Essential Oil Biodiversity of Achillea ligustica All. Obtained from Mainland and Island Populations.

BACKGROUND: The genus Achillea is rich in essential oil (EO) with high chemical diversity. In this study, eight EO samples obtained from flowers and leaves of Achillea ligustica All. collected on the Mediterranean mainland and island locations were analyzed to evaluate their possible chemical diversity. METHODS: Sixteen samples of EO were analyzed by GC-MS, leading to the identification of 95 compounds in the leaves and 86 compounds in the flowers; a statistical analysis was performed to determine the chemical polymorphism. RESULTS: Monoterpenes, such as ß-pinene, borneol, ɑ-terpineol and isobornyl acetate, were more abundant in the continental samples, while the insular samples were richer in 1,8-cineole. Fragranyl acetate and fragranol were detected in remarkable concentrations in sample 8. The fruits of sample 8 were then cultivated under controlled agronomic conditions, providing plants rich in these compounds (sample 9). The geographical variability influenced the EO compositions, with unique observed chemotypes and a high degree of diversity among samples collected in various areas (mainland or island). Statistical analyses did not reveal any pattern between the geographical provenience and the compositions. CONCLUSION: Samples were distributed based on the plant organ, confirming the already reported high degree of chemical polymorphism of this species. Sample 8 could be used as a source of fragranol and fragranyl acetate, with potential applications in the insecticidal and pheromone industries.

Proapoptotic Activity of Achillea membranacea Essential Oil and Its Major Constituent 1,8-Cineole against A2780 Ovarian Cancer Cells.

Among the hundreds of reported Achillea species, A. membranacea (Labill.) DC. is one of the six that grow in Jordan. Many species of this genus are used in folk medicine to treat a variety of ailments and several biological and pharmacological activities have been ascribed to their essential oil (EO). For this study, the EO obtained from a specimen of A. membranacea grown in Jordan was analyzed by GC-MS. Ninety-six compounds were detected, of which oxygenated monoterpenes was the predominant class (47.9%), followed by non-terpene derivatives (27.9%), while sesquiterpenes represented 14.2% of the total composition. The most abundant compound in the EO was 1,8-cineole (21.7%). The cytotoxic activity of the EO was evaluated against three cancer cell lines (MCF7, A2780 and HT29), and one normal fibroblast cell line (MRC5) by MTT assay. Significant growth inhibition was observed in EO-exposed A2780 and HT29 cells (IC50 = 12.99 and 14.02 µg/mL, respectively), while MCF7 and MRC5 were less susceptible. The EO induced apoptosis and increased the preG1 events in A2780 cells. 1,8-Cineole, the major constituent of the EO, exhibited submicromolar cytotoxicity against A2780 cells, and was 42 times more selective against MRC5 cells. Its cytotoxicity against A2780 cells was comparable with that of doxorubicin, but 1,8-cineole was more selective for MRC5 normal cells. Interestingly, 1,8-cineole enhanced apoptosis in A2780, and caused a remarkable dose-dependent increase in preG1 events. Thus, 1,8-cineole has demonstrated promising cytotoxic and proapoptotic properties.

Urease inhibitory potential of extracts and active phytochemicals of Hypochaeris radicata (Asteraceae).

Urease inhibition potential of compound (1), guaiane-type sesquiterpene (2), confertin (3) and scopoletin (4) was carried out with high throughout mechanism-based assay. These compounds were isolated from Hypochaeris radicata L., an Asteraceae family member. The pure compounds were screened for their urease and carbonic anhydrase inhibitory activities. The ethyl acetate fractions were subjected to column chromatography, which resulted in the isolation and purification of four compounds (1-4). On evaluation, compounds (1-4) exhibited selective activity against urease enzyme with an IC50 value of 180.11 ± 2.00, 27.18 ± 0.80, 24.12 ± 0.2 and 30.12 ± 1.10 µM respectively. The compounds (1-4) were found to be inactive against carbonic anhydrase enzyme. Thiourea was used as standard inhibitor (21 ± 0.14 µM) of urease enzyme.

In Vivo Study on Analgesic, Muscle-Relaxant, Sedative Activity of Extracts of Hypochaeris radicata and In Silico Evaluation of Certain Compounds Present in This Species.

