Simultaneous analytical method for 296 pesticide multiresidues in root and rhizome based herbal medicines with GC-MS/MS.

A method for the simultaneous analysis of pesticide multiresidues in three root/rhizome-based herbal medicines (Cnidium officinale, Rehmannia glutinosa, and Paeonia lactiflora) was developed with GC-MS/MS. To determine the concentrations of pesticide residues, 5 g of dried samples were saturated with distilled water, extracted with 10 mL of 0.1% formic acid in acetonitrile/ethyl acetate (7:3, v/v), and then partitioned using magnesium sulfate and sodium chloride. The organic layer was purified with Oasis PRiME HLB plus light, followed by a cleanup with dispersive solid-phase extraction containing alumina. The sample was then injected into GC-MS/MS (2 µL) using a pulsed injection mode at 15 psi and analyzed using multiple reaction monitoring (MRM) modes. The limit of quantitation for the 296 target pesticides was within 0.002-0.05 mg/kg. Among them, 77.7-88.5% showed recoveries between 70% and 120% with relative standard deviations (RSDs) ≤20% at fortified levels of 0.01, and 0.05 mg/kg. The analytical method was successfully applied to real herbal samples obtained from commercial markets, and 10 pesticides were quantitatively determined from these samples.

Effect of postoperative radiotherapy for patients with differentiated thyroid cancer.

OBJECTIVE: We evaluated the efficacy and safety of postoperative radiotherapy (PORT) for differentiated thyroid cancer (DTC) with high risk features. MATERIALS AND METHODS: This retrospective study analyzed 187 patients treated for DTC from 1985 to 2019. DTC referred to nonanaplastic thyroid cancer originating from follicular cells. PORT was defined as the administration of external beam radiation to the thyroid and regional lymph nodes following surgery for initially diagnosed DTC. The patients were included in the analysis if they received PORT or exhibited any of the following features: (a) pT4 or pN1b according to the 8th American Joint Committee on Cancer, (b) poorly differentiated thyroid cancer (PDTC), or (c) unfavourable variants such as anaplastic foci and etc. After 1:1 propensity matching, a total of 108 patients were analyzed according to PORT receipt. The median follow-up duration of the matched group was 10.4 years. RESULTS: After matching, most of the variables became balanced, but the PORT group still had more PDTC and DTC with anaplastic foci. Radioactive iodine (RAI) was less frequently administered in the PORT group. PORT yielded a significantly higher 5-year locoregional recurrence free survival (LRFS) than the No PORT group (5-year LRFS 86.1% vs. 72.7%, p = 0.022), but the 10-year cancer specific survival (CSS) was similar between them (97.8% vs. 85.9%, p = 0.122). The multivariable analysis indicated that PORT was a favourable prognostic factor (Hazard ratio 0.3, 95% Confidence interval 0.1-0.8, p = 0.02) for LRFS, but not for CSS. Among 133 patients without PORT for initial disease, 39 of them received salvage surgery followed by salvage PORT. No severe toxicity after PORT was reported. CONCLUSION: PORT reduced locoregional recurrence in DTC patients without severe toxicity. PORT can be an effective and safe treatment to improve locoregional control in DTC with high risk features. However, further study is warranted to identify those who can benefit from PORT.

Incidence of Subacute Thyroiditis During the COVID-19 Pandemic in South Korea Using the National Health Insurance Service Database.

Background: Subacute thyroiditis (SAT) is a thyroid disease initiated by viral infection. Whether severe acute respiratory syndrome coronavirus 2 infection can cause SAT is unclear. This study investigated changes in the nationwide incidence of SAT during the coronavirus disease 2019 (COVID-19) pandemic. Methods: This is a retrospective, cross-sectional population-based study. Data regarding SAT and related viral diseases, including COVID-19, from 2017 to 2020 were collected from the National Health Insurance Service and Korea Disease Control and Prevention Agency databases. Results: In a total of 15,447 patients, 2484 men and 12,963 women diagnosed with SAT from 2017 to 2020 were included in this study. The incidence of SAT was significantly higher in 2020 than in 2017-2019 (8.30 vs. 7.27 per 100,000 persons, p < 0.001), while the incidence of SAT-related respiratory viral diseases, except for COVID-19, markedly decreased in 2020. The peak age of SAT incidence in 2020 was 50-59 years, and the women-to-men ratio was 5.4 (similar to that in 2017-2019). Corticosteroids were prescribed more often (72% vs. 58%, p < 0.001), and the prescription rate exceeding 1 month was significantly higher (45% vs. 40%, p < 0.01) in 2020 than in 2017-2019. Conclusions: The incidence of SAT increased in 2020 in association with COVID-19. A diagnostic approach to COVID-19 needs to be considered in patients with SAT during the COVID-19 pandemic.

