• The Journal of Dong Guk Oriental Medicine
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• v.1
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• pp.209-236
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• 1992

The microculture XTT antiviral assay method is used to quantitate HIV-1 induced cytopathic effects as modulated by test substances. This relatively simple assay facilitated the safe and rapid determination of in vitro antiviral activity of selected chemicals as well as direct cytotoxicity. This experiment also confirmed that this system measures infection and subsequent viral replication in target cells and XTT formazan formations correlated with the accumulation of extracellular virions, as measured by quantitative HIV-1 induced syncytium foramtion. The present results with Glycyrrhizin using this in vitro culture system demonstrated that effective dose, EC50(the concentration at which increases XTT formazan production in infected cultures to 50% of that in untreated, uninfected controls) was 250ml. As comparison, AZT was included in this experiment and demonstrated that EC50 AZT of was 0.05g/ml, approximately 5,000 times more potent than Glycyrrhizin based on EC50 ratio's alone. However, this potency is limited by severe cytotoxicity of AZT, while Glycyrrhizin is approximately 16 times less toxic(IC50 of Glycyrrhizin 800 and AZT 51 g/ml). While AZT's anti-HIV-1 viral activity is mediated by inhibition of reverse transcriptase of the virus, Glycyrrhizin faild to demonstrate any inhibitory activity against reverse transcriptase. Further study is necessary in order to understand the precise mechanisms of Glycyrrhizin action against HIV-1 viruses. Althouth Glycyrrhizin is less effective antiviral agent than AZT, much less toxicity of Glycyrrhizin is desirable in terms of chronic treatment. Combination treatment of AZT and Glycyrrhizin may be therapeutically beneficial. Clinical effectiveness of two drug combination therapy for AIDS patient is unknown at this time. However, this experimental investigation presents the scientific rational basis for such therapeutic approach.

• Fisheries and Aquatic Sciences
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• v.19 no.9
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• pp.37.1-37.5
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• 2016

Human immunodeficiency virus (HIV) is the causative agent of acquired immune deficiency syndrome (AIDS). Anti-HIV agents targeting various steps in HIV life cycle have been developed; however, so far, no effective drugs have been found. We show here that a peptide isolated from Spirulina maxima (SM-peptide) inhibits HIV-1 infection in a human T cell line MT4. SM-peptide inhibited $HIV-1_{IIIB}$-induced cell lysis with a half-maximal inhibitory concentration ($IC_{50}$) of 0.691 mM, while its 50 % cytotoxic concentration ($CC_{50}$) was greater than 1.457 mM. Furthermore, the SM-peptide inhibited the HIV-1 reverse transcriptase activity and p24 antigen production. This suggests that SM-peptide is a novel candidate peptide, which may be developed as a therapeutic agent for acquired immunodeficiency syndrome patients.

• The Journal of Internal Korean Medicine
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• v.27 no.4
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• pp.888-894
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• 2006

Objectives : For the purpose of developing new anti-HIV agents from natural sources, the extracts of Ricinus communis were tested for their inhibitory effects on essential enzymes reverse transcriptase (RT), protease and alpha-glucosidase. Inhibition activity of major compounds of Ricinus communis were predicted from quantitative structure activity relationships (QSAR) in silico. Methods and Results : In the anti-HIV-1 RT using enzyme-linked oligonucleotide sorbent assay (ELOSA) method, water and methanol extracts (100ug/ml) of Ricinus communis showed strong activity of 94.2% and 82.7%, respectively. In the HIV-1 protease and alpha-glucosidase inhibition assay, neither water nor methanol extracts of Ricinus communis inhibited the activity of the enzyme to cleave any substrates as oligopeptides and oligosaccharides. Conclusions : We found that for these samples it is possible that the inhibition of the RT in vitro is due to the secondary metabolites of Ricinus communis such as ricinine and quercetin. It would beof great interest to identify the compounds which are responsible for this inhibition, since all therapeutically useful agents up to date are RT inhibitors.

