-academia partnerships in nanoscience, and showcase the contributions of students and trainees in nanotechnology fields. The 2019 NanoFlorida International Conference expanded this vision to emphasize national and international participation, with a focus on advances made in translating nanotechnology. This review highlights notable research in the areas of engineering especially in optics, photonics and plasmonics and electronics; biomedical devices, nano-biotechnology, nanotherapeutics including both experimental nanotherapies and nanovaccines; nano-diagnostics and -theranostics; nano-enabled drug discovery platforms; tissue engineering, bioprinting, and environmental nanotechnology, as well as challenges and directions for future research.
ABSTRACT
Postconcussive syndrome is an increasingly recognized outcome of sports-related concussion (SRC), characterized by a constellation of poorly defined symptoms. Treatment of PCS is significantly different from that of SRC alone. Primary care physicians often are the first to evaluate these patients, but some are unfamiliar with the available therapeutic approaches. This review provides an overview of the pathophysiology of SRC and descriptions of both pharmacologic and nonpharmacologic treatment options to allow primary care physicians to provide evidence-based care to patients experiencing postconcussive syndrome.
Subject(s)
Athletic Injuries/complications , Post-Concussion Syndrome/etiology , Post-Concussion Syndrome/therapy , Primary Health Care , Amantadine/therapeutic use , Antidepressive Agents/therapeutic use , Cognitive Behavioral Therapy , Dopamine Agents/therapeutic use , Humans , Physicians, Primary Care , Post-Concussion Syndrome/physiopathology , Return to SportABSTRACT
Adverse drug reactions (ADRs) are a major public health concern and cause significant patient morbidity and mortality. Pharmacogenomics is the study of how genetic polymorphisms affect an individual's response to pharmacotherapy at the level of a whole genome. This article updates our knowledge on how genetic polymorphisms of important genes alter the risk of ADR occurrence after an extensive literature search. To date, at least 244 pharmacogenes identified have been associated with ADRs of 176 clinically used drugs based on PharmGKB. At least 28 genes associated with the risk of ADRs have been listed by the Food and Drug Administration as pharmacogenomic biomarkers. With the availability of affordable and reliable testing tools, pharmacogenomics looks promising to predict, reduce, and minimize ADRs in selected populations.
Subject(s)
Drug-Related Side Effects and Adverse Reactions/genetics , Pharmacogenetics , Humans , Polymorphism, Genetic/geneticsABSTRACT
Heart disease is a major cause of death in US and worldwide. The complex interplay of the mechanisms between diabetes, obesity and inflammation raises concerns for therapeutic understanding and developing treatment options for patients. Recent advances utilizing pharmacogenomics has helped researchers to probe in to disease pathophysiology and physicians to detect and, diagnose the disease in patients. The understanding developed in the area primarily addresses the issue focusing on the nature and asks the question 'Why' some individuals respond to the standard medication regimen and others do not. The central idea that genomics play a vital part in how the healthcare providers: physician, pharmacist, and nurse provide treatment utilizing the best practices available for maximum benefits. Pharmacogenomics is the scientific basis which offers the fundamental understanding for diseases, based on which therapeutic approaches can be designed and delivered. The discovery that not all humans respond to the drug in the same way is a 'paradigm shift' in how current therapies are offered. The area of pharmacogenomics at its core is linked to the genetic basis for the disease and the response to treatment. Given that diabetes and obesity are major metabolic ailments globally wherein patients also often suffer from cardiac disorders, a comprehensive genetic and pharmacogenomic understanding of these conditions enable the development of effective therapeutic strategies. In this review, we discuss various pharmacogenomic approaches with special emphasis on heart disease as it relates to diabetes and obesity. Recent information in regard to relevant patents in this topic are also discussed.
