tannins and HIV-Infections

Highly active antiretroviral therapy (HAART) comprises a combination of two or three antiretroviral (ARV) drugs that are administered together in a single tablet. These drugs target different steps within the human immunodeficiency virus (HIV) life cycle, providing either a synergistic or additive antiviral effect; this enhances the efficiency in which viral replication is suppressed. HIV cannot be completely eliminated, making HAART a lifetime treatment. With long-term HAART usage, an increasing number of patients experience a broadening array of complications, and this significantly affects their quality of life, despite cautious use. The mechanism through which ARV drugs induce toxicity is associated with metabolic complications such as mitochondrial dysfunction, oxidative stress, and inflammation. To address this, it is necessary to improve ARV drug formulation without compromising its efficacy; alternatively, safe supplementary medicine may be a suitable solution. The medicinal plant

Topics: Anti-Inflammatory Agents; Antimutagenic Agents; Antiretroviral Therapy, Highly Active; Antiviral Agents; DNA; Free Radicals; HIV Infections; Humans; Minerals; Moringa oleifera; Quality of Life; Tablets; Tannins; Vitamins

The present article reviewed the biological activities and possible dental application of three major polyphenols, i.e., lignin-carbohydrate complexes, tannins, and flavonoids, citing mostly our in vitro studies together with those from other groups. All these polyphenols showed much lower tumor-selective cytotoxicity against oral squamous cell carcinoma cells vs. normal oral cells (gingival fibroblast, pulp cell, periodontal ligament fibroblast), in comparison to popular chemotherapeutic antitumor drugs. Several compounds showing higher tumor-selectivity did not induce internucleosomal DNA fragmentation, a biochemical hallmark of apoptosis, in oral carcinoma cell lines. Lignin-carbohydrate complex protected the cells from the cytopathic effects of HIV infection and UV irradiation more efficiently than other polyphenols. Limited digestion of lignin-carbohydrate complex suggests that the lignin moiety is involved in the prominent anti-HIV activity, whereas the carbohydrate moiety may function in immunopotentiating activity through a cell surface receptor. Alkaline extract of plant leaf, which contains higher amounts of lignin-carbohydrate complex, showed potent anti-inflammatory action against IL-1β-stimulated human gingival fibroblasts. Local application of lignin-carbohydrate complex through oral mucosa is recommended, considering its poor intestinal absorption.

Topics: Adjuvants, Immunologic; Anti-HIV Agents; Anti-Inflammatory Agents; Antineoplastic Agents; Apoptosis; Carcinoma, Squamous Cell; Cell Line, Tumor; Cytopathogenic Effect, Viral; DNA Fragmentation; Flavonoids; Gingivitis; HIV Infections; Humans; Lignin; Mouth Neoplasms; Nucleosomes; Polyphenols; Sunscreening Agents; Tannins; Ultraviolet Rays

Polyphenols are a versatile class of compounds that represent secondary metabolites from higher plants and which are abundantly present in the human diet. Epidemiological data suggest protective effects of polyhenols in relation to cancer, cardiovascular diseases, diabetes, infectious diseases and age-related conditions. HIV/AIDS remains prevalent in many parts of the world as acute infection and as anti-retroviral drug (ARV)-managed chronic disease. Due to the nature of the human immune deficiency virus (HIV) and an increased use of ARVs many drug-resistant HIV strains have emerged and continue to do so. This makes it impossible to rely on one standard drug treatment regime. This review summarizes anti- HIV activities of polyphenols. It highlights the diversity of modes of action by which polyphenols - according to their respective compound classes - exert their activities. Additionally, this review discusses polyphenols as multi-target anti-HIV agents and provides the context of in-vivo and clinical data. Based on the presented data, a three-pronged approach for further anti-HIV drug discovery is suggested applying methods of combinatorial medicinal chemistry on the diverse and sometimes unique scaffolds of polyphenols. The latter being selected according to the approach of 'reverse pharmacology' as a creative way to place safety and other clinical consideration at the beginning of the drug discovery- and development process.

Topics: Animals; Anti-HIV Agents; Drug Interactions; Flavonoids; HIV Infections; HIV-1; Humans; Phenols; Tannins

In recent years, elucidation of novel bioactive substances from different marine organisms is gaining importance rapidly not only from the research and publications but also from controlled clinical studies of natural product-derived substances. They offer important leads for the development of antiviral drugs against viral infections caused by human immunodeficiency virus type 1 (HIV-1). Regarding this issue, numerous anti-HIV-1 therapeutic agents from marine resources have been reported for their potential medicine/medical application as novel functional ingredients in anti-HIV therapy. In detail, marine macroalgae have attracted much of attention as a reliable source for potential anti-HIV compounds. Up to date, several types of compounds such as tannins, polysaccharides, lectins, and derivatives have been isolated, identified, and reported to possess significant anti-HIV-1 activity.

