In our study, we investigated the chemical composition and cytotoxic activity of essential oils isolated from Dalmatian sage (Salvia officinalis L.) collected along the Adriatic coast of Croatia. Scanning electron microscopy (SEM) was used to examine the morphology of the stem and leaf surfaces. Essential oil excretory glands were detected on both the leaves and stem surfaces. The essential oils were isolated by hydrodistillation, and their chemical composition was determined by gas chromatography and mass spectrometry (GC-MS). Sage essential oils were mixtures of terpene compounds, among which the most common were: α- and β-thujone, camphor, and 1,8-cineol. Cytotoxic activity was tested using MTS assay on multiple cell lines: normal and immortalized fibroblasts (HF77FA and HDF-Tert), immortalized lung line (BEAS-2B), and breast adenocarcinoma (MDA-MB-231). The growth of treated cells was determined relative to control conditions without treatment. The immortalized lung line was the least resistant to the activity of the essential oils, whereas immortalized fibroblasts were the most resistant. Statistical analysis has connected the cytotoxic effect and chemical composition of the studied essential oils. To the best of our knowledge, this work is the first testing of the cytotoxic activity of S. officinalis EO’s on the BEAS-2B, HF77FA, and HDF-Tert cell lines. The presented data on essential oil chemical composition and cytotoxic effect on 4 types of human cells supports pharmacotherapeutic potential this plant is known to have.

The essential oils from the Centaurea genus are well known for their pharmacological properties. The most abundant and dominant chemical components in Centaurea essential oils are ß-caryophyllene, hexadecanoic acid, spathulenol, pentacosane, caryophyllene oxide, and phytol. However, whether these dominant components are the key drivers for observed antimicrobial activity remains unclear. Thus, the aim of this study was dual. Here we provide comprehensive, literature-based data to correlate the chemical compounds in Centaurea essential oils with the tested antimicrobial activity. Secondly, we characterized the essential oil of Centaurea triumfettii All. squarrose knapweed using coupled system gas chromatography–mass spectrometry and tested its phytochemicals for antimicrobial activity against E. coli and S. epidermis using disc diffusion assay and monitoring their growth in Muller Hinton broth. The most abundant compounds in C. triumfettii essential oil were hexadecanoic acid (11.1%), spathulenol (10.8%), longifolene (8.8%), germacrene D (8.4%), aromadendrene oxide (6.0%) and linoleic acid (5.3%). Based on our analysis of literature data from other Centaurea essential oils, they were positively correlated with antimicrobial activity. Using an agar disk diffusion method, tested chemical constituents did not show experimental evidence to support this positive correlation to antimicrobial activity when we tested them as pure components. The antibacterial effect of essential oil constituents may be related to a complex synergistic, rather than a single component as suggested by performed network pharmacology analysis, underlying the theoretical interactions between the essential oil phytochemicals listed as potentially responsible for antimicrobial activity and should be confirmed in further in-depth studies. This is the first report on the comparative analysis of Centaurea essential oils with good antimicrobial activity, as well as the first analysis of chemical components of the essential oil from C. triumfettii and the first report of antimicrobial activity of the representative, pure components: aromadendrene, germacrene D, spathulenol, longifolene, and the mixture of selected chemical compounds. This work contributes to the body of knowledge on the genus Centaurea and C. triumfettii species.

Helichrysum italicum (Roth) G. Don (Asteraceae), also known as immortelle, usually grows in the Mediterranean area. The composition of the essential oil (EO) of immortelle is a mixture of various aromatic substances, mainly monoterpenes and sesquiterpenes. Distillation is the most widely used method for extraction of EO immortelle, although the yield is very low (<1%). In this work, we aim to investigate how the use of different distillation methods affects the yield and chemical composition of immortelle EO. For this purpose, we applied two conventional methods: steam distillation (SD) and hydrodistillation (HD), and a modern (environmentally friendly) technique—microwave-assisted distillation (MAD). Wild immortelles from four different locations in Croatia were collected and carefully prepared for extraction. Each sample was then analyzed by gas chromatography–mass spectrometry (GC-MS). GraphPad Prisma statistical software was used to study the statistics between different groups of connections and analyze the data on the number of connections. The results show that HD gives a significantly higher yield (0.31 ± 0.09%) compared to MAD (0.15 ± 0.03%) and SD (0.12 ± 0.04%). On the other hand, the highest number of chemical compounds was identified with MAD (95.75 ± 15.31%), and most of them are subordinate compounds with complex structures. SD isolated EOs are rich in derived acyclic compounds with the highest percentage of ketones. The results show that the application of different distillation methods significantly affects the composition of the obtained immortelle EO, considering the yield of EO, the number of isolated, derived and non-derived compounds, chemotypes and compounds with simple (acyclic) and complex structures.

