tannins and thiazolyl-blue

In the present study phytochemical analysis and anticancer activity of Misopates orontium L. and Dicliptera bupleuroides Nees was carried out. Methanolic extracts of M. orontium and D. bupleuroides were selected for phytochemical analysis. The present analysis showed the presence of phytochemical such as carbohydrates, proteins, tannins, glycosides, alkaloids, saponins, phenols and flavonoids in M. orontium and D. bupleuroides. Anticancer assays including MTT, Alamar Blue (AB), Neutral Red (NR) and lactate dehydrogenase (LDH) were employed on whole herb methanolic extract and all other fractions of both plants to calculate the % age of cell viability and cell cytotoxicity. The percentage of cell viability was highly significant in all anticancer assays for all fractions. Therefore, ethyl acetate and aqueous fractions showed the excellent profile in evaluation of cytotoxicity in each assay. All above findings indicated that the whole herb of both selected plants have strong anticancer activity.

Topics: Acanthaceae; Alkaloids; Carbohydrates; Cell Survival; Drug Screening Assays, Antitumor; Flavonoids; Glycosides; Hep G2 Cells; Humans; In Vitro Techniques; Indicators and Reagents; L-Lactate Dehydrogenase; Neutral Red; Oxazines; Plant Extracts; Plant Proteins; Plantaginaceae; Saponins; Tannins; Terpenes; Tetrazolium Salts; Thiazoles; Xanthenes

Phenolic compounds are widely known for their roles as antioxidants and anti-inflammatory agents, as well as for their epidemiological association with reduced risks for certain types of diseases. In the present study, we used rabbit peripheral blood mononuclear cells (PBMCs) to evaluate possible artifacts that result from the reactivity of polyphenolics. We evaluated several common methods for cytotoxicity tests using nine polyphenolics, representing several major classes of tannins and their subunits. For three of those phenolics, we investigated whether or not the bioactivities of the phenolics were altered by spontaneous oxidation. Our study showed that many of the nine tested tannins interfered with the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) assay, which is commonly used to measure cell viability. A better method for determining cell viability is the luciferin/luciferase ATP assay, and using that method, we found that several tannins are toxic to PBMCs. We measured TNF-alpha production to assess possible anti-inflammatory activity, and found that only apigenin inhibited TNF-alpha production in LPS-stimulated cells (EC 50 1.0 microg/mL). The other polyphenolic compounds we tested either had no effect on TNF-alpha or increased its production. However, our data indicated that spontaneous oxidation altered the activity of phenolics, eliminating their toxicity. This study shows that the chemical reactivity of phenolics can significantly affect attempts to evaluate bioactivity in cultured cells and that particular attention should be paid to both methods for determining toxicity and to spontaneous oxidation of tannins during cell testing.

Topics: Animals; Anti-Inflammatory Agents; Cell Survival; Cells, Cultured; Flavonoids; Leukocytes, Mononuclear; Lipopolysaccharides; Oxidation-Reduction; Phenols; Polyphenols; Rabbits; Tannins; Tetrazolium Salts; Thiazoles; Tumor Necrosis Factor-alpha

Brackenridgea zanguebarica is a small tree that is used in traditional African medicine as a type of cure-all for many diseases, including the treatment of wounds. The yellow bark of B. zanguebarica was used for the preparation of an ethanolic extract, which was tested in various concentrations against eleven bacteria, Herpes simplex virus type 1 (HSV-1) and different human tumour cell lines. The extract that contains different polyphenolic substances like calodenin B. Cell growth inhibition, assessed via MTT-assay, was found in all tested human cell lines with IC50 values (concentration of extract that reduced cell viability by 50%) between 33 microg dry extract/mL for HL-60 human myeloid leukaemia cells and 93 microg dry extract/mL for HaCaT human keratinocytes. Staining with Annexin-V-FLUOS and JC-1 followed by subsequent analysis via flow cytometry revealed significant apoptosis-inducing properties. Analysis of caspase activity using a fluorogenic caspase-3 substrate showed a significant caspase activity in Jurkat T-cells after incubation with the extract. The bark extract had a pronounced activity against free HSV-1 and a strong antibacterial activity against Gram-positive strains (MICs: 6-24 microg dry extract/mL), which are often involved in skin infections. Additionally, no irritating properties of the extract could be observed in hen-egg test chorioallantoic membrane (HET-CAM) assay. These findings give a rationale for the traditional use of B. zanguebarica and are a basis for further analysis of the plant's components, their biological activity, and its use in modern phytotherapy.

Topics: Anti-Bacterial Agents; Antineoplastic Agents, Phytogenic; Antiviral Agents; Apoptosis; Bacteria; Cell Line, Tumor; Chromatography, High Pressure Liquid; Flavonoids; Gram-Positive Bacteria; HL-60 Cells; Humans; Jurkat Cells; Microbial Sensitivity Tests; Ochnaceae; Plant Bark; Plant Extracts; Spectrometry, Mass, Electrospray Ionization; Tannins; Tetrazolium Salts; Thiazoles; Viral Plaque Assay; Viruses

Geum quellyon Sweet, a perennial herb of the Rosaceae family, has been used in the traditional medicine of the Mapuche Amerindians of Chile to treat tooth neuralgia, gastric inflammation, prostatitis and to regulate menstruation, and for its diuretic and aphrodisiac properties. Although many benefits have been claimed for this plant, few scientific studies are available in the literature. In this study, we investigated the antioxidant activity of a methanolic extract of Geum quellyon roots. We also examined the anticancer action of this plant on Caco-2 (colon adenocarcinoma cells), DU-145 (androgen-insensitive prostate cancer cells) and KB (oral squamous carcinoma cells) human tumor cell lines. Our data showed that Geum quellyon extract, containing tannins, exhibits interesting antioxidant properties, expressed by its capacity to scavenge 1,1-diphenyl-2-picryl-hydrazyl radical (DPPH) and superoxide anion (O(2)*-), to inhibit xanthine oxidase activity, to chelate metals, and to protect plasmid DNA from cleavage induced by hydroxyl radicals (*OH) and nitric oxide (NO). These results may explain, at least in part, its use in Mapuche traditional medicine for gastric inflammation and prostatitis. The assays on human tumor cell lines demonstrated that this natural product exhibits a inhibitory effect on all human cancer cells examined, and seem to indicate that necrosis cell death is triggered in KB cells and Caco-2, while apoptotic cell demise appears to be induced in DU-145. The effect evidenced in Caco-2 cells can be in part correlated to a modulation of redox-sensitive mechanisms.

Topics: Antineoplastic Agents, Phytogenic; Antioxidants; Biphenyl Compounds; Caco-2 Cells; Cell Line, Tumor; Chelating Agents; Chile; Comet Assay; DNA, Neoplasm; Drug Screening Assays, Antitumor; Enzyme Inhibitors; Free Radical Scavengers; Geum; Humans; Hydrazines; Hydrogen Peroxide; KB Cells; L-Lactate Dehydrogenase; Male; Medicine, Traditional; Picrates; Plant Extracts; Plant Roots; Prostatic Neoplasms; Reactive Oxygen Species; Tannins; Tetrazolium Salts; Thiazoles; Ultraviolet Rays; Xanthine Oxidase