Co-Treatment with the Herbal Medicine SIP3 and Donepezil Improves Memory and Depression in the Mouse Model of Alzheimer's Disease.

BACKGROUND: Alzheimer's disease (AD) is a lethal, progressive neurodegenerative disorder that has been linked to a deficiency of the neurotransmitter acetylcholine. Currently, many acetylcholinesterase inhibitors, such as donepezil, are widely used for the treatment of AD. On the other hand, the efficacy of long-term donepezil use is limited. SIP3, a mixture of three herbal extracts from Santalum album, Illicium verum, and Polygala tenuifolia, is a new formula derived from traditional Korean herbal medicine. OBJECTIVE: We assessed the synergistic effect of SIP3 and donepezil co-treatment on symptoms of AD using APP/PS1 transgenic mice. METHODS: In this study, a Drosophila AD model and SH-SY5Y clles were used to assess the toxicity of SIP3, and APPswe/PS1dE9 (APP/PS1) transgenic mice were used to evaluate the cognitive-behavioral and depression-like behavior effect of SIP3 and donepezil co-treatment on symptoms of AD. The cerebral cortex or hippocampus transcriptomes were analyzed by RNA sequencing and miRNA to investigate the molecular and cellular mechanisms underlying the positive effects of SIP3 on AD. RESULTS: In the passive avoidance test (PAT) and Morris water maze (MWM) test, the combination of SIP3 and donepezil improved the learning capabilities and memory of APP/PS1 mice in the mid-stage of AD compared to the group treated with donepezil only. In addition, co-administration of SIP3 and donepezil effectively reduced the depression-like behavior in the forced swimming and tail suspension tests. Furthermore, RNA sequencing of the cerebral cortex transcriptome and miRNA of the hippocampus showed that the gene expression profiles after a low dose SIP3 co-treatment were more similar to those of the normal phenotype mice than those obtained after the donepezil treatment alone. The Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways, showed that differentially expressed genes were involved in the locomotor behavior and neuroactive ligand-receptor interactions. These results suggest that a co-treatment of low dose SIP3 and donepezil improves impaired learning, memory, and depression in the mid-stage of AD in mice. CONCLUSION: Co-treatment of low dose SIP3 and donepezil improves impaired learning, memory, and depression in the mid-stage of AD in mice.

Day Temperature Difference and Aggravation of Low Urinary Tract Symptom in Benign Prostate Hypertrophy Patients in Korea: A National Health Insurance Service-National Cohort-based Study.

OBJECTIVE: To investigate the symptom deterioration of patients with benign prostatic hyperplasia (BPH) according to the difference in daily temperature. PATIENTS AND METHODS: From the National Health Insurance Service database, we collected and analyzed data on patients with BPH in 6 major metropolitan areas in Korea between January 2008 and December 2017. We investigated the rate of emergency room visits as well as the rate of urethral catheter insertion. RESULTS: In total, 1,446,465 patients were enrolled in this study. When the daily temperature difference was below 4°C, 28.5 patients visited the emergency room daily, while 42.2 patients visited the emergency room daily when the daily temperature difference exceeded 14°C. When the daily temperature difference was more than 14°C, about 48.0% more patients visited the emergency room than when the daily temperature difference was below 4°C. After visiting the emergency room, there were 11.9 patients who had a catheter inserted daily at the daily temperature difference below 4°C. When the daily temperature difference was more than 14°C, the number of catheter insertion cases was 17.8 patients daily, which was 49.2% higher than that of below 4°C. By time, surgery was performed most frequently within 3 months after visiting the emergency room. CONCLUSION: Day temperature difference appear to be related to the Lower urinary tract symptom of BPH patients.

Short-term benefits of balneotherapy for patients with chronic pelvic pain: a pilot study in Korea.

