Lipophilic Compounds and Antibacterial Activity of Opuntia ficus-indica Root Extracts from Algeria.

The chemical composition, investigated by gas chromatography-mass spectrometry, and antibacterial activity of lipophilic extractives of three varieties of Opuntia ficus-indica roots from Algeria are reported in this paper for the first time. The results obtained revealed a total of 55 compounds, including fatty acids, sterols, monoglycerides and long chain aliphatic alcohols that were identified and quantified. ß-Sitosterol was found as the major compound of the roots of the three varieties. Furthermore, considerable amounts of essential fatty acids (ω3, ω6, and ω9) such as oleic, linoleic, and linolenic acids were also identified. The green variety was the richest among the three studied varieties. The antibacterial activity, evaluated with disc diffusion method, revealed that lipophilic extracts were effective mainly against Gram-positive Staphylococcus aureus and methicillin-resistant Staphylococcus aureus (MRSA) (19~23 mm). Gram-negative strains mainly Pseudomonas aeruginosa gave an inhibition zone of 18 mm, which is considered high antibacterial activity. The minimal inhibitory concentrations of the tested bacteria revealed interesting values against the majority of bacteria tested: 75-100 µg mL-1 for Bacillus sp., 250-350 µg/mL for the two Staphylococcus strains, 550-600 µg mL-1 for E. coli, and 750-950 µg mL-1 obtained with Pseudomonas sp. This study allows us to conclude that the lipophilic fractions of cactus roots possess interesting phytochemicals such as steroids, some fatty acids and long chain alcohols that acted as antibiotic-like compounds countering pathogenic strains.

Chemical Profile of Lipophilic Fractions of Different Parts of Zizyphus lotus L. by GC-MS and Evaluation of Their Antiproliferative and Antibacterial Activities.

Zizyphus lotus L. is a perennial shrub particularly used in Algerian folk medicine, but little is known concerning the lipophilic compounds in the most frequently used parts, namely, root bark, pulp, leaves and seeds, which are associated with health benefits. In this vein, the lipophilic fractions of these morphological parts of Z. lotus from Morocco were studied by gas chromatography-mass spectrometry (GC-MS), and their antiproliferative and antimicrobial activities were evaluated. GC-MS analysis allowed the identification and quantification of 99 lipophilic compounds, including fatty acids, long-chain aliphatic alcohols, pentacyclic triterpenic compounds, sterols, monoglycerides, aromatic compounds and other minor components. Lipophilic extracts of pulp, leaves and seeds were revealed to be mainly composed of fatty acids, representing 54.3-88.6% of the total compounds detected. The leaves and seeds were particularly rich in unsaturated fatty acids, namely, (9Z,12Z)-octadeca-9,12-dienoic acid (2431 mg kg-1 of dry weight) and (9Z)-octadec-9-enoic acid (6255 mg kg-1 of dry weight). In contrast, root bark contained a high content of pentacyclic triterpenic compounds, particularly betulinic acid, accounting for 9838 mg kg-1 of dry weight. Root bark extract showed promising antiproliferative activity against a triple-negative breast cancer cell line, MDA-MB-231, with a half-maximal inhibitory concentration (IC50) = 4.23 ± 0.18 µg mL-1 of extract. Leaf extract displayed interesting antimicrobial activity against Escherichia coli, methicillin-sensitive Staphylococcus aureus and Staphylococcus epidermis, presenting minimum inhibitory concentration (MIC) values from 1024 to 2048 µg mL-1 of extract. Our results demonstrate that Zizyphus lotus L. is a source of promising bioactive components, which can be exploited as natural ingredients in pharmaceutical formulations.

Unveiling the bioactivity of Allium triquetrum L. lipophilic fractions: chemical characterization and in vitro antibacterial activity against methicillin-resistant Staphylococcus aureus.

The lipophilic composition of Allium triquetrum L. bulbs, flowers and leaves was studied for the first time by GC-MS. Sixty compounds were firstly identified in A. triquetrum L. Fatty acids represented the major lipophilic family among the studied extracts, with (9Z,12Z,15Z)-octadeca-9,12,15-trienoic and (9Z,12Z)-octadeca-9,12-dienoic acids being the major constituents of this family. A long chain aliphatic ketone, namely hentriacontan-16-one, was mainly found in flowers and leaves. Flowers and leaves were also found to be rich in long chain aliphatic alkanes and alcohols, respectively. Sterols, monoglycerides, aromatic compounds and long chain aliphatic aldehydes were found in lower amounts. The antibacterial activity of A. triquetrum bulb, flower and leaf extracts against methicillin-resistant Staphylococcus aureus (MRSA) growth was in vitro assessed. Bulb and flower extracts showed significant MRSA growth inhibition. Overall, these valuable findings can contribute to the valorization of A. triquetrum L. as a source of value-added phytochemicals, specifically as antibacterial agents and for nutraceutical applications.

The Health-Promoting Potential of Salix spp. Bark Polar Extracts: Key Insights on Phenolic Composition and In Vitro Bioactivity and Biocompatibility.

