tannins and casuarinin

Topics: Anti-Infective Agents; Candida; Chromatography, High Pressure Liquid; Escherichia coli; Hydrolyzable Tannins; Magnetic Resonance Spectroscopy; Mass Spectrometry; Microbial Sensitivity Tests; Myrtales; Plant Extracts; Solid Phase Extraction; Tannins

In search of anti-inflammatory lead compounds from traditional Chinese medicines, a bioassay-guided phytochemical study on Melastoma dodecandrum was carried out. As a result, 18 compounds have been isolated. Their chemical structures were determined on the basis of their physicochemical properties and spectral data. Among the isolates, three pentacyclic triterpenoids, ursolic acid (1), asiatic acid (3) and terminolic acid (6), together with one tannin casuarinin (17), were found to significantly decrease interleukin-8 (IL-8) production in human colon cancer cells. The results imply, at least in part, that the anti-inflammatory effect of M. dodecandrum could be due to inhibition of IL-8 production, demonstrated by these naturally occurring compounds described above.

Topics: Anti-Inflammatory Agents; Drugs, Chinese Herbal; HT29 Cells; Humans; Hydrolyzable Tannins; Interleukin-8; Melastomataceae; Molecular Structure; Pentacyclic Triterpenes; Plant Leaves; Tannins; Triterpenes; Ursolic Acid

Casuarinin, a hydrolyzable tannin isolated from the bark of Terminalia arjuna Linn. (Combretaceae), was investigated for its antiviral activity on herpes simplex type 2 (HSV-2) in vitro. Results showed that the IC(50) of casuarinin in XTT and plaque reduction assays were 3.6+/-0.9 and 1.5+/-0.2 microM, respectively. The 50% cytotoxic concentration for cell growth (CC(50)) was 89+/-1 microM. Thus, the selectivity index (SI) (ratio of CC(50) to IC(50)) of casuarinin was 25 and 59 for XTT and plaque reduction assays, respectively. Casuarinin continued to exhibit antiviral activity even added 12 h after infection. During the attachment assay, casuarinin was shown to prevent the attachment of HSV-2 to cells. Furthermore, casuarinin also exhibited an activity in inhibiting the viral penetration. Interestingly, casuarinin was virucidal at a concentration of 25 microM, reducing viral titers up to 100,000-fold. This study concludes that casuarinin possesses anti-herpesvirus activity in inhibiting viral attachment and penetration, and also disturbing the late event(s) of infection.

Topics: Animals; Antiviral Agents; Chlorocebus aethiops; Herpes Simplex; Herpesvirus 2, Human; Hydrolyzable Tannins; Plant Bark; Plants, Medicinal; Tannins; Terminalia; Vero Cells; Viral Plaque Assay; Virion