Effect of Allium cepa on LAC1 gene expression and physiological activities in Cryptococcus neoformans

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: This study aimed to investigate the effects of Allium cepa ethanolic extract (EAC) on Cryptococcus neoformans biological activities and LAC1 gene expression.
Materials and Methods: The minimum inhibitory concentration (MIC) of EAC was determined based on the Clinical and Laboratory Standards Institute M27-A4 method at a concentration range of 125- 4000 µg/ml. The EAC synergism activity was determined in combination with fluconazole (FCZ) as an antifungal azole. Laccase activity, melanin production, and cell membrane ergosterol content of C. neoformans were assessed at the 0.5× MIC concentration of EAC (1000 μg/ml) and FCZ (64
μg/ml) by approved methods. The expression of the LAC1 gene was studied in the fungus exposed to 0.5× MIC concentration of EAC and FCZ using the real-time polymerase chain reaction.
Results: Based on obtained results, MIC of EAC and FCZ were 2000 and 128 μg/ml,respectively. A combinatory effect was reported for FCZ and EAC by a fractional inhibitory concentration index of 0.25. The cell membrane ergosterol content was inhibited in EAC- and FCZ-treated C. neoformans by 58.25% and 49.85%, respectively.The laccase activity and melanin production were reduced in EAC-treated C. neoformans by 45.37% and 51.57%, and in FCZ-treated fungus by 54.64% and 53.68%, respectively.The expression of fungal LAC1 at messenger RNA (mRNA) level was measured 0.46
and 0.58 folds and significantly decreased in both EAC- and FCZ-treated C. neoformans at the 0.5×MIC concentration, respectively (p <0.05).
Conclusion: The findings revealed that EAC contains inhibitory compounds which interact with biological activities in C. neoformans and thereby, it could be considered as a potential source for the development of novel antifungal drugs.


1. Rajasingham, R., et al., Global burden of disease of HIVassociated cryptococcal meningitis: an updated analysis. The
Lancet Infectious Diseases.2017;
17(8): p. 873-881.
2. Park BJ, Wannemuehler KA, Marston BJ, Govender N, Pappas
PG, Chiller TM. Estimation of the current global burden of
cryptococcal meningitis among persons living with HIV/AIDS.
AIDS. 2009;23(4):525-30.
3. Almeida F, Wolf JM, Casadevall A. Virulence-associated
enzymes of
Cryptococcus neoformans. Eukaryot Cell. 2015;
4. Zaragoza O. Basic principles of the virulence of
Virulence. 2019;10(1):490-501.
5. Piscitelli, Alessandra P, Amore A, Vincenza F. Last advances in
synthesis of added value compounds and materials by laccase
mediated biocatalysis. Curr Organ Chem. 2012;16(21): 2508-2524.
6. Rossi SA, de Oliveira HC, Agreda-Mellon D, Lucio J, MendesGiannini MJ, García-Cambero JP, Zaragoza O. Identification of
off-patent drugs that show synergism with Amphotericin B or
that present antifungal action against
Cryptococcus neoformans
and Candida spp. Antimicrobial Agents and Chemotherapy.
7. Cheuka PM, Mayoka G, Mutai P, Chibale K. The role of natural
products in drug discovery and development against neglected
tropical diseases. Molecules. 2017;22(1):58.
8. Arif T, Bhosale JD, Kumar N, Mandal TK, Bendre RS, Lavekar
GS, Dabur R. Natural products–antifungal agents derived from
plants. J Asian Natural Products Res. 2009;11(7):621-38.
9. Alviano DS, Alviano CS. Plant extracts: search for new
  alternatives to treat microbial diseases. Current Pharmaceutical
Biotechnology. 2009;10(1):106-21.
10. Abad MJ, Ansuategui M, Bermejo P. Active antifungal
substances from natural sources. Arkivoc. 2007;7(11):6-145.
11. Negri M, Salci TP, Shinobu-Mesquita CS, Capoci IR, Svidzinski
TI, Kioshima ES. Early state research on antifungal natural
products. Molecules. 2014;19(3):2925-56.
12. Li X, Hou Y, Yue L, Liu S, Du J, Sun S. Potential targets for
antifungal drug discovery based on growth and virulence in
Candida albicans. Antimicrob Agents Chemother. 2015;
13. Thammasit P, Iadnut A, Mamoon K, Khacha-Ananda S,
Chupradit K, Tayapiwatana C, Kasinrerk W, Tragoolpua Y,
Tragoolpua K. A potential of propolis on major virulence factors
Cryptococcus neoformans. Microbial pathogen. 2018;
14. de Aguiar Cordeiro R, Nogueira GC, Brilhante RS, Teixeira CE,
Mourão CI, Castelo DD, Paiva MD, Ribeiro JF, Monteiro AJ,
Sidrim JJ, Rocha MF. Farnesol inhibits in vitro growth of the
Cryptococcus neoformans species complex with no significant
changes in virulence-related exoenzymes. Vet Microbiol.
15. Samie S, Trollope KM, Joubert LM, Makunga NP, Volschenk
H. The antifungal and
Cryptococcus neoformans virulence
attenuating activity of
Pelargonium sidoides extracts. J
Ethnopharma. 2019;235:122-32.
16. Upadhyay RK. Nutraceutical, pharmaceutical and therapeutic
uses of
Allium cepa: A review. Int J Green Pharmacy (IJGP).
17. Bystrická J, Musilová J, Vollmannová A, Timoracká M,
Kavalcová P. Bioactive components of onion (Allium cepa L.)—
A Review. Acta Alimentaria. 2013;42(1):11-22.
