In Vitro Fungicidal Photodynamic Effect of Hypericin on Candida Species^†

Abstract

Hypericin is a natural photosensitizer considered for the new generation of photodynamic therapy (PDT) drugs. The aim of this study was to evaluate the in vitro fungicidal effect of hypericin PDT on various Candida spp., assessing its photocytotoxicity to keratinocytes (HaCaT) and dermal fibroblasts (hNDF) to determine possible side effects. A 3 log fungicidal effect was observed at 0.5 McFarland for two Candida albicans strains, Candida parapsilosis and Candida krusei with hypericin concentrations of 0.625, 1.25, 2.5 and 40 μm, respectively, at a fluence of 18 J cm(-2) (LED lamp emitting at 602 ± 10 nm). To obtain a 6 log reduction, significantly higher hypericin concentrations and light doses were needed (C. albicans 5 μM, C. parapsilosis 320 μM and C. krusei 320 μM; light dose 37 J cm(-2)). Keratinocytes and fibroblasts can be preserved by keeping the hypericin concentration below 1 μm and the light dose below 37 J cm(-2). C. albicans appears to be suitable for treatment with hypericin PDT without significant damage to cutaneous cells.

Malassezia Growth on Peritumoral Skin After Routine Methyl-5-Aminolevulinate Photodynamic Therapy for Actinic Keratosis and Nonmelanoma Skin Cancer

“…In line with this view, differential sensitivity to PDT in vitro has been described for other yeast species, such as Candida. 7 In most patients, we observed a decrease in the number of Malassezia colonies in the control area after exposure to red light illumination, in agreement with previous reports describing the inhibitory effects of a red light-emitting diode on the growth of bacteria and yeast. 8 There are 2 main limitations to our study.…”

Fungicidal effect of combined nano TiO2 with erythrosine for mediated photodynamic therapy on Candida albicans: an in vitro study

“…A previous study demonstrated that, with hypericin, an anthraquinone dye, the incubation time had no influence on photoinactivation of C. albicans [21], but too brief of an exposure might lead to the incomplete incorporation of the photosensitizer in microorganisms. The practical application time of the photosensitizer needs further investigation.…”

Photodynamic and Tissue Tolerable Plasma Therapies as Alternatives to Antimicrobials to Control Pathogenic Biofilms

“…The oral cavity sustains more than 700 species of microorganisms, few of which participate in the pathogenesis of various oral diseases, such as dental caries and candidiasis [35,36]. The main challenge regarding the treatment of these diseases resides in antimicrobial resistance, reoccurrence (treatment fail), interactions with other medical regimens, organ toxicity, staining potential, taste alteration, and compliance of the patients to achieve therapy success [36].…”

“…The main challenge regarding the treatment of these diseases resides in antimicrobial resistance, reoccurrence (treatment fail), interactions with other medical regimens, organ toxicity, staining potential, taste alteration, and compliance of the patients to achieve therapy success [36].…”