Estrazione di composti biologicamente attivi da piante della Sardegna

This research work has been focused on the supercritical fluid extraction and characterization of volatile oils having interesting biological activities, possibly susceptible of therapeutic applications. A further aim of this work was to separate biologically active molecules and nutraceuticals by means of SFE at high pressure. The investigated species have been selected on the basis of ethnobotanic information regarding, in particular, species endemic of Sardinia or that can be easily cultivated there and containing compounds of pharmacological interest. Extraction by means of supercritical CO2 has been preferred to the traditional techniques because of a number of advantages. First of all the obtaining of pure extracts deprived of organic solvents and of degradation compounds and not being modified by the loss of water-soluble compounds. The chemical characterization of extracts has been realized by means of different chromatographic techniques such as GC-MS, GC-FID and HPLC. Concerning the main results, the supercritical extraction at 250 bar on Salvia desoleana aerial parts allowed us to obtain an extract containing a relevant amount of sclareole: 811 μg/mg, determined by the internal standard method. These samples, tested on human cells model, showed a good antioxidant and cytoprotective activity. As far as the wheath germ oil is concerned, the SFE carried out at 250 bar supplied extracts of good quality. The HPLC and GC-FID analyses of these extracts highlighted a PUFA and Vitamin E content greater than the those obtained by traditional solvent extractions. The SFE Pistacia lentiscus essential oil, tested in vivo on an oxidative model of the mice frontal cortex induced by hyschemia/riperfusion, BCCAO, showed a relevant protection against lipidic peroxidation. The Myrtus communis essential oil, tested in vivo on mice, demonstrated a good antinflammatory action against the ear edema induced by croton oil and against the cotton pellet-induced granuloma. Among the investigated Sardinian verbenacee and lamiacee such as Vitex agnus-castus, Satureja thymbra and Thymus capitatus, containing an essential oil particularly rich in phenolic compounds, showed a good antimicrobial activity and could be employed in therapeutic applications. A comparative analysis on the composition of essential oils obtained from Sardinian and Portuguese plants (Bupleurum fruticosum, Smyrnium olusatrum, Calamintha nepeta nepeta and Achillea millefolium) showed the existence of different chemotypes and showed that derivatives of Sardinian origin have a greater antimicrobial activity. Among the studied vegetable species coming from regions outside Sardinia, it is noteworthy the comparison among the Laurus nobilis leaves oil from Tunisia and Algeria that showed a strong variability of composition related to their geographical origin. Tunisian oils showed a greater biological activity than the Algerian ones. It has been also demonstrated that berries essential oil of Juniperus oxycedrus ssp. macrocarpa, J. oxycedrus ssp. rufescens and J. phoenicea possess a relevant antioxidant activity

