Antifungal activity of eugenol on Cryptococcus neoformans biological activity and Cxt1p gene expression

Document Type : Original Articles


1 Department of Mycology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran

2 Department of Mycology, Pasteur Institute of Iran, Tehran, Iran


Background and Purpose: The present study was targeted toward investigating the effects of eugenol on Cryptococcus neoformans biological activity and Cxt1p gene expression.
Materials and Methods: For the purpose of the study, the growth, urease, synergism activity, and disk diffusion of C. neoformans were assessed in eugenol-treated culture. The minimum inhibitory concentration (MIC) was determined by the Clinical and Laboratory Standards Institute M27-A3 method at a concentration range of 0.062-2 mg/mL. Subsequently, the expression of Cxt1p genes was studied at the MIC50 concentration of eugenol using real-time polymerase chain reaction.
Results: The obtained results showed that eugenol at the concentrations of 125 and 500 μg/mL resulted in 50% and 100% growth inhibition in C. neoformans, respectively. In terms of urease activity, the results showed that the addition of MIC50 of eugenol and fluconazole to urea medium reduced urease activity in C. neoformans. In the culture treated with eugenol, the inhibition zone of antifungal drugs, namely amphotericin B, itraconazole, and fluconazole, was increased to 36±0.002, 22±0.001, and 12±0.002 mm, respectively. The expression levels of Cxt1p in the eugenol-treated, fluconazole-treated, and non-treated samples were estimated at 46%, 58%, and 100%, respectively.
Conclusion: The findings of the current study revealed that eugenol could cause C. neoformans growth inhibition and reduce Cxt1p expression in this species. As the results indicated, the susceptibility of C. neoformans to fluconazole was increased when combined with eugenol.


