Antibacterial and antioxidant potential of the phenolic extract and its fractions isolated from Allium ascalonicum (onion) peel.

Aqueous methanolic (20:80) crude extract of the outer peel of Allium ascalonicum (onions) was fractionated into anthocyanin (II), acidic (i.e., phenolic acids, Ia), neutral A (i.e., flavanols, Ib) and neutral B (i.e., flavonols, Ic) phenols using C-18 and hydrophilic-lipophilic balanced (HLB) Co-polymer cartridges. The fractions were analysed for total phenolic, total flavonoids, antibacterial activity, antioxidant potential and lipoxygenase (LOX) inhibition. The recovery of total phenols and bio functional activity in all fractions were found to be more in HLB. All fractions showed antimicrobial activity against tested strains with phenolic acids (Ia) being most active and flavanol (Ib) least active, while the highest free radical scavenging, reducing power and LOX inhibition was exhibited by flavonol (Ic) and least by flavanols (Ib). HPLC analysis revealed the presence of vanillic acid and quercetin in non-anthocyanin I and cyanidin in anthocyanin II.

Development of active packaging film from sodium alginate/carboxymethyl cellulose containing shallot waste extracts for anti-browning of fresh-cut produce.

Owing to growing concerns about making pollution-free sustainable environment by reducing the dumping of agricultural waste and convert it into valuable product is a key to carry out the present study. The ultimate goal of this study is to convert shallot onion wastes (SOWs) into active packaging and evaluating the anti-browning effect due to the SOWs holding rich polyphenols and antioxidants. The active packaging film was fabricated by using sodium alginate (SA) and carboxymethyl cellulose (CMC) along with shallot onion waste extract (SOWEs) such as peel and stalk at 0.2% and 0.5% concentration. The film made with SA/CMC/SOWEs had good physical, mechanical, optical and barrier property, higher phenolic and antioxidant activity compared to control. In addition, the effect of SA/CMC/SOWEs film packaging on anti-browning and quality of fresh-cut apple and potato stored at 4 °C was studied. The results show the SA/CMC/SOWEs film had better effect on controlling browning index in fresh-cut apple and potato over the storage of 12 days and 5 days. This study concludes that the SA/CMC film developed with shallot stalk extract can be used for wrapping of fresh-cut fruits and vegetables. It also prevents browning and maintains the overall quality than control and shallot peel incorporated film.

Analysis of volatile compound changes in fried shallot (Allium cepa L. var. aggregatum) oil at different frying temperatures by GC-MS, OAV, and multivariate analysis.

Flavor is a key attribute of fried oil that shows a critical correlation with temperature. Therefore, selecting the appropriate temperature is important in preparing fried shallot oil (FSO). Volatile compounds from five different FSOs were identified and comparatively studied using gas chromatography-mass spectrometry (GC-MS) coupled with multivariate data analysis, including principal component analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS-DA). GC-MS results identified a total of 93 volatiles, among which aldehydes, alcohols, pyrazines, and sulfur-containing compounds were the major compounds. Eighteen compounds had odor active values (OAV) >1. Among the compounds, hexanal, (E)-2-heptenal, (E)-2-octenal, dipropyl disulfide, 2-ethyl-3,5-dimethylpyrazine, and 1-octen-3-ol were important to the overall aroma profile of FSOs. In the PCA model, all the detected FSOs were divided into three clusters, which were assigned as cluster A (FSO5), B (FSO4), and C (the rest FSOs). Multivariate data analyses revealed that nonanal, 2-ethyl-5-methylpyrazine, (E,E)-2,4-decadienal, (E)-2-heptenal, and hexanal contributed positively to the classification of different FSOs. GC-MS coupled with multivariate data analysis could be used as a convenient and efficient analytical method to classify raw materials.

Metabolome-Based Discrimination Analysis of Shallot Landraces and Bulb Onion Cultivars Associated with Differences in the Amino Acid and Flavonoid Profiles.