• Journal of Physiology & Pathology in Korean Medicine
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• v.18 no.4
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• pp.1129-1133
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• 2004

For the purpose of developing new anti-HIV agents from natural sources, the extracts of Kalopanax pictus were tested for their inhibitory effects on HIV-1 replication and its essential enzymes as the reverse transcriptase (RT). protease and α-glucosidase. In the assay of HIV-1-infected human T-cell line, water extracts of stem and leafstalk inhibited the HIV-1-induced cytopathic effects with Ie (inhibitory concentration) of 25 and 50㎍/㎖, respectively. Moreover water extracts (100㎍/㎖) of stem and leafstalk showed strong activity of 80% and 90% on anti-HIV-1 RT using Enzyme Linked Oligonucleotide Sorbent Assay (ELOSA) method. In the HIV-1 protease inhibition assay, aqueous stem extract inhibited the activity of the enzyme to cleave an oligopeptide, resembling one of the cleavage sites in the viral polyprotein which can only be processed by HIV-1 protease with 58%, but no glucosidase inhibitory activities. We found out this result, for these samples it is possible that the inhibition of the viral replication in vitro is due to the inhibition at least one of RT and protease. It would be of great interest to identify the compounds which are responsible for this inhibition, since all therapeutically useful agent up to date are RT, PR and α-glucosidase inhibitors.

• Korean Journal of Pharmacognosy
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• v.29 no.4
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• pp.338-346
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• 1998

In order to elucidate the relationship between anti-HIV-1 enzyme activity and inhibition of HIV-1 replication by natural sources, extracts from some plants using the foods and oriental medicines were tested for inhibitory effects on the viral replication, reverse transcriptase (RT), protease and ${\alpha}-glucosidase$. In the anti-RT test, water extracts of Ficus carica (leaf), Houttuynia cordata (aerial part) and Ixeris tamagawaensis (aerial part) showed more than 79% inhitibion at a concentration of $100\;{\mu}g/ml$. The protease and ${\alpha}-glucosidase-inhibiting$ samples in the screening were water extract of Syringa dilatata (leaf) and methanol extract of Hibiscus syriacus (leaf and stem), which showed more than 40% inhibition at a concentration of $100\;{\mu}g/ml$. In the primary anti-HIV-1 test, water extracts of Equisetum arvense (aerial part), Hibiscus syriacus (leaf), Ixeris tamagawaensis (aerial part) and Pueraira thunbergiana (leaf) showed the potent inhibition against HIV-1 induced cytopathic effects.

• Journal of Life Science
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• v.32 no.9
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• pp.734-741
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• 2022

Currently, around 40 million people worldwide are living with human immunodeficiency virus (HIV) infection making HIV a critical global health risk. Present therapies for HIV infection consist of drug cocktails that target different steps of the HIV life cycle to prevent infection, replication, and release of the virus. Due to its mutating nature, drug resistance coupled with side-effects of long-term drug use, novel strategies, and pharmaceuticals to treat and manage HIV infection are constant needs and continuously being studied. Plants allocate a major repertoire of chemical diversity and are therefore regarded as an important source of new bioactive agents that can be utilized against HIV. Since the early 1990s, upon recommendations of the World Health Organization, numerous studies reported phytochemicals from different structural classes such as flavonoids, coumarins, tannins and terpenes with strong inhibitory effects against HIV infection. The present review gathered and presented recent research (2021-present) on plant extracts and phytochemicals that exhibit anti-HIV properties with the aim of providing insights into future studies where ethnomedical and underutilized plant sources may yield important natural products against HIV. Considering the relation and importance of HIV treatment with current viral infection risks such as SARS-CoV-2, screening plants for anti-HIV agents is an important step towards the discovery of novel antivirals.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1998.11a
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• pp.123-123
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• 1998

A number of uracil derivatives have been developed as anti-AIDS drugs having a mechanism of inhibiting cellular reverse transcriptase. A simple and rapid assay technique for recently synthesized KR-V analogues was developed using a high-performance liquid chromatography, and oral pharmacokinetics was examined for assessing their oral bioavailabilites. Plasma samples were analyzed by reversed-phase HPLC using an ODS column with an ultraviolet detection system. All the analogues were eluted within 12 min and the LOQ was 15-30 ng/$m\ell$. The extraction recoveries were higher than 85%, except KR-V1039, 1068 and 1720 having ester group. This chromatic method was well applied to the kinetic studies for KR-V analogues. Among 16 analogues tested in the present work, the 6 compounds including KR-V1123, 1122, 1784, 1783, 1736 and 1700 were found to be bioavailable for oral administration to rats.