1. Franco-Paredes C, Chastain DB, Rodriguez-Morales AJ, Marcos LA. Cryptococcal meningoencephalitis in HIV/AIDS: when to start antiretroviral therapy? Ann Clin Microbiol Antimicrob. 2017; 16(1):9.
2. Doering TL. How sweet it is! Cell wall biogenesis and polysaccharide capsule formation in Cryptococcus neoformans. Ann Rev Microbiol. 2009; 63:223-47.
3. Zaragoza O, Rodrigues ML, De Jesus M, Frases S, Dadachova E, Casadevall A. The capsule of the fungal pathogen Cryptococcus neoformans. Adv Appl Microbiol. 2009; 68:133-216.
4. Razzaghi-Abyaneh M, Shams-Ghahfarokhi M, Rai M. Medical mycology: current trends and future prospects. Florida: CRC Press; 2015. P. 442.
5. Anaissie EJ, McGinnis MR, Pfaller MA. Clinical mycology. Ann Internal Med. 2003; 138(9):776.
6. Bose I, Reese AJ, Ory JJ, Janbon G, Doering TL. A yeast under cover: the capsule of Cryptococcus neoformans. Eukaryot Cell. 2003; 2(4):655-63.
7. Klutts JS, Doering TL. Cryptococcal xylosyltransferase 1 (Cxt1p) from Cryptococcus neoformans plays a direct role in the synthesis of capsule polysaccharides. J Biol Chem. 2008; 283(21):14327-34.
8. Lemos Jde A, Passos XS, Fernandes Ode F, Paula JR, Ferri PH, Souza LK, et al. Antifungal activity from Ocimum gratissimum L. towards Cryptococcus neoformans. Mem Inst Oswaldo Cruz. 2005; 100(1):55-8.
9. Baptista R, Madureira AM, Jorge R, Adão R, Duarte A, Duarte N, et al. Antioxidant and antimycotic activities of two native Lavandula species from Portugal. Evid Based Complement Alternat Med. 2015; 2015:570521.
10. Razzaghi-Abyaneh M, Shams-Ghahfarokhi M, Rai M. Antifungal plants of Iran: an insight into ecology, chemistry, and molecular biology, in Antifungal Metabolites from Plants. Berlin: Springer; 2013. P. 27-57.
11. Shams-Ghahfarokhi M, Shokoohamiri MR, Amirrajab N, Moghadasi B, Ghajari A, Zeini F, et al. In vitro antifungal activities of Allium cepa, Allium sativum and ketoconazole against some pathogenic yeasts and dermatophytes. Fitoterapia. 2006; 77(4):321-3.
12. Alinezhad S, Kamalzadeh A, Shams-Ghahfarokhi M, Rezaee M,
Jaimand K, Kawachi M, et al. Search for novel antifungals from 49 indigenous medicinal plants: Foeniculum vulgare and Platycladus orientalis as strong inhibitors of aflatoxin production by Aspergillus parasiticus. Ann Microbiol. 2011; 61(3):673-81.
13. Ghorbanian M, Razzaghi-Abyaneh M, Allameh A, Shams-Ghahfarokhi M, Qorbani M. Study on the effect of neem (Azadirachta indica A. juss) leaf extract on the growth of Aspergillus parasiticus and production of aflatoxin by it at different incubation times. Mycoses. 2008; 51(1):35-9.
14. Zielińska S, Matkowski A. Phytochemistry and bioactivity of aromatic and medicinal plants from the genus Agastache (Lamiaceae). Phytochemistry Rev. 2014; 13(2):391-416.
15. Shams GM, Refaei J, Alameh A, Razzaghi AM. Effects of aqueous and essential oils of onion (Allium cepa) on growth and lipase activity in Malassezia furfur. Danehvar Med. 2004; 11(52):31-8.
16. Jalali-Heravi M, Parastar H. Recent trends in application of multivariate curve resolution approaches for improving gas chromatography-mass spectrometry analysis of essential oils. Talanta. 2011; 85(2):835-49.
17. Razzaghi-Abyaneh M, Shams-Ghahfarokhi M, Chang PK. Aflatoxins: mechanisms of inhibition by antagonistic plants and microorganisms. Aflatoxins: Biochemistry and Molecular Biology; 2011.
18. Razzaghi-Abyaneh M, Yoshinari T, Shams-Ghahfarokhi M, Rezaee MB, Nagasawa H, Sakuda S. Dillapiol and apiol as specific inhibitors of the biosynthesis of aflatoxin G1 in Aspergillus parasiticus. Biosci Biotechnol Biochem. 2007; 71(9):2329-32.
19. Razzaghi-Abyaneh M, Allameh A, Tiraihi T, Shams-Ghahfarokhi M, Ghorbanian M. Morphological alterations in toxigenic Aspergillus parasiticus exposed to neem (Azadirachta indica) leaf and seed aqueous extracts. Mycopathologia. 2005; 159(4):565-70.
20. Jahanshiri Z, Shams-Ghahfarokhi M, Allameh A, Razzaghi-Abyaneh M. Inhibitory effect of eugenol on aflatoxin B 1 production in Aspergillus parasiticus by downregulating the expression of major genes in the toxin biosynthetic pathway. World J Microbiol Biotechnol. 2015; 31(7):1071-8.
21. Haynes BC, Skowyra ML, Spencer SJ, Gish SR, Williams M, Held EP, et al. Toward an integrated model of capsule regulation in Cryptococcus neoformans. PLoS Pathog. 2011; 7(12): e1002411.
