lignans and Chlamydia-Infections

Background To evaluate the individual and combined effects of enterolactone, vitamin D, free testosterone, Chlamydia trachomatis and HPV-18 on the risk of prostate cancer in a large population-based biochemical material that combined three Nordic serum sample banks. Material and methods A joint cohort of 209 000 healthy men was followed using cancer registry linkages. From this cohort altogether 699 incident cases of prostate cancer were identified. Four controls were selected by incidence density sampling and matching for country, age and date of the blood sampling. Complete data for all investigated exposures was available for 483 eligible cases and 1055 eligible controls. Multivariate regression analyses were performed to investigate the solitary and combined effects. Results The solitary effects were small. Significantly increased risk [rate ratio 1.6 (95% CI 1.0-2.5)] was found in those seronegative for C. trachomatis infection. The joint effect in risk levels of enterolactone and vitamin D was antagonistic [observed rate ratio (RR) 1.4 (1.0-2.1), expected RR 2.0 (1.0-4.1)] as well as that of HPV-18 and C. trachomatis [observed RR 1.9 (0.8-4.5), expected RR 9.9 (1.1-87.0)]. Conclusion A large follow-up study combining data from several previously investigated exposures to investigate joint effects found no evidence that exposure to two risk factors would increase the risk of prostate cancer from that expected on basis of exposure to one risk factor. If anything, the results were consistent with antagonistic interactions.

Topics: 4-Butyrolactone; Adult; Blood Banks; Case-Control Studies; Chlamydia Infections; Chlamydia trachomatis; Cohort Studies; Finland; Human papillomavirus 18; Humans; Lignans; Longitudinal Studies; Male; Middle Aged; Norway; Papillomavirus Infections; Prostatic Neoplasms; Risk Factors; Sweden; Testosterone; Vitamin D

Lignans from Schisandra chinensis berries show various pharmacological activities, of which their antioxidative and cytoprotective properties are among the most studied ones. Here, the first report on antibacterial properties of six dibenzocyclooctadiene lignans found in Schisandra spp. is presented. The activity was shown on two related intracellular Gram-negative bacteria Chlamydia pneumoniae and Chlamydia trachomatis upon their infection in human epithelial cells. All six lignans inhibited C. pneumoniae inclusion formation and infectious progeny production. Schisandrin B inhibited C. pneumoniae inclusion formation even when administered 8 h post infection, indicating a target that occurs relatively late within the infection cycle. Upon infection, lignan-pretreated C. pneumoniae elementary bodies had impaired inclusion formation capacity. The presence and substitution pattern of methylenedioxy, methoxy and hydroxyl groups of the lignans had a profound impact on the antichlamydial activity. In addition our data suggest that the antichlamydial activity is not caused only by the antioxidative properties of the lignans. None of the compounds showed inhibition on seven other bacteria, suggesting a degree of selectivity of the antibacterial effect. Taken together, the data presented support a role of the studied lignans as interesting antichlamydial lead compounds.

Topics: Anti-Bacterial Agents; Bacteria; Cell Line; Chlamydia Infections; Chlamydia trachomatis; Chlamydophila pneumoniae; Cyclooctanes; Humans; Lignans; Microbial Sensitivity Tests; Polycyclic Compounds; Reactive Oxygen Species; Schisandra

The purpose of this study was to investigate the effect and selectivity of an extract of Schisandra chinensis berries against Chlamydia pneumoniae and C. trachomatis. Among the ethnopharmacological uses of the extract from Schisandrae fructus are cough and pneumonia. Therefore we focused on respiratory pathogens. The extract completely inhibited the growth of C. pneumoniae strain CV6 at 250 μg/mL concentration. The inhibition of C. pneumoniae and C. trachomatis growth was dose dependent and established with three different strains. The extract inhibited C. pneumoniae production of infectious progeny in a dose dependent manner. Chlamydia selectivity was elucidated with growth inhibition measurements of three other respiratory bacterial species. A pure compound found in Schisandra chinensis berries, schisandrin B at 20.0 μg/mL concentration inhibited the growth of both C. pneumoniae and C. trachomatis. The extract was found to be non-toxic to the human host cells. These findings highlight the potential of the extract from Schisandra chinensis berries as a source for antichlamydial compounds.

Topics: Chlamydia; Chlamydia Infections; Fruit; HeLa Cells; Humans; Lignans; Plant Extracts; Schisandra