Abstract
Scedosporium spp. are human pathogenic fungi causing infections among non-Aspergillus spp. especially in immunocompetent and immunocompromised individuals. Moreover, these pathogenic fungi are highly resistant to standard antifungal drugs whereas effective drugs are highly expensive and give several side effects. Co-treatment drugs have begun to be developed to increase the effectiveness of treatment against Scedosporium infections. One of them is the quorum sensing molecules (QSMs). These QSMs are produced from fungi and play a role in reducing the growth of fungi, especially in the drug resistance group. One of the substances that are increasingly being studied for their role in fungi is Tryptophol (TOH). This research aimed to investigate the role of TOH in the inhibition of fungal infections that were common in Thailand including Scedosporium apiospermum, S. boydii, S aurantiacum, and Lomentospora prolificans. Our study revealed that TOH exhibits an MFC of 8 mM, which is able to stimulate THP-1(Macrophage) and Jurkat cells (T cells) at different time point, 3 and 6 hours post treated respectively. The up regulated cytokines after co-culture with TOH including M1 cytokine , which play a role in the elimination of microorganisms as IL-6 (2, 2.2 folds). T-helper cells cytokines such as คือ IL-17 (4.2, 1.9 folds) and IL-23 (3.8, 2.1 folds), as well as the specific eumycetoma IL-1β (1.7, 2.7 folds), IL-12(3.2, 3.2 folds), IL-37(3.0, 2.6 folds), and IL-35(2.7, 1.9 folds), but not induce apoptosis in both fibroblasts and macrophages. Instead, TOH induced fungal apoptosis as determined using Ethidium bromide/Acridine orange, which corresponded to a 2.2-fold decrease in CARD-9 and a 2.6-fold increase in BCL-2 expressions. After obtaining the laboratory results, our research team began a series of experiments to develop a prototype of neutropenic mouse model of eumycetoma. To produce neutropenic mice, injection of cyclophosphamide at 150 mg/kg were administered. Then, eumycetoma formation was observed in day 3 after intradermal injecting 1x106conidia of Scedosporium spp. at the back of neutropenic mouse. Moreover, our team also developed a prototype emulsion-gel product containing TOH and tested the effectiveness against Scedosporium spp. infection. Our study revealed that the tumor size was reduced after treating with TOH emulsion-gel in infected mice. Moreover, we also expanded our study using an invertebrate in vivo model of Caenorhabditis elegans. Our preliminary results revealed that life span virulence tests and the efficacy of TOH against all four Scedosporium spp. infections exhibited similar promising results to neutropenic mouse model of eumycetoma, suggesting that C. elegans can be used as a powerful alternative model for researchers in microbiology, pathology, and pharmacology in the future.