Estrazione di composti biologicamente attivi da piante della Sardegna

This research work has been focused on the supercritical fluid extraction and characterization of volatile oils having interesting biological activities, possibly susceptible of therapeutic applications. A further aim of this work was to separate biologically active molecules and nutraceuticals by means of SFE at high pressure. The investigated species have been selected on the basis of ethnobotanic information regarding, in particular, species endemic of Sardinia or that can be easily cultivated there and containing compounds of pharmacological interest. Extraction by means of supercritical CO2 has been preferred to the traditional techniques because of a number of advantages. First of all the obtaining of pure extracts deprived of organic solvents and of degradation compounds and not being modified by the loss of water-soluble compounds. The chemical characterization of extracts has been realized by means of different chromatographic techniques such as GC-MS, GC-FID and HPLC. Concerning the main results, the supercritical extraction at 250 bar on Salvia desoleana aerial parts allowed us to obtain an extract containing a relevant amount of sclareole: 811 μg/mg, determined by the internal standard method. These samples, tested on human cells model, showed a good antioxidant and cytoprotective activity. As far as the wheath germ oil is concerned, the SFE carried out at 250 bar supplied extracts of good quality. The HPLC and GC-FID analyses of these extracts highlighted a PUFA and Vitamin E content greater than the those obtained by traditional solvent extractions. The SFE Pistacia lentiscus essential oil, tested in vivo on an oxidative model of the mice frontal cortex induced by hyschemia/riperfusion, BCCAO, showed a relevant protection against lipidic peroxidation. The Myrtus communis essential oil, tested in vivo on mice, demonstrated a good antinflammatory action against the ear edema induced by croton oil and against the cotton pellet-induced granuloma. Among the investigated Sardinian verbenacee and lamiacee such as Vitex agnus-castus, Satureja thymbra and Thymus capitatus, containing an essential oil particularly rich in phenolic compounds, showed a good antimicrobial activity and could be employed in therapeutic applications. A comparative analysis on the composition of essential oils obtained from Sardinian and Portuguese plants (Bupleurum fruticosum, Smyrnium olusatrum, Calamintha nepeta nepeta and Achillea millefolium) showed the existence of different chemotypes and showed that derivatives of Sardinian origin have a greater antimicrobial activity. Among the studied vegetable species coming from regions outside Sardinia, it is noteworthy the comparison among the Laurus nobilis leaves oil from Tunisia and Algeria that showed a strong variability of composition related to their geographical origin. Tunisian oils showed a greater biological activity than the Algerian ones. It has been also demonstrated that berries essential oil of Juniperus oxycedrus ssp. macrocarpa, J. oxycedrus ssp. rufescens and J. phoenicea possess a relevant antioxidant activity

Biological Assays and Chemical Composition of Volatile Oils of Bupleurum fruticosum L. (Apiaceae)

The composition of supercritical CO 2 extracts and essential oils obtained by hydrodistillation of Bupleurum fruticosum L., growing spontaneously in Italy and Portugal, and its antifungal activity is reported. The collected extracts were analyzed by GC-FID and GC-MS methods. The minimal inhibitory concentration (MIC) and the minimal lethal concentration (MLC) were used to evaluate the antifungal activity of the oils against Candida albicans, C. tropicalis, C. krusei, C. guillermondii, C. parapsilosis, Cryptococcus neoformans, Trichophyton rubrum, T. mentagrophytes, Microsporum canis, M. gypseum, Epidermophyton floccosum, Aspergillus niger, A. fumigatus and A. flavus

Essential Oil Constituents and Antioxidant Activity of Asplenium Ferns

Two fern species Asplenium adiantum-nigrum L. and Asplenium trichomanes L. collected from the Kroumiria region (Northwest of Tunisia) were individually submitted to hydrodistillation in a Clevenger type apparatus. Volatile organic compounds were identified by GC-MS and GC-FID. Thus, 35 compounds were identified in A. adiantum-nigrum essential oil accounting for 77.5% of the whole constituents dominated by palmitic acid (34.5%); however, only 29 volatiles were identified in A. trichomanes showing a high amount of phytol, an odorous diterpene alcohol, representing 14.4% of the total oil contents. The total phenolic content and the antioxidant effects of crude extracts from both pteridophytes were determined using Folin-Ciocalteu and 2,2′-diphenyl-1-picrylhydrazyl free radical-scavenging assays, respectively. A. adiantum-nigrum ethyl acetate extract is shown to be lower in total phenolic contents (49.3 mg gallic acid equivalent/g) than similar extract from A. trichomanes (55.4 mg GAE/g)

Characterization of Essential Oils from Different Taxa Belonging to the Genus Teucrium in Sardinia Island, Italy

