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Background and objectives: Antibiotic resistance is a major public health challenge. The pervasive antibiotic misuse can lead to increased antibiotic resistance. Thus, there is a need for discovery of new compounds against drug-resistant microorganisms. We synthesized new series of 1, 3, 4-oxadiazole derivatives (4a-4d) and evaluated the antibacterial and antifungal activity of the derivatives against Staphylococcus aureus, Staphylococcus epidermidis, Acinetobacter baumannii, Klebsiella pneumoniae, Aspergillus fumigatus and Aspergillus flavus.
Methods: The new derivatives of 1, 3, 4-oxadiazole were synthesized using a single-stage, high-yield method. The structure of the new compounds was confirmed by infrared spectroscopy, carbon-nuclear magnetic resonance and hydrogen- nuclear magnetic resonance. Then, antibacterial and antifungal activities of the prepared derivatives (1 mg/ml) were evaluated by determining minimum inhibitory concentration and minimum bactericidal/fungicidal concentration using the agar well diffusion method.
Results: All synthesized compounds, especially (4d) with methoxyphenyl group, exhibited powerful antibacterial activity against the tested bacteria. However, the compounds had no antifungal effect.
Conclusion: Our findings indicate the antibacterial potential of the novel synthetic 1, 3, 4-oxadiazole compounds.

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Background and objectives: Human Dermal Fibroblasts (HDF) are involved in the production of the extracellular matrix, formation of the connective tissue, and wound healing. Considering the role of ciprofloxacin in the treatment of skin infections and the subsequent oxidative stress as well as the protective effects of vitamin E and low power laser against inflammation and oxidative stress, we evaluated combined effects of low power laser and vitamin E on inflammation and oxidative stress in HDF cells treated with ciprofloxacin.
Methods: Morphology of the cells was studied using an inverted microscope. Viability of the cells was assessed using the MTT assay, and the concentration of reactive oxygen species was determined after exposure of the cells to ciprofloxacin (5, 25, 50, 75, and 100 μg/ml), vitamin E (1 mg/ml), and low power laser (660 nm; power density: 30 mW.cm⁻²).
Results: The survival rate of the cells increased significantly after the treatment with ciprofloxacin, vitamin E, and low power laser compared with the cells treated with ciprofloxacin and vitamin E (p<0.001). The amount of reactive oxygen species increased in the treated cells when compared with those only treated with ciprofloxacin and vitamin E.
Conclusion: The low power laser treatment has favorable effects on the growth of HDF cells, which can be beneficial for wound healing, even in the presence of ciprofloxacin.