• Proceedings of the Korean Society of Applied Pharmacology
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• 2001.11a
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• pp.110-110
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• 2001

Histone deacetylase(HDAC), a neuclear enzyme that regulates gene trascription and the assembly of newly synthesized chromatin, has received much attention in recent literature. The explosion of activity in this field has yielded the cloning of a mammalian gene which encodes a complementary histone acetyl trasferases. Several cyclic tetrapeptide inhibitors of HDAC has been reported to affect the hyperacetylation of mammalian and plant histones. Apicidin, a natural product HDAC inhibitor recently isolated at Merck Research Laboratories, induces therapeutic applications as a broad spectrum antiprotozoal agent to multi-drug resistant malaria and a potential antitumor agnet. The biological activity of apicidin appears to be attributable to inhibition of apicocomplexan HDAC at low nanomolar concentrations.

• Journal of Preventive Medicine and Public Health
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• v.51 no.2
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• pp.109-120
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• 2018

Objectives: This study aimed to investigate the current status of infectious disease research in North Korea by analyzing recent trends in medical journals from North Korea in comparison with research from South Korea. Methods: Three medical journals (Preventive Medicine, Basic Medicine, and Chosun Medicine) were analyzed from 2012 to 2016. Articles on tuberculosis (TB), malaria, and parasitic diseases were selected and classified by their subtopics and study areas. Two medical journals published in the South Korea were selected for a comparative analysis of research trends. Results: Of the 2792 articles that were reviewed, 93 were extracted from North Korea journals. TB research in North Korea was largely focused on multi-drug resistant TB and extrapulmonary TB, whereas research in South Korea more frequently investigated non-tuberculous mycobacteria. Research on parasitic diseases in North Korea was focused on protozoan and intestinal nematodes, while the corresponding South Korea research investigated various species of parasites. Additionally, the studies conducted in North Korea were more likely to investigate the application of traditional medicine to diagnosis and treatment than those conducted in South Korea. Conclusions: This study presents an analysis of research trends in preventive medicine in North Korea focusing on infectious diseases, in which clear differences were observed between South and North Korea. Trends in research topics suggest a high prevalence of certain parasitic diseases in North Korea that are no longer widespread in South Korea. The large proportion of studies examining traditional medicine implies a lack of affordable medicine in North Korea.

• Parasites, Hosts and Diseases
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• v.53 no.1
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• pp.35-41
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• 2015

Pyronaridine and artesunate have been shown to be effective in falciparum malaria treatment. However, pyronaridine is rarely used in Hainan Island clinically, and artesunate is not widely used as a therapeutic agent. Instead, conventional antimalarial drugs, chloroquine and piperaquine, are used, explaining the emergence of chloroquine-resistant Plasmodium falciparum. In this article, we investigated the sensitivity of P. falciparum to antimalarial drugs used in Hainan Island for rational drug therapy. We performed in vivo (28 days) and in vitro tests to determine the sensitivity of P. falciparum to antimalarial drugs. Total 46 patients with falciparum malaria were treated with dihydroartemisinin/piperaquine phosphate (DUO-COTECXIN) and followed up for 28 day. The cure rate was 97.8%. The mean fever clearance time ($22.5{\pm}10.6hr$) and the mean parasite clearance time ($27.3{\pm}12.2hr$) showed no statistical significance with different genders, ages, temperatures, or parasite density (P>0.05). The resistance rates of chloroquine, piperaquine, pyronarididine, and artesunate detected in vitro were 71.9%, 40.6%, 12.5%, and 0%, respectively (P<0.0001). The resistance intensities decreased as follows: chloroquine>piperaquine>pyronarididine>artesunate. The inhibitory dose 50 ($IC_{50}$) was $3.77{\times}10^{-6}mol/L$, $2.09{\times}10^{-6}mol/L$, $0.09{\times}10^{-6}mol/L$, and $0.05{\times}10^{-6}mol/L$, and the mean concentrations for complete inhibition (CIMC) of schizont formation were $5.60{\times}10^{-6}mol/L$, $9.26{\times}10^{-6}mol/L$, $0.55{\times}10^{-6}mol/L$, and $0.07{\times}10^{-6}mol/L$, respectively. Dihydroartemisinin showed a strong therapeutic effect against falciparum malaria with a low toxicity.

