Background: Nowadays, the encapsulation of cytotoxic chemotherapeutic agents is attracting interest as a method for drug delivery. We hypothesized that the efficiency of helenalin might be maximized by encapsulation in β-cyclodextrin nanoparticles. Helenalin, with a hydrophobic structure obtained from flowers of Arnica chamissonis and Arnica Montana, has anti-cancer and anti-inflammatory activity but low water solubility and bioavailability. β-Cyclodextrin (β-CD) is a cyclic oligosaccharide comprising seven D-glucopyranoside units, linked through 1,4-glycosidic bonds. Materials and Methods: To test our hypothesis, we prepared β-cyclodextrinhelenalin complexes to determine their inhibitory effects on telomerase gene expression by real-time polymerase chain reaction (q-PCR) and cytotoxic effects by colorimetric cell viability (MTT) assay. Results: MTT assay showed that not only β-cyclodextrin has no cytotoxic effect on its own but also it demonstrated that β-cyclodextrinhelenalin complexes inhibited the growth of the T47D breast cancer cell line in a time and dose-dependent manner. Our q-PCR results showed that the expression of telomerase gene was effectively reduced as the concentration of β-cyclodextrin-helenalin complexes increased. Conclusions: β-Cyclodextrin-helenalin complexes exerted cytotoxic effects on T47D cells through down-regulation of telomerase expression and by enhancing Helenalin uptake by cells. Therefore, β-cyclodextrin could be superior carrier for this kind of hydrophobic agent.

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In this study, we demonstrated that the NC-helenalin complex is more effective than free helenalin in inhibiting the growth of breast cancer cells.

Bacterial overgrowth in the inner layer of the catheter as a biofilm is highly encountered in routine medical care, and it may occur in a few days after inserting a catheter as an access in hemodialysis (HD) patients. Catheter-induced bacteremia is often due to the development of biofilms. Locking catheters with antimicrobial agents is an effective way of reducing the risk of catheter-related infection. In a controlled, randomized clinical trial, 64 chronic HD patients (32 men and 32 women with a mean age of 57.5 ± 15.6 years) were divided into case and control groups, with 32 patients in each group. The case group received systemic antibiotic and a lock of catheters with 60% ethanol and the control group received only systemic antibiotic. The results were evaluated after three weeks of treatment. The success rate of clearing infection in group A (29 patients) and group B (18 patients) was 90.6% and 56.2%, respectively (P = 0.002). We conclude that the significant difference in the success rate of clearing catheter infection in HD patients is due to the use of 60% ethanol-lock along with antibiotic therapy, and suggest this for routine use.