Chemical composition, antioxidant, and antimicrobial activities of two essential oils from Algerian propolis.

This study aims to investigate the chemical composition, antioxidant, and antimicrobial activity of two essential oils (EOs) from Algerian propolis. The volatile constituents were analyzed by gas chromatography-mass spectrometry. Fifty components were identified from the oils. The major components were found to be: cedrol (17.0%), ß-eudesmol (7.7%), and α-eudesmol (6.7%) in EO of propolis from Oum El Bouaghi (EOPO) whilst α-pinene (56.1%), cis-verbenol (6.0%), and cyclohexene,3-acetoxy-4-(1-hydroxy-1-methylethyl)-1-methyl (4.4%) in EO of propolis from Batna (EOPB). The antioxidant properties of EOPO and EOPB were determined using 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonate) (ABTS•+) and cupric reducing antioxidant capacity (CUPRAC assays), respectively. Both EOs had more cupric ion reducing ability than scavenging ABTS•+ radicals. The antimicrobial potential of the two EOs against eight pathogens was assayed by the agar diffusion method and the mode of action was determined by microdilution assay. The results revealed that EOPB was bactericidal for all tested pathogenic bacteria and fungicidal for Candida albicans ATCC 10231, whereas, EOPO showed bacteriostatic effect against Escherichia coli O157:H7 and Pseudomonas aeruginosa ATCC27853 and fungistatic effect against C. albicans ATCC 10231. Thus, the obtained results suggest the important use of propolis EOs as preservative agents.

Ethanolic extract of Algerian propolis decreases androgen receptor transcriptional activity in cultured LNCaP cells.

Antiandrogens have a peculiar place in the treatment of metastatic prostate cancer by blocking the androgen receptor (AR). Unfortunately, aggressive tumors could rapidly develop into a castration resistant state. It is therefore essential to look for new molecules that are more effective, affecting not only the androgen signaling and with minimum undesirable effects. Natural products are an interesting source of new therapeutics, especially for cancer therapy as 70% of them have botanical origin. Based on an ethnobotany screening, we evaluated the effects of ethanolic extract of propolis (EEP) from Algeria on LNCaP cells. Results pointed out that EEP reduces the survival of LNCaP cells with an IC50 of 0.04 mg/ml, induces the apoptosis and blocks the cell cycle at G0/G1 phase. Interestingly, EEP decreased the accumulation of AR suggesting some anti-androgen activity. Indeed, secreted amount of the androgen target protein PSA was decreased when LNCaP cells were incubated with EEP, starting after 4 h of treatment. This anti-androgen activity was also shown on the androgen target genes Fkbp5 and Sgk1. Finally, the capacity of EEP to block AR functioning was demonstrated in transient transfections with human AR and the reporter gene ARE-tk-Luc. Propolis antagonizes the induction of the luciferase activity induced by the natural androgen DHT (10-8M) or the synthetic AR agonist R1881 (10-7M). Altogether, these results highlight the potential pharmacological effects of EEP in future treatments of prostate cancer.

Chemical composition, antioxidant, anticholinesterase, antimicrobial and antibiofilm activities of essential oil and methanolic extract of Anthemis stiparum subsp. sabulicola (Pomel) Oberpr.