Salix spp. have been exploited for energy generation, along with folk medicine use of bark extracts for antipyretic and analgesic benefits. Bark phenolic components, rather than salicin, have demonstrated interesting bioactivities, which may ensure the sustainable bioprospection of Salix bark. Therefore, this study highlights the detailed phenolic characterization, as well as the in vitro antioxidant, anti-hypertensive, Staphylococcus aureus growth inhibitory effects, and biocompatibility of Salix atrocinerea Brot., Salix fragilis L., and Salix viminalis L. bark polar extracts. Fifteen phenolic compounds were characterized by ultra-high-performance liquid chromatography-ultraviolet detection-mass spectrometry analysis, from which two flavan-3-ols, an acetophenone, five flavanones, and a flavonol were detected, for the first time, as their bark components. Salix bark extracts demonstrated strong free radical scavenging activity (5.58-23.62 µg mL-1 IC50 range), effective inhibition on angiotensin-I converting enzyme (58-84%), and S. aureus bactericidal action at 1250-2500 µg mL-1 (6-8 log CFU mL-1 reduction range). All tested Salix bark extracts did not show cytotoxic potential against Caco-2 cells, as well as S. atrocinerea Brot. and S. fragilis L. extracts at 625 and 1250 µg mL-1 against HaCaT and L929 cells. These valuable findings can pave innovative and safer food, nutraceutical, and/or cosmetic applications of Salix bark phenolic-containing fractions.

High pressure extraction of bioactive diterpenes from the macroalgae Bifurcaria bifurcata: an efficient and environmentally friendly approach.

The brown macroalgae Bifurcaria bifurcata have gained special attention due to their ability to biosynthesize linear diterpenes (rarely found in other species). However, the conventional extraction methods normally used to extract these compounds involve organic solvents and often high temperatures, leading to the degradation of thermo-labile compounds. In this context, the main objective of this work was to study and optimize for the first time the extraction of diterpenes from B. bifurcata through an environmentally friendly methodology, namely, high pressure extraction (HPE) using ethanol : water. This was compared with conventional Soxhlet extraction, using dichloromethane. Box-Behnken design was employed to evaluate the linear, quadratic, and interaction effects of 3 independent variables (pressure (X 1), ethanol percentage (X 2), and time of extraction (X 3)) on response variables (extraction yield and diterpenes content (mg g-1 of extract and mg kg-1 of dry weight)) and the optimal extraction conditions (X 1: 600 MPa; X 2: 80%; X 3: 5 min) were estimated by response surface methodology (RSM). B. bifurcata extract obtained under HPE optimal conditions showed a diterpenes content (612.2 mg g-1 of extract) 12.2 fold higher than that obtained by conventional extraction (50.1 mg g-1 of extract). The HPE extract, obtained under optimal conditions, showed antioxidant and antibacterial (against Staphylococcus aureus) activities considerably higher than the Soxhlet extract, and also presented a promising synergic effect with antibiotics, improving the antibiotic efficacy against S. aureus. In conclusion, these results indicate that HPE is a promising methodology, compared to conventional methodologies to obtain linear diterpene rich extracts from B. bifurcata with great potential to be exploited in pharmaceutical or biomedical applications.

Antiproliferative Effects of Cynara cardunculus L. var. altilis (DC) Lipophilic Extracts.

Besides being traditionally used to relieve hepatobiliary disorders, Cynara cardunculus L. has evidenced anticancer potential on triple-negative breast cancer (TNBC). This study highlights the antiproliferative effects of lipophilic extracts from C. cardunculus L. var. altilis (DC) leaves and florets, and of their major compounds, namely cynaropicrin and taraxasteryl acetate, against MDA-MB-231 cells. Our results demonstrated that MDA-MB-231 cells were much less resistant to leaves extract (IC50 10.39 µg/mL) than to florets extract (IC50 315.22 µg/mL), during 48 h. Moreover, leaves extract and cynaropicrin (IC50 6.19 µg/mL) suppressed MDA-MB-231 cells colonies formation, via an anchorage-independent growth assay. Leaves extract and cynaropicrin were also assessed regarding their regulation on caspase-3 activity, by using a spectrophotometric assay, and expression levels of G2/mitosis checkpoint and Akt signaling pathway proteins, by Western blotting. Leaves extract increased caspase-3 activity, while cynaropicrin did not affect it. Additionally, they caused p21Waf1/Cip1 upregulation, as well as cyclin B1 and phospho(Tyr15)-CDK1 accumulation, which may be related to G2 cell cycle arrest. They also downregulated phospho(Ser473)-Akt, without changing total Akt1 level. Cynaropicrin probably contributed to leaves extract antiproliferative action. These promising insights suggest that cultivated cardoon leaves lipophilic extract and cynaropicrin may be considered toward a natural-based therapeutic approach on TNBC.

Lipophilic extracts of Cynara cardunculus L. var. altilis (DC): a source of valuable bioactive terpenic compounds.

Lipophilic extracts of Cynara cardunculus L. var. altilis (DC) from the south of Portugal (Baixo Alentejo) were studied by gas chromatography-mass spectrometry. One sesquiterpene lactone, four pentacyclic triterpenes, and four sterols were reported for the first time as cultivated cardoon components, namely, deacylcynaropicrin, ß- and α-amyrin, lupenyl and ψ-taraxasteryl acetates, stigmasterol, 24-methylenecholesterol, campesterol, and Δ(5)-avenasterol. In addition, other new compounds were identified: ten fatty acids, eight long-chain aliphatic alcohols, and six aromatic compounds. Four triterpenyl fatty acid esters were also detected. Sesquiterpene lactones and pentacyclic triterpenes were the major lipophilic families, representing respectively 2-46% and 10-89% of the detected compounds. Cynaropicrin was the most abundant sesquiterpene lactone, while taraxasteryl acetate was the main pentacyclic triterpene. Fatty acids and sterols, mainly hexadecanoic acid and ß-sitosterol, were present at lower amounts (1-20% and 1-11% of the detected compounds). Long-chain aliphatic alcohols and aromatic compounds were detected at reduced abundances (1-6% of the detected compounds).