The aim of this study was to evaluate whether balneotherapy might be effective in patients with chronic pelvic pain (CPP) in the short term. This was an open and prospective pilot study. The balneotherapy programme was performed in a spa resort located in Wando Island, Republic of Korea from August 26 2018 to September 1 2018. It consisted of 10 heated seawater baths (38 °C, 20 minutes) and 10 mud-pack applications (40 °C, 10 minutes) for five days. Sixteen patients were enrolled. Upon analysing responses from a patient questionnaire, we found improvement in parameters such as pain, bladder irrigation symptoms and quality of life after balneotherapy. Inflammatory marker IL-1 and TNF-α was significantly decreased after treatment compared to baseline. There were no adverse events during treatment. Our data suggest that five-day balneotherapy can be beneficial for patients with CPP in the short term.Impact statementWhat is already known on this subject? The majority of articles in the field of balneotherapy discuss the treatment of rheumatic or dermatological disease. However, data on the effectiveness of balneotherapy for chronic pelvic pain are very limited.What the results of this study add? Our study suggests that balneotherapy can be beneficial for patients with CPP in the short-term. The duration of balneotherapy was five days, which is shorter than that of the European studies. Intuitively, it may be doubtful whether short-term therapy has any practical effect. As most people living in Korea have a vacation period of about one week each in summer and winter, the choice of a five-day programme in our study reflects the reality of vacation schedules.What the implications are of these findings for clinical practice and/or further research? Further studies are necessary to demonstrate the persistence of these benefits on the long term, as well as their existence in appropriate control group and different duration of treatment.

National practice patterns and direct medical costs for prostate cancer in Korea across a 10 year period: a nationwide population-based study using a national health insurance database.

BACKGROUND: A complete enumeration study was conducted to evaluate trends in national practice patterns and direct medical costs for prostate cancer (PCa) in Korea over a 10-year retrospective period using data from the Korean National Health Insurance Service. METHODS: Reimbursement records for 874,924 patients diagnosed between 2002 and 2014 with primary PCa according to the International Classification of Disease (ICD) 10th revision code C61 were accessed. To assess direct medical costs for patients newly diagnosed after 2005, data from 68,596 patients managed between January 2005 and 31 December 2014 were evaluated. RESULTS: From 2005 to 2014, the total number of PCa patients showed a 2.6-fold increase. Surgery and androgen deprivation therapy were the most common first-line treatment, alone or within the context of combined therapy. Surgery as a monotherapy was performed in 23.5% of patients in 2005, and in 39.4% of patients in 2014. From 2008, the rate of robot-assisted RP rose sharply, showing a similar rate to open RP in 2014. Average total treatment costs in the 12 months post-diagnosis were around 10 million Korean won. Average annual treatment costs thereafter were around 5 million Korean won. Out-of-pocket expenditure was highest in the first year post-diagnosis, and ranged from 12 to 17% thereafter. CONCLUSIONS: Between 2005 and 2014, a substantial change was observed in the national practice pattern for PCa in Korea. The present data provide a reliable overview of treatment patterns and medical costs for PCa in Korea.

α-Blocker and Risk of Dementia in Patients with Benign Prostatic Hyperplasia: A Nationwide Population Based Study Using the National Health Insurance Service Database.

PURPOSE: A recent study demonstrated that tamsulosin increased the risk of dementia in patients with benign prostatic hyperplasia. However, this study had a number of limitations. We evaluated the association between α-blockers and dementia in patients with benign prostatic hyperplasia. MATERIALS AND METHODS: From the National Health Insurance Service database we collected and analyzed data on α-blockers and dementia in the entire Korean adult population with benign prostatic hyperplasia between January 2011 and December 2011. These patients were followed until September 2017. We tested the effect of α-blockers on the risk of dementia using propensity score matched Cox proportional hazard regression models and Kaplan-Meier survival analysis. RESULTS: During a mean ± SD followup of 1,580 ± 674.3 days all study inclusion and exclusion criteria were met by 59,263 patients with benign prostatic hyperplasia. In the unadjusted cohort the incidence of dementia in the tamsulosin, doxazosin, terazosin, alfuzosin and no medication cohorts were 17.97%, 18.55%, 20.64%, 17.62% and 22.60%, respectively. After propensity score matching the risk of dementia did not significantly differ in the tamsulosin cohort vs the doxazosin and alfuzosin cohorts (HR 1.038, 95% CI 0.960-1.121 and HR 1.008, 95% CI 0.925-1.098), respectively. Compared to the tamsulosin cohort the terazosin cohort had a higher risk of dementia (HR 1.112, 95% CI 1.052-1.196). However, the risk of dementia was significantly lower in the terazosin cohort than in the no medication cohort. CONCLUSIONS: The study findings indicate that benign prostatic hyperplasia medication is not associated with a risk of dementia by duration of use or by type.