BACKGROUND: Hypochaeris radicata (flatweed) from the family Asteraceae is a medicinal plant found in Europe, Middle East, and India. In folkloric medication, it is used to heal jaundice, dyspepsia, constipation, rheumatism, and hypoglycemia as well as renal problems. Leaves and roots of the plant have antioxidant and antibacterial properties. The plant is a rich source of pharmacologically active phytochemicals; however, it is explored scantily. The objective of the current study was to identify the chemical composition and investigate the in vivo biological potency of crude extracts of this plant. METHODS: The crude extract and the fractions were screened for various phytochemical groups of constituents following standard procedures. The acute toxicity was assayed for safe range of dose determination. The analgesic potential of the extract and fractions was assessed by acetic acid-induced writhing test. The muscle-relaxant activity was examined by standard inclined-plane test and traction test. Sedative potential of extract/fractions was assessed by using standard white wood procedures. Furthermore, docking analysis of two compounds present in the ethyl acetate fraction of the plant was assessed against 3D cyclooxygenase-1 and -2 (COX-1 and COX-2). RESULTS: The extract/fractions of H. radicata showed significant analgesic effect in in vivo model of peripheral algesia. The docking analysis of previously isolated molecules from the plant also exhibited promising interaction with COX-1 and COX-2. Also, the plant has a mild sedative and muscle-relaxant potential. Thus, our study provided pharmacological rationale for the traditional uses of the plant as analgesic and anti-inflammatory remedy. CONCLUSION: The crude extracts and fractions exhibited excellent activity due to active phytochemicals. These active phytochemicals also exhibited promising interaction with COX-1 and COX-2. These findings directed researcher to isolate active compounds from H. radicata which may be used as a potential source of active secondary metabolites.

Formulation of Saudi Propolis into Biodegradable Chitosan Chips for Vital Pulpotomy.

BACKGROUND: Propolis has been widely used to treat oral cavity disorders, such as endodontal and periodontal diseases and microbial infections. OBJECTIVE: The study aimed at the formulation of commercial Saudi propolis into biodegradable chitosan chips and evaluation of its effectiveness as a pulpotomy agent. METHODS: The standardization of 80% ethanolic propolis extract was performed regarding its total phenolic content, total flavonoid content, quantitative estimation of main polyphenolic constituents and antioxidant activity. Chitosan chips containing propolis extract were prepared by the solvent/ casting method. The investigated variables were % of chitosan polymer (2, 2.5 and 3%), % of plasticizer (1, 5 and 10%) and incorporation of different concentrations of hydroxypropyl methylcellulose (5, 10 and 20% of polymer weight). The chips were characterized for weight and thickness uniformity, content uniformity, pH, percentage moisture loss, swelling index, tensile strength and in vitro propolis release. The optimal propolis chip formulation was further investigated in dogs regarding the short term response of primary dental pulp to propolis chips compared with the most commonly used formocresol preparation. RESULTS: The prepared films were flexible and demonstrated satisfactory physicochemical characteristics. The optimal formulation showed an initial release of about 41.7% of the loaded propolis followed by a sustained release extended up to 7 days. The kinetics study demonstrated that propolis release was controlled by Fick´s diffusion. The optimal propolis chip formulation resulted in less pulpal inflammation compared to formocresol, and produced hard tissue formation in all specimens. CONCLUSION: Formulation of commercial Saudi propolis as a biodegradable chitosan chip is an effective alternative to the commercially available chemical agents for the treatment of vital pulpotomy.

Flavonoidal Constituents, Antioxidant, Antimicrobial, and Cytotoxic Activities of Dipterygium glaucum Grown in Kingdom of Saudi Arabia.