• Journal of Physiology & Pathology in Korean Medicine
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• v.19 no.1
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• pp.102-105
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• 2005

Eighteen methanol extracts of herb-medicine used for malarial and antipyretic therapies in Korea were assessed for their antimalarial activities. Eighteen extracts showed evident antimalarial activity with $EC_50$ values ranged from $2.8\;to\;110mg/m{\ell}$. Evodia fructus showed the antimalarial activity of $EC_50\;=\;4.1\;mg/m{\ell}$ and higher selective toxicity(>8) with no cytotocixity for mammalian cells. This indicated that Evodia fructus is potent for a new effective and safe antimalarial agent. The methanol extract of Physalli radix had also strongest antiplasmodial activity with $EC_50$ value of $2.8{\mu}g/m{\ell}$.

• Parasites, Hosts and Diseases
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• v.62 no.1
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• pp.42-52
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• 2024

Antimalarial drugs are an urgently need and crucial tool in the campaign against malaria, which can threaten public health. In this study, we examined the cytotoxicity of the 9 antimalarial compounds chemically synthesized using SKM13-2HCl. Except for SKM13-2HCl, the 5 newly synthesized compounds had a 50% cytotoxic concentration (CC₅₀) >100 μM, indicating that they would be less cytotoxic than SKM13-2HCl. Among the 5 compounds, only SAM13-2HCl outperformed SKM13-2HCl for antimalarial activity, showing a 3- and 1.3-fold greater selective index (SI) (CC₅₀/IC₅₀) than SKM13-2HCl in vitro against both chloroquine-sensitive (3D7) and chloroquine -resistant (K1) Plasmodium falciparum strains, respectively. Thus, the presence of morpholine amide may help to effectively suppress human-infectious P. falciparum parasites. However, the antimalarial activity of SAM13-2HCl was inferior to that of the SKM13-2HCl template compound in the P. berghei NK65-infected mouse model, possibly because SAM13-2HCl had a lower polarity and less efficient pharmacokinetics than SKM13-2HCl. SAM13-2HCl was more toxic in the rodent model. Consequently, SAM13-2HCl containing morpholine was selected from screening a combination of pharmacologically significant structures as being the most effective in vitro against human-infectious P. falciparum but was less efficient in vivo in a P. berghei-infected animal model when compared with SKM13-2HCl. Therefore, SAM13-2HCl containing morpholine could be considered a promising compound to treat chloroquine-resistant P. falciparum infections, although further optimization is crucial to maintain antimalarial activity while reducing toxicity in animals.

• Journal of Physiology & Pathology in Korean Medicine
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• v.23 no.2
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• pp.494-498
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• 2009

The emergence and spread of drug-resistant malaria parasites is a serious public health problem in the tropical world. Useful antimalarial drugs such as chloroquine have resistance in the world now. Moreover, other antimalarialdrugs such as mefloquine, halofantrine, atovaquone, proguanil, artemether and lumefantrine retain efficacy but have limitations, one of which is their high cost. New antimalarial drugs are clearly needed now. Cytotoxicity assay and susceptibility assay were performed for the selectivity of herb extracts in vitro. On the basis of high selectivity, 4-day suppressive test and survival test were progressed in Plasmodium berghei-infected mice. The selectivity of Areca catechu L. (ACL) and butanol extract of ACL (ACL-BuOH extract) were 3.4 and 3.0 in vitro, respectively. Moreover in vivo, 4-day suppressive test showed 39.1 % inhibition effect after treated with 150 mg/kg/day ACL-BuOH to P. berghei-infected mice. Survival test also showed 60% survival rate with ACL-BuOH-treated group while all other group mice died. In this study, ACL and ACL-BuOH were investigated for antimalarial activity in vitro and in vivo and they showed a potent antimalarial activity. In particular,ACL-BuOH could specifically lead higher survival rate of mice in vivo. Therefore ACL-BuOH would be a candidate of antimalarial drugs.