Subject(s)
Cardiovascular Diseases/etiology , Diabetes Mellitus/genetics , Obesity/genetics , Pharmacogenetics , Animals , Atrial Fibrillation/etiology , Cardiovascular Diseases/drug therapy , Cytochrome P-450 CYP2D6/genetics , Cytochrome P-450 CYP2D6/metabolism , Diabetes Mellitus/drug therapy , Diabetes Mellitus/pathology , Humans , Ion Channels/genetics , Ion Channels/metabolism , Membrane Transport Modulators/metabolism , Membrane Transport Modulators/therapeutic use , Obesity/complications , Patents as Topic , Polymorphism, Single Nucleotide , Receptors, Adrenergic/genetics , Receptors, Adrenergic/metabolismABSTRACT
Despite its narrow therapeutic window, lithium is still regarded as the gold standard comparator and benchmark treatment for mania. Recent attempts to find new drugs with similar therapeutic activities have yielded new chemical entities. However, these potential new drugs have yet to match the many bioactivities attributable to lithium's efficacy for the treatment of neuropsychiatric diseases. Consequently, an intense effort for re-engineering lithium therapeutics using crystal engineering is currently underway. We sought to improve the likelihood of success of these endeavors by evaluating the pharmacokinetics of previously unexplored lithium salts with organic anions (lithium salicylate and lithium lactate). We report that these lithium salts exhibit profoundly different pharmacokinetics compared to the more common FDA approved salt, lithium carbonate, in rats. Remarkably, lithium salicylate produced elevated plasma and brain levels of lithium beyond 48 hours post-dose without the sharp peak that contributes to the toxicity problems of current lithium therapeutics. These findings could be important for the development of the next generation of lithium therapeutics.
ABSTRACT
Ventricular arrhythmias account for high mortality in cardiopulmonary patients in intensive care units. Cardiovascular alterations and molecular-level changes in response to the commonly used oxygen treatment remains unknown. In the present study we investigated cardiac hypertrophy and cardiac complications in mice subjected to hyperoxia. Results demonstrate that there is a significant increase in average heart weight to tibia length (22%) in mice subjected to hyperoxia treatment vs. normoxia. Functional assessment was performed in mice subjected to hyperoxic treatment, and results demonstrate impaired cardiac function with decreased cardiac output and heart rate. Staining of transverse cardiac sections clearly demonstrates an increase in the cross-sectional area from hyperoxic hearts compared with control hearts. Quantitative real-time RT-PCR and Western blot analysis indicated differential mRNA and protein expression levels between hyperoxia-treated and control left ventricles for ion channels including Kv4.2 (-2 ± 0.08), Kv2.1 (2.54 ± 0.48), and Scn5a (1.4 ± 0.07); chaperone KChIP2 (-1.7 ± 0.06); transcriptional factors such as GATA4 (-1.5 ± 0.05), Irx5 (5.6 ± 1.74), NFκB1 (4.17 ± 0.43); hypertrophy markers including MHC-6 (2.17 ± 0.36) and MHC-7 (4.62 ± 0.76); gap junction protein Gja1 (4.4 ± 0.8); and microRNA processing enzyme Drosha (4.6 ± 0.58). Taken together, the data presented here clearly indicate that hyperoxia induces left ventricular remodeling and hypertrophy and alters the expression of Kv4.2 and MHC6/7 in the heart.
Subject(s)
Cardiomegaly/metabolism , Heart Ventricles/metabolism , Hyperoxia/complications , Shal Potassium Channels/metabolism , Animals , Cardiac Output , Cardiomegaly/etiology , Cardiomegaly/physiopathology , Connexin 43/genetics , Connexin 43/metabolism , Heart Rate , Heart Ventricles/diagnostic imaging , Heart Ventricles/physiopathology , Kv Channel-Interacting Proteins/genetics , Kv Channel-Interacting Proteins/metabolism , Male , Mice , Mice, Inbred C57BL , Myosin Heavy Chains/genetics , Myosin Heavy Chains/metabolism , NAV1.5 Voltage-Gated Sodium Channel/genetics , NAV1.5 Voltage-Gated Sodium Channel/metabolism , Ribonuclease III/genetics , Ribonuclease III/metabolism , Shab Potassium Channels/genetics , Shab Potassium Channels/metabolism , Shal Potassium Channels/genetics , Transcription Factors/genetics , Transcription Factors/metabolism , Transcription, Genetic , UltrasonographyABSTRACT
Conditioned taste aversion (CTA) is an adaptive behavior that benefits survival of animals including humans and also serves as a powerful model to study the neural mechanisms of learning. Memory formation is a necessary component of CTA learning and involves neural processing and regulation of gene expression in the amygdala. Many studies have been focused on the identification of intracellular signaling cascades involved in CTA, but not late responsive genes underlying the long-lasting behavioral plasticity. In this study, we explored in silico experiments to identify persistent changes in gene expression associated with CTA in rats. We used oligonucleotide microarrays to identify 248 genes in the amygdala regulated by CTA. Pathway Studio and IPA software analyses showed that the differentially expressed genes in the amygdala fall in diverse functional categories such as behavior, psychological disorders, nervous system development and function, and cell-to-cell signaling. Conditioned taste aversion is a complex behavioral trait which involves association of visceral and taste inputs, consolidation of taste and visceral information, memory formation, retrieval of stored information, and extinction phase. In silico analysis of differentially expressed genes is therefore necessary to manipulate specific phase/stage of CTA to understand the molecular insight.
