Cytotoxic Action of Artemisinin and Scopoletin on Planktonic Forms and on Biofilms of Candida Species

Abstract

We investigated the antifungal activities of purified plant metabolites artemisinin (Ar) and scopoletin (Sc) including inhibition, effects on metabolic activities, viability, and oxidative stress on planktonic forms and on preformed biofilms of seven Candida species. The characteristic minimum inhibitory concentration (MIC90) of Ar and Sc against Candida species ranged from 21.83–142.1 µg/mL and 67.22–119.4 µg/mL, respectively. Drug concentrations causing ≈10% CFU decrease within 60 min of treatments were also determined (minimum effective concentration, MEC10) using 100-fold higher CFUs than in the case of MIC90 studies. Cytotoxic effects on planktonic and on mature biofilms of Candida species at MEC10 concentrations were further evaluated with fluorescent live/dead discrimination techniques. Candida glabrata, Candida guilliermondii, and Candida parapsilosis were the species most sensitive to Ar and Sc. Ar and Sc were also found to promote the accumulation of intracellular reactive oxygen species (ROS) by increasing oxidative stress at their respective MEC10 concentrations against the tested planktonic Candida species. Ar and Sc possess dose-dependent antifungal action but the underlying mechanism type (fungistatic and fungicidal) is not clear yet. Our data suggest that Ar and Sc found in herbal plants might have potential usage in the fight against Candida biofilms.

Antibacterial Potency of Medicinal Plants including Artemisia annua and Oxalis corniculata against Multi-Drug Resistance E. coil

“…Aside from the emergence of antibiotic resistance, the side effects of antibiotics have prompted researchers to seek out new antimicrobials, particularly those derived from plants [42]. Although several studies, especially on A. annua, have been conducted due to their anti-malarial properties, the antimicrobial activity of A. annua and O. corniculata extracts was investigated in this study because of the importance and necessity of replacing antibiotics with plant products [21].…”

“…The explanation for this may be due to a greater variety of antibacterial compounds, the antimicrobial efficiency of essential oil materials, the type of plant cultivar, or the solvents used in the essential oil extraction, preparation, and so on [44]. The essential oil of this plant was the subject of the majority of antimicrobial studies performed on it [21][22][23][24]. The extracts of this plant had almost similar bacteriostatic and bacteriocide effects.…”

“…This plant has been used to treat malaria since ancient times [19]. The anti-malarial property of this plant is due to the presence of artemisinin sesquiterpene, and this plant has the potential for commercial development because of this compound [21,22]. Moreover, this plant has antimicrobial, anticancer, anti-inflammatory, antipyretic, antiparasitic properties due to the existence of secondary metabolites such as flavonoids, monoterpenoids, sesquiterpenoids, coumarins, and aliphatic and lipid compounds [23,24].…”

Artemisia scoparia and Metabolic Health: Untapped Potential of an Ancient Remedy for Modern Use

“…Efforts are ongoing to develop synthetic derivatives of scopoletin and to characterize and improve its bioavailability and pharmacokinetic properties (96). Finally, a handful of other bioactivities have been reported for scopoletin, among them the promotion of melanogenesis (296-298) and osteoprotective (292,293), antitussive (515), gastrokinetic (294), and antimicrobial properties (165,(265)(266)(267)(268)(269)(270)(271)(272)(273)(274)(275)(276)(277)(278)516), as well as antiaging effects in skin and lung fibroblasts (289,290).…”

Fungal Biofilms as a Valuable Target for the Discovery of Natural Products That Cope with the Resistance of Medically Important Fungi—Latest Findings

“…In addition, this compound was able to modulate the transcription of related genes in this fungus, as described in Table 4 . Das et al [ 158 ] showed that artemisinin (Ar), the sesquiterpene lactone isolated from Artemisia annua L. (Asteraceae), and scopoletin (Sc), the 7-hydroxy-6-methoxy coumarin present in several spp., were tested on mature biofilms of different albicans and non- albicans Candida strains. The results demonstrated that Ar was more active than Sc in disrupting the preformed EPM-covered biofilm structure and in killing the sessile cell population at their respective MBEC 10 .…”