The Rosa alba L. and Rosa damascena Mill. growing in Bulgaria are known for their extremely fine essential oil and valuable hydrosols. Irrespectively of its wide use in human life, little research exists on the cytotoxic and genotoxic activity of the hydrosols. This set our goal to conduct cytogenetic analyses to study these effects. A complex of classical cytogenetic methods was applied in three types of experimental test systems—higher plant in vivo, ICR mice in vivo, and human lymphocytes in vitro. Mitotic index, PCE/(PCE + NCE) ratio, and nuclear division index were used as endpoints for cytotoxicity and for genotoxicity—induction of chromosome aberrations and micronuclei. Rose hydrosol treatments range in concentrations from 6% to 20%. It was obtained that both hydrosols did not show considerable cytotoxic and genotoxic effects. These effects depend on the type of the tested rose hydrosols, the concentrations applied in the experiments, and the sensitivity and specificity of the test systems used. Human lymphocytes in vitro were the most sensitive to hydrosols, followed by higher plant and animal cells. Chromosomal aberrations and micronucleus assays suggested that R. damascena and R. alba hydrosols at applied concentrations possess low genotoxic risk. Due to the overall low values in terms of cytotoxic and/or genotoxic effects in all test systems, hydrosols are promising for further use in various areas of human life.

Regulatory changes in the EU for safety purposes require strict control and high safety standards for essential oils obtained by steam distillation, as they are classified as chemical mixtures with potential toxic effects. Subcritical water extracts (SWEs) are considered safer. This study evaluated the cytotoxicity and genotoxicity of SWEs from Rosa damascena Mill. and Rosa alba L. in three test systems at different hierarchical levels: higher plants (root meristems of Hordeum vulgare), somatic cells of Mus musculus ICR strain, and human lymphocytes in vitro. The chromatographic fingerprint of the extracts revealed the presence of key components such as flavonoids, phenolic acids, and glycoside derivatives, with species-dependent variations and concentrations. No significant cytotoxicity was detected in the concentration range of 6–20%. SWE from R. alba showed a higher level of safety at high doses. Genotoxicity tests showed a weak, dose-dependent induction of chromosomal aberrations and micronuclei in barley and lymphocytes (greater in R. alba), a lack of genotoxicity in mouse bone marrow, and a slight increase in micronuclei in mouse erythrocytes after exposure to R. alba extract. The results highlight the suitability of SWEs from R. damascena and R. alba for safe application in the medical, food, and cosmetic industries.

Rosa centifolia L. and Rosa gallica L. (Rosaceae) are grown as raw materials for valuable essential oils and hydrosols. There are scarce data about the biological activities and the genoprotective potential of the hydrosols of these roses. The aim of the study was to provide information on their cytotoxic/genotoxic activity and anti-cytotoxic/anti-genotoxic capacity against mutagenic N-methyl-N′-nitro-N-nitrosoguanidine (MNNG). The evaluation was performed using classical tests for chromosomal aberrations and micronuclei in the higher plant Hordeum vulgare and human lymphocyte test systems. The experimental schemes included combined hydrosol and mutagen treatment. Both hydrosols (6, 14, 20%) had no cytotoxic effect on barley and showed low genotoxicity in both test systems as the injuries were enhanced to a lesser extent compared to the controls. Lymphocytes were more susceptible than H. vulgare. Under the conditions of combined treatment, it was found that the two hydrosols possessed good anti-cytotoxic and anti-genotoxic potential against MNNG. Both rose products exerted genoprotective potential to a similar extent, decreasing the frequencies of aberrations in chromosomes and micronuclei to a significant degree in both types of cells when non-toxic concentrations of hydrosols were applied before MNNG. This was performed both with and without any inter-treatment time. The observed cytoprotective/genoprotective potential suggests that these hydrosols are promising for further application in phytotherapy and medicine.

The highly valued oil of Rosa damascena Mill. (Rosaceae), widely used in high perfumery, cosmetics, and other spheres of human life, obliges us to know and study the safety profile of the product obtained from the water–steam distillation of fresh rose petals. The genotoxicity of the essential oil (EsO) has not been thoroughly studied despite its wide range of applications. That predetermined the object of this study—to evaluate, through classical cytogenetic methods, the possible cytotoxic/genotoxic activities of R. damascena Mill. EsO (EsORdm) in three different test systems: plant root meristem cells, mammalian bone marrow cells, and human lymphocyte cultures. The rose essential oil showed varying concentration- and time-dependent cytotoxic and genotoxic effects depending on the test system used, and it was established that the oil showed moderate cytotoxicity in lymphocyte cultures and non-high cytotoxicity in ICR mice but none in barley. Both barley and human lymphocytes showed a genotoxic effect with a dose-dependent increase in chromosomal aberrations (CAs) and a substantial rise in micronucleus (MN) frequency, while no genotoxicity was observed in bone marrow cells at the applied concentrations. Human lymphocytes exhibited the highest susceptibility to cytotoxic and genotoxic actions of the EsO. As a valuable plant-derived aromatic product with versatile uses in human life, R. damascena Mill. essential oil should be used in an appropriate concentration range tailored to cellular sensitivity.

Bulgarian Rosa damascena Mill. is has been known since ancient times for its high-quality oil, hydrosol, and other aromatic products. Rose hydrosol has various biological activities, but no research on its anticytotoxic/antigenotoxic effects exists. This study aimed to assess its defense potential against the genotoxin N-methyl-N′-nitro-N-nitrosoguanidine and to test its cytotoxic/genotoxic activity in plant and human lymphocyte test systems. Endpoints for cytotoxicity (mitotic index and nuclear division index) and genotoxicity (chromosome aberration and micronuclei) were used. Hydrosol was applied as a single treatment in concentrations ranging from 3% to 20% (4 h) to assess its cytotoxic and genotoxic effects. Its protective potential against MNNG was tested by applying an experimental scheme involving (i) conditioning treatment with non-toxic or slightly toxic concentrations of hydrosol, followed by genotoxin challenge (50 μg/mL) with a 4 h intertreatment time and (ii) treatment with hydrosol and mutagen with no time between the treatments. Hydrosol induces low cytotoxicity and clastogenicity, demonstrating cytoprotective/genoprotective effects against the mutagen in both applied test systems. The hydrosol defense potential was expressed by a more than twofold reduction in both chromosomal aberrations and micronuclei and by enhancing the mitotic activity compared with that of the mutagen, regardless of the experimental conditions. The results are promising for further hydrosol applications in pharmaceutical and medical practice.