ABSTRACT
INTRODUCTION: Racial and ethnic minorities have disproportionately higher cancer incidence and mortality than their White counterparts. In response to this inequity in cancer prevention and care, community-based lay health advisors (LHAs) may be suited to deliver effective, culturally relevant, quality cancer education, prevention/screening, and early detection services for underserved populations. APPROACH AND STRATEGIES: Consistent with key tenets of community-based participatory research (CBPR), this project engaged community partners to develop and implement a unique LHA training curriculum to address cancer health disparities among medically underserved communities in a tricounty area. Seven phases of curriculum development went into designing a final seven-module LHA curriculum. In keeping with principles of CBPR and community engagement, academic-community partners and LHAs themselves were involved at all phases to ensure the needs of academic and community partners were mutually addressed in development and implementation of the LHA program. DISCUSSION AND CONCLUSIONS: Community-based LHA programs for outreach, education, and promotion of cancer screening and early detection, are ideal for addressing cancer health disparities in access and quality care. When community-based LHAs are appropriately recruited, trained, and located in communities, they provide unique opportunities to link, bridge, and facilitate quality cancer education, services, and research.
Subject(s)
Community Health Workers/education , Curriculum , Early Detection of Cancer , Health Promotion/organization & administration , Adult , Community-Based Participatory Research , Female , Florida , Healthcare Disparities , Humans , Male , Medically Underserved Area , Program Development , Program EvaluationABSTRACT
Previous animal and clinical studies have shown that acupuncture is an effective alternative treatment in the management of hypertension, but the mechanism is unclear. This study investigated the proteomic response in the nervous system to treatment at the Taichong (LR3) acupoint in spontaneously hypertensive rats (SHRs). Unanesthetized rats were subject to 5-min daily acupuncture treatment for 7 days. Blood pressure was monitored over 7 days. After euthanasia on the 7(th) day, rat medullas were dissected, homogenized, and subject to 2D gel electrophoresis and MALDI-TOF analysis. The results indicate that blood pressure stabilized after the 5th day of acupuncture, and compared with non-acupoint treatment, Taichong-acupunctured rat's systolic pressure was reduced significantly (P<0.01), though not enough to bring blood pressure down to normal levels. The different treatment groups also showed differential protein expression: the 2D images revealed 571 ± 15 proteins in normal SD rats' medulla, 576 ± 31 proteins in SHR's medulla, 597 ± 44 proteins in medulla of SHR after acupuncturing Taichong, and 616 ± 18 proteins in medulla of SHR after acupuncturing non-acupoint. In the medulla of Taichong group, compared with non-acupoint group, seven proteins were down-regulated: heat shock protein-90, synapsin-1, pyruvate kinase isozyme, NAD-dependent deacetylase sirtuin-2, protein kinase C inhibitor protein 1, ubiquitin hydrolase isozyme L1, and myelin basic protein. Six proteins were up-regulated: glutamate dehydrogenase 1, aldehyde dehydrogenase 2, glutathione S-transferase M5, Rho GDP dissociation inhibitor 1, DJ-1 protein and superoxide dismutase. The altered expression of several proteins by acupuncture has been confirmed by ELISA, Western blot and qRT-PCR assays. The results indicate an increase in antioxidant enzymes in the medulla of the SHRs subject to acupuncture, which may provide partial explanation for the antihypertensive effect of acupuncture. Further studies are warranted to investigate the role of oxidative stress modulation by acupuncture in the treatment of hypertension.
