Recently, essential rose oils and rose products have gained increasing importance in both the cosmetic and food industries, as well as in the composition of medicinal products. We investigated the in vitro antiviral activity of essential oil and floral water from Rosa damascena Mill against herpes simplex virus type 1 (HSV-1) infection in rabbit retinal cells (RRCs). The composition of the main chemical components in the rose essential oil was determined by means of gas chromatographic analysis. The effect on the viral replication cycle was determined using the cytopathic effect (CPE) inhibition assay. The virucidal activity, the effect on the adsorption stage of the virus to the host cell, and the protective effect on healthy cells were evaluated using the endpoint dilution method. The effects were determined as deviation in the viral titer, Δlg, for the treated cells from the one for the untreated viral control. The identified main active components of rose oil are geraniol (28.73%), citronellol (21.50%), nonadecane (13.13%), nerol (5.51%), heneicosane (4.87%), nonadecene (3.93), heptadecane (2.29), farnesol (2.11%), tricosane (1.29%), eicosane (1.01%), and eugenol (0.85%). The results demonstrated that both rose products do not have a significant effect on the virus replication but directly affect the viral particles and reduce the viral titer by Δlg = 3.25 for floral water and by Δlg = 3.0 for essential oil. Significant inhibition of the viral adsorption stage was also observed, leading to a decrease in the viral titers by Δlg = 2.25 for floral water and by Δlg = 2.0 for essential oil. When pretreating healthy cells with rose products, both samples significantly protected them from subsequent infection with HSV-1. This protective effect was more pronounced for the oil (Δlg = 2.5) compared to the one for the floral water (Δlg = 2.0). We used the in silico molecular docking method to gain insight into the mechanism of hindrance of viral adsorption by the main rose oil compounds (geraniol, citronellol, nerol). These components targeted the HSV-1 gD interaction surface with nectin-1 and HVEM (Herpesvirus Entry Mediator) host cell receptors, at N-, C-ends, and N-end, respectively. These findings could provide a structural framework for further development of anti-HSV-1 therapeutics.

The side effects of conventional cancer treatments, such as chemotherapy, radiotherapy, etc., worsen the quality of life of patients. Therefore, it is necessary to explore the possibilities of creating new drugs containing natural products with low toxicity. The experimental scientific pharmacological research of rose preparations in Bulgaria began in the first half of the 20th century. Bulgarian rose essential oil (BREO) is qualified by GC FID analysis. To study the effect of the BREO, we used HCT-8 and HT-29 tumor cell lines. As a model of healthy tissue, we used the non-tumorigenic cells MCF-12F. Cells were treated with twofold increasing concentrations of BREO from 7.5 µg/mL to 1000 µg/mL. The NRU test and MTT assay were used for evaluation of the safety, antiproliferative activity and colony formation assay. Our results showed low cytotoxicity (CC₅₀ = 629.72 ± 22.38 μg/mL) and high level of photosafety (PIF = 0.92) of BREO. The antiproliferative activity test shows that the BREO has an IC₅₀ = 290.45 ± 10.79 μg/mL for the HT-29 cells. In the normal cell line MCF-12F, this effect is lower (IC₅₀ = 383.90 ± 34.75 μg/mL). Furthermore, colony forming assay showed a significant reduction in IC₅₀ value (IC₅₀ = 163.79 ± 10.25 μg/mL) in HT-29 cells. The in silico experiments confirmed the potential of the BREO for antiproliferative effect and further activation of different pathways leading to apoptosis.