Shallot landraces and varieties are considered an important genetic resource for Allium breeding due to their high contents of several functional metabolites. Aiming to provide new genetic materials for the development of a novel bulb onion cultivar derived from intraspecific hybrids with useful agronomic traits from shallots, the metabolic profiles in the bulbs of 8 Indonesian shallot landraces and 7 short-day and 3 long-day bulb onion cultivars were established using LC-Q-TOF-MS/MS. Principal component analysis, partial least squares discriminant analysis, and dendrogram clustering analysis showed two major groups; group I contained all shallot landraces and group II contained all bulb onion cultivars, indicating that shallots exhibited a distinct metabolic profile in comparison with bulb onions. Variable importance in the projection and Spearman's rank correlation indicated that free and conjugated amino acids, flavonoids (especially metabolites having flavonol aglycone), and anthocyanins, as well as organic acids, were among the top metabolite variables that were highly associated with shallot landraces. The absolute quantification of 21 amino acids using conventional HPLC analysis showed high contents in shallots rather than in bulb onions. The present study indicated that shallots reprogrammed their metabolism toward a high accumulation of amino acids and flavonoids as an adaptive mechanism in extremely hot tropical environments.

Effect of Extraction Methods on Antioxidant Activity of Papery Skin Extracts and Fractions of Maja Cipanas Onion (Allium cepa L. var. ascalonicum).

Extraction can be carried out at ambient temperature or high temperature to accelerate the extraction process of secondary metabolites from simplicia. This study aimed to determine the effectiveness of extraction methods on antioxidant activity of secondary metabolites of papery skin extracts and fractions of Maja Cipanas onion (Allium cepa L. var. ascalonicum). Extraction methods were maceration, percolation, reflux, and Soxhlet method, and then, concentrated extracts were fractionated by liquid-liquid extraction based on the polarity of secondary metabolites. Antioxidant activity was determined by the DPPH (2,2-diphenyl-1-picrylhydrazyl) method. The phytochemical screening showed that onion papery skin contained alkaloids, polyphenols, flavonoids, and tannins. The IC50 value of the extract, ethyl acetate fraction, and water fraction of the four extraction methods in the concentration range 25-400 µg/mL were in the range of 55.62-107.08, 31.31-84.06, and 126.05-139.82 µg/mL, respectively, while the IAA value was in the ranges of 0.25-0.49, 0.32-0.86, and 0.19-0.21, respectively. Variation in IC50 and IAA values indicate that the extraction method affects antioxidant activity, due to extracted secondary metabolites from simplicia. The highest antioxidant activity was an ethyl acetate fraction by the reflux method, while the lowest was water fraction by the percolation method.

Chemical Composition, Oxidative Stability, and Antioxidant Activity of Allium ampeloprasum L. (Wild Leek) Seed Oil.

Allium ampeloprasum L., commonly known as wild leek, is an edible vegetable that has been cultivated for centuries. However, no detailed studies have been undertaken to valorize A. ampeloprasum seed oil. This study aims to evaluate the physicochemical properties, chemical composition, and antioxidant activity of A. ampeloprasum seed oil. The seed oil content was found to be 18.20%. Gas chromatographymass spectrometry (GC-MS) showed that linoleic acid (71.65%) was the dominant acid, followed by oleic acid (14.11%) and palmitic acid (7.11%). A. ampeloprasum seed oil exhibited an oxidative stability of 5.22 h. Moreover, γ- and δ-tocotrienols were the major tocols present (79.56 and 52.08 mg/100 g oil, respectively). The total flavonoid content (16.64 µg CE /g oil) and total phenolic content (62.96 µg GAE /g oil) of the seed oil were also determined. The antioxidant capacity of the oil, as evaluated using the ABTS assay (136.30 µM TEAC/g oil), was found to be significant. These findings indicate that A. ampeloprasum seeds can be regarded as a new source of edible oil having health benefits and nutritional properties.

Bioactive 2-(Methyldithio)Pyridine-3-Carbonitrile from Persian Shallot (Allium stipitatum Regel.) Exerts Broad-Spectrum Antimicrobial Activity.

Antibiotic resistance is a problem that continues to challenge the healthcare sector, especially in clinically significant pathogens like methicillin-resistant Staphylococcus aureus (MRSA). Herein is described the isolation and structure elucidation of a bioactive compound from Allium stipitatum with antimicrobial activity. Crude Allium stipitatum dichloromethane extract (ASDE) was subjected to systematic purification by chromatographic procedures to afford various bioactive fractions. A fraction that exhibited anti-MRSA activity (4 µg·mL-1) was further characterized to determine the structure. The structure of the compound was elucidated as 2-(methyldithio)pyridine-3-carbonitrile (2-Medpy-3-CN). The 2-Medpy-3-CN compound, which was screened for antimicrobial activity, exhibited minimum inhibitory concentrations (MICs) in the range of 0.5 to >64 µg·mL-1 for tested bacterial species and 0.25 to 2 µg·mL-1 for Candida spp. Further studies are important to confirm the drug target and mechanism of action.

