Photoactivated riboflavin inhibits planktonic and biofilm growth of Candida albicans and non-albicans Candida species

Nuratiqah Farah; Chee Woei Lim; Voon Kin Chin; Pei Pei Chong; Rusliza Basir; Wendy Wai Yeng Yeo; Sun Tee Tay; Sulin Choo; Tze Yan Lee

doi:10.1016/j.micpath.2024.106665

Photoactivated riboflavin inhibits planktonic and biofilm growth of Candida albicans and non-albicans Candida species

Microb Pathog. 2024 Apr 27:191:106665. doi: 10.1016/j.micpath.2024.106665. Online ahead of print.

Authors

Nuratiqah Farah¹, Chee Woei Lim¹, Voon Kin Chin², Pei Pei Chong³, Rusliza Basir⁴, Wendy Wai Yeng Yeo⁵, Sun Tee Tay⁶, Sulin Choo³, Tze Yan Lee⁷

Affiliations

¹ Department of Medicine, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, 43400, UPM Serdang, Selangor, Malaysia.
² Faculty of Medicine, Nursing, and Health Sciences, SEGi University, Kota Damansara, 47810, Petaling Jaya, Selangor, Malaysia.
³ School of Biosciences, Taylor's University, No 1, Jalan Taylor's, 47500, Subang Jaya, Selangor, Malaysia.
⁴ Department of Human Anatomy, Faculty of Medicine & Health Sciences, Universiti Putra Malaysia, 43400, UPM Serdang, Selangor, Malaysia.
⁵ School of Pharmacy, Monash University Malaysia, Jalan Lagoon Selatan, 47500, Bandar Sunway, Selangor Darul Ehsan, Malaysia.
⁶ Department of Medical Microbiology, Faculty of Medicine, University of Malaya, 50603, Kuala Lumpur, Wilayah Persekutuan, Malaysia.
⁷ Perdana University School of Liberal Arts, Science and Technology (PUScLST), Suite 9.2, 9th Floor, Wisma Chase Perdana, Changkat Semantan, Damansara Heights, 50490, Kuala Lumpur, Malaysia. Electronic address: tzeyan.lee@perdanauniversity.edu.my.

PMID: 38685359
DOI: 10.1016/j.micpath.2024.106665

Abstract

Fungal infections caused by Candida species pose a serious threat to humankind. Antibiotics abuse and the ability of Candida species to form biofilm have escalated the emergence of drug resistance in clinical settings and hence, rendered it more difficult to treat Candida-related diseases. Lethal effects of Candida infection are often due to inefficacy of antimicrobial treatments and failure of host immune response to clear infections. Previous studies have shown that a combination of riboflavin with UVA (riboflavin/UVA) light demonstrate candidacidal activity albeit its mechanism of actions remain elusive. Thus, this study sought to investigate antifungal and antibiofilm properties by combining riboflavin with UVA against Candida albicans and non-albicans Candida species. The MIC₂₀ for the fluconazole and riboflavin/UVA against the Candida species tested was within the range of 0.125-2 μg/mL while the SMIC₅₀ was 32 μg/mL. Present findings indicate that the inhibitory activities exerted by riboflavin/UVA towards planktonic cells are slightly less effective as compared to controls. However, the efficacy of the combination towards Candida species biofilms showed otherwise. Inhibitory effects exerted by riboflavin/UVA towards most of the tested Candida species biofilms points towards a variation in mode of action that could make it an ideal alternative therapeutic for biofilm-related infections.

Keywords: Candida albicans; Fluconazole; Non-albicans Candida species; Riboflavin; UVA light.