Hyperforin Exhibits Antigenotoxic Activity on Human and Bacterial Cells.

Hyperforin (HF), a substance that accumulates in the leaves and flowers of Hypericum perforatum L. (St. John's wort), consists of a phloroglucinol skeleton with lipophilic isoprene chains. HF exhibits several medicinal properties and is mainly used as an antidepressant. So far, the antigenotoxicity of HF has not been investigated at the level of primary genetic damage, gene mutations, and chromosome aberrations, simultaneously. The present work is designed to investigate the potential antigenotoxic effects of HF using three different experimental test systems. The antigenotoxic effect of HF leading to the decrease of primary/transient promutagenic genetic changes was detected by the alkaline comet assay on human lymphocytes. The HF antimutagenic effect leading to the reduction of gene mutations was assessed using the Ames test on the standard Salmonella typhimurium (TA97, TA98, and TA100) bacterial strains, and the anticlastogenic effect of HF leading to the reduction of chromosome aberrations was evaluated by the in vitro mammalian chromosome aberration test on the human tumor cell line HepG2 and the non-carcinogenic cell line VH10. Our findings provided evidence that HF showed antigenotoxic effects towards oxidative mutagen zeocin in the comet assay and diagnostic mutagen (4-nitroquinoline-1-oxide) in the Ames test. Moreover, HF exhibited an anticlastogenic effect towards benzo(a)pyrene and cisplatin in the chromosome aberration test.

Photoactivated hypericin is not genotoxic.

The study was designed to test the potential photogenotoxicity of hypericin (HYP) at three different levels: primary DNA damages, gene mutations and chromosome aberrations. Primary genetic changes were detected using the comet assay. The potential mutagenic activity of HYP was assessed using the Ames/Salmonella typhimurium assay. Finally, the ability of photoactivated HYP to induce chromosome aberrations was evaluated by the in vitro mammalian chromosome aberration test and compared to that of non-photoactivated HYP. The results have shown that photoactivated HYP can only induce primary DNA damages (single-strand DNA breaks), acting in a dose-response manner. This activity depended both on HYP concentrations and an intensity of the light energy needed for its photoactivation. However, mutagenic effect of photoactivated HYP evaluated in the Ames assay using three bacterial strains S. typhimurium (TA97, TA98 and TA100) was not confirmed. Moreover, photoactivated HYP in the range of concentrations (0.005-0.01 µg/ml) was not found to be clastogenic against HepG2 cells. Our findings from both the Ames assay and the chromosome aberrations test provide evidence that photoactivated HYP is not genotoxic, which might be of great importance mainly in terms of its use in the photodynamic therapy.

Deregulation of energetic metabolism in the clear cell renal cell carcinoma: A multiple pathway analysis based on microarray profiling.

Clear cell renal cell carcinoma (ccRCC) is the most frequent type of kidney cancer. In order to better understand the biology of ccRCC, we accomplished the gene profiling of fresh tissue specimens from 11 patients with the renal tumors (9 ccRCCs, 1 oncocytoma and 1 renal B-lymphoma), in which the tumor-related data were compared to the paired healthy kidney tissues from the same patients. All ccRCCs exhibited a considerably elevated transcription of the gene coding for carbonic anhydrase IX (CAIX). Moreover, the ccRCC tumors consistently displayed increased expression of genes encoding the glycolytic pathway enzymes, e.g. hexokinase II (HK2) and lactate dehydrogenase A (LDHA) and a decreased expression of genes for the mitochondrial electron transport chain components, indicating an overall reprogramming of the energetic metabolism in this tumor type. This appears to be accompanied by altered expression of the genes of the pH regulating machinery, including ion and lactate transporters. Immunohistochemical staining of tumor tissue sections confirmed the increased expression of CAIX, HK2 and LDHA in ccRCC, validating the microarray data and supporting their potential as the energetic metabolism-related biomarkers of the ccRCC.