BACKGROUND: Dipterygium glaucum Decne. herb is one of the common traditional plants with multiple medicinal uses. OBJECTIVE: To isolate the major constituents and to investigate the antioxidant, antimicrobial, and cytotoxic activities of this herb. MATERIALS AND METHODS: Methanolic extract of D. glaucum herb was fractionated using n-hexane, dichloromethane, and n-butanol. Butanol fraction was chromatographed using column chromatography and preparative thin layer chromatography to isolate the major constituents. Isolated compounds were elucidated by means of spectroscopic methods, including 1D, 2D NMR (1H, 13C, DEPT, COSY, HSQC, HMBC, NEOSY) and MS analysis. Total phenolic content using Folin-Ciocalteu reagent and antioxidant activity using 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay of the total methanolic extract were evaluated. Cytotoxic potential of both methanolic extract and butanol fraction was tested using a crystal violet viability assay. Antimicrobial activities of both extracts were investigated using diffusion agar technique. RESULTS: Apigenin 6, 8-di-C-glucopyranoside (vicenin-2), quercetin-3`-O-methyl-3-O-glucopyranoside, quercetin-3`-O-methyl-3-O-galactopyranoside, quercetin-3-O-ß-D-glucopyranoside, and quercetin-3-O-ß-D-galactopyranoside were isolated and elucidated. Total phenolic content was (83.89 mg gallic acid equivalent/g extract). The EC50 value of scavenging DPPH radical was 152.0 ± 2 mg/mL. Butanol fraction showed the highest cytotoxic activity against cervical and breast carcinoma cells (IC50 3.6 and 6.1 mg/mL, respectively). Both methanolic extract and butanol fraction showed wide spectrum antimicrobial activity against Gram-positive and Gram-negative bacteria and some fungi. The highest activity was from methanolic extract against Enterococcus faecalis (83.25%) and against Candida tropicalis (77.03%) as compared to reference antibiotics. CONCLUSION: Data obtained from this study demonstrate that D. glaucum possesses significant antioxidant, cytotoxic, and antimicrobial activities which could be ascribed to its flavonoidal content. SUMMARY: Dipterygium glaucum Decne. herb is one of the common traditional plants with multiple medicinal uses in KSAFive flvonidal glycosides were isolated and elucidatedThis study demonstrated that D. glaucum possesses significant antioxidant, cytotoxic, and antimicrobial activities. Abbreviations used: KSA: Kingdom of Saudi Arabia; TLC: Thin Layer Chromatography; DPPH: 2,2`-diphenyl-1-picrylhydrazyl; EC50: Half maximal effective concentration; IC50: Half maximal inhibitory concentration; DMSO: dimethyl sulfoxide; NMR: Nuclear Magnetic Resonance; ESIMS: Electrospray ionization mass spectrometry; MeOH: Methyl alcohol.

A New Sucrase Enzyme Inhibitor from Azadirachta indica.

BACKGROUND: Sucrase enzyme inhibitor considered as an oral anti-diabetic therapy that delays the absorption of eaten carbohydrates, reducing the postprandial glucose and insulin peaks to reach normoglycemia. MATERIALS AND METHODS: Chromatographic fractionation of the hydroalcoholic extract of leaves of Azadirachta indica growing in KSA, followed by in-vitro assay of sucrase enzyme inhibition activity. RESULTS: This investigation led to the isolation of a new remarkable sucrase enzyme inhibitor; 4'-methyl Quercetin-7-O-ß-D-glucuronopyranoside (1) alongside with four known compounds; 2,3-hexahydroxydiphenoyl-(α/ß)-D-(4)C1-glucopyranose (2), Avicularin (3), Castalagin (4) and Quercetin-3-O-glucoside (5). The structure of the new compound (1) was elucidated on the basis of its spectral data, including ESI-MS, UV, (1)H NMR, (13)C NMR, (1)H-(1)H COSY, HSQC, NOESY and HMBC. CONCLUSION: Under the assay conditions, hydroalcoholic extract of A. indica and compounds 1-5 exhibited significant sucrase enzyme inhibitory activity. SUMMARY: Chromatographic fractionation of the hydroalcoholic extract of leaves of Azadirachta indica, led to the Isolation of a new flavonoid glycoside named 4'-methyl Quercetin-7-O-ß-D-glucuronopyranoside, alongside to other 4 known polyphenols. The hydroalcoholic extract as well as the isolated compounds exhibited significant sucrase enzyme inhibitory activity. Abbreviations used: ESI-MS; electrospray ionization-mass spectrometry, UV; ultraviolet, NMR; nuclear magnetic resonance, 1H-1H COSY; 1H-1H correlation spectroscopy, NOESY; nuclear overhauser effect spectroscopy, and HSQC; heteronuclear multiple bond correlation. A. indica; Azadirachta indica.