Medical Travel among Non-Seoul Residents to Seek Prostate Cancer Treatment in Medical Facilities of Seoul.

PURPOSE: This study aims to investigate the trend in medical travel by non-Seoul residents to Seoul for treatment of prostate cancer and also to investigate the possible factors affecting the trend. MATERIALS AND METHODS: This study represents a retrospective cohort study using data from theKoreanNationalHealth Insurance System from 2002 to 2015. Annual trends were produced for proportions of patients who traveled according to the age group, economic status and types of treatment. Multiple logistic analysiswas used to determine factors affecting surgeries at medical facilities in Seoul among the non-Seoul residents. RESULTS: A total of 68,543 patients were defined as newly diagnosed prostate cancer cohorts from 2005 to 2014. The proportion of patients who traveled to Seoul for treatment, estimated from cases with prostate cancer-related claims, decreased slightly over 9 years (28.0 at 2005 and 27.0 at 2014, p=0.02). The average proportion of medical travelers seeking radical prostatectomy increased slightly but the increase was not statistically significant (43.1 at 2005 and 45.4 at 2014, p=0.26). Income level and performance ofrobot-assisted radical prostatectomy were significant positive factors for medical travel to medical facilities in Seoul. Combined comorbidity diseases and year undergoing surgery were significant negative factors for medical travel to medical facilities in Seoul. CONCLUSION: The general trend of patients travelling from outside Seoul for prostate cancer treatment decreased from 2005 to 2014. However, a large proportion of traveling remained irrespective of direct distance from Seoul.

Correlation of Androgen Deprivation Therapy with Cognitive Dysfunction in Patients with Prostate Cancer: A Nationwide Population-Based Study Using the National Health Insurance Service Database.

PURPOSE: The purpose of this study was to evaluate the association of androgen deprivation therapy (ADT) with cognitive dysfunction. MATERIALS AND METHODS: Using the National Health Insurance Service database of the entire Korean adult prostate cancer population (n=236,391), data on ADT and cognitive dysfunction between 2008 and 2015 were analyzed. We excluded patients previously diagnosed with cognitive dysfunction, dementia, or a cerebral event history. We tested the effect of ADT on the risk of cognitive dysfunction using propensity score-matched Cox proportional hazards regression models and Kaplan-Meier survival analysis. Our final cohort comprised of 35,401 individuals with prostate cancer, including 24,567 men (70.6%) who underwent ADT. RESULTS: During a mean follow-up period of 4.1 years, 4,741 patients were newly diagnosed with cognitive dysfunction. A statistically significant association was found between ADT and the risk of cognitive dysfunction (hazard ratio, 1.169; p=0.002). Meanwhile, age (≥ 70 years), diabetes, hypertension, cardiovascular history, and peripheral vascular disease were identified as factors that contribute to the increased risk of cognitive dysfunction. In contrast, the use of statins and aspirin was associated with a lower risk of cognitive dysfunction. Kaplan-Meier analysis demonstrated that patients aged 70 years or older who underwent ADT had the lowest cumulative probability of remaining cognitive dysfunction-free (log-rank p < 0.001). CONCLUSION: Our. RESULTS: revealed an association between the use of ADT for the treatment of prostate cancer and an increased risk of cognitive dysfunction in a nationwide population-based study. This finding should be further evaluated in prospective studies.

Bee venom stimulation of a lung meridian acupoint reduces inflammation in carrageenan-induced pleurisy: an alternative therapeutic approach for respiratory inflammation.