Anthemis species are traditionally used to treat infectious and inflammatory processes, among others clinical disturbances. In the current study, the chemical composition, the total phenolic and flavonoid contents, the antioxidant, anticholinesterase, antimicrobial, and antibiofilm activities of Anthemis stiparum subsp. sabulicola aerial parts methanolic extract (As-ME) and essential oil (As-EO) were investigated. The chemical composition of As-EO was established by GC-MS and GC-FID. Total phenolic and flavonoid contents of As-ME were spectrophotometrically determined. Diphenyl-1-picrylhydrazyl (DPPH●) radical scavenging, cupric reducing antioxidant capacity (CUPRAC) and ß-carotene bleaching assays were applied to evaluate the antioxidant potential. The anticholinesterase activity against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes were carried out spectrophotometrically. The antimicrobial activity was assessed by Minimal Inhibitory Concentration (MIC) using broth microdilution method against 7 ATCC® bacterial and one ATCC® yeast reference strains. The antibiofilm effect was determined quantifying the percentage of adhesion inhibition. GC-MS and GC-FID identified 72 compounds (99.02%), being As-EO predominantly constituted by germacrene D (11.13%), t-cadinol (11.01%), camphor (6.73%), spathulenol (6.50%) and isoamyl salicylate (6.45%). The total phenolic and flavonoid contents of As-ME were 13.6 ±â€¯0.03 and 5.9 ±â€¯0.04 pyrocatechol equivalents and quercetin equivalents, respectively. In ß-carotene-linoleic acid assay, As-ME showed the best lipid peroxidation inhibition activity with an IC50 = 9.96 µg/mL followed by As-EO with an IC50 = 619.98 µg/mL. In contrast, in DPPH assay, As-ME and As-EO showed moderate to low activity with an IC50 = 92.69 µg/mL for As-ME and 917.69 µg/mL for As-EO. While in CUPRAC assay, As-EO and As-ME indicated a less to moderate reducing activity. As-ME inhibited AChE (IC50 = 490.46 µg/mL) and BChE (IC50 = 142.07 µg/mL), while As-EO was inactive against AChE and revealed a discreet inhibitory action against BChE (IC50 = 212.14 µg/mL). As-ME displayed better antimicrobial activity than As-EO, being active against Staphylococcus aureus (ATCC® 25923) and Bacillus subtilis (ATCC® 6633), with MIC of 1.56 mg/mL. An expressive fungal adhesion inhibition (80.02%) on Candida albicans (ATCC® 10239) was detected with As-ME at 6.25 mg/mL. These results showed that A. stiparum subsp. sabulicola is a natural source of active compounds with antibiotic and antibiofilm effects against S. aureus and B. subtilis, and C. albicans, respectively, and also presents antioxidant and anticholinesterase properties.

Biological properties of propolis extracts: Something new from an ancient product.

Natural products are an interesting source of new therapeutics, especially for cancer therapy as 70% of them have botany origin. Propolis, a resinous mixture that honey bees collect and transform from tree buds, sap flows, or other botanical sources, has been used by ethnobotany and traditional practitioners as early in Egypt as 3000 BCE. Enriched in flavonoids, phenol acids and terpene derivatives, propolis has been widely used for its antibacterial, antifungal and anti-inflammatory properties. Even though it is a challenge to standardize propolis composition, chemical analyses have pointed out interesting molecules that also present anti-oxidant and anti-proliferative properties that are of interest in the field of anti-cancer therapy. This review describes the various geographical origins and compositions of propolis, and analyzes how the main compounds of propolis could modulate cell signaling. A focus is made on the putative use of propolis in prostate cancer.

Chemical constituents of essential oil of endemic Rhanterium suaveolens Desf. growing in Algerian Sahara with antibiofilm, antioxidant and anticholinesterase activities.

Twenty compounds were detected in the essential oil of Rhanterium suaveolens representing 98.01% of the total oil content. Perillaldehyde (45.79%), caryophyllene oxide (24.82%) and ß-cadinol (5.61%) were identified as the main constituents. In ß-carotene-linoleic acid assay, both the oil and the methanol extract exhibited good lipid peroxidation inhibition activity, with IC50 values of 17.97 ± 5.40 and 11.55 ± 3.39 µg/mL, respectively. In DPPH and CUPRAC assays, however, the methanol extract exhibited a good antioxidant activity. The highest antibiofilm activity has been found 50.30% against Staphylococcus epidermidis (MU 30) at 20 µg/mL for essential oil and 58.34% against Micrococcus luteus (NRRL B-4375) at 25 mg/mL concentration for methanol extract. The in vitro anticholinesterase activity of methanol extract showed a moderate acetylcholinesterase inhibitory (IC50 = 168.76 ± 0.62 µg/mL) and good butyrylcholinesterase inhibitory (IC50 = 54.79 ± 1.89 µg/mL) activities. The essential oil was inactive against both enzymes.