The genus Teucrium L. (Lamiaceae) is a genus growing in mild climate zones, particularly in the Mediterranean Basin and Central Asia. It is represented by 11 taxa in Sardinia (Italy), living commonly in sunny habitats. In this study, the following eight Sardinian Teucrium taxa were selected, and the essential oils (EOs), obtained by stem distillation, were analyzed by GC–FID and GC–MS: T. capitatum subsp. capitatum, T. chamaedrys subsp. chamaedrys, T. flavum subsp. glaucum, T. marum, T. massiliense, T. scordium subsp. scordioides, T. scorodonia, and T. subspinosum. The comprehensive analyses led to the identification of 87 constituents representing the majority of the volatile compounds. Significant differences, both qualitative and quantitative, were observed between the taxa. Overall, monoterpenes and sesquiterpenes characterized all Teucrium EOs: T. capitatum subsp. capitatum and T. flavum subsp. glaucum revealed the highest content of monoterpene hydrocarbons, while in the other Teucrium taxa sesquiterpene hydrocarbons prevailed. Worthy of note, diterpenes were found only in T. marum and T. subspinosum, whereas T. massiliense was rich in non-terpenic oxygenated compounds. To the best of our knowledge, this is the first comprehensive report on the chemical composition of EOs obtained from Sardinian Teucrium species

Advances in Sardinian Withania somnifera (L.) Dunal crops through phytochemical and biological approaches

Withania somnifera (L.) Dunal is widely used in the Indian traditional system of medicine to promote general health, wellness, and longevity. Its pharmacological properties are attributed to a group of molecules called withanolides, among which Withaferin A holds great interest for its anti-carcinogenic action. For this reason, numerous studies in recent years have focused on different metabolic or genetic engineering solutions to increase its yield. Here, we present the Sardinian chemotype of Withania somnifera as a potential crop for the extraction of Withaferin A. W. somnifera was cultivated from Sardinian wild germplasm collected in the northeast of the island. After 18 months, the leaves and the roots were collected and their methanolic extract was analyzed by HPLC. 0.3 mg/g DW of Withanolide A (WA), 1.0 mg/g DW of Withanolide B (WB) and 17.7 mg/g DW of Withaferin A (WF) were detected in the leaf sample, while lower values were detected in the roots (0.1 mg/g WF, 0.3 WA mg/g, 0.1 mg/g WB, 0.2 mg/g WO). This research not only confirms the high Withaferin A content found in the wild population leaves, but shows how they are reproducible in cultivated specimens, highlighting Sardinian W. somnifera leaves as a potential source of high-content Withaferin A products. Finally, we focused on the leaves extract by characterizing the phenolic and flavonoid content, as well as the in-vitro antioxidant capacity by DPPH and ABTS assays, revealing a significant amount of phenolic compounds and a related free radical scavenging activity. The leaves extract was further characterized for its anti-aging properties for potential cosmetic application, by the inhibition of tyrosinase, elastase, and collagenase enzymes

Agroprospecting of Biowastes: Globe Artichoke (Cynara scolymus L. Cultivar Tema, Asteraceae) as Potential Source of Bioactive Compounds

Artichokes (Cynara scolymus L.) are valuable foods, thanks to their health benefits, but they generate significant waste during their production, harvesting, and processing, which poses sustainability issues. This study applied an agroprospecting approach to convert Tema artichoke biowaste (TB) into valuable resources, starting from a global perspective of the production chain to the targeted applications based on chemical and biological analysis. The major TB was identified in the outer bracts of the immature flower heads, which were collected throughout the harvesting season, extracted, and analyzed. The most abundant compounds were phenolic acids including chlorogenic acid and caffeoylquinic derivatives. Among flavonoids, cynaroside was the most abundant compound. Multivariate analysis distinguished batches by collection period, explaining 77.7% of the variance, with most compounds increasing in concentration later in the harvest season. Subsequently, TB extracts were analyzed for their potential in wound healing and anti-aging properties. Fibroblasts were used to assess the effect of selected extracts on cell migration through a scratch wound assay and on cellular senescence induced by etoposide. The results show a significant decrease in senescence-associated beta-galactosidase activity, gamma H2AX nuclear accumulation, and both p53 and p21 protein levels. Overall, this study ascribes relevant anti-skin aging effects to TB, thus increasing its industrial value in cosmeceutical and nutraceutical applications