Respiratory inflammation is a frequent and fatal pathologic state encountered in veterinary medicine. Although diluted bee venom (dBV) has potent anti-inflammatory effects, the clinical use of dBV is limited to several chronic inflammatory diseases. The present study was designed to propose an acupoint dBV treatment as a novel therapeutic strategy for respiratory inflammatory disease. Experimental pleurisy was induced by injection of carrageenan into the left pleural space in mouse. The dBV was injected into a specific lung meridian acupoint (LU-5) or into an arbitrary non-acupoint located near the midline of the back in mouse. The inflammatory responses were evaluated by analyzing inflammatory indicators in pleural exudate. The dBV injection into the LU-5 acupoint significantly suppressed the carrageenan-induced increase of pleural exudate volume, leukocyte accumulation, and myeloperoxidase activity. Moreover, dBV acupoint treatment effectively inhibited the production of interleukin 1 beta, but not tumor necrosis factor alpha in the pleural exudate. On the other hand, dBV treatment at non-acupoint did not inhibit the inflammatory responses in carrageenan-induced pleurisy. The present results demonstrate that dBV stimulation in the LU-5 lung meridian acupoint can produce significant anti-inflammatory effects on carrageenan-induced pleurisy suggesting that dBV acupuncture may be a promising alternative medicine therapy for respiratory inflammatory diseases.

Radioactive Iodine Therapy Did Not Significantly Increase the Incidence and Recurrence of Subsequent Breast Cancer.

CONTEXT: Previous studies on the extent to which radioactive iodine (RAI) therapy for thyroid cancer increases the risk of subsequently developing breast cancer have given conflicting results. OBJECTIVE: This study aimed to evaluate the effect of RAI treatment on breast cancer development and recurrence among female patients with primary thyroid cancer. DESIGN: This was a retrospective cohort study. The risk of subsequent breast cancer associated with RAI and its dose in hazard ratios (HRs) with 95% confidential intervals (CIs) were calculated using time-dependent Cox proportional hazard models. PATIENTS: A total of 6150 patients with thyroid cancer enrolled between 1973 and 2009 were followed until December 2012. Of these, 3631 (59.0%) received RAI therapy. During the follow-up period, 99 primary breast cancers were diagnosed. MAIN OUTCOME MEASURE: Risk of breast cancer development according to RAI therapy and RAI dose during treatment for primary thyroid cancer. RESULTS: RAI therapy did not significantly increase the incidence of subsequent breast cancer among female patients (hazard ratio [HR], 0.49; 95% confidence interval [CI], 0.22-1.06) when a 2-year latency period was accounted for. High-dose RAI (≥120 mCi) was associated with a reduced incidence of subsequent breast cancer (HR, 0.17; 95% CI, 0.05-0.62) in the cohort with a 2-year latency period. CONCLUSIONS: The long-term follow-up results of this study suggest that RAI treatment for patients with thyroid cancer may not increase the risk or recurrence of breast cancer.

The risk of second primary malignancy is increased in differentiated thyroid cancer patients with a cumulative (131)I dose over 37 GBq.

BACKGROUND: The aim of this study was to investigate the risk factors for second primary malignancy (SPM) diagnosed after differentiated thyroid cancer (DTC). METHODS: A total of 2468 DTC patients who underwent thyroidectomy were reviewed. SPM was defined as a non-thyroidal malignancy, diagnosed at least 1 year after the diagnosis of thyroid cancer. Patients were divided into five groups according to cumulative (131)I dose: very high-activity (≥ 37.0 GBq), high-activity (22.3-36.9 GBq), intermediate-activity (5.56-22.2 GBq), low-activity (1.1-5.55 GBq) and no RAI. RESULTS: Among the 2468 patients, 61 (2.5%) had SPMs during 7.0 (1.0-33.0) years of median follow-up. Age above 40 years, male sex and very high-activity RAI were independent risk factors for the development of SPM. SPM-related mortality was highest in the very high-activity group, while DTC-related mortality was highest in the high-activity group. The overall mortality both from SPM and DTC was highest in the high-activity group. CONCLUSION: A cumulative (131)I dose <37.0 GBq did not increase the risk of SPM. A cumulative (131) I dose ≥ 37.0 GBq increased the risk of SPM and SPM-related mortality and decreased the DTC-specific mortality, resulting in a similar all-cause mortality compared with the low-activity RAI group. Using repeated high-dose RAI for treating RAI-responsive but persistent DTC patients needs careful consideration of the individual benefits from RAI vs the risk of developing SPM.

Prediction of persistent storage symptoms after transurethral resection of the prostate in patients with benign prostatic enlargement.

