In Vitro Evaluation of the Combination of <i>Melaleuca alternifolia</i> (Tea Tree) Oil and Dimethyl Sulfoxide (DMSO) against Trophozoites and Cysts of <i>Acanthamoeba</i> Strains. Oxygen Consumption Rate (OCR) Assay as a Method for Drug Screening
Ameobae belonging to the genus <i>Acanthamoeba</i> are responsible for the human diseases Acanthamoeba keratitis (AK) and granulomatous amoebic encephalitis (GAE). The treatment of these illnesses is hampered by the existence of a resistance stage (cysts). In an attempt to add new agents...
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MDPI AG
2021-04-01
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| Online Access: | https://www.mdpi.com/2076-0817/10/4/491 |
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| author | Tania Martín-Pérez Irene Heredero-Bermejo Cristina Verdú-Expósito Jorge Pérez-Serrano |
| author_facet | Tania Martín-Pérez Irene Heredero-Bermejo Cristina Verdú-Expósito Jorge Pérez-Serrano |
| author_sort | Tania Martín-Pérez |
| collection | DOAJ |
| description | Ameobae belonging to the genus <i>Acanthamoeba</i> are responsible for the human diseases Acanthamoeba keratitis (AK) and granulomatous amoebic encephalitis (GAE). The treatment of these illnesses is hampered by the existence of a resistance stage (cysts). In an attempt to add new agents that are effective against trophozoites and cysts, tea tree oil (TTO) and dimethyl sulfoxide (DMSO), separately and in combination, were tested In Vitro against two <i>Acanthamoeba</i> isolates, T3 and T4 genotypes. The oxygen consumption rate (OCR) assay was used as a drug screening method, which is to some extent useful in amoebicide drug screening; however, evaluation of lethal effects may be misleading when testing products that promote encystment. Trophozoite viability analysis showed that the effectiveness of the combination of both compounds is higher than when either compound is used alone. Therefore, the TTO alone or TTO + DMSO in combination were an amoebicide, but most of the amoebicidal activity in the combination’s treatments seemed to be caused mainly by the TTO effect. In fact, DMSO alone seems to be a non-amoebicide, triggering encystment. Regarding cytotoxicity, these compounds showed toxicity in human corneal epithelial cells (HCEpiC), even at low concentrations when tested in combination. In conclusion, the use of TTO and DMSO, in combination or alone, cannot be recommended as an alternative for AK treatment until more cytotoxicity and cyst adhesion tests are performed. |
| first_indexed | 2024-03-10T12:12:01Z |
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| id | doaj.art-ec129c7ce73747c481bd07440c8687a6 |
| institution | Directory Open Access Journal |
| issn | 2076-0817 |
| language | English |
| last_indexed | 2024-03-10T12:12:01Z |
| publishDate | 2021-04-01 |
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| series | Pathogens |
| spelling | doaj.art-ec129c7ce73747c481bd07440c8687a62023-11-21T16:08:54ZengMDPI AGPathogens2076-08172021-04-0110449110.3390/pathogens10040491In Vitro Evaluation of the Combination of <i>Melaleuca alternifolia</i> (Tea Tree) Oil and Dimethyl Sulfoxide (DMSO) against Trophozoites and Cysts of <i>Acanthamoeba</i> Strains. Oxygen Consumption Rate (OCR) Assay as a Method for Drug ScreeningTania Martín-Pérez0Irene Heredero-Bermejo1Cristina Verdú-Expósito2Jorge Pérez-Serrano3Department of Biomedicine and Biotechnology, Faculty of Pharmacy, University of Alcalá, Alcalá de Henares, 28805 Madrid, SpainDepartment of Biomedicine and Biotechnology, Faculty of Pharmacy, University of Alcalá, Alcalá de Henares, 28805 Madrid, SpainDepartment of Biomedicine and Biotechnology, Faculty of Pharmacy, University of Alcalá, Alcalá de Henares, 28805 Madrid, SpainDepartment of Biomedicine and Biotechnology, Faculty of Pharmacy, University of Alcalá, Alcalá