• Proceedings of the Plant Resources Society of Korea Conference
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• 2023.04a
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• pp.44-44
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• 2023

Syneilesis palmata (SP) has been used as a traditional medicinal plant and vegetable. SP was reported to exert pharmacological activities such as anti-inflammation, anti-cancer, and anti-HIV. However, there are no studies on the immunostimulatory activity of SP. Thus, in this study, we report that S. palmata leaves (SPL) induce the activation of macrophages. An increase in both secretions of immunostimulatory mediators and phagocytotic activity was observed in SPL-treated RAW264.7 cells. However, this was reversed by inhibition of TLR2/4. In addition, the p38 inhibition reduced the SPL-mediated secretion of immunostimulatory mediators, and the SPL-mediated p38 activation was blocked by the TLR2/4 inhibition. SPL augmented both p62/SQSTM1 and LC3-II. TLR2/4 inhibition blocked the SPL-mediated increase of p62/SQSTM1 and LC3-II. These findings indicate that SPL may activate macrophages through TLR2/4-dependent p38 activation and activate autophagy through TLR2/4 stimulation.

• Bulletin of the Korean Chemical Society
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• v.29 no.5
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• pp.993-997
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• 2008

Two directional ring-closing metathesis (RCM) was applied successfully to the synthesis of 4'-vinylated carbocyclic nucleoside analogues from the trivinyl intermediate 12, which was readily made using a sequential Claisen rearrangement and ring-closing metathesis (RCM) starting from Weinreb amide 5. An antiviral evaluation of the synthesized compounds against various viruses such as HIV, HSV-1, HSV-2 and HCMV revealed that the guanine analogue 20 have moderate anti-HIV activity in the MT-4 cell line ($EC_{50}$ = 10.2 $\mu$ M).

• Proceedings of the Korean Society of Applied Pharmacology
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• 1996.04a
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• pp.19-29
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• 1996

The neurological manifestations of AIDS include dementia, encountered even in the absence of opportunistic superinfection or malignancy. The AIDS Dementia Complex appears to be associated with several neuropathological abnormalities, including astrogliosis and neuronal injury or loss. How can HIV-1 result in neuronal damage if neurons themselves are only rarely, if ever, infected by the vitus\ulcorner In vitro experiments from several different laboratiories have lent support to the existence of HIV- and immune-related toxins. In one recently defined pathway to neuronal injury, HIV-infected macrophages/microglia as well as macrophages activated by HIV-1 envelope protein gp120 appear to secrete excitants/neurotoxins. These substances may include arachidonic acid, platelet-activating factor, free radicals (NO - and O$_2$), glutamate, quinolinate, cysteine, cytokines (TNF-${\alpha}$, IL1-B, IL-6), and as yet unidentified factors emanating from stimulated macrophages and possibly reactive astrocytes. A final common pathway for newonal suscepubility appears to be operative, similar to that observed in stroke, trauma, epilepsy, and several neurodegenerative diseases, including Huntington's disease, Parkinson's disease, and amyotrophic lateral sclerosis. This mechanism involves excessive activation of N-methyl-D-aspartate (NMDA) receptor-operated channels, with resultant excessive influx of Ca$\^$2+/ leading to neuronal damage, and thus offers hope for future pharmacological intervention. This chapter reviews two clinically-tolerated NMDA antagonists, memantine and nitroglycerin; (ⅰ) Memantine is an open-channel blocker of the NMDA-associated ion channel and a close congener of the anti-viral and anti-parkinsonian drug amantadine. Memantine blocks the effects of escalating levels of excitotoxins to a greater degree than lower (piysiological) levels of these excitatory amino acids, thus sparing to some extent normal neuronal function. (ⅱ) Niuoglycerin acts at a redox modulatory site of the NMDA receptor/complex to downregulate its activity. The neuroprotective action of nitroglycerin at this site is mediated by n chemical species related to nitric oxide, but in a higher oxidation state, resulting in transfer of an NO group to a critical cysteine on the NMDA receptor. Because of the clinical safety of these drugs, they have the potential for trials in humans. As the structural basis for redox modulation is further elucidated, it may become possible to design even better redox reactive reagents of chinical value. To this end, redox modulatory sites of NMDA receptors have begun to be characterized at a molecular level using site-directed mutagenesis of recombinant subunits (NMDAR1, NMDAR2A-D). Two types of redox modulation can be distinguished. The first type gives rise to a persistent change in the functional activity of the receptor, and we have identified two cysteine residues on the NMDARI subunit (#744 and #798) that are responsible for this action. A second site, presumably also a cysteine(s) because <1 mM N-ethylmaleimide can block its effect in native neurons, underlies the other, more transient redox action. It appears to be at this, as yet unidentified, site on the NMDA receptor that the NO group acts, at least in recombinant receptors.

