• 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.

• 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.

• Natural Product Sciences
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• v.5 no.4
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• pp.162-164
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• 1999

Dehydroaltenusin (1) was isolated from the chloroform extract of the culture filtrate of a Streptomyces sp. and its structure was determined from spectral data as well as by comparison with published values. In an XTT-based in vitro anti-HIV assay, dehydroaltenusin effectively inhibited the cytopathic effects of HIV infection at a concentration of $1-5\;{\mu}g/mL$.

• Archives of Pharmacal Research
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• v.29 no.11
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• pp.957-962
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• 2006

A novel series of 2-(m-Chlorobenzyl)-4-substituted-1, 1, 3-trioxo-2H, 4H-pyrazolo[4, 5-e][1, 2, 4] thiadiazines (7a-k) were synthesized, and evaluated for their anti-HIV replication in MT-4 cell cultures. Compound (7a) showed activity against HIV-1-induced cytopathicity, with an $EC_{50}$ value of $45.6\;{\mu}M$, but none of the compounds exhibited inhibitory activity against HIV-2.

• 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.

• The Korea Journal of Herbology
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• v.21 no.4
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• pp.115-121
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• 2006

Objectives : For the purpose of developing new anti-HIV agents from natural sources, the extracts of Actinidia arguta were tested for their inhibitory effects on essential enzymes as the reverse transcriptase (RT), protease and ${\alpha}-\;glucosidase$. And we predicted inhibition activity of major compounds of Actinidia arguta using Quantitative Structure Activity Relationships (QSAR). Methods : In this assay the activity of HIV-1 reverse transcriptase is measured as the formation of a strand of copy-DNA (cDNA) using RNA as a template. The activity of HIV-1 protease is measured as the cleavage of an oligopeptide by HIV-1 protease. Results : In the anti-HIV-1 RT using Enzyme Linked Oligonucleotide Sorbent Assay (ELOSA) method, water extracts (100ug/ml) of stem and leaf showed strong activity of 93.9% and 91.9%, respectively. 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 56.8%. In the ${\alpha}-glucosidase$ inhibition assay, aqueous stem extract showed activity of 73.1%. Conclusion : 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 ${\alpha}-glucosidase$. 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 ${\alpha}-glucosidase$ inhibitors.

• Parasites, Hosts and Diseases
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• v.55 no.1
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• pp.99-103
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• 2017

Toxoplasma gondii is an important opportunistic agent especially in immunocompromised hosts and can cause significant morbidity and mortality. Hence, detection and monitoring of anti-Toxoplasma antibodies are of a great interest in HIV-infected patients. A study on the prevalence of toxoplasmosis and associated risk factors was carried out among HIV-infected patients in Jahrom, southern Iran. The prevalence of anti-Toxoplasma IgG antibodies was 21.1% in HIV-infected patients by ELISA. PCR was performed on all of the samples, and 1 of the blood samples was positively detected. Among the HIV patients, anti-Toxoplasma IgG antibodies were significantly higher in age group of 30-39 years old (P=0.05). The seroprevalence of toxoplasmosis in patients with $CD4^+$ < $100cells/{\mu}l$ was 33.3% that was significantly higher than the other groups (P=0.042) with or without IgG antibodies. The $CD4^+$ count mean of seropositive patients was lower than that of seronegative patients. The seroprevalence of toxoplasmosis in patients with highly active antiretroviral therapy was significantly less than patients without therapy (P=0.02). In conclusion, this study showed low seroprevalence of latent toxoplasmosis among HIV-infected patients in the region and confirmed the need for intensifying prevention efforts among this high-risk population and also the risk of toxoplasmosis reactivation which could be important among this population.

• The Journal of Korean Society of Virology
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• v.30 no.3
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• pp.161-170
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• 2000

Continuous efforts are being made to find effective therapeutic agents against HIV-1, the causative agents of AIDS. In this study, we developed a cell-based assay system employing a trans-complementation for production of recombinant viruses which are capable of undergoing one round of replication in CD4+ T cells. This assay system was tested for ability to screen the agents that act at late stage of HIV-1 life cycle. The effect of a protease inhibitor on the trans-complementation assay was assessed. Recombinant HIV-1 viruses were prepared from a trans-complementation in the presence of various concentrations of protease inhibitor. Inhibition of single round infection of these recombinant viruses by protease inhibitor was observed to be a dose-dependent manner. Inhibitory effects of a protease inhibitor on HIV-1 Gag polyprotein processing by HIV-1 protease was detected at concentrations of the protease inhibitor compatible with inhibition of virus infection, confirming that the corresponding step was involved in the inhibitory mechanism of this compound. Together, these results provide evidence that a cell-based assay system established in this study can be used to screen the agents that target the late stage of HIV-1 life cycle.

• Journal of Microbiology and Biotechnology
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• v.10 no.5
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• pp.663-669
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• 2000

The fur (ferric uptake regulation) expression vector pMON2064 was modified to produce a Fur-fusion expression vector. A kinker site, factor Xa cleavage site, and several restriction endonuclease sites were introduced to facilitate easy cloning and isolating of the fusion protein. The resulting fusion expression vector, pMONSTER, was then used to make fusion expression vector, pMONSTER, was then used to make fusion proteins with $\beta$-galactosidase and the protease of the human immunodeficiency virus type 1 (HIV-1 PR). Strain SW4020 harboring the Fur $\beta$-galactosidase fusion vector produced blue colonies on a 5-bromo-4-chloro-3-indolyl-$\beta$-D-galactoside plate and the resulting 133 kDa fusion protein reacted with an anti-Fur antibody. The strain harboring the Fur-HIV-1 PR fusion vector produced a 29 kDa fusion protein, which also reacted with an anti-Fur antibody. The Fur-HIV-1 PR fusion protein was purified by a single column application that was designed to isolate the Fur protein. The purified Fur-HIV-1 PR fusion protein digested with factor Xa cleaved a recombinant Gag protein to release smaller fragments, including a p24 capsid protein. The Fur-HIV-1 PR fusion protein itself did not exhibit any proteolytic activity.

• 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.