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[Effect of intense pulsed light on Trichophyton rubrum growth in vitro]
Hao Huang1, Hong-Feng Tang, Ying Chen
1Department of Dermatology, Shunde First People's Hospital Affiliated to Southern Medical University, Foshan 528300, China.
Objective:
To investigate the inhibitory effect of 420 nm intense pulsed light on Trichophyton rubrum growth in vitro and explore the mechanism.
Methods:
The fungal conidia were divided into treatment group with intense pulse light irradiation and control group without irradiation. The surface areas of the fungal colonies were photographed before irradiation and on the 2nd and 3rd days after irradiation to observe the changes in fungal growth. The viability of the fungus in suspension was detected at 6 h after irradiation using MTT assay. The intracellular reactive oxygen species (ROS) level in the fungus was determined using DCFH-DA fluorescent probe, and the MDA content was detected using TBA method.
Results:
Intense pulse light (420 nm) irradiation caused obvious injuries in Trichophyton rubrum with the optimal effective light dose of 12 J/cm2 in 12 pulses. At 6 h after the irradiation, the fungus in suspension showed a 30% reduction of viability (P<0.05), and the fungal colonies showed obvious growth arrest without further expansion. Compared to the control group, the irradiated fungus showed significant increases in ROS level and MDA content (P<0.05).
Conclusion:
Intense pulse light (420 nm) irradiation can induce oxidative stress in Trichophyton rubrum to lead to fungal injuries and death.
Insights
Intense pulsed light (420 nm) effectively inhibits Trichophyton rubrum growth by inducing oxidative stress. This light therapy causes significant fungal injury and death, offering a potential new treatment for fungal infections.
Area of Science:
- Dermatology
- Mycology
- Photobiology
Background:
- Trichophyton rubrum is a common cause of superficial fungal infections.
- Current treatments for T. rubrum infections can be limited by resistance and side effects.
Purpose of the Study:
- To evaluate the antifungal efficacy of 420 nm intense pulsed light (IPL) against Trichophyton rubrum in vitro.
- To elucidate the underlying mechanism of IPL-induced fungal cell death.
Main Methods:
- Fungal conidia were exposed to 420 nm IPL (12 J/cm², 12 pulses) or left untreated (control).
- Fungal growth, viability (MTT assay), intracellular reactive oxygen species (ROS), and malondialdehyde (MDA) levels were assessed post-irradiation.
Main Results:
- IPL treatment resulted in significant growth inhibition and a 30% reduction in fungal viability at 6 hours.
- Irradiated fungi exhibited elevated levels of ROS and MDA, indicating oxidative stress.
- The optimal effective dose was determined to be 12 J/cm² delivered in 12 pulses.
Conclusions:
- 420 nm IPL induces significant oxidative stress in Trichophyton rubrum.
- This oxidative stress leads to fungal injury and cell death, demonstrating the potential of IPL as an antifungal therapy.
