HPLC and CMS Analysis of Clomipramine Metabolism: A Multi-Drug Study

Daily use of multiple medications is commonplace for many Americans. While pharmacists monitor prescriptions for drug interactions, consumers rarely check the possible side effects when using an over-the-counter product. In this fictional case study, Sam is prescribed clomipramine and ciprofloxacin, while also taking Tylenol PM. All three medications are orally administered, and drug metabolism is catalyzed in the liver by cytochrome P450 enzymes (CYP450). CYP isoenzymes CYP1A2, CYP3A4 and CYP2C19 are responsible for clomipramine metabolism and formation of major bioactive metabolite desmethylclomipramine, while CYP2D6 hydroxylates clomipramine and metabolite into hydroxyclomipramine and hydroxydesmethylclomipramine, respectively. Multi-drug use can inhibit or induce metabolic activity. The extent to which activity is affected is determined by dose and ligand-enzyme binding strength. Ciprofloxacin is a known CYP1A2 inhibitor, while diphenhydramine inhibits CYP2D6. Quantification and visualization of metabolites formed from clomipramine, ciprofloxacin, and diphenhydramine in rat liver microsomes was performed using compact mass spectrometry and high-performance liquid chromatography. Chromatograms were analyzed for molecular weights of parent clomipramine and metabolized products. Data indicated a reduction ranging from 21.1% to 30.1% inhibition of clomipramine metabolism into desmethylclomipramine. It was concluded that CYP isoenzymes CYP1A2, CYP3A4, and CYP2C19 played a role in diminishing clomipramine metabolite formation. These results illustrate the need for research and education when administering multiple drugs

HPLC and CMS Analysis of Clomipramine Metabolism: A Multi-Drug Study

Daily use of multiple medications is commonplace for many Americans. While pharmacists monitor prescriptions for drug interactions, consumers rarely check the possible side effects when using an over-the-counter product. In this fictional case study, Sam is prescribed clomipramine and ciprofloxacin, while also taking Tylenol PM. All three medications are orally administered, and drug metabolism is catalyzed in the liver by cytochrome P450 enzymes (CYP450). CYP isoenzymes CYP1A2, CYP3A4 and CYP2C19 are responsible for clomipramine metabolism and formation of major bioactive metabolite desmethylclomipramine, while CYP2D6 hydroxylates clomipramine and metabolite into hydroxyclomipramine and hydroxydesmethylclomipramine, respectively. Multi-drug use can inhibit or induce metabolic activity. The extent to which activity is affected is determined by dose and ligand-enzyme binding strength. Ciprofloxacin is a known CYP1A2 inhibitor, while diphenhydramine inhibits CYP2D6. Quantification and visualization of metabolites formed from clomipramine, ciprofloxacin, and diphenhydramine in rat liver microsomes was performed using compact mass spectrometry and high-performance liquid chromatography. Chromatograms were analyzed for molecular weights of parent clomipramine and metabolized products. Data indicated a reduction ranging from 21.1% to 30.1% inhibition of clomipramine metabolism into desmethylclomipramine. It was concluded that CYP isoenzymes CYP1A2, CYP3A4, and CYP2C19 played a role in diminishing clomipramine metabolite formation. These results illustrate the need for research and education when administering multiple drug

FIRST - Flexible interactive retrieval SysTem for visual lifelog exploration at LSC 2020

Lifelog can provide useful insights of our daily activities. It is essential to provide a flexible way for users to retrieve certain events or moments of interest, corresponding to a wide variation of query types. This motivates us to develop FIRST, a Flexible Interactive Retrieval SysTem, to help users to combine or integrate various query components in a flexible manner to handle different query scenarios, such as visual clustering data based on color histogram, visual similarity, GPS location, or scene attributes. We also employ personalized concept detection and image captioning to enhance image understanding from visual lifelog data, and develop an autoencoderlike approach for query text and image feature mapping. Furthermore, we refine the user interface of the retrieval system to better assist users in query expansion and verifying sequential events in a flexible temporal resolution to control the navigation speed through sequences of images