Delaying microbial proliferation in freshly peeled shallots by active packaging incorporating ethanol vapour-controlled release sachets and low storage temperature.

This research was conducted to investigate effects of ethanol vapour released in active packaging and storage temperatures on the quality of freshly peeled shallots. The package tested was a solid polypropylene tray incorporating an ethanol vapour-controlled release sachet. The sachet was made of an aluminium foil film on one side and either low-density polyethylene or nylon/polyethylene on the other. Individual sachets contained silica gel adsorbent as the carrier pre-loaded with ethanol. One sachet was placed in each tray containing the peeled shallots and the tray was heat sealed with the low-density polyethylene film lid. Packages were stored at either 10 or 25 ℃ for 10 d. Trays containing only peeled shallots were designated as controls. High storage temperature stimulated quality changes in the shallots. Although ethanol vapour accumulated in the active package headspace, the extent to which ethanol concentrations increased within the shallots was not significantly different from that in the control packages. Microbial proliferation in terms of yeast and mould counts could be delayed through a combination of 10 ℃ and ethanol vapour released from the low-density polyethylene sachet. The ethanol vapour accumulated in the packages did not have a significant effect on mass loss, firmness, and colour changes in the peeled shallots, or on the concentrations of oxygen and carbon dioxide in the packages.

Isolation and characterization of Cepa2, a natural alliospiroside A, from shallot (Allium cepa L. Aggregatum group) with anticancer activity.

Exploration of new and promising anticancer compounds continues to be one of the main tasks of cancer research because of the drug resistance, high cytotoxicity and limitations of tumor selectivity. Natural products represent a better choice for cancer treatment in comparison with synthetic compounds because of their pharmacokinetic properties and lower side effects. In the current study, we isolated a steroidal saponin, named Cepa2, from the dry roots of shallot (Allium cepa L. Aggregatum group), and determined its structure by using two-dimensional nuclear manganic resonance (2D NMR). The 1H NMR and 13C NMR data revealed that the newly isolated Cepa2 compound is identical to alliospiroside A (C38H60O12) [(25S)-3ß-hydroxyspirost-5-en-1ß-yl-2-O-(6-deoxy-α-L-mannopyranosyl)-α-L-arabinopyranoside], whose anticancer activity remains elusive. Our in vitro examination of the cytotoxic activity of the identified Cepa2 against P3U1 myeloma cancer cell line showed its high efficiency as an anticancer with 91.13% reduction in P3U1 cell viability 12 h post-treatment. The reduction of cell viability was correlated with the increase in reactive oxygen species levels in Cepa2-treated P3U1 cells, as compared with untreated cells. Moreover, scanning electron microscope results demonstrated apoptosis of the Cepa2-treated P3U1 cells in a time course-dependent manner. The results of our study provide evidence for the anticancer properties of the natural Cepa2/alliospiroside A extracted from shallot plants, and a strong foundation for in-depth investigations to build theoretical bases for cell apoptosis and development of novel anticancer drugs.

TLC determination of flavonoids from different cultivars of Allium cepa and Allium ascalonicum.

This study comprises the optimization and validation of a new TLC method for determination of flavonols in the bulbs of seven cultivars of onions and shallots. Separation was performed on RP-18 plates with the solvent mixture tetrahydrofuran/water/formic acid (40+60+6, V/V/V) as a mobile phase. The method was evaluated for precision, linearity, LOD, LOQ, accuracy and robustness. Chromatographic analysis of the extracts revealed the presence of three main flavonols, quercetin, quercetin-4'-O-glucoside and quercetin-3,4'-O-diglucoside in the majority of analyzed cultivars. The content of flavonols in the analyzed extracts of onion bulbs varied from 123 ('Exihibition') to 1079 mg kg-1 fresh mass (fm) ('Hybing') in edible parts, and from 1727 ('Hyline') to 28949 mg kg-1 fm ('Red Baron') in outer scales. The bulbs of two shallot cultivars contained 209 ('Ambition') and 523 mg kg-1 fm ('Matador') of flavonols in edible parts and 5426 and 8916 mg kg-1 fm in outer scales, respectively.

Residue level and dissipation pattern of lepimectin in shallots using high-performance liquid chromatography coupled with photodiode array detection.