de Henares, 28805 Madrid, SpainAmeobae belonging to the genus <i>Acanthamoeba</i> are responsible for the human diseases Acanthamoeba keratitis (AK) and granulomatous amoebic encephalitis (GAE). The treatment of these illnesses is hampered by the existence of a resistance stage (cysts). In an attempt to add new agents that are effective against trophozoites and cysts, tea tree oil (TTO) and dimethyl sulfoxide (DMSO), separately and in combination, were tested In Vitro against two <i>Acanthamoeba</i> isolates, T3 and T4 genotypes. The oxygen consumption rate (OCR) assay was used as a drug screening method, which is to some extent useful in amoebicide drug screening; however, evaluation of lethal effects may be misleading when testing products that promote encystment. Trophozoite viability analysis showed that the effectiveness of the combination of both compounds is higher than when either compound is used alone. Therefore, the TTO alone or TTO + DMSO in combination were an amoebicide, but most of the amoebicidal activity in the combination’s treatments seemed to be caused mainly by the TTO effect. In fact, DMSO alone seems to be a non-amoebicide, triggering encystment. Regarding cytotoxicity, these compounds showed toxicity in human corneal epithelial cells (HCEpiC), even at low concentrations when tested in combination. In conclusion, the use of TTO and DMSO, in combination or alone, cannot be recommended as an alternative for AK treatment until more cytotoxicity and cyst adhesion tests are performed.https://www.mdpi.com/2076-0817/10/4/491<i>Acanthamoeba</i> spp.genotype T3genotype T4cystsdimethyl sulfoxidetea tree oil |
| spellingShingle | Tania Martín-Pérez Irene Heredero-Bermejo Cristina Verdú-Expósito Jorge Pérez-Serrano In Vitro Evaluation of the Combination of <i>Melaleuca alternifolia</i> (Tea Tree) Oil and Dimethyl Sulfoxide (DMSO) against Trophozoites and Cysts of <i>Acanthamoeba</i> Strains. Oxygen Consumption Rate (OCR) Assay as a Method for Drug Screening Pathogens <i>Acanthamoeba</i> spp. genotype T3 genotype T4 cysts dimethyl sulfoxide tea tree oil |
| title | In Vitro Evaluation of the Combination of <i>Melaleuca alternifolia</i> (Tea Tree) Oil and Dimethyl Sulfoxide (DMSO) against Trophozoites and Cysts of <i>Acanthamoeba</i> Strains. Oxygen Consumption Rate (OCR) Assay as a Method for Drug Screening |
| title_full | In Vitro Evaluation of the Combination of <i>Melaleuca alternifolia</i> (Tea Tree) Oil and Dimethyl Sulfoxide (DMSO) against Trophozoites and Cysts of <i>Acanthamoeba</i> Strains. Oxygen Consumption Rate (OCR) Assay as a Method for Drug Screening |
| title_fullStr | In Vitro Evaluation of the Combination of <i>Melaleuca alternifolia</i> (Tea Tree) Oil and Dimethyl Sulfoxide (DMSO) against Trophozoites and Cysts of <i>Acanthamoeba</i> Strains. Oxygen Consumption Rate (OCR) Assay as a Method for Drug Screening |
| title_full_unstemmed | In Vitro Evaluation of the Combination of <i>Melaleuca alternifolia</i> (Tea Tree) Oil and Dimethyl Sulfoxide (DMSO) against Trophozoites and Cysts of <i>Acanthamoeba</i> Strains. Oxygen Consumption Rate (OCR) Assay as a Method for Drug Screening |
| title_short | In Vitro Evaluation of the Combination of <i>Melaleuca alternifolia</i> (Tea Tree) Oil and Dimethyl Sulfoxide (DMSO) against Trophozoites and Cysts of <i>Acanthamoeba</i> Strains. Oxygen Consumption Rate (OCR) Assay as a Method for Drug Screening |
| title_sort | in vitro evaluation of the combination of i melaleuca alternifolia i tea tree oil and dimethyl sulfoxide dmso against trophozoites and cysts of i acanthamoeba i strains oxygen consumption rate ocr assay as a method for drug screening |
| topic | <i>Acanthamoeba</i> spp. genotype T3 genotype T4 cysts dimethyl sulfoxide tea tree oil |
| url | https://www.mdpi.com/2076-0817/10/4/491 |
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