Foad Mahmoudzadeh, Razzagh Mahmoudi , Peyman Ghajarbeygi , Masoud Kezeminia,
Volume 11, Issue 1 (Jan-Feb- 2017 2017)
Abstract
ABSTRACT
Background and Objectives: Due to their antimicrobial, anticancer and antioxidant properties (due to the presence of free radical scavengers), essential oils and extracts of medicinal plants are of great importance as natural medicinal compounds in public health, treatment of diseases, and protection of raw and processed foods.
Methods: Chemical composition and content of essential oil of Thymus kotschyanus was determined by gas chromatography–mass spectrometry. The amount of phenolic and flavonoid compounds in the essential oil was determined by spectrophotometry using gallic acid and quercetin as standards. The antioxidant properties of the essential oil were evaluated by the DPPH method.
Results: The analysis of essential oil with gas chromatography–mass spectrometry showed that thymol (51.1%), p-cymene (13.78%) and α-pinene (7.42%) are the main components. The amount of phenolic compounds was 82 ± 6.43 μg gallic acid/ml essential oil, while the flavonoid content was 30.79 ± 0.5 μg quercetin/ml essential oil. In terms of antioxidant activity, the IC50 value of T. kotschyanus essential oil was determined as 32.35 μg/ml, which is weaker than synthetic antioxidant butylated hydroxytoluen.
Conclusion: The results indicate that the essential oil of T. kotschyanus has good antioxidant activity and can be used in combination with other preservatives to protect food against a variety of oxidative systems.
Keywords: Essential Oil, Antioxidant Activity, Thymus Kotschyanus.
Mohammad Hassan Jokar, Fatemeh Mohamadkhani, Maliheh Moradzadeh, Samira Beygi, Ashraf Mohamadkhani,
Volume 16, Issue 2 (Mar-Apr 2022)
Abstract
Background and objectives: Recycled polyethylene terephthalate (RPET) nanofibers have become an important part of human life, with a continuous increase in their production and consumption. Herein, the antibacterial activity of nickel nanoparticles/recycled polyethylene terephthalate nanofibers (NiNP/RPET NF web) was evaluated by analyzing alginate expression in Pseudomonas aeruginosa, as an opportunistic microorganism.
Methods: NiNPs were synthesized and NiNP/RPET NF was produced by adding 25 μg/ml of NiNP to 10% solutions of RPET at a weight ratio of 3%. After exposing P. aeruginosa (PA01) to NiNP/RPET NF, the biofilm-forming capacity was determined and real-time PCR was performed to measure algD expression.
Results: Treatment with 25 μg/ml of NiNP/RPET NF reduced growth of P. aeruginosa on Mueller Hinton agar but did not result in complete inhibition. The biofilm optical density (550 nm) was 0.464 ± 0.021 after treatment with NiNP/RPET NF and 0.082± 0.011 in the absence of NiNP/RPET NF. This indicates the significant reduction of biofilm formation after exposure to NiNP/RPET NF (p=0.01). In addition, a 0.6-fold (p=0.03) reduction in alginate expression was detected by real-time quantitative real-time PCR.
Conclusion: Our results indicate the potential of NiNP/RPET NF for application in nano-based antibacterial medical systems.