Investigation of Drug-Drug Effects of Propranolol and Clomipramine in Rat Liver Microsome using HPLC and Compact Mass Spectrometry

Polypharmacy is widely practiced today. One example is the combination of antidepressants and hypertensive drugs, as it has been found that 57.5% of people with hypertension also develop depression symptoms. The effects of propranolol (a beta blocker) on the metabolism of clomipramine (a tricyclic antidepressant) were investigated to recreate this combination, using rat liver microsomes, HPLC (high performance liquid chromatography), and CMS (compact mass spectrometry). In the experiment, varying quantities of clomipramine, propranolol (inhibitor), NADPH, and rat liver microsome were incubated and diluted in HPLC mobile phase to be loaded onto the CMS fitted with a reverse phase column. Rat liver microsomes have similar metabolizing enzymes as the human liver. Clomipramine in the liver is metabolized by enzymes CYP2D6, CYP1A2, CYP3A4, and CYP2C19. These enzymes catalyze the metabolism of different functional groups on the clomipramine (CYP2D6 catalyzes aromatic hydroxylation, while CYP1A2, CYP2C19, and CYP3A4 drives demethylation of the amino group). The metabolism type we specifically probed was mono-demethylation of the amino group on clomipramine. The results agree with the hypothesized inhibitory effect of propranolol. The concentration of propranolol at 50% inhibition of demethylation under these conditions was found to be 1.33 mM. (IC50 = 1.33 mM). Concentration of unmetabolized clomipramine increased by 9.3% with increasing concentration of propranolol. Propranolol is a substrate for enzymes CYP1A2 and CYP3A4, competing with clomipramine in binding the active sites of the enzymes, thus decreasing the concentration of desmethylated clomipramine while increasing the concentration of clomipramine. This experiment could guide medical practitioners when prescribing antidepressants and hypertensive drugs together

The Impact of Green Tea Extract (GTE) on the Metabolism of Clomipramine in Rat Liver Microsome Using HPLC and Compact Mass Spectrometry

Clomipramine is a commonly used tricyclic antidepressant in treating a variety of disorders such as obsessive-compulsive disorder, anxiety, depression, and panic disorders. Clomipramine is metabolized primarily by the isoenzyme CYP450 2D6 in the liver. It can also be metabolized by three other enzymes, CYP450 1A2, CYP450 2C19, and CYP450 3A4 isoenzymes. These are four isoenzymes for metabolizing Clomipramine, but the focus for this experiment is CYP450 1A2 with rat liver microsome using HPLC and compact mass spectrometry (CMS). Today, roughly $11 billion is spent on green tea consumption. One form of consuming green tea is through green tea extract. Green tea extract, in a pill or powder form, contains high amounts of antioxidants, polyphenols, minerals, caffeine, carbohydrates, and various amounts of vitamins. The question of interest is how much is too much? for clomipramine users. This experiment explores green tea extract in a powder and the effects it has on the metabolization of clomipramine. Green tea extract is known to inhibit two metabolizing enzymes, CYP450 1A2 and CYP450 2D6, but it is unknown which is primarily inhibited. To carry out the experiment, four negative controls and various concentrations of green tea extracts were used. The negative controls contained varying amounts of clomipramine, NADPH, microsomal suspension, and buffer. The experimental samples contained varying amounts of green tea extract (inhibitor) in addition to clomipramine, microsome, and NADPH. The samples were incubated at 37 °C . The metabolite was extracted and mixed with the mobile phase to be injected through a compact mass spectrometer fitted with a C18 reverse phase column. The CMS data showed a 51.4% decreased level of desmethylated clomipramine, indicating that the CYP450 1A2 isoenzyme is being inhibited. From the data gathered through CMS, a graphical analysis determined the concentration of green tea extract at a 50% inhibition under the experimental condition. These results showed that IC50 was 28.3 mg/mL green tea extract under the experimental condition. This can be significant for informing individuals who consume green tea extract and clomipramine together