Gentiana asclepiadea protects human cells against oxidation DNA lesions.

The objectives of this study were to examine whether the methanolic and aqueous extracts from the haulm and flower of Gentiana asclepiadea exhibited free radical scavenging and protective (antigenotoxic) effect against DNA oxidation induced by H(2)O(2) in human lymphocytes and human embryonic kidney cells (HEK 293). All four extracts exhibited high scavenging effect on 1,1-diphenyl-2-picrylhydrazyl radicals at concentrations 2.5 and 25 mg ml(-1). The level of DNA damage was measured using the alkaline version of single-cell gel electrophoresis (comet assay). Challenge with H(2)O(2) shows that the pre-treatment of the cells with non-genotoxic doses of Gentiana extracts protected human DNA-either eliminated or significantly reduced H(2)O(2) induced DNA damage. The genotoxic activity of H(2)O(2) was most effectively decreased after 30 min of pre-incubation with 0.05 mg ml(-1) (range, 93.5%-96.3% of reduction in lymphocytes) and 0.25 mg ml(-1) (range, 59.5%-71.4% and 52.7%-66.4% of reduction in lymphocytes and HEK 293 cells, respectively) of G. asclepiadea extracts. These results suggest that the tested G. asclepiadea extracts could be considered as an effective natural antioxidant source.

Cytotoxic and genotoxic effect of methanolic flower extract from Gentiana asclepiadea on COS 1 cells.

OBJECTIVE: The purpose of this study was to assess whether a methanol extract isolated from the flower of Gentiana asclepiadea had potential cytotoxic or genotoxic effect on COS 1 (monkey kidney) cell line. Five various concentrations of the extract were investigated for cytotoxicity and genotoxicity and to determine non-cytotoxic and non-genotoxic concentrations suitable for utilization in pharmacology and medicine. METHODS: Cytotoxicity was determined using the proliferation (growth activity) and the plating efficiency (colony forming ability) assays after 24 hour incubation of COS 1 cells with different concentrations of methanolic flower extract from G. asclepiadea. To assess potential genotoxicity, the comet assay or SCGE (Single-Cell Gel Electrophoresis) was used. RESULTS: We found that only the highest (5 and 25 mg/ml) concentrations of the extract revealed cytotoxic and genotoxic effect. We have also determined concentrations that stimulated cell growth (0.25 mg/ml) and colony forming ability (0.25-2.5 mg/ml) and did not exhibit genotoxic effect (0.25-2.5 mg/ml). CONCLUSIONS: We found out that extract of G. asclepiadea was neither cytotoxic nor genotoxic in a wide range of concentrations (0.25-2.5 mg/ml) and thus can be used to further investigate potential beneficial usage in pharmacology and medicine.

Potential antioxidant activity, cytotoxic and apoptosis-inducing effects of Chelidonium majus L. extract on leukemia cells.

OBJECTIVES: The purpose of this study was to assess whether a methanol extract isolated from the greater celandine Chelidonium majus L. (CME) had antioxidant effect and was able to inhibit proliferation and to induce apoptosis in leukemia cells in vitro. METHODS: The potential antioxidant activity of CME was proved by the 1,1-diphenyl- 2-picrylhydrazyl (DPPH) radical scavenging assay. The cytotoxicity of CME was measured by the cell growth inhibition assay using murine leukemia L1210 cell line and human promyelocytic HL-60 leukemia cells. Apoptosis-inducing effect was determined by fluorescence microscopy (chromatin condensation and nuclear DNA fragmentation). RESULTS: In the DPPH assay CME acted as a scavenger of DPPH free radical. The results on antiproliferative properties assessment clearly demonstrated that CME had a cytotoxic effect towards both leukemia cell lines in a dose-dependent manner. In addition, the human promyelocytic HL-60 cells were more sensitive to CME treatment than the L1210 cells. CONCLUSIONS: We concluded that the extract of C. majus L. had a strong antioxidant potential and exerted the antiproliferative activity via apoptosis on leukemia cells. CME due to the presence of the isoquinoline alkaloids and the flavonoid components may play an important role in both cancer chemoprevention through its antioxidant activity and modern cancer chemotherapy as cytotoxic and apoptosis-inducing agent.