Effect of growth stage on essential-oil yield and composition of Daucus sahariensis.

The essential oils obtained by hydrodistillation from Daucus sahariensis Murb. harvested at three different growth stages were characterized by GC/MS analysis. In total, 88 compounds were identified, with myristicin (29.8-51.7%), myrcene (6.7-31.1%), α-pinene (11.6-14.8%), and limonene (5.3-11.5%) as main constituents. Monoterpene hydrocarbons were the most represented compounds in the oils of the plant samples collected during the flower-budding and full-flowering periods. On the contrary, during the fruiting stage, the oils were dominated by phenylpropanoids. The essential oils were subject of considerable variation in their composition during the various developmental stages, particularly concerning the content of myrcene that decreased significantly passing from the vegetative to the fruiting stage. Conversely, for myristicin, the opposite trend was observed. Furthermore, the essential-oil yields were quite low during the flower-budding phase (0.27%), but rapidly increased during plant development (0.63 and 0.68% for the flowering and fruiting phases, resp.).

Analysis of pyrrolizidine alkaloids and evaluation of some biological activities of Algerian Senecio delphinifolius (Asteraceae).

Although Senecio species are known as sources of potentially toxic pyrrolizidine alkaloids (PAs), some species of this genus are traditionally used as remedies, notably in Algeria. In this paper, the evaluation of biological activities and the analysis of PAs of Algerian specimens of Senecio delphinifolius Vahl are reported. The n-butanolic extract of the herb showed a weak antibacterial effect against Escherichia coli with a MIC of 1 mg/mL, but was inactive against Staphylococcus aureus and Pseudomonas aeruginosa. The n-butanolic extracts of the roots, stems and herb showed a modest antioxidant activity, scavenging the free radical DPPH with respective IC50 values of 55.3, 50.2 and 13.3 microg/mL. A cytotoxic effect against a series of human tumor cell lines was observed with the n-butanolic extract from stems (IC50 ranging between 34 and 88 microg/mL). The herb of the evaluated sample contains 140 ppm of PAs (senecionine, seneciphylline, integerrimine, senkirkine) and PA-related alkaloids (dehydrosenkirkine and neosenkirkine). As the major PAs belong to the toxic series (1,2-unsaturation in the pyrrolizidine cycle and macrocyclic diester), the use of S. delphinifolius should be discouraged in traditional medicine.

Antioxidant compounds from Algerian Convolvulus tricolor (Convolvulaceae) seed husks.

Seed husk extracts of Convolvulus tricolor L. (Convolvulaceae) afforded six compounds, identified for the first time from this plant: isorhamnetin 3-O-beta-D-galactopyranoside (1), isorhamnetin 3-O-beta-D-(6"-acetyl)-galactopyranoside (2), isorhamnetin 3-O-robinobioside (3), 3,4-di-O-caffeoylquinic acid (4), gentisic acid 5-O-glucoside (5), and scopoletin (6). Separation of compounds was carried out by CC and CPC. Structural elucidations were performed by HPLC-UV-DAD, HPLC-ESI/MS (negative mode) and NMR.

Chemical composition and antibacterial activity of the essential oils from Launaea resedifolia L.