Lepimectin, as an emulsifiable concentrate, was sprayed on shallots at the recommended dose rate (10 mL/20 L) to determine its residue levels, dissipation pattern, pre-harvest residue limits (PHRLs), and health risk. Samples were randomly collected over 10 days, extracted with acetonitrile, purified using an amino solid-phase extraction (NH2 -SPE) cartridge and analyzed using a high-performance liquid chromatography-photodiode array detection method. Field-incurred samples were confirmed using ultra-performance liquid chromatography-tandem mass spectrometry. The linearity was excellent, with a determination coefficient (R2 ) of ≥0.9991. The recoveries at two spiking levels (0.2 and 1.0 mg/kg) ranged from 84.49 to 87.64% with relative standard deviations of ≤7.04%. The developed method was applied to field samples grown in separate greenhouses, one located in Naju and one in Muan, in the Republic of Korea. The dissipation pattern was described by first-order kinetics with half-lives of 1.9 (Naju) and 1.7 days (Muan). The PHRL curves indicated that, if the lepimectin residues are <0.18 (Naju) and <0.13 mg/kg (Muan) 5 days before harvest, the residue levels will be lower than the maximum residue limit (0.05 mg/kg) upon harvesting. The risk assessment data indicated that lepimectin is safe for use in the cultivation of shallots, with no risk of detrimental effects to the consumer.

An investigation of antimicrobial and wound healing potential of Allium ascalonicum Linn.

BACKGROUND: The pharmacological properties of Allium ascalonicum Linn., commonly called shallot, have been reported as including those that are antibacterial and antioxidant. OBJECTIVE: The present study aimed to evaluate the antimicrobial effect and wound-healing activity ofthe ethanolic extracts of Allium ascalonicum Linn. (AAE). MATERIAL AND METHOD: The antimicrobial activity of AAE was tested in vitro against using the disc diffusion method and a broth micro-dilution technique to determine the minimal inhibition concentrations (MIC) and the minimal microbicidal concentrations (MMC). Wound-healing activity of the extract was performed on rat test subjects. RESULTS: The AAE showed potential antimicrobial activity by inhibiting gram-positive bacteria Staphylococcus epidermidis and Bacillus subtilis ATCC 6633. MIC and MMC varied from 25-50 mg/ml and 25-200 mg/ml, respectively. After surgery 14 days, wound contractions oftreated groups and standard group were 78.61 +/- 1.20%, 78.55 +/- 1.93% and 100%, respectively; but, in the control group, wound contraction was 64.90 +/- 3.55%. Histological studies showed the complete epidermis and found the collagen fibers and fibroblasts as similar appearance as standard group in dermis. The results of histological evaluation have confirmed remarkable wound-healing activities of AAE. CONCLUSION: Taken together the present study provides evidence that AAE extract processes antimicrobial and wound-healing activities.

Combined use of high-resolution α-glucosidase inhibition profiling and high-performance liquid chromatography-high-resolution mass spectrometry-solid-phase extraction-nuclear magnetic resonance spectroscopy for investigation of antidiabetic principles in crude plant extracts.

Type 2 diabetes is a metabolic disorder affecting millions of people worldwide, and new drug leads or functional foods containing selective α-glucosidase inhibitors are needed. Crude extract of 24 plants were assessed for α-glucosidase inhibitory activity. Methanol extracts of Cinnamomum zeylanicum bark, Rheum rhabarbarum peel, and Rheum palmatum root and ethyl acetate extracts of C. zeylanicum bark, Allium ascalonicum peel, and R. palmatum root showed IC50 values below 20 µg/mL. Subsequently, high-resolution α-glucosidase profiling was used in combination with high-performance liquid chromatography-high-resolution mass spectrometry-solid-phase extraction-nuclear magnetic resonance spectroscopy for identification of metabolites responsible for the α-glucosidase inhibitory activity. Quercetin (1) and its dimer (2), trimer (3), and tetramer (4) were identified as main α-glucosidase inhibitors in A. ascalonicum peel, whereas (E)-piceatannol 3'-O-ß-D-glucopyranoside (5), (E)-rhapontigenin 3'-O-ß-D-glucopyranoside (6), (E)-piceatannol (8), and emodin (12) were identified as main α-glucosidase inhibitors in R. palmatum root.

Effect of processing conditions on the organosulfides of shallot (Allium cepa L. Aggregatum group).