22. Clinical and Laboratory Standards Institute. Reference method for broth dilution antifungal susceptibility testing of yeasts. 3rd ed. Wayne, PA: Clinical and Laboratory Standards Institute; 2008. P. 28.
23. Pfaller MA, Messer SA, Boyden L, Rice C, Tendolkar S, Hollis RJ, et al. Evaluation of the NCCLS M44-P disk diffusion method for determining susceptibilities of 276 clinical isolates of Cryptococcus neoformans to fluconazole. J Clin Microbiol. 2004; 42(1):380-3.
24. Barbosa Júnior AM, Santos BF, Carvalho ED, Mélo DL, Trindade RD, Stoianoff MA. Biological activity of Cryptococcus neoformans and Cryptococcus gattii from clinical and environmental isolates. J Bras Patol Med Lab. 2013; 49(3):160-8.
25. Tolouee M, Alinezhad S, Saberi R, Eslamifar A, Zad SJ, Jaimand K, et al. Effect of Matricaria chamomilla L. flower
essential oil on the growth and ultrastructure of Aspergillus niger van Tieghem. Int J Food Microbiol. 2010; 139(3):127-33.
26. Asghari F, Jahanshiri Z, Imani M, Shams-Ghahfarokhi M,
Razzaghi-Abyaneh M. Antifungal nanomaterials: synthesis, properties, and applications. Nanobiomater Antimicrob Ther. 2016; 6:343-83.
27. Razzaghi-Abyaneh M, Shams-Ghahfarokhi M, Yoshinari T, Rezaee MB, Jaimand K, Nagasawa H, et al. Inhibitory effects of Satureja hortensis L. essential oil on growth and aflatoxin production by Aspergillus parasiticus. Int J Food Microbiol. 2008; 123(3):228-33.
28. Shams-Ghahfarokhi M, Kalantari S, Razzaghi-Abyaneh M. Terrestrial bacteria from agricultural soils: versatile weapons against aflatoxigenic fungi. Aflatoxins. 2013; 23:23-40.
29. Razzagh-parast A, Shams GM, Yadegari MH, Razzaghi AM. Antifungal effects of Allium cepa and some azoles in intact forms and in combinations to each other against pathogenic yeasts. Kowsar Med J. 2008; 13(2):103-13.
30. Nasiri S, Shams-Ghahfarokhi M, Razzaghi-Abyaneh M. Inhibitory effect of Carum carvi essential oils on growth of Candida albicans. Sci J Microb. 2014; 3(7):74-7.
31. Ghahfarokhi MS, Goodarzi M, Abyaneh MR, Al-Tiraihi T,
Seyedipour G. Morphological evidences for onion-induced growth inhibition of Trichophyton rubrum and Trichophyton mentagrophytes. Fitoterapia. 2004; 75(7-8):645-55.
32. Jahanshiri Z, Shams-Ghahfarokhi M, Allameh A, Razzaghi-Abyaneh M. Effect of curcumin on Aspergillus parasiticus growth and expression of major genes involved in the early and late stages of aflatoxin biosynthesis. Iran J Public Health. 2012; 41(6):72-9.
33. Jamalian A, Shams-Ghahfarokhi M, Jaimand K, Pashootan N, Amani A, Razzaghi-Abyaneh M. Chemical composition and antifungal activity of Matricaria recutita flower essential oil against medically important dermatophytes and soil-borne pathogens. J Mycol Med. 2012; 22(4):308-15.
34. Shams-Ghahfarokhi M, Razafsha M, Allameh A, Razzaghi-Abyaneh M. Inhibitory effects of aqueous onion and garlic extracts on growth and keratinase activity in Trichophyton mentagrophytes. Iran Biomed J. 2003; 7(3):113-8.
35. Alves JC, Ferreira GF, Santos JR, Silva LC, Rodrigues JF, Neto WR, et al. Eugenol induces phenotypic alterations and increases the oxidative burst in Cryptococcus. Front Microbiol. 2017; 8:2419.
36. Kumari P, Mishra R, Arora N, Chatrath A, Gangwar R, Roy P, et al. Antifungal and anti-biofilm activity of essential oil active components against Cryptococcus neoformans and Cryptococcus laurentii. Front Microbiol. 2017; 8:2161.
37. Thirach S, Tragoolpua K, Punjaisee S, Khamwan C, Jatisatienr C, Kunyanone N. Antifungal activity of some medicinal plant extracts against Candida albicans and Cryptococcus neoformans. Acta Horticulturae. 2003; 597:217-21.
38. Ahmad A, Khan A, Khan LA, Manzoor N. In vitro synergy of eugenol and methyleugenol with fluconazole against clinical Candida isolates. J Med Microbiol. 2010; 59(Pt 10):1178-84.
39. Liaw SJ, Wu HC, Hsueh PR. Microbiological characteristics of clinical isolates of Cryptococcus neoformans in Taiwan: serotypes, mating types, molecular types, virulence factors, and antifungal susceptibility. Clin Microbiol Infect. 2010; 16(6): 696-703.
40. Yörük E, Sefer Ö, Sezer AS, Konukcu Z, Develi ES. Eugenol’ün Fusarium culmorum üzerindeki etkilerinin incelenmesi. J Instit Sci Technol. 2018; 8(2):215-21.