Bioassay-guided isolation and POM analyses of a new immunomodulatory polyphenolic constituent from Callistemon viridiflorus.

Chromatographic separation of 80% EtOH extract of Callistemon viridiflorus leaves led to the isolation of six known constituents (1-6) along with a new polyphenolic compound 7 identified as apigenin 4'-O-ß-d-glucopyranosyl-(1″' â†’ 4″)-O-ß-d-glucopyranoside. The ethanolic extract of C. viridiflorus leaves and isolated compounds were evaluated for in vitro immunomodulatory activity by means of RAW 264.7 macrophages proliferation (MTT) assay. Ethanolic extract of leaves and compounds 1, 3, 4, 6 and 7 caused a significant increase in macrophage proliferation; these findings may suggest that this medicinal plant could be utilised as an excellent source of compounds for immunomodulatory activity.

Antioxidant and cytotoxic activity of polyphenolic compounds isolated from the leaves of Leucenia leucocephala.

CONTEXT: Cancer is a serious clinical problem to the health care system. Anticancer drugs have been extracted from plants containing phenolic compounds. Leucenia species (Fabaceae) contain a variety of bioactive components of numerous biological and pharmacological properties. OBJECTIVE: This study explored the constitutive polyphenols of Leucenia leucocephala Lam. growing in Egypt and evaluated the antioxidant and cytotoxic activity. MATERIALS AND METHODS: Chemical structures of the isolated compounds from the leaves of L. leucocephala were established by spectral techniques (UV, (1)H, and (13)C NMR, MS). RESULTS: Chromatographic separation of 80% MeOH extract of the leaves of L. leucocephala have resulted in a novel flavonoid-galloyl glycoside [myricetin 3-O-(2',3'4'-tri-O-galloyl)-α-L-rhamnopyranoside] with three known polyphenolic compounds isolated for the first time from this species (apigenin 7-O-ß-D-glucuronopyranoside methyl ester, luteolin 7-O-ß-D-glucuronopyranoside methyl ester, and 1,3,6-tri-O-galloyl-ß-D-glucopyranose) and seven known previously isolated compounds. Also, 80% methanol extract exhibited high antioxidant activity (SC(50) = 3.94 µg/ml), which is correlated with its phenolic content. The extract also showed cytotoxic activity against Hep G2 (IC(50) value 1.41 µg/ml) confirming its anticancer activity against hepatocellular carcinoma. Among the tested compounds (4-8) for antioxidant property, compound 7 was the most active compound (SC(50) = 2.49 µg/ml). Also compounds 7 and 8 exhibited high cytotoxic activity (IC(50) = 2.41 and 2.81 µg/ml, respectively). DISCUSSION AND CONCLUSION: These findings demonstrate that the leaves of L. leucocephala contain a considerable amount of polyphenolic compounds with high antioxidant properties, thus it has great potential as a source for natural health products.

Homospermidine in transgenic tobacco results in considerably reduced spermidine levels but is not converted to pyrrolizidine alkaloid precursors.

Homospermidine synthase is the first specific enzyme in the biosynthesis of pyrrolizidine alkaloids. Whereas the substrates putrescine and spermidine are part of the highly dynamic polyamine pool of plants, the product homospermidine is incorporated exclusively into the necine base moiety of pyrrolizidine alkaloids. Recently, the gene encoding homospermidine synthase has been shown to have been recruited several times independently during angiosperm evolution by the duplication of the gene encoding deoxyhypusine synthase. To test whether high levels of homospermidine suffice for conversion, at least in traces, to precursors of pyrrolizidine alkaloids, transgenic tobacco plants were generated expressing homospermidine synthase. Analyses of the polyamine content revealed that, in the transgenic plants, about 80% of spermidine was replaced by homospermidine without any conspicuous modifications of the phenotype. Tracer-feeding experiments and gas chromatographic analyses suggested that these high levels of homospermidine were not sufficient to explain the formation of alkaloid precursors. These results are discussed with respect to current models of pathway evolution.