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.

This study provides evidence that the expression of Drosha is impaired in breast cancer. However, the molecular basis of observed expression pattern have remained inexplicable and should be further investigated.

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.

Cerebral ischemia-reperfusion (CIR) injury is initiated by the generation of reactive oxygen species (ROS), which leads to the oxidation of cellular proteins, DNA, and lipids as an initial event. The reperfusion process impairs critical cascades that support cell survival, including mitochondrial biogenesis and antioxidant enzyme activity. Failure to activate prosurvival signals may result in increased neuronal cell death and exacerbation of CIR damage. Melatonin, a hormone produced naturally in the body, has high concentrations in both the cerebrospinal fluid and the brain. However, melatonin production declines significantly with age, which may contribute to the development of age-related neurological disorders due to reduced levels. By activating various signaling pathways, melatonin can affect multiple aspects of human health due to its diverse range of activities. Therefore, understanding the underlying intracellular and molecular mechanisms is crucial before investigating the neuroprotective effects of melatonin in cerebral ischemia-reperfusion injury.