Subject(s)
Acupuncture Therapy , Hypertension/metabolism , Hypertension/therapy , Proteomics/methods , Acupuncture Points , Animals , Blood Pressure , Blotting, Western , Enzyme-Linked Immunosorbent Assay , Gene Expression Regulation , Hypertension/physiopathology , Isoelectric Point , Medulla Oblongata/metabolism , Medulla Oblongata/physiopathology , Models, Biological , Proteome/genetics , Proteome/metabolism , RNA, Messenger/genetics , RNA, Messenger/metabolism , Rats , Rats, Inbred SHR , Rats, Sprague-Dawley , Reverse Transcriptase Polymerase Chain Reaction , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization , SystoleABSTRACT
Herbal medicines are often used in combination with conventional drugs, and this may give rise to the potential of harmful herb-drug interactions. This paper updates our knowledge on clinical herb-drug interactions with an emphasis of the mechanistic and clinical consideration. In silico, in vitro, animal and human studies are often used to predict and/or identify drug interactions with herbal remedies. To date, a number of clinically important herb-drug interactions have been reported, but many of them are from case reports and limited clinical observations. Common herbal medicines that interact with drugs include St John's wort (Hypericum perforatum), ginkgo (Ginkgo biloba), ginger (Zingiber officinale), ginseng (Panax ginseng), and garlic (Allium sativum). For example, St John's wort significantly reduced the area under the plasma concentration-time curve (AUC) and blood concentrations of cyclosporine, midazolam, tacrolimus, amitriptyline, digoxin, indinavir, warfarin, phenprocoumon and theophylline. The common drugs that interact with herbal medicines include warfarin, midazolam, digoxin, amitriptyline, indinavir, cyclosporine, tacrolimus and irinotecan. Herbal medicines may interact with drugs at the intestine, liver, kidneys, and targets of action. Importantly, many of these drugs have very narrow therapeutic indices. Most of them are substrates for cytochrome P450s (CYPs) and/or P-glycoprotein (P-gp). The underlying mechanisms for most reported herb-drug interactions are not fully understood, and pharmacokinetic and/or pharmacodynamic mechanisms are implicated in many of these interactions. In particular, enzyme induction and inhibition may play an important role in the occurrence of some herbdrug interactions. Because herb-drug interactions can significantly affect circulating levels of drug and, hence, alter the clinical outcome, the identification of herb-drug interactions has important implications.
Subject(s)
Herb-Drug Interactions , Plant Preparations/pharmacokinetics , Plants, Medicinal/metabolism , Humans , Pharmaceutical Preparations/metabolismABSTRACT
Community-based participatory research methods allow for community engagement in the effort to reduce cancer health disparities. Community engagement involves health professionals becoming a part of the community in order to build trust, learn from the community and empower them to reduce disparities through their own initiatives and ideas. Audience Response Systems (ARS) are an innovative and engaging way to involve the community and obtain data for research purposes using keypads to report results via power point. The use of ARS within communities is very limited and serves to widen the disparity gap by not delivering new advances in medical knowledge and technology among all population groups. ARS was implemented at a community town hall event sponsored by a National Institute on Minority Health and Health Disparities Exploratory Center of Excellence, the Center for Equal Health. Participants appreciated being able to see how everyone else answered and felt included in the research process. ARS is beneficial because the community can answer truthfully and provides instant research results. Additionally, researchers can collect large amounts of data quickly, in a non-threatening way while tracking individual responses anonymously. Audience Response Systems proved to be an effective tool for successfully accomplishing community-based participatory research.
ABSTRACT
We have previously examined the binding patterns of various substrates to human cytochrome P450 2D6 (CYP2D6) using a series of molecular modeling methods. In this study, we further explored the binding modes of various types of inhibitors to CYP2D6 using a combination of ligand- and protein-based modeling approaches. Firstly, we developed and validated a pharmacophore model for CYP2D6 inhibitors, which consisted of two hydrophobic features and one hydrogen bond acceptor feature. Secondly, we constructed and validated a quantitative structure-activity relationship (QSAR) model for CYP2D6 inhibitors which gave a poor to moderate prediction accuracy. Thirdly, a panel of CYP2D6 inhibitors were subject to molecular docking into the active site of wild-type and mutated CYP2D6 enzyme. We demonstrated that 8 residues in the active site (Leu213, Glu216, Ser217, Gln244, Asp301, Ser304, Ala305, and Phe483) played an important role in the binding to the inhibitors via hydrogen bond formation and/or π-π stacking interaction. Apparent changes in the binding modes of the inhibitors have been observed with Phe120Ile, Glu216Asp, Asp301Glu mutations in CYP2D6. Finally, we screened for potential binders/inhibitors from the Chinese herbal medicine Scutellaria baicalensis (Huangqin, Baikal Skullcap) using the established pharmacophore model for CYP2D6 inhibitors and molecular docking approach. Overall, 18 out of 40 compounds from S. baicalensis were mapped to the pharmacophore model of CYP2D6 inhibitors and most herbal compounds from S. baicalensis could be docked into the active site of CYP2D6. Our study has provided insights into the molecular mechanisms of interaction of synthetic and herbal compounds with human CYP2D6 and further benchmarking studies are needed to validate our modeling and virtual screening results.