There is a growing account of the health benefits of H2S as an endogenous cell-signaling molecule. H2S from organic polysulfides, in particular, is increasingly gaining attention for their beneficial effects to cardiovascular health. Here, we studied shallot as a potential dietary source of organic polysulfides and examined the effects of processing conditions on its polysulfide profiles. Boiling, autoclaving, and freeze-drying were tested on whole and crushed shallot bulbs, analyzing their effect on the yield of organosulfides. Seventeen organosulfides, including disulfides, trisulfides, and cyclic polysulfides, were identified. Significant differences in the quantitative and qualitative profiles of organosulfides in the hydrodistilled and solvent extracted oils were observed. Freeze-drying retained the majority of the organosulfides, but the whole-autoclaved and whole-boiled shallots lost more than 95% of their organic polysulfides. Crushed-boiled and crushed-autoclaved shallot lost 76-80% of their organosulfides, likely due to the thermal sensitivity of these compounds. The organosulfide profiles are sensitive to the pH values of the processing media. In general, disulfides increased at basic pH (pH 9.0) while trisulfides and cyclic organosulfides are much higher at the acidic to neutral pH values (pH 3.0-5.0). Our results provide important information on the effects of processing conditions that are relevant for optimizing extraction of organosulfides from shallot for further studies evaluating their H2S-releasing activity.

Identification and biological activity of antifungal saponins from shallot ( Allium cepa L. Aggregatum group).

The n-butanol extract of shallot basal plates and roots showed antifungal activity against plant pathogenic fungi. The purified compounds from the extract were examined for antifungal activity to determine the predominant antifungal compounds in the extract. Two major antifungal compounds purified were determined to be alliospiroside A (ALA) and alliospiroside B. ALA had prominent antifungal activity against a wide range of fungi. The products of acid hydrolysis of ALA showed a reduced antifungal activity, suggesting that the compound's sugar chain is essential for its antifungal activity. Fungal cells treated with ALA showed rapid production of reactive oxygen species. The fungicidal action of ALA was partially inhibited by a superoxide scavenger, Tiron, suggesting that superoxide anion generation in the fungal cells may be related to the compound's action. Inoculation experiments showed that ALA protected strawberry plants against Colletotrichum gloeosporioides , indicating that ALA has the potential to control anthracnose of the plant.

Single-step modified QuEChERS for determination of chlorothalonil in shallot (Allium ascalonicum) using GC-µECD and confirmation via mass spectrometry.

A single extraction method was developed for chlorothalonil in shallot using gas chromatography with an electron capture detector (GC-µECD). Samples were extracted with single-step modified quick, easy, cheap, effective, rugged, and safe (QuEChERS) method using ethyl acetate as an extraction solvent. Significant matrix effects were observed, and the calibration curve was constructed from the matrix. The linearity of the analytical response across the studied range of concentrations (0.01-1.00 mg/L) was excellent, obtaining a correlation coefficient (r(2) ) of 0.996. >0.996. Recovery studies were carried out on spiked shallot blank samples, at two concentration levels (0.4 and 2.0 mg/kg) with three replicates performed at each level. Mean recoveries of 97.2-104.9% with RSDs of 1.3-2.7% were obtained. The method is demonstrated to be suitable for the determination of chlorothalonil in shallot. The dissipation rates of chlorothalonil were described using first-order kinetics, and its half-life was 2.8 days. Based on the dissipation pattern of the pesticide residues, the pre-harvest residue limit (PHRL) was also calculated. Residues were confirmed via mass spectrometry.

Analysis of imidacloprid and pyrimethanil in shallot (Allium ascalonicum) grown under greenhouse conditions using tandem mass spectrometry: establishment of pre-harvest residue limits.

In this study, the original Quick, Easy, Cheap, Effective, Rugged and Safe method was used for the extraction of imidacloprid and pyrimethanil followed by a rapid clean-up through dispersive solid-phase extraction technique with primary secondary amine sorbent and magnesium sulfate in shallot. Residues were analyzed using LC-tandem mass spectrometry in positive-ion electrospray ionization mode. The limits of detection and quantification were estimated to be 0.006 and 0.02 mg/kg, respectively. The samples were fortified at two different concentration levels (0.2 and 1.0 mg/kg), and the recoveries ranged between 79.7 and 83.9% with relative standard deviation values < 6%. The method was successfully applied for the establishment of the pre-harvest residue limits (PHRL). The rate of disappearance of imidacloprid and pyrimethanil on shallot was described with first-order kinetics (imidacloprid, y(2) = 0.9670; pyrimethanil, y(2) = 0.9841), with half-lives of 2.87 and 2.08 days, respectively. Based on the dissipation patterns of the pesticide residues, the PHRL was recommended at 7.86 mg/kg for 14 days (PHRL14 ) and 1.98 mg/kg for 7 days (PHRL7 ) before harvest for imidacloprid, and 21.64 mg/kg for 7 days (PHRL7 ) and 9.28 mg/kg for 4 days (PHRL4 ) before harvest for pyrimethanil in shallot.