OBJECTIVE: To identify the prognostic factors causing persistent storage symptoms following transurethral resection of the prostate in patients with benign prostatic enlargement (BPE). METHODS: A total of 116 men with symptomatic BPE requiring surgery were enrolled in the study between January 2011 and December 2012. The patients underwent basic clinical evaluations including transrectal ultrasound, International Prostate Symptom Score and urodynamic study. After 6 months, International Prostate Symptom Score and uroflowmetry were rechecked. The definition of persistent storage symptoms was patients with storage scores >7 points. Logistic regression analysis and receiver operating characteristic analysis were conducted. RESULTS: The 116 patients were divided into a persistent storage symptom-positive group (n = 33) and a storage symptom-negative group (n = 83). Multivariate analysis showed that the degrees of worse initial storage symptoms (odds ratio [OR] = 8.32), small bladder capacity (OR = 4.31), impaired detrusor contractility (OR = 2.96) and age (OR = 1.05) were consistently associated with persistent storage symptoms. CONCLUSIONS: This short-term study confirms the positive and consistent correlations between the baseline degree of worse initial storage symptoms, bladder capacity, detrusor contractility and age and the improvement in storage symptoms.

High-dose dietary zinc promotes prostate intraepithelial neoplasia in a murine tumor induction model.

To evaluate the role of high-dose dietary zinc in the process of prostate malignancy, 60 Sprague-Dawley rats were randomly divided into four groups: tumor induction with carcinogen and hormone (group 1), oral zinc administration without tumor induction (group 2), oral zinc administration with tumor induction (group 3) and a control without zinc administration or tumor induction (group 4). Zinc was supplied orally in the form of zinc sulfate heptahydrate dissolved in drinking water to groups 2 and 3 for 20 weeks. Although the serum level of zinc measured at 20 weeks was maintained similarly in each group (P = 0.082), intraprostatic zinc concentrations were statistically different. Group 1 prostates contained the least amount of zinc in both the dorsolateral and ventral lobes at levels of 36.3 and 4.8 microg g(-1), respectively. However, in group 3, zinc levels increased in both lobes to 59.3 and 12.1 microg g(-1), respectively, comparable with that of group 4 (54.5 +/- 14.6 and 14.1 +/- 2.4 microg g(-1)). In spite of these increases in zinc concentration, the prevalence of prostate intraepithelial neoplasm was rather increased in group 3 (53.3% and 46.7%) compared with group 1 (33.3% and 33.3%) in both dorsolateral and ventral prostate lobes. Although prostate intraepithelial neoplasm did not develop in any prostate in group 4, zinc administration did induce prostate intraepithelial neoplasm in group 2 (46.7% and 40.0%). Thus, although high dietary zinc increased intraprostatic zinc concentrations, it promoted, instead of preventing, prostate intraepithelial neoplasm in a murine prostate malignancy induction model.

Identification and characterization of potent CYP2B6 inhibitors in Woohwangcheongsimwon suspension, an herbal preparation used in the treatment and prevention of apoplexy in Korea and China.

Woohwangcheongsimwon is a traditional medicine for treating hypertension, arteriosclerosis, coma, and stroke in China and Korea. To assess potential interactions of herb and drug metabolism, commercially available Woohwangcheongsimwon suspensions were examined for their potential to inhibit the activity of nine human cytochrome P450 enzymes. The Woohwangcheongsimwon suspensions showed strong inhibition of CYP2B6 activity. To identify individual constituents with inhibitory activity, the suspension was partitioned using hexane, ethyl acetate, and dichloromethane, and each fraction was tested for its inhibitory effect on CYP2B6-catalyzed bupropion hydroxylation. The hexane fraction possessed inhibitory activity, and gas chromatography/mass spectrometry analysis identified borneol and isoborneol as major constituents of the hexane fraction. These two terpenoids moderately inhibited CYP2B6-catalyzed bupropion hydroxylase activity in a competitive manner, with K(i) values of 9.5 and 5.9 microM, respectively, as well as efavirenz 8-hydroxylase activity, with K(i) values of 22 and 26 microM, respectively. Additionally, reconstituted mixtures of borneol and isoborneol, at the same concentrations as in the Woohwangcheongsimwon suspension, had comparable potency in inhibiting bupropion hydroxylation. These in vitro data indicate that Woohwangcheongsimwon preparations contain constituents that can potently inhibit the activity of CYP2B6 and suggest that these preparations should be examined for potential pharmacokinetic drug interactions in vivo.