• Proceedings of the PSK Conference
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• 2000.04a
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• pp.183.2-183.2
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• 2000

• Journal of Microbiology and Biotechnology
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• v.33 no.7
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• pp.934-940
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• 2023

Syneilesis palmata (SP) is a traditional medicinal plant. SP has been reported to have anti-inflammatory, anticancer, and anti-human immunodeficiency virus (HIV) activities. However, there is currently no research available on the immunostimulatory activity of SP. Therefore, in this study, we report that S. palmata leaves (SPL) activate macrophages. Increased secretion of both immunostimulatory mediators and phagocytic activity was observed in SPL-treated RAW264.7 cells. However, this effect was reversed by the inhibition of TLR2/4. In addition, inhibition of p38 decreased the secretion of immunostimulatory mediators induced by SPL, and inhibition of TLR2/4 decreased the phosphorylation of p38 induced by SPL. SPL augmented p62/SQSTM1 and LC3-II expression. The increase in protein levels of p62/SQSTM1 and LC3-II induced by SPL was decreased by the inhibition of TLR2/4. The results obtained from this study suggest that SPL activates macrophages via TLR2/4-dependent p38 activation and induces autophagy in macrophages via TLR2/4 stimulation.

• Journal of Microbiology and Biotechnology
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• v.28 no.8
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• pp.1367-1375
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• 2018

Silver nanoparticles have been widely applied for biomedical areas owing to their potent antiviral and antibacterial activities. Synthesis of silver nanoparticles using biomacromolecules is more efficient, environment-friendly, and cost-saving compared with the traditional approach. In this paper, a novel approach was developed to establish a reaction system with $Ag^+-BH4^--sericin$ to synthesize silver nanoparticles conjugated to sericin (AgNPs-Sericin). Sericin could be as a good dispersant and stabilizing agent, which is able to modify nanoscaled AgNPs, the average diameter of which was only $3.78{\pm}1.14nm$ prepared in a 0.3 mg/ml sericin solution. The characterizations of the AgNPs-Sericin were determined by FTIR, thermogravimetry, and XRD analyses. The results showed that the synthesized AgNPs conjugated with sericin as organic phase. Via SAED and XRD analysis, we showed that these AgNPs formed polycrystalline powder with a face-centered cubic structure of bulk metals. Moreover, we investigated the antiviral and antibacterial activities of AgNPs-Sericin, and the results showed that AgNPs-Sericin exhibited potent anti-HIV-1 activity against CCR5-tropic and CXCR4-tropic strains, but no significant cytotoxicity was found toward human genital epithelial cells compared with free silver ions, which are accepted as a commonly used potent antimicrobial agent. Moreover, its antibacterial activity was determined via flow cytometry. The results showed that AgNPs-Sericin could suppress gram-negative (E. coli) and gram-positive (S. aureus) bacteria, but more was potent for the gram-negative one. We concluded that our AgNPs-Sericin could be a potential candidate as a microbicide or antimicrobial agent to prevent sexually transmitted infections.

• KSBB Journal
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• v.25 no.1
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• pp.18-24
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• 2010