Topics: Anti-HIV Agents; HIV Infections; Humans; Lectins; Seaweed; Tannins

The high number of citations of the previous review on anti-HIV compounds from plants published in 1998 in Planta Medica indicates the importance of natural products research in the battle against HIV. Therefore, we have decided to write an update of our previous review paper, this time covering the time span 1998 - 2007. The following antiviral chemical classes are discussed in detail: alkaloids, carbohydrates, coumarins, flavonoids, lignans, phenolics, proteins, quinones/xanthones, tannins and terpenes. If available, chemical structures, antiviral activity and selectivity, mechanism of action, and structure-activity relationship are presented.

Topics: Alkaloids; Anti-HIV Agents; Carbohydrates; Flavonoids; HIV Infections; Humans; Lignans; Phenols; Phytotherapy; Plant Proteins; Plants; Tannins; Terpenes

Carpobrotus edulis (Mesembryanthemaceae), also known as igcukuma in Xhosa language is a medicinal plant used by the traditional healers to treat common infections in HIV/AIDS patients. Based on this information, we researched on the plant phytoconstituents, as well as its inhibitory effect using aqueous and three different organic solvent extracts in order to justify its therapeutic usage.. Antioxidant activity of the extracts were investigated spectrophotometrically against 1,1- diphenyl-2-picrylhydrazyl (DPPH), 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) diammonium salt, hydrogen peroxide (H2O2), nitric oxide (NO), and ferric reducing power, Total phenols, flavonoids, flavonols, proanthocyanidins, tannins, alkaloids and saponins were also determined using the standard methods.. Quantitative phytochemical analysis of the four solvent extracts revealed a high percentage of phenolics (55.7 ± 0.404%) in the acetone extract, with appreciable amount of proanthocyanidins (86.9 ± 0.005%) and alkaloids (4.5 ± 0.057%) in the aqueous extract, while tannin (48.9 ± 0.28%) and saponin (4.5 ± 0.262%) were major constituents of the ethanol extract. Flavonoids (0.12 ± 0.05%) and flavonols (0.12 ± 0.05%) were found at higher level in the hexane extract in comparison with the other extracts. The leaf extracts demonstrated strong hydrogen peroxide scavenging activity, with the exception of water and ethanol extracts. IC50 values of the aqueous and ethanolic extract against DPPH, ABTS, and NO were 0.018 and 0.016; 0.020 and 0.022; 0.05 and 0.023 mg/ml, respectively. The reducing power of the extract was found to be concentration dependent.. The inhibitory effect of the extracts on free radicals may justify the traditional use of this plant in the management of common diseases in HIV/AIDs patients in Eastern Cape Province. Overall, both aqueous and ethanol were found to be the best solvents for antioxidant activity in C. edulis leaves.

Topics: AIDS-Related Opportunistic Infections; Alkaloids; Antioxidants; HIV Infections; Humans; Magnoliopsida; Phytotherapy; Plant Extracts; Plant Leaves; Polyphenols; Saponins; South Africa; Tannins

Five South African medicinal plants, Bulbine alooides (L.) Willd. (Asphodelaceae), Crinummacowani Baker (Amaryllidaceae), Hypoxis sobolifera var. sobolifera (Jacq.) Nel (Hypoxidaceae), Leonotisleonurus (L.) R.Br. (Lamiaceae) and Tulbaghiaviolacea Harv (Liliaceae) used for the treatment of various ailments, including infectious diseases, were screened for activity against human immunodeficiency virus (HIV).. Aqueous and ethanol extracts were tested for inhibitory activity in HIV-1 infected CEM.NK(R)-CCR5 cells, and against HIV-1 reverse transcriptase (RT) and HIV-1 protease (PR).. In CEM.NK(R)-CCR5 cells, ethanol extracts of Leonotisleonurus inhibited HIV-1 significantly (33% reduction in HIV-1 p24, P<0.05). HIV-1 RT inhibition (> or =50%) was shown for extracts of Bulbine alooides (aqueous and ethanol), Hypoxis sobolifera (aqueous and ethanol) and Leonotisleonurus (aqueous), but inhibitory activity was lost upon dereplication for removal of non-specific tannins/polysaccharides. HIV-1 PR inhibition was observed for extracts of Hypoxis sobolifera (aqueous), Bulbine alooides (aqueous and ethanol) and Leonotisleonurus (ethanol). Only ethanolic extracts of Bulbine alooides and Leonotisleonurus retained HIV-1 PR inhibition after dereplication with IC50 of 94 microg/ml and 120 microg/ml, respectively.. The dereplicated ethanolic extracts of Leonotisleonurus and Bulbine alooides showed the greatest anti-HIV potential in this study through inhibition of HIV-1 PR.