Helichrysum italicum (Roth) G. Don., immortelle, is a plant species used in ethnomedicine and the food industry as a spice added to food, beverages, and bakery products. It has been shown to possess various biological activities, such as antioxidant and antibacterial activity, making it useful as a natural preservative. We investigated the phytochemical profile and biological activity of H. italicum essential oils from wild-grown plant material collected from natural habitats in the Republic of Croatia and Bosnia and Herzegovina. Using high-resolution scanning electron microscopy (SEM), a visual investigation of plant organs (stem, leaf, and flower) was performed, confirming the presence of essential oil reservoirs on the surface of all examined plant organs. Essential oils were isolated by hydrodistillation in the Clevenger apparatus. The chemical composition of the essential oils was determined using the GC-MS analytical technique. Cytotoxic activity tests were performed in vitro on three cell lines: skin (fibroblast), lung, and breast cancer. Using statistical tools, the synergistic and selective effects of H. italicum essential oil on healthy and tumor cells were correlated to chemical composition and cytotoxic activity. The synergistic and antagonistic effects of H. italicum essential oil’s individual components were simulated by testing pure compounds and their mixture of cytotoxic activity on fibroblasts and breast cancer cells. The results confirm that essential oil’s biological activity is much greater than the sum of the effects of its components. The present data are novel contributions to the body of knowledge on the biological activity of this species used in the food industry.

Airborne particulate matter (PM) is a vector of many toxic pollutants, including polyaromatic hydrocarbons (PAHs) and their derivatives. Especially harmful is the fine fraction (PM_2.5), which penetrates deep into the lungs during inhalation and causes various diseases. Amongst PM_2.5 components with toxic potential are nitrated PAHs (NPAHs), knowledge of which is still rudimentary. Three of the measured NPAHs (1-nitropyrene (1-nP), 9-nitroanthracene (9-nA), and 6-nitrochrysene (6-nC)) were detected in ambient PM_2.5 from Ljubljana, Slovenia, along with thirteen non-nitrated PAHs. The highest concentrations of pollutants, which are closely linked with incomplete combustion, were observed in the cold part of the year, whereas the concentrations of NPAHs were roughly an order of magnitude lower than those of PAHs throughout the year. Further on, we have evaluated the toxicity of four NPAHs, including 6-nitrobenzo[a]pyrene (6-nBaP), to the human kidney cell line, HEK293T. The most potent was 1-nP (IC₅₀ = 28.7 µM), followed by the other three NPAHs, whose IC₅₀ was above 400 or 800 µM. According to our cytotoxicity assessment, atmospheric 1-nP is the most harmful NPAH among the investigated ones. Despite low airborne concentrations of NPAHs in ambient air, they are generally considered harmful to human health. Therefore, systematic toxicological assessment of NPAHs at different trophic levels, starting with cytotoxicity testing, is necessary in order to accurately evaluate their threat and adopt appropriate abatement strategies.

DNA-protein cross-links (DPCs) are highly toxic DNA lesions that block replication and transcription, but their impact on organismal physiology is unclear. We identified a role for the metalloprotease SPRTN in preventing DPC-driven immunity and its pathological consequences. Loss of SPRTN activity during replication and mitosis lead to unresolved DNA damage, chromosome segregation errors, micronuclei formation, and cytosolic DNA release that activates the cyclic GMP-AMP synthase (cGAS)–stimulator of interferon genes (STING) pathway. In a Sprtn knock-in mouse model of Ruijs-Aalfs progeria syndrome, chronic cGas-Sting signaling caused embryonic lethality through inflammation and innate immune responses. Surviving mice displayed aging phenotypes beginning in embryogenesis, which persisted into adulthood. Genetic or pharmacological inhibition of cGas-Sting rescued embryonic lethality and alleviated progeroid phenotypes.