• Journal of Microbiology and Biotechnology
• /
• v.17 no.8
• /
• pp.1324-1329
• /
• 2007

Resveratrol (3,5,4'-trihydroxystilbene) is a naturally occurring, multi-biofunctional chemical existing in grapes and various other plants as a polyphenol type, and it is one of the best known natural anticancer and antiatherosclerosis reagents. In this study, we investigated the antifungal action by resveratrol in Candida albicans, which is a human infectious fungi as an agent of candidiasis. Resveratrol displayed potent fungicidal activity in an energy-dependent manner, without any hemolytic effects against human erythrocytes. It was found that the serum-induced mycelial forms, which playa crucial role in the pathogenesis of C. albicans during host tissue invasion, were disrupted by resveratrol. To understand the correlation between lethal effects and resveratrol action, we examined the physiological changes of C. albicans. A significant accumulation of intracellular trehalose was induced by stress responses to resveratrol action, and a remarkable arrest of cell-cycle processes at the S-phase in C. albicans occured. Therefore, the fungicidal effects of resveratrol demonstrate that this compound is a potential candidate as an antifungal agent in treating infectious diseases by candidal infections.

• Korean Journal of Pharmacognosy
• /
• v.29 no.4
• /
• pp.331-337
• /
• 1998

Most Annonaceous acetogenins are potently bioactive and offer exciting potential as new antitumor, pesticidal and other bioactivites. The major mode of action of the acetogenin is inhibition of electron transport in the mitochodria. Two known cytotoxic ketolactone Annonaceous acetogenins, (2,4-cis)-isoannonacin (compound 1) and (2,4-trans)-isoannonacin (compound 2), have been isolated from Asimina triloba (Annonaceae) by bioactivity directed fractionation. The structures were characterized on the basis of chemical and spectral data. Compounds 1 and 2, which are known but are first isolated from the seeds of this species, were ob-tained. In brine shrimp lethality test (BST), 1 and 2 exhibited cytotoxicity.

• PNF and Movement
• /
• v.16 no.2
• /
• pp.287-294
• /
• 2018

Purpose: The neurodynamic test used to implicate symptoms arising from the nerve is proposed to selectively increase the strain of the nerve without increasing the strain of adjacent tissue, although this has not yet been established in the time of nerve tension application. This study aimed to investigate the acute effects of nerve stretching time on nerve excitability using compound nerve action potential (CNAP) analysis. Methods: Thirty healthy young adults (mean age=23.10 years) with no medical history of neurological or musculoskeletal disorder voluntarily participated in this study. Nerve excitability was assessed using the median nerve conduction velocity test. The amplitude of the CNAP was measured under three conditions: resting phase (supra-maximal stimulus, without nerve stretching), baseline phase (two-thirds of the supra-maximal stimulus, without nerve stretching), and stretch phase (two-thirds of the supra-maximal stimulus, with 1-5 minutes nerve stretching). One-way repeated measures ANOVA was conducted to compare the latency and amplitude of CNAP. A post-hoc test was analyzed using the contrast test. Results: The latency was significantly delayed after 1 min. of nerve stretching in comparison with the baseline test. However, no significant difference was found during the nerve stretching (1-5 min.). The amplitude was significantly increased by nerve stretching. Conclusion: Nerve stretching can induce nerve excitability without any nerve injury. Based on the results, more than 1 min. of nerve stretching as a neurodynamic test can be a useful method in the clinical setting.

• Journal of the Institute of Electronics and Information Engineers
• /
• v.50 no.6
• /
• pp.287-293
• /
• 2013

Cochlear implant (CI) is an auditory prosthesis that delivers electrical stimulation via inserted electrodes into a cochlea. To evaluate CI performance, it is important to understand how auditory nerves are responded to electrical stimulations. In clinic, electrically evoked compound action potential (ECAP) is measured. In this study, we developed 3D finite element (FE) cochlear model to simulate ECAP in response to electrical stimulation. The model prododuced ECAP similar to that measured in animal experiments and clinics. This 3D FE cochlear model could be used in electrical stimulus method study to improve CI by analyzing neural responses to electrical stimulations.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
• /
• v.15 no.2
• /
• pp.33-52
• /
• 2002

The effects of Arctii fructus extract on allegenic inflammation were investigated using in vivo and in vitro test models. Firstly, the cytotoxicity of Arctii fructus extract was validated using MTT assay. As a result, Arctii fructus extract showed no cytotoxic potential, while SDS, a positive control, revealed strong cytotoxic effect. In LLNA assay, Arctii fructus extract showed no skin allergenicity. Next, the anti-allergic actions of Arctii fructus extract were evaluated using rodent experimental models. The oral, intraperitoneal and intradermal administration of Arctii fructus extract significantly inhibited the compound 48／80-induced vascular permeability documented by Evans blue extravasation. In addition, Arctii fructus extract showed potent inhibitory effect on passive cutaneous anaphylaxis activated by anti-dinitrophenyl (DNP) IgE when orally administered. In an in vitro study, Arctii fructus extract revealed to possess inhibitory potential on the compound 48／80-induced histamine release from rat peritoneal mast cells. Moreover, Arctii fructus extract inhibited the IL-4 and TNF-${\alpha}$ mRNA induction by PMA and A23187 in human leukemia mast cells, HMC-1. Finally, it revealed that Arctii fructus extract significantly suppressed histamin-provoked antigenic inflammation reactions in human prick test. Taken together, these results suggest that anti-allergic action of Arctii fructus extract may be due to the inhibition of histamine release and cytokine gene expression in the mast cells.