BACKGROUND: Several species of the genus Launaea are used in folk medicine such as in bitter stomachic, skin diseases, and reported to have antitumor, insecticide, and cytotoxic activities. The antimicrobial activities of coumarin constituents and the neuropharmacological properties have been investigated as well. In this study, the chemical composition of essential oils from Launaea resedifolia L. has been identified using the ordinary GC-MS technique to reveal the presence of 19 compounds dominated by dioctyl phthalate. Moreover, the antibacterial activity of the crude oil has been carried out using disk diffusion method against seven bacteria strains. RESULTS: Nineteen compounds of essential oil of L. resedifolia L. were identified, representing 86.68% of the total oil. The compounds were identified by spectral comparison to be mainly esters, alcohols, ketones, and terpenes. The principal constituents are dioctyl phthalate (39.84%), Decanoic acid, decyl ester (12.09%), 11-Octadecenal (11.24%), and Eucalyptol (07.31%), while others were present in relatively small amounts. As far as antibacterial essays are concerned, it was found that the oils are active against most of the tested bacterial strains. CONCLUSION: A major constituent in visible parts was Dioctyl phthalate (39.84%) and the yield of essential oils was 0.9%. These extracts reveal in vitro antibacterial activity on the studied bacterial, confirmed by the inhibition zone diameter ranging from 11 to 37 mm and a MIC value between 0.09 and 0.69 depending on the microorganism being tested.

A myristicin-rich essential oil from Daucus sahariensis growing in Algeria.

The essential oils obtained by hydrodistillation from leaves and fruits of Daucus sahariensis Murb. were analyzed by GC/MS. The main constituents of the essential oil from the leaves were myristicin (34.3%), alpha-pinene (5.4%), cis-chrysanthenyl acetate (5.3%) and epi-alpha-bisabolol (4.8%), and those from the fruits myristicin (43.9%), alpha-pinene (13.1%), limonene (9.4%), and cis-chrysanthenyl acetate (7.4%). Myristicin, the main constituent of both essential oils, is generally absent in the oils from other Daucus species, permitting the hypothesis that this compound is a chemical marker of this Saharan species.

Ferulsinaic acid, a sesquiterpene coumarin with a rare carbon skeleton from Ferula species.

Fractionation of methylene chloride extracts of the resin of Ferula vesceritensis and F. sinaica afforded three sesquiterpene coumarins and a glucose derivative. One of them was a sesquiterpene with a rare carbon skeleton. The structures of these compounds were determined by extensive NMR studies, including DEPT, COSY, NOE, HMQC, and HMBC.

The interaction of new plant flavonoids with rat liver mitochondria: relation between the anti- and pro-oxydant effect and flavonoids concentration.

Flavonoids are polyphenols derivatives of plant origin that possesses a broad range of pharmacological properties, including protection of cells and tissues against the deleterious effects of reactive oxygen species. Their antioxidant activity results from scavenging of free radicals and other oxidizing intermediates, from the chelation of iron or copper ions and from inhibition of oxidases. But a number of studies have found both anti and prooxidant effects for many of these compounds. These reasons prompted us to investigate whether flavonoids compounds alone or combined flavonoids had antioxidant, free radical scavenger and antiapoptotic properties. The investigation was carried in vitro using rat hepatic mitochondria. Respiratory control ratio (RCR), oxygen consumption, adenosine tri phosphate (ATP) synthesis, scavenging action, enzymatic activities of involved complexes, superoxide anion and the release of cytochrome C were measured to assess the mechanisms of action of these drugs. Our data showed that the decrease of RCR induced by high concentrations (0.1 mM and 0.01 mM) of all flavonoids tested was due to a common inhibition of oxidative phosphorylation (State 4) and activation of state 3. At the opposite mitochondrial swelling was slightly induced only by low concentrations (10(-8) and 10(-9) M) of the flavonoids. They had no effects on the mitochondrial complexes (I to V) activity. Furthermore the mitochondrial membrane potential was not affected by any flavonoids. The effect of flavonoids on superoxide anion generation was variable. All the flavonoids studied acted between 10(-4) M and 10(-6) M with no effects at lower concentrations. These effects were similar on lipid peroxidation (malondialdehyde [MDA] levels). We remarked a concentration-dependent in the effect of flavonoids since they acted as antioxidant and also as uncoupler at high concentrations, which is a risk for the cells. We conclude that flavonoids extracted from algerian plants have some protecting effects against oxidative stress by protecting the mitochondria.