18. Fredotović Ž, Puizina J. Edible Allium species: Chemical
composition, biological activity and health effects. Italian
Journal of Food Science. 2019;31(1).
19. Akash MS, Rehman K, Chen S. Spice plant
Allium cepa: Dietary
supplement for treatment of type 2 diabetes mellitus. Nutrition.
20. Khan SA, Jameel M, Kanwal S, Shahid S. Medicinal importance
Allium species: a current review. Int J Pharm Sci Res.
21. Pareek S, Sagar NA, Sharma S, Kumar V. Onion (
Allium cepa
L.). Fruit and vegetable phytochemicals: chemistry and human
health. 2nd ed. Hoboken, NJ: Wiley Blackwell. 2017:1145-62.
22. S Bisen P, Emerald M. Nutritional and therapeutic potential of
garlic and onion (
Allium sp.). Current Nutrition & Food Science.
23. Shafiq S, Shakir M, Ali Q. Medicinal uses of onion (
Allium cepa
L.): an overview. Life Science Journal. 2017;14(6).
24. Shams-Ghahfarokhi M, Shokoohamiri MR, Amirrajab N,
Moghadasi B, Ghajari A, Zeini F, Sadeghi G, RazzaghiAbyaneh M. In vitro antifungal activities of
Allium cepa, Allium
and ketoconazole against some pathogenic yeasts and
dermatophytes. Fitoterapia. 2006;77(4):321-3.
25. Lanzotti V, Romano A, Lanzuise S, Bonanomi G, Scala F.
Antifungal saponins from bulbs of white onion,
Allium cepa L.
Phytochem. 2012;74:133-9.
26. Kocić
Tanackov S, Dimić G, Mojović L, GvozdanovićVarga J,
Vuković A, Tomović V, Šojić B, Pejin J. Antifungal
activity of the onion (Allium cepa L.) essential oil against
Aspergillus, Fusarium and Penicillium species isolated from
food. Journal of Food Processing and Preservation.
27. Balamanikandan T, Balaji S, Pandirajan J. Biological Synthesis
of silver nanoparticles by using onion (
Allium cepa) extract and
their antibacterial and antifungal activity. World App Sci J.
28. Ikegbunam M, Ukamaka M, Emmanuel O. Evaluation of the
antifungal activity of aqueous and alcoholic extracts of six
spices. American Journal of Plant Sciences. 2016;7(1):118-25.
29. CLSI. Reference Method for Broth Dilution Antifungal
Susceptibility Testing of Yeasts. 4
th ed. CLSI standard M27-Ed4.
Wayne, PA: Clinical and Laboratory Standards Institute; 2017.
30. Pfaller, M. and Diekema D. Rare and emerging opportunistic
fungal pathogens: concern for resistance beyond
and Aspergillus fumigatus. Journal of clinical
microbiology, 2004. 42(10):4419-31.
31. Hassanpour P, Shams-Ghahfarokhi M, Razzaghi-Abyaneh M.
Antifungal activity of eugenol on
Cryptococcus neoformans
biological activity and Cxt1p gene expression. Curr Med Mycol.
32. Arthington-Skaggs BA, Jradi H, Desai T, et al. Quantitation of
ergosterol content: novel method for determination of
fluconazole susceptibility of
Candida albicans. J Clin Microbiol.
33. Ikeda R, Sugita T, Jacobson ES, Shinoda T. Effects of melanin
upon susceptibility of
Cryptococcus to antifungals. Microbiol
Immunol. 2003;47(4):271-7.
34. Albino A. Dias, António J.S. Matos, Irene Fraga, Ana Sampaio,
Rui M.F. Bezerra. An easy method for screening and detection
of laccase activity. The Open Biotechnol J. 2017; 11:89-93.
35. Jahanshiri Z, Shams-Ghahfarokhi M, Allameh A, RazzaghiAbyaneh M. Inhibitory effect of eugenol on aflatoxin B
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.
36. García-Rodas R, Trevijano-Contador N, Román E, Janbon G,
Moyrand F, Pla J, Casadevall A, Zaragoza O. Role of Cln1
during melanization of
Cryptococcus neoformans. Front
Microbiol. 2015;6:798.
37. Tagoe DNA, Nyarko HD, Akpaka R. A comparison of the
antifungal properties of onion (
Allium cepa), Ginger (Zingiber
) and garlic (Allium sativum) against Aspergillus
Aspergillus niger and Cladosporium herbarum. Res J
Medicin Plant 5(3):281-7
38. Shams-Ghahfarokhi M, Goodarzi M, Al-Tiraihi T, RazzaghiAbyaneh M, Seyedipour GH. Morphological evidences for
onion-induced growth inhibition of
Trichophyton rubrum and
Trichophyton mentagrophytes. Fitoterapia. 2004;75: 645-55.
39. Genatrika E., Sundhani E, Oktaviana MI. Gel potential of red
onion (
Allium cepa L.) ethanol extract as antifungal cause tinea
pedis. J Pharm Bioallied Sci. 2020; 12(6), 733-6.
40. Nickavara B., Yousefian N. Inhibitory effects of Six Allium
species on α-amylase enzyme activity. Iran J Pharm Res. 2009;8
(1): 53-7.
Volume 7, Issue 1
March 2021
Pages 38-43
  • Receive Date: 16 February 2021
  • Revise Date: 03 May 2021
  • Accept Date: 05 May 2021
  • First Publish Date: 05 May 2021
  • Publish Date: 01 March 2021