Effects of turmeric, shallot extracts, and their combination on quality characteristics of vacuum-packaged rainbow trout stored at 4 ± 1 °C.

The effects of turmeric extract (T), shallot extract (Sh), and their combination (T + Sh) on the quality of vacuum-packaged rainbow trout (Oncorhynchus mykiss) were examined during refrigerated storage (4 ± 1 °C) over a period of 20 d. Fish samples were divided into 4 batches; 3 batches were treated by dipping for 30 min in aqueous solution of turmeric extract (1.5%; v/v), shallot extract (1.5%; v/v), or turmeric and shallot extract combination (1.5%+ 1.5% v/v), while the fourth batch was dipped in distilled water as a control sample. The control and the treated fish samples were analyzed periodically for microbiological (total viable count, psychrotrophic count), chemical (total volatile base nitrogen [TVB-N], peroxide value [PV], and thiobarbituric acid [TBA] value), and sensory characteristics. The results indicated that the effect of the T, Sh, and T + Sh on the fish samples were to enable the good quality characteristics to be retained longer and to extend the shelf life during the refrigerated storage.

Evaluation of sub-chronic oral toxicity of Joloo: a traditional medicinal decoction.

CONTEXT: Joloo is a Nigerian herbal decoction used for managing breast tumor, ulcer, pain, fever and general malaise in southwestern Nigeria. OBJECTIVE: The evaluation of the sub-chronic toxicity of Joloo, a Nigerian herbal decoction, is done by investigating its effects on biochemical, antioxidant, histopathologic and hematologic indices in normal albino rats. MATERIALS AND METHODS: Albino rats of either sex weighing between 128 and 160 g were divided into 4 groups of 10 rats each. Three test groups were orally administered 400, 800 and 1600 mg kg(-1) body weight (b. wt.) doses of Joloo while control animals received distilled water over 28 days. Animal were weighed weekly and sacrificed after day 28. Organs were harvested, weighed and subjected to histopathologic assessment. Liver and blood samples were used for biochemical, antioxidant and hematological studies. RESULTS: Mortality and signs of toxicity were absent in animals treated with 400 and 800 mg kg(-1) doses of Joloo. At 1600 mg kg(-1) dose, 20% mortality occurred. Decreased body weight and red blood cells (P < 0.05) observed at 1600 mg kg(-1) differed significantly from control animals. No significant changes in body and organ weights presented. Significant increases in biochemical analytes and histopathologic parameters were unobserved. Rather, Joloo increased leukopoiesis and exhibited antioxidant activities at all doses. DISCUSSION: Joloo proved safe at lower doses. The mortality at 1600 mg kg(-1) could be due to disturbances in the physiology of the animals. The significant reduction in erythropoiesis could indicate early signs of toxicity. However, the unremarkable increases in hepatic and antioxidant enzymes may suggest that Joloo modulated oxidative status in the animals. CONCLUSION: Joloo seems safe at lower doses, but caution is advised at higher doses.

In vitro and in vivo anti-angiogenesis effect of shallot (Allium ascalonicum): a heat-stable and flavonoid-rich fraction of shallot extract potently inhibits angiogenesis.

This study has been undertaken to elucidate the anti-angiogenic properties of shallot extract in vitro and in vivo and also to define the responsible fraction and its stability. After preparation of the extract of shallot bulbs with 50% ethanol, the extract was successively fractionated into n-hexane, ethyl acetate, n-butanol and aqueous fractions. The ethyl acetate fraction was further fractionated to three subfractions using thin layer chromatography. Anti-angiogenic activity of fractions and subfractions were examined on human umbilical vein endothelial cells (HUVECs) in collagen matrix and chicken chorioallantoic membrane (CAM) models. Among the fractions, ethyl acetate fraction and one of its subfractions potently inhibited angiogenesis in vitro and in vivo. Furthermore, ethyl acetate fraction sustained its inhibitory effect significantly even after treatment in high thermal and low pH conditions. These findings provided a useful basis for further investigations on shallot as a useful herb with therapeutic or preventive activity against angiogenesis related disorders.