Topics: Anti-Retroviral Agents; Antiviral Agents; Cell Line; HIV Core Protein p24; HIV Infections; HIV-1; Humans; Leukocytes, Mononuclear; Magnoliopsida; Phytotherapy; Plant Extracts; Plant Roots; Plants, Medicinal; Polysaccharides; Tannins

Phyllanthus amarus derived preparations were previously shown to inhibit RT inhibitor-resistant HIV variants as efficiently as wild-type strains. The drugs target different steps of the HIV life cycle, thereby presenting multiple antiviral activities. Here we show that a water/alcohol extract blocks HIV-1 attachment and the HIV-1 enzymes integrase, reverse transcriptase and protease to different degrees. A gallotannin containing fraction and the isolated ellagitannins geraniin and corilagin were shown to be the most potent mediators of these antiviral activities. The P. amarus derived preparations blocked the interaction of HIV-1 gp120 with its primary cellular receptor CD4 at 50% inhibitory concentrations of 2.65 (water/alcohol extract) to 0.48 microg/ml (geraniin). Inhibition was also evident for the HIV-1 enzymes integrase (0.48-0.16 microg/ml), reverse transcriptase (8.17-2.53 microg/ml) and protease (21.80-6.28 microg/ml). In order to prove the in vivo relevance of these biological activities, plant material was administered orally to volunteers and a potent anti-HIV activity in blood could be demonstrated. Sera at a final concentration of 5% reduced HIV replication by more than 30%. These results support the conclusion that P. amarus has inhibitory effects on HIV not only in vitro but also in vivo.

Topics: Enzyme Inhibitors; HeLa Cells; HIV Infections; HIV-1; Humans; Phyllanthus; Plant Extracts; Plant Leaves; Plants, Medicinal; Tannins; Virus Replication

Tannins and lignins are natural compounds contained in plants such as tea leaves. Previously, we demonstrated that tannic acid represses 12-o-tetra-decanoyl phorbol-13-acetate (TPA)-induced human immunodeficiency virus (HIV) promoter activity. Furthermore, we demonstrated that a 30-bp element located just downstream of the NF-kappaB element in the HIV promoter responds negatively to tannic acid. However, the kinds of molecules responsible for this suppressive effect have remained unknown, because tannic acid is a mixture of various galloylglucoses. Here, we examined structure-defined natural compounds for HIV promoter-suppressive effects. We found that ellagitannins suppress TPA-induced HIV promoter activity to the same extent as tannic acid. 3-phenylcoumarins, isoflavone and chalcones have more suppressive effects than ellagitannins. On the other hand, other flavonoids and acetogenins have no suppressive effect. 3-phenylcoumarins and chalcones showed no suppressive effect on the cytomegalovirus (CMV) promoter, suggesting that they act specifically on the HIV promoter. These results suggest that 3-phenylcoumarin or chalcone compounds could be used to develop novel anti-HIV drugs with an action targeted at HIV promoter activity.

Topics: Anti-HIV Agents; Chalcone; Coumarins; Flavonoids; Gene Expression Regulation, Viral; HIV; HIV Infections; Humans; Hydrolyzable Tannins; Jurkat Cells; Promoter Regions, Genetic; Tannins; Tetradecanoylphorbol Acetate; Transfection

To identify substances with anti-human immunodeficiency virus (HIV) activity in traditional medicines, 101 extracts of Korean medicinal plants were screened for their inhibitory effects on HIV type 1 protease (PR). The enzyme activity was determined by HPLC. Of the extracts tested, strong inhibitory effects were observed in the acetone extracts of the pericarp and leaves of Camellia japonica, the water extract of the leaves of Sageretia theezans and the methanol extract of the aerial part of Sophora flavescens. Camelliatannin H from the pericarp of C. japonica, showed a potent inhibitory activity on HIV-1 PR with IC(50) of 0.9 microM.

Topics: Camellia; Chromatography, High Pressure Liquid; HIV Infections; HIV Protease; HIV Protease Inhibitors; HIV-1; Hydrolyzable Tannins; Korea; Molecular Structure; Phytotherapy; Plant Extracts; Plant Structures; Plants, Medicinal; Tannins