Anti-fungal potential of ozone against some dermatophytes

Background

Dermatophytes are a group of fungi that cause common skin, hair and nail infections such as ringworm and athlete's foot. Standard antifungal drugs can clear these infections, but long-term use is sometimes linked to side effects, prompting researchers to look for alternative antimicrobial approaches. Ozone has known germicidal properties, and this study set out to test whether ozone gas and ozonised oil could inhibit dermatophyte growth in the laboratory.

Study design

This was a laboratory (in vitro) study. Researchers tested five common dermatophyte species - Microsporum canis, Microsporum gypseum, Trichophyton rubrum, Trichophyton mentagrophytes and Trichophyton interdigitale - grown in culture. Fungal samples were exposed to varying concentrations of gaseous ozone (2-20 micrograms per millilitre, applied for two hours) or ozonised oil (0.1-3.2 micrograms per millilitre, applied for two minutes). The team then measured the minimum concentration needed to inhibit growth, the effect on spore formation (sporulation), leakage of electrolytes and sugars from fungal cells (an indicator of damage to the cell membrane), and the fungi's production of enzymes - including keratinase, urease, alkaline phosphatase, amylase and lipase - that they use to break down skin and other tissue.

Findings

Both forms of ozone inhibited fungal growth, but ozonised oil was consistently more effective than gaseous ozone at lower concentrations and shorter exposure times. Susceptibility varied by species: Microsporum species were the most sensitive, while Trichophyton species were comparatively more resistant. In the most susceptible species, ozonised oil reduced sporulation by 97-99%. Treated fungal cells also leaked more electrolytes and sugars than untreated controls, consistent with damage to the fungal cell membrane, and produced significantly less of the enzymes they rely on to digest keratin and other substrates.

What the authors concluded

The authors concluded that ozone - particularly in the form of ozonised oil - showed clear antifungal activity against dermatophytes in this laboratory setting, working by damaging fungal cell membranes and reducing the enzymes fungi need to invade tissue. They suggested ozone therapy warrants further investigation as an alternative or complementary antifungal strategy, especially given concerns about side effects from long-term use of conventional antifungal drugs.

Limitations of this study

This was a laboratory study using fungal cultures, not a clinical trial in people with skin infections, so the results cannot be assumed to translate directly to real-world treatment outcomes. Only five dermatophyte species were tested, and the study did not directly compare ozone to standard antifungal medications. Further research, including studies on human skin and controlled clinical trials, would be needed before drawing conclusions about ozone's effectiveness as a treatment for dermatophyte infections in people.