Subject(s)
Cytochrome P-450 CYP2D6 Inhibitors , Drugs, Chinese Herbal/chemistry , Enzyme Inhibitors/isolation & purification , Enzyme Inhibitors/pharmacology , High-Throughput Screening Assays , Scutellaria baicalensis/chemistry , Catalytic Domain/drug effects , Cytochrome P-450 CYP2D6/genetics , Cytochrome P-450 CYP2D6/metabolism , Enzyme Inhibitors/chemistry , Humans , Ligands , Models, Molecular , Structure-Activity RelationshipABSTRACT
Human CYP1A2 is an important enzyme for drug metabolism and procarcinogen activation. This study aimed to explore the binding mode of ligands with CYP1A2 and to screen potential inhibitors from a library of herbal compounds using computational and in vitro approaches. The heme prosthetic group and six residues (Thr124, Phe125, Phe226, Phe260, Gly316, and Ala317) in the active site of CYP1A2 were identified as important residues for ligand binding using the LIGPLOT program. Ala317 in helix I immediately above heme was highly conserved in most human CYPs with known crystal structures. In molecular docking, 19 of the 56 herbal compounds examined were identified as potential inhibitors of CYP1A2. Up to 21 of the 56 herbal compounds were hit by the pharmacophore model of CYP1A2 inhibitors developed and validated in this study. In the in vitro inhibition study, 8 herbal compounds were identified as moderate to potent inhibitors of CYP1A2. Five of the 8 herbal compounds predicted to be potential inhibitors were confirmed as CYP1A2 inhibitors in the in vitro study. A combination of computational and in vitro approaches, represent a useful tool to identify potential inhibitors for CYP1A2 from herbal compounds.
Subject(s)
Computer Simulation , Cytochrome P-450 CYP1A2 Inhibitors , Enzyme Inhibitors/pharmacology , Models, Molecular , Plant Preparations/pharmacology , Amino Acid Sequence , Amino Acids/metabolism , Binding Sites , Biocatalysis/drug effects , Conserved Sequence , Crystallography, X-Ray , Cytochrome P-450 CYP1A2/chemistry , Drug Evaluation, Preclinical , Enzyme Inhibitors/chemistry , Heme/metabolism , Humans , Ligands , Molecular Sequence Data , Plant Preparations/chemistry , Protein Structure, Secondary , Reproducibility of Results , Substrate Specificity/drug effectsABSTRACT
There have been increasing reports on the adverse reactions associated with herbal consumption. For many of these adverse reactions, the underlying biochemical mechanisms are unknown, but bioactivation of herbal compounds to generate reactive intermediates have been implicated. This minireview updates our knowledge on metabolic activation of herbal compounds, molecular targets and the toxicity relevance. A number of studies have documented that some herbal compounds can be converted to toxic or even carcinogenic metabolites by Phase I [e.g. cytochrome P450s (CYPs)] and less frequently by Phase II enzymes. For example, aristolochic acids (AAs) in Aristolochia spp, which undergo reduction of the nitro group by hepatic CYP1A1/2 or peroxidases in extrahepatic tissues to generate highly reactive cyclic nitrenium ions. The latter can react with macromolecules (DNA and protein), resulting in activation of H-ras and myc oncogenes and gene mutation in renal cells and finally carcinogenesis of the kidneys. Teucrin A and teuchamaedryn A, two diterpenoids found in germander (Teuchrium chamaedrys) used as an adjuvant to slimming herbal supplements that caused severe hepatotoxicity, are converted by CYP3A4 to reactive epoxide which reacts with proteins such as CYP3A and epoxide hydrolase and inactivate them. Some naturally occurring alkenylbenzenes (e.g. safrole, methyleugenol and estragole) and flavonoids (e.g. quercetin) can undergo bioactivation by sequential 1-hydroxylation and sulfation, resulting in reactive intermediates capable of forming DNA adducts. Extensive pulegone metabolism generated p-cresol that is a glutathione depletory. The hepatotoxicity of kava is possibly due to intracellular glutathione depletion and/or quinone formation. Moreover, several herbal compounds including capsaicin from chili peppers, dially sulfone in garlic, methysticin and dihydromethysticin in kava, oleuropein in olive oil, and resveratrol found in grape seeds are mechanism-based (suicide) inhibitors of various CYPs. Together with advances of proteomics, metabolomics and toxicogenomics, an integrated systems toxicological approach may provide deep insights into mechanistic aspects of herb-induced toxicities, and contribute to bridging the relationships between herbal bioactivation, protein/DNA adduct formation and the toxicological consequences.