The chemical composition of essential oil from Seseli tortuosum subsp. tortuosum and S. tortuosum subsp. maritimum (Apiaceae) aerial parts growing in Sicily (Italy)

Seseli L. genus, belonging to the Apiaceae family, includes more than eighty taxa, mainly growing in Europe and Asia. Due to the several biological properties, species of this genus have been largely investigated, showing to be a rich source of coumarins, as well as, of essential oils with anti-inflammatory, antiviral, antifungal, cytotoxic, etc. properties. In the present study, the chemical composition of the essential oils from aerial parts of Sicilian accessions of Seseli tortuosum subsp. tortuosum and S. tortuosum subsp. maritimum were analysed by GC-MS. No one report has been previously published on the subsp. maritimum. The results showed the presence, in both oils, of large quantity of monoterpene hydrocarbons. Main metabolites were β-pinene (15.81-19.84%), α-pinene (14.63-18.52%), sylvestrene (11.18-17.45%) and 3-carene (14.58%), the last one being absent in the oil of subsp. maritimum. Chemotaxonomic considerations with respect to other oils of Seseli taxa were carried out.

Seseli bocconei Guss. and S. tortuosum subsp. maritimum Guss. essential oils inhibit colon cancer cell viability

In this study, the chemical compositions of two essential oils (EOs) obtained from different parts (flowers, leaves, stems, and roots) of Seseli bocconei Guss. and of Seseli tortuosum subsp. maritimum Guss., wild endemic species of Sicily, were investigated. The main classes of metabolites for the essential oils of S. bocconei were, respectively, monoterpenes hydrocarbons for flowers, sesquiterpenes hydrocarbons for leaves, and a breakdown between the two previously mentioned classes for stems. In the case of S. tortuosum subsp. maritimum, on the other hand, the main metabolite class for all the vegetative parts analyzed (flowers, stems, and roots) was monoterpene hydrocarbons, with a slight percentage in other non-terpenoid compounds. Furthermore, the EOs' antitumor effects against HCT116, human colon cancer cells were evaluated. Cell viability assays evidenced that stems' EOs of both plants exhibit strong cytotoxic effects at low concentrations, while the EOs from other vegetative parts do not show a relevant effect. In fact, EO of stems of S. tortuosum subsp. maritimum reduced the cell viability of 82% at the concentration of 125 μg/mL, while at the concentration of 250 μg/mL of stems EO of S. bocconei the 97% of cells resulted dead. The analysis of the effects exerted by the main phytocostituents (S-(-)-limonene, R-(+)-limonene, sabinene, (1S)-(-)-α-pinene, (1R)-(+)-α-pinene, and (-)-β-pinene, and germacrene D) of these EOs on colon cancer cells revealed germacrene D as a new promising molecule with anticancer properties that deserve to be explored in future directions.

Chemical Composition and Evaluation of Insecticidal Activity of Seseli bocconei Essential Oils against Stored Products Pests

In this study, the chemical composition of the essential oils (EOs) obtained from different aerial parts (flowers, leaves, and stems) of Seseli bocconei Guss., a wild species endemic of Sicily, was investigated. Furthermore, the EOs' biocidal effects towards two pests of stored products, Sitophilus oryzae and Callosobruchus maculates, were evaluated. This activity was evaluated in Petri dish bioassays to establish the survival rate of adults treated with the EOs comparing them with solvent and a commonly used insecticide (pyrethrum). The data obtained from the toxicity bioassay evidenced that stems' EOs and leaves' EOs have a contact/fumigation effect towards the two insect species tested, while the EOs from the flowers did not exhibit a different mortality than the solvent. The EOs from the stem and leaves of S. bocconei, tested at 10 mg/petri dish, determined a LT50 of 53.38 and 42.97 h, respectively, on S. oryzae adults, and of 45.23 and 42.97 h, respectively, on C. maculatus adults. The promising bioactivity of S. bocconei leaves' EOs and stems' EOs toward S. oryzae and C. maculatus is encouraging in the perspective to test these oils and their main constituents for further experiments in the laboratory and field.

The chemical composition of essential oil from Seseli bocconei (Apiaceae) aerial parts growing in Sicily (Italy)

Seseli is a large genus of aromatic and economically important herbs of the Apiaceae family that includes eighty-seven taxa, mainly distributed in Europe and Asia. Several species of this genus are extensively used in various popular medicines and based on their traditional uses, much research concerning biological activities have been carried out. In the present study, the chemical composition of the essential oil from aerial parts of Seseli bocconei Guss., a rare plant endemic of Sicily, was analysed by GC-MS. No one report has been previously published on the essential oil of this species. The result showed the presence of large quantity of monoterpene and sesquiterpene hydrocarbons whereas it was practically devoid of oxygenated terpenes. Main metabolites of the oil were germacrene D (18.48%) and sabinene (17.46%). Chemotaxonomic considerations with respect to other oils of Seseli taxa were carried out.

Comprehensive Biological and Chemical Evaluation of Two Seseli Species (S. gummiferum and S. transcaucasicum)

Seseli L. is one of the largest genera of the Apiaceae family widely known for their traditional uses as herbal remedies. In the present study, the methanolic and water extracts of two Seseli species, S. gummiferum and S. transcaucasicum were evaluated for their bioactive contents and biological activities. The total phenolic and flavonoid contents in the extracts ranged from 19.09 to 24.33 mg GAE/g and from 0.45 to10.09 mg RE/g, respectively. Moreover, while narcissin was detected as the most abundant component in the methanolic extract of S. transcaucasicum (261.40 µg/g), chlorogenic acid was identified as the major component in all the other extracts, although a high amount was also present in the methanolic S. transcaucasicum extract (107.48-243.12 µg/g). The total antioxidant capacity was also determined by the phosphomolybdenum assay (0.66-1.18 mM TE/g). Other antioxidant assays such as the radical scavenging assays (DPPH: 5.51-11.45 mg TE/g; ABTS: 43.46-51.91 mg TE/g), reducing assays (CUPRAC: 41.67-53.20 mg TE/g; FRAP: 31.26-34.14 mg TE/g), as well as the metal chelating activity assay (14.38-38.57 mg EDTAE/g) were conducted. All the extracts showed inhibitory potential against the enzyme's amylase (0.12-0.78 mM ACAE/g), acetyl- and butyryl-cholinesterase (0.15-9.71 mg GALAE/g), while only the methanolic extracts acted as inhibitors of tyrosinase (107.15 and 109.37 mg KAE/g) and only the water extract of S. gummiferum displayed anti-glucosidase activity (0.13 mM ACAE/g). Interestingly, the methanolic extracts of both Seseli species showed lower cytotoxicity towards HaCaT cells (IC50: >500 µg/mL), compared to the water extracts (IC50: 267.8 and 321.41 µg/mL). Besides, only the methanolic extracts showed a slight wound healing effect (28.21 and 31.23%). All extracts showed antibacterial action against Staphylococcus lugdunensis (minimum inhibitory and bactericidal concentrations: 0.025-2 mg/mL). S. gummiferum methanolic extract, which exhibited the highest antibacterial potency was found to inhibit adhesion and invasion of S. lugdunensis to HaCaT cells as well. Taken together, this study demonstrated the two Seseli species to harbour interesting bioactive components, in particular polyphenolics and to exhibit several biological properties that could be further investigated for their potential exploitation as healing agents as supported by various traditional medicinal uses.