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

Essential Oil of Myrtus communis Inhibits Inflammation in Rats by Reducing Serum IL-6 and TNF-α:

The topical anti-inflammatory activity of the essential oil of Myrtus communis L. was studied using croton oil induced ear edema and myeloperoxidase (MPO) activity in mice, and cotton pellet induced granuloma, and serum tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in rats. On topical application, the oil exhibited a significant decrease in the ear edema as well as MPO activity. The oil also inhibited cotton pellet-induced granuloma and serum TNF-α and IL-6. It can be concluded that the essential oil of Myrtus communis reduces leukocyte migration to the damaged tissue and exhibits anti-inflammatory activity

Chemical composition and biological activity of the volatile extracts of Achillea millefolium.

In this study, flowering aerial parts of wild Achillea millefolium growing on the Mediterranean coast (Sardinia Island, Italy) and on the Atlantic coast (Portugal- Serra de Montemuro) were used as a matrix for supercritical extraction of volatile oil with CO2 (SFE). The collected extracts were analyzed by GC-FID and GC-MS methods and their composition were compared with that of the essential oil isolated by hydrodistillation. A strong chemical variability in essential oils depending on the origin of the samples was observed. The results showed the presence of two type oils. The Italian volatile extracts (SFE and essential oil) are predominantly composed by α-asarone (25.6-33.3%, in the SFE extract and in the HD oil, respectively), β-bisabolene (27.3-16.6%) and α-pinene (10.0-17.0%); whereas the main components of the Portuguese extracts are trans-thujone (31.4-29.0%), trans-crhysanthenyl acetate (19.8-15.8%) and β-pinene (1.2-11.1%). 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, T. mentagrophytes var. interdigitale, T. verrucosum, Microsporum canis, M. gypseum, Epidermophyton floccosum, Aspergillus niger, A. fumigatus and A. flavus. The oils showed the highest activity against dermatophyte strains, with MIC values ranging from 0.32-1.25 μL mL−1

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

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)

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

Isolation of the Volatile Oil from Satureja thymbra by Supercritical Carbon Dioxide Extraction: Chemical Composition and Biological Activity:

Satureja thymbra L. is well known in Italy by the popular name of "Santoreggia sarda". It grows only in Sardinia and nowadays it is restricted to the slope of the Colle San Michele in Cagliari. The composition of the aromatic extracts obtained by supercritical CO2 and by hydrodistillation and their antifungal activity is reported. The collected extracts were analyzed by GC-FID and GC-MS methods. No significant differences were observed in the composition of the volatile extracts depending on the extraction method. The results showed the presence of thymol, γ-terpinene, β-caryophyllene, p-cymene, carvacrol and borneol as main components. 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, T. mentagrophytes var. interdigitale, Trichophyton rubrum, T. verrucosum, Microsporum canis, M. gypseum, Epidermophyton floccosum, Aspergillus niger, A. fumigatus and A. flavus. The volatile extracts revealed a wide-spectrum antifungal activity. They were fungicidal and similarly potent against yeasts, dermatophyte and Aspergillus stains, with MICs ranging from 0.16 to 0.32 μL.mL−1

Effect of acute administration of Pistacia lentiscus L. essential oil on rat cerebral cortex following transient bilateral common carotid artery occlusion

<p>Abstract</p> <p>Background</p> <p>Ischemia/reperfusion leads to inflammation and oxidative stress which damages membrane highly polyunsaturated fatty acids (HPUFAs) and eventually induces neuronal death. This study evaluates the effect of the administration of <it>Pistacia lentiscus </it>L. essential oil (E.O.), a mixture of terpenes and sesquiterpenes, on modifications of fatty acid profile and endocannabinoid (eCB) congener concentrations induced by transient bilateral common carotid artery occlusion (BCCAO) in the rat frontal cortex and plasma.</p> <p>Methods</p> <p>Adult Wistar rats underwent BCCAO for 20 min followed by 30 min reperfusion (BCCAO/R). 6 hours before surgery, rats, randomly assigned to four groups, were gavaged either with E.O. (200 mg/0.45 ml of sunflower oil as vehicle) or with the vehicle alone.</p> <p>Results</p> <p>BCCAO/R triggered in frontal cortex a decrease of docosahexaenoic acid (DHA), the membrane highly polyunsaturated fatty acid most susceptible to oxidation. Pre-treatment with E.O. prevented this change and led further to decreased levels of the enzyme cyclooxygenase-2 (COX-2), as assessed by Western Blot. In plasma, only after BCCAO/R, E.O. administration increased both the ratio of DHA-to-its precursor, eicosapentaenoic acid (EPA), and levels of palmytoylethanolamide (PEA) and oleoylethanolamide (OEA).</p> <p>Conclusions</p> <p>Acute treatment with E.O. before BCCAO/R elicits changes both in the frontal cortex, where the BCCAO/R-induced decrease of DHA is apparently prevented and COX-2 expression decreases, and in plasma, where PEA and OEA levels and DHA biosynthesis increase. It is suggested that the increase of PEA and OEA plasma levels may induce DHA biosynthesis via peroxisome proliferator-activated receptor (PPAR) alpha activation, protecting brain tissue from ischemia/reperfusion injury.</p