The action of cytochalasins, actin-disrupting agents on human Kv1.5 channel (hKv1.5) stably expressed in Ltk Ϫ cells was investigated using the whole cell patchclamp technique. Cytochalasin B inhibited hKv1.5 currents rapidly and reversibly at ϩ60 mV in a concentration-dependent manner with an IC 50 of 4.2 M. Cytochalasin A, which has a structure very similar to cytochalasin B, inhibited hKv1.5 (IC 50 of 1.4 M at ϩ60 mV). Pretreatment with other actin filament disruptors cytochalasin D and cytochalasin J, and an actin filament stabilizing agent phalloidin had no effect on the cytochalasin B-induced inhibition of hKv1.5 currents. Cytochalasin B accelerated the decay rate of inactivation for the hKv1.5 currents. Cytochalasin B-induced inhibition of the hKv1.5 channels was voltage dependent with a steep increase over the voltage range of the channel's opening. However, the inhibition exhibited voltage independence over the voltage range in which channels are fully activated. Cytochalasin B produced no significant effect on the steady-state activation or inactivation curves. The rate constants for association and dissociation of cytochalasin B were 3.7 M/s and 7.5 s Ϫ1 , respectively. Cytochalasin B produced a use-dependent inhibition of hKv1.5 current that was consistent with the slow recovery from inactivation in the presence of the drug. Cytochalasin B (10 M) also inhibited an ultrarapid delayed rectifier K ϩ current (IK,ur) in human atrial myocytes. These results indicate that cytochalasin B primarily blocks activated hKv1.5 channels and endogenous IK,ur in a cytoskeleton-independent manner as an open-channel blocker.

Background: The aim of this study was to analyze published papers on the use of herbal medicine in obesity research over the past 20 years using bibliometric methods and present an overview of global research trends. Methods: English articles on herbal medicine for obesity published from 2001 to 2020 were retrieved from the Web of Science Core Collection database using the search terms “herbal” AND “obesity”. Microsoft Office Excel was used to sort and analyze the statistical data. Bibliographic analysis and data visualization were performed using visualization of similarities viewer based on publication year, country of publication, journal, research area, author, affiliated institution, and keywords. Results: A total of 463 English articles were retrieved, and we observed a trend in which the number of publications on herbal medicine for obesity has gradually increased over the past 20 years. The most productive countries and research organizations in this field were Korea and Kyunghee University, respectively. Many papers have been published in research areas, such as pharmacology pharmacy and integrative complementary medicine, and the journals with the most published articles in this field were Journal of Ethnopharmacology and Evidence-Based Complementary and Alternative Medicine. The main research keywords formed 3 clusters, and keywords with the most occurrences were “obesity,” “adipose-tissue,” and “insulin resistance.” Conclusion: This study presents an overview of the global research trend of herbal medicine for obesity from the bibliographic analysis. An increased understanding of the recently changing research topics provides a new perspective on future research directions. This study may help guide the research in the field of obesity in the future.