Related Experiment Video
Updated: Jul 6, 2026
Legionella pneumophila Outer Membrane Vesicles: Isolation and Analysis of Their Pro-inflammatory Potential on Macrophages
Published on: February 22, 2017
Interactions between U-937 human macrophages and tyloxapol
Jung-Hua Steven Kuo1, Yi-Lin Lin, Jo-Wen Tseng
1Graduate Institute of Pharmaceutical Science, Chia Nan University of Pharmacy and Science, 60 Erh-Jen Road, Sec. 1, Jen-Te, Tainan 717, Taiwan. kuojunghua@yahoo.com.tw
Abstract:
Tyloxapol is reported to prevent macrophages from reacting to endotoxin. However, the intracellular responses that tyloxapol induces in macrophages are still not fully explored. Hence, the objective of this study was to evaluate the intracellular events in macrophages treated with tyloxapol and assess the antioxidant properties of tyloxapol in endotoxin-activated macrophages. Using flow cytometry, we examined intracellular responses in macrophages: reactive oxygen species (ROS) content, mitochondria membrane potential, and cell cycle profiles. We also assessed the antioxidant properties of tyloxapol in endotoxin-activated macrophages. Kinetic hydrogen peroxide production tended to decline with increasing doses. Tyloxapol produced a progressive increase followed by a decline in superoxide anion production in macrophages with increasing doses. Tyloxapol also caused unstable fluctuations in mitochondrial membrane potential. Apoptosis had developed at higher doses after 4h of incubation time. After 2h of tyloxapol-pretreatment, tyloxapol acted as an antioxidant only at lower doses. Most tyloxapol-pretreated cells at lower doses fully recovered from the changes in superoxide anion and hydrogen peroxide production. Our findings contribute to a better understanding of the molecular action of tyloxapol in macrophages and how it protects macrophages against endotoxin.
Insights
Tyloxapol influences macrophage responses to endotoxin by altering intracellular events. At lower doses, tyloxapol exhibits antioxidant properties, protecting macrophages from oxidative stress.
Area of Science:
- Immunology
- Cell Biology
- Pharmacology
Background:
- Tyloxapol is known to inhibit macrophage responses to endotoxin.
- The intracellular mechanisms underlying tyloxapol's effects on macrophages remain incompletely understood.
Purpose of the Study:
- To investigate the intracellular effects of tyloxapol on macrophages.
- To evaluate tyloxapol's antioxidant capacity in endotoxin-activated macrophages.
Main Methods:
- Flow cytometry was employed to analyze reactive oxygen species (ROS) production, mitochondrial membrane potential, and cell cycle progression.
- Macrophages were treated with varying doses of tyloxapol, with and without prior endotoxin activation.
Main Results:
- Tyloxapol modulated superoxide anion and hydrogen peroxide production in a dose-dependent manner.
- Mitochondrial membrane potential showed unstable fluctuations, and apoptosis was observed at higher tyloxapol concentrations.
- Tyloxapol demonstrated antioxidant effects at lower doses, promoting recovery of macrophage function.
Conclusions:
- Tyloxapol modulates key intracellular events in macrophages, including oxidative stress markers and mitochondrial function.
- Tyloxapol exhibits dose-dependent antioxidant properties, offering protection to macrophages against endotoxin-induced damage at lower concentrations.
- These findings enhance the understanding of tyloxapol's molecular actions and its protective role in macrophage biology.