• Natural Product Sciences
• /
• v.27 no.3
• /
• pp.151-160
• /
• 2021

Under some pathological conditions such as osteoarthritis, matrix metalloproteinases (MMPs) including MMP-13 have an important role in degrading cartilage materials. When the regulatory effects of some herbal extracts on MMP-13 expression were examined to evaluate the cartilage-protective potential, the ethanol extract of the radix of Viscum album was found to strongly downregulate MMP-13 induction in IL-1β-treated chondrocytes, SW1353 cells. Based on this finding, activity-guided separation was carried out, which yielded five constituents identified as 3,5-dihydroxy-1,7-bis(4-hydroxyphenyl)heptane (1), hesperetin-7-glucoside (2), syringin (3), homoflavoyadorinin B (4), and 4,4'-dihydroxy-3,6'-dimethoxychalcone-2'-glucoside (5). Of these, 1 and 5 significantly inhibited MMP-13 expression in SW1353 cells, with 5 being the most potent. Compound 5, a chalcone derivative, showed the downregulation of MMP-13 at 20 - 100 μM. The mechanism study revealed that 5 exerted MMP-13 down-regulatory action, at least in part, by interrupting the signal transducer and activator of transcription 1 (STAT1) activation pathway. Furthermore, this compound protected against cartilage degradation in an IL-1-treated rabbit cartilage explant culture. All these findings demonstrated for the first time that Viscum album and its constituents, especially chalcone derivative (5), possessed cartilage-protective activity. These natural products may have the potential for alleviating cartilage degradation.

• Biotechnology and Bioprocess Engineering:BBE
• /
• v.7 no.4
• /
• pp.185-193
• /
• 2002

With Increasing awareness towards environment-friendly and non-toxic pesticide azadirachtin obtained from neon tree (Azadirachta indica) is gaining more and more importance. Its broad-spectrum activity, Peculiar mode of action. eco-friendly and non-toxic action towards beneficial organisms has offered many advantages over chemical pesticides. All currently use commercial formulations based on azadirachtin contains azadirachtin extracted from seeds of naturally grown whole plants which is labour intensive process depending upon many uncontrollable geographical and climatic factors. Plant tissue culture can be a potential process for the pro-duction, offering consistent, stable and controlled supply of this bioactive compound, However the research on tissue culture aspects of production are in preliminary stage and requires culture and process optimization for the development of a commercially viable process. This review states the present status and future challenges of plant tissue culture for azadirachtin production.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.56 no.11
• /
• pp.2040-2050
• /
• 2007

In this study, we present a novel method for estimating the information of MU(motor unit) which is the basic element of human muscle by using surface EMG. Some of the method developed in this field could only estimate the numbers of MU that is activated. However, in our study the MU-simulator based on the line source model was designed to estimate the MU information including the numbers of MU and muscle fiber, conduction velocity, MU diameter, fiber diameter, and end plate position. The SMUAP(single motor unit action potential) detector was designed and CMAP(compound muscle action potential) by electrical stimulus was recorded. With these data, the MU-simulator can estimate the MU information by varying muscle paramater settings through MSE(mean square error) method. Our results shows that the proposed method can be comparable with the method of anatomical studies. Moreover, our system can be utilized to build a tool for diagnosis and treatment assessment of neuromuscular patients.

• Physical Therapy Korea
• /
• v.14 no.3
• /
• pp.57-63
• /
• 2007

The purpose of this study was to evaluate inter-rater reliability of the amplitude and first knee extension angles in deep tendon reflex test by using an electrical hammer. Twenty-five healthy adults participated in the study. Compound muscle action potential is elicited by tapping the knee tendon with an electrical hammer in deep tendon reflex tests. The amplitude and knee extension angle were simultaneously measured. The mean value of the amplitude and the knee extension angles through three time trials for each tester, are used for determining the inter-rater and Intra-class Correlation Coefficients (ICCs) reliabilities. According to the results, the ICCs of the amplitude is .280 and that of the knee extension angle is .789. Pearson correlation coefficients of the amplitude of the action potential and the knee extension angles are .685, showing significant statistically moderate correlation. Inter-rater reliability in the amplitude was not significant. More objective and quantitative deep tendon reflex tests should be done to obtain higher reliability in further studies.

• Annals of Clinical Neurophysiology
• /
• v.5 no.1
• /
• pp.27-33
• /
• 2003

Background: Motor unit number estimation (MUNE) can directly assess motor neuron populations in muscle and quantify the degree of physiologic and/or pathologic motor neuron degeneration. A high degree of reproducibility and reliability is required from a good quantitative tool. MUNE, in various ways, is being increasingly applied clinically and statistical MUNE has several advantages over alternative techniques. Nevertheless, the optimal method of applying statistical MUNE to improve reproducibility has not been established. Methods: We performed statistical MUNE by selecting the most compensated compound muscle action potential (CMAP) area as a test area and modified the results obtained by weighted mean surface-recorded motor unit potential (SMUP). Results: MUNE measures in amyotrophic lateral sclerosis (ALS) patients showed better reproducibility with sizeweighted modification. Conclusions: We suggest size-weighted MUNE testing of "neurogenically compensated"CMAP areas present an optimal method for statistical MUNE in ALS patients.