Juglans mandshurica belongs to the family Juglandaceae is known to contain a wide range of pharmacological activities including anti-cancer, anti-inflammation, astringent, and anti-human immunodeficiency virus-type 1 (HIV-1). Melanogenesis refers to the biosynthesis of melanin pigment in melanocytes. In this study, to investigate the whitening activity of the extracts from Juglans mandshurica, we measured effects on a tyrosinase activity, a melanogenesis, and a tyrosinase synthesis in the B16/BL6 melanoma cells and an antioxidant activity. The extracts significantly scavenged a 1,1-diphenyl-2-picrylhydrazyl (DPPH) and a superoxide anion radicals in a dose-dependent manner with a $SC_{50}$ value of $20\;{\mu}g/mL$ and $25\;{\mu}g/mL$, respectively. Also, the tyrosinase activity and melanogenesis were significantly inhibited by the extracts. Furthermore, the synthesis of tyrosinase protein was significantly decreased by the extracts in enzyme-linked immunosorbent assay. Double blind study on the clinical efficacy of a cream containing 2% of the extracts showed that the extracts have a significant skin whitening effect. Therefore, this study demonstrates that the extracts from Juglans mandshurica may be useful as a potential agent for skin whitening.

• Parasites, Hosts and Diseases
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• v.57 no.1
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• pp.1-8
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• 2019

There is no effective treatment modality available against different forms of leishmaniasis. Therefore, the aim of this study was to improve the penetration and efficacy of selenium and glucantime coupled with niosomes and compared them with their simple forms alone on in vitro susceptibility assays. In this study, the niosomal formulations of selenium and in combination with glucantime were prepared. The size and morphology of the niosomal formulations were characterized and the effectivity of the new formulation was also evaluated using in vitro MTT assay, intra-macrophage model, and gene expression profile. From the results obtained, no cytotoxicity effect was observed for niosomal and simple forms of drugs, as alone or in combination. Niosomal formulations of the drugs significantly showed more inhibitory effects ($P{\leq}0.001$) than the simple drugs when the selectivity index was considered. The gene expression levels of Interleukin (IL-10) significantly decreased, while the level of IL-12 and metacaspase significantly increased ($P{\leq}0.001$). The results of the present study showed that selenium plus glucantime niosome possess a potent anti-leishmanial effect and enhanced their lethal activity as evidenced by the in vitro experiments.

• The Journal of Korean Medicine
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• v.18 no.1
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• pp.157-168
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• 1997

The purpose of this study is the separation of biologically active ingredients from Coptidis Rhizoma which has been widely used as one of oriental herbal medicine for body fever. In this study, berberine-type alkaloids were tested on their biological activities in the aspect of antibacterial, antitumor, anti-herpetic and anti-HIV activity. Contents of five major alkaloids for the various origin of Coptidis Rhizoma were assayed by HPLC. As the results, the content of berberine from Coptis chinensis and Coptis japonica were 6.78% and 7.09%, respectively. The contents of coptisine, jatrorrhizine, berberastine from Coptis chinensis were higher than those of Coptis japonica. The amount of palmatine from both species were almost the same. Surprisingly for antitumor experiment, all compounds have been shown remarkable activity, especially against SNU-l(human stomach cancer) cell line. Among the compounds purified through column chromatography, palmatine, coptisine, and jatrorrhizine inhibited the growth of K-562(human chronic myelogenous leukemia) cell line whereas jatrorrhizine has been shown the effective inhibition of A-549 (human lung) cell line at the same time.

• Journal of Microbiology and Biotechnology
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• v.8 no.3
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• pp.229-236
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• 1998

6-Substituted derivatives of 1-［(2-hydroxyethoxy)methyl］-6-(phenylthio)thymine (HEPT) were synthesized by introducing alkyl groups with the aid of chlorotrimethylsilane, and then purified ranging 40 to 81 % of yield. Because of their peculiar structures, we presumed that HEPT derivatives would contain extra biological activities other than their already known anti-human immunodeficiency viral (HIV -1) activities. In this study, we investigated the possible effects of the HEPT derivatives on bacterial growth and found their selective antibiotic activities against gram-positive strains. We could not observe the corresponding activity from a disc-zone test, but confirmed the activity by liquid cultivation. Since the growth rate of cells was easily recovered, the antibiotic function was suggested to be bacteriostatic. We also suggested that the intracellular fate of HEPT derivatives would be fast. A HEPT derivative f-3 was shown to synergize unidirectionally toward chloramphenicol (Chr). With 0.1 mM f-3, the Chr-directed growth-inhibitory curve appeared 4 hours earlier than found without the additive. Interestingly, from the data of SDS-polyacrylamide gel electrophoresis (PAGE), we found that a membrane-bound protein having a molecular weight of 70-kDa was overexpressed by f-3 in S. aureus.