Effect of Thyme, Clove and Cinnamon Essential Oils on Candida Albicans and Moulds Isolated from Different Sources

Investigations of the Surface of Heritage Objects and Green Bioremediation: Case Study of Artefacts from Maramureş, Romania

Old textiles are important elements of thecultural heritage. As a result of their composition mostly of natural elements old textiles are extremely prone to physical and chemical degradation due to fungal action. The treatments usually applied for the cleaning of heritage textiles target the use of synthetic fungicides, which are potentially harmful to both human health and the environment. Numerous studies highlight as an alternative to the use of conventional antifungals, the employment of essential oils and plant extracts, which are environmentally friendly and which have no adverse effects on human health. Against this background the present study aims to test six essential oils (Lavandula angustifolia, Citrus limon, Mentha piperita, Marjoram, Melaleuca alternifolia, Origanum vulgare) to establish their inhibitory effects against fungi identified on an old piece of traditional Romanian clothing from Maramureş. For the study, the types of fungi present on the objects was determined primarily through the open plates technique and microscopic identification. After identification, the essential oils were applied to the delimited surfaces, and their effects observed up to 32 days after application. The results show that these essential oils have a strong inhibitory effect on such fungal genera as Penicillinum sp., Cladosporium sp., Aspergillus spp., Candida guillermondii, Botrys sp., Mucor sp., having no observable side-effects on the physical properties of the materials concerned. The antimicrobial effects that essential oils and plant extracts have in the short term must be tested in future to ensure the enhanced preservation of heritage textiles and the health integrity of the restorers and visitors who view them in museums, collections or exhibitions.

An In Vitro Study on the Antimicrobial Properties of Essential Oil Modified Resin Composite against Oral Pathogens

Modifying the composition of dental restorative materials with antimicrobial agents might induce their antibacterial potential against cariogenic bacteria, e.g., S. mutans and L. acidophilus, as well as antifungal effect on C. albicans that are major oral pathogens. Essential oils (EOs) are widely known for antimicrobial activity and are successfully used in dental industry. The study aimed at evaluating antibacterial and antifungal activity of EOs and composite resin material (CR) modified with EO against oral pathogens. Ten EOs (i.e., anise, cinnamon, citronella, clove, geranium, lavender, limette, mint, rosemary thyme) were tested using agar diffusion method. Cinnamon and thyme EOs showed significantly highest antibacterial activity against S. mutans and L. acidophilus among all tested EOs. Anise and limette EOs showed no antibacterial activity against S. mutans. All tested EOs exhibited antifungal activity against C. albicans, whereas cinnamon EO showed significantly highest and limette EO significantly lowest activity. Next, 1, 2 or 5 µL of cinnamon EO was introduced into 2 g of CR and microbiologically tested. The modified CR showed higher antimicrobial activity in comparison to unmodified one. CR containing 2 µL of EO showed the best antimicrobial properties against S. mutans and C. albicans, while CR modified with 1 µL of EO showed the best antimicrobial properties against L. acidophilus.

Electrospun essential oil-polycaprolactone nanofibers as antibiofilm surfaces against clinical Candida tropicalis isolates

OBJECTIVE

As an approach to prevent biofilm infections caused by Candida tropicalis on various surfaces, determination of effect of biodegradable polycaprolactone nanofibers (PCLNFs) with different concentrations of two different essential oils were tested in this study.

RESULTS

Both of the tested essential oils exhibited antifungal effect (minimal inhibitory concentration; 0.25-0.49 µL/mL, minimal fungicidal concentration; 0.25-0.49 µL/mL, depending on the C. tropicalis strain) (Zone of inhibition caused by 500 μL/mL concentration of oils; 28-56 mm). 0, 2, 4% clove oil PCLNFs and 0, 2, 4% red thyme oil-PCLNFs were free from bead formation and uniform in diameter. Diameters of all essential oil containing PCLNFs were ranged from 760 to 1100 nm and were significantly different from 0% essential oil-PCLNF (P < 0.05). 0, 2, 4% clove oil-PCLNFs were significantly more hydrophobic compared to 8% clove oil-PCLNF (P < 0.01), whereas 0% and 2% red thyme oil-PCLNFs were significantly more hydrophobic compared to 4% and 8% red thyme oil PCLNFs (P < 0.01). Highest amount of biofilm inhibition was observed by 4% clove oil-PCLNF and by 4% red thyme oil-PCLNF.

CONCLUSIONS

Clove and red thyme oils may be used not only as antifungals but also as biofilm inhibitive agents on surfaces of biomaterials that are frequently contaminated by C. tropicalis, when they are incorporated into PCLNFs.