Onion Extract Research Articles

Effects of onion extracts (Allium cepa) inclusion in diets on growth performance, carcass characteristics, and bone morphometric of broiler chickens.

Animal feed companies and researchers are currently embarking on quests for feed additives that could combat the pathogens while promoting growth as well as maintaining quality products. The current study aimed to evaluate the effects of onion extracts on growth performance, carcass quality, and bone morphometrics of broiler chickens. A total number of 200 one-day-old unsexed Ross 308 broiler chicks were assigned to 5 treatment groups, replicated 4 times. Each replicate (pens) held 10 chickens in a completely randomized design. The experimental diets were then randomly allotted to the pens which act as experimental units. The isoenergetic and isonitrogenous diets were formulated by including onion extracts at 0, 5, 10, 15, or 25 g/kg in a complete broiler diet. Feed intake, and body weight, were recorded then used to calculate feed conversion ratio. At the end of the experiment (42 days), four chickens from each pen were randomly selected for slaughter for carcass, bone morphology and sensory evaluation. Results showed that onion extract supplementation did not affect (p>0.05) growth performances and meat sensory evaluation. However, there was a significantly increased (p<0.05) meat shear force in groups receiving onion extracts dietary treatments. Furthermore, onion extracts improved (p<0.05) bone morphology of broiler chickens in terms of weight, diameter, calcium, and phosphorous contents. In conclusion, onion extracts can be safely included in a commercial broiler diet as a growth promoter without causing adverse effects on growth performance traits and carcass quality in chickens. Onion extract supplementation improved tibia bone growth and strength in broiler chickens.

Effects of Fermented Onion on Gut Health in Dextran Sodium Sulfate (DSS)-Induced Inflammatory Bowel Disease (IBD) Rats

Onion is a well-known health-beneficial vegetable. However, fresh onion is high in FODMAPs (fermentable oligosaccharides, disaccharides, monosaccharides, and polyols) which may be problematic for IBD. Fermentation of onion may help to lower FODMAP problems and increase the availability of bioactive compounds, especially quercetin. We investigated the effect of fermented onion on DSS-induced IBD in rats. Rats were divided into six groups and treated orally with saline as a control and negative control (DSS), probiotics, low and high doses of fermented onion, or fresh onion extract for 3 weeks. After two weeks, rats were given drinking water containing 0.2% DSS for 5 days, except for the control followed by two days of regular water. The colonic histomorphology, immunity, oxidative stress, short-chain fatty acids, and biochemical analysis showed improved IBD conditions in the fermented onion groups. In contrast, the consumption of fresh onion appeared to exacerbate the IBD condition. These results suggest that the consumption of a high dose of fermented onion can ameliorate IBD symptoms.

Natural colours could be used as dye to identify Tribolium castaneum (Herbst) eggs

Identification of eggs in grain/flour is critical for managing stored grain pests. Chemical dyes, which are typically used to identify eggs, may irritate skin and eyes. The current study seeks to uncover naturally coloured materials that could be employed as natural stains to differentially colour Tribolium castaneum (Herbst) eggs from the grain. In the current research, the colour, pH, total phenolics, anthocyanin, and flavonoid content were measured in onion, beetroot, turmeric powder, black grapes, and teak leaves’ aqueous extracts. The highest anthocyanin concentration was found in turmeric extracts (1.55 mg equivalent of cyanidin-3-glucoside g−1), while the highest flavonoid level was found in teak extract (12.13 mg equivalent catechine g−1). Total phenols were highest in onion extract (5.03 mg gallic acid equivalent g−1). Beetroot and teak stains might readily colour the flour red and dark brown, respectively while leaving the eggs uncolored. Grape and onion stains gave a slight purplish and light pink colour to the eggs while remaining particles were dark violet and dark pink, respectively. Since the eggs and flour were both coloured yellow, the turmeric stain proved ineffective. Highest percentage of hatchability (80.99%) was observed in original grape extract treatment. Colour and pH of the extracts determined the ability of a natural dye to stain flour, keeping the eggs unstained. The hatched larvae from the stained eggs did not exhibit any morphological alteration, and their growth time was unchanged. These natural dyes are indeed cheap, easily procurable and innocuous and can be sustainable substitutes of chemical dyes.

Identification of The Addition of Bran and Shallot Extract to the Quantity of Merang Mushroom Production

This study aims to identify the addition of bran and onion extract to the quantity of merang mushroom production. This research was carried out at the mushroom house merang Dusun Repok Tunjang Taman Indah Village, Pringgarata District, Lombok center NTB. This research is a descriptive experiment. The study was conducted with treatment and control design. The treatment medium was given fine bran and onion extract while the control added coarse bran rice milling waste. The data obtained are described in the form of graphs and photos. The researchers' findings show that the quality of merang mushroom production in media needs to be 36.03% higher when compared to control media. This is supported by the growth of mycelium, a faster fine head in the treatment medium. The application of bran and onion extract to the growing medium of merang mushrooms has a positive impact on the productivity and quality of merang mushrooms.

Effectiveness of Garlic Extract Pesticide (Allium sativum) Against Leaf Films in Saws (Brassica juncean)

Indonesia has a large part of its territory in the form of agricultural land which results in some of its people working as farmers. Land processing and maintenance in the agricultural sector were found to be obstacles so that production decreased from what it should have been. This is the reason why the number of requests for crops cannot be fulfilled, which results in an increase in prices. The method used in a non-factorial Completely Randomized Design (CRD) by carrying out 4 comparisons of pesticide concentrations including K1 (10 cc of onion extract mixed with 90 ml of water), K2 (15 cc of onion extract mixed with 85 ml of water), K3 (20 cc of onion extract mixed with 80 ml of water), K4 (25 cc of onion extract mixed with 75 ml of water), K5 (30 cc of onion extract mixed with 70 ml of water). The materials used in this study included garlic extract and water. The tools used are hoes, soil testers, thermometers, gembor, measuring tools and dippers. The conclusion from this study was that the concentration comparison was carried out that the V treatment (30 cc + 70 ml liters of water) was effective in the use of natural garlic pesticides (Allium sativum) by reducing the number of leaf pests on mustard greens (Brassica juncean) by 23 individuals for 2 week of observation and 2 times of spraying.

Topical delivery of natural extract for accelerated wound healing

The present research work aimed at developing a topical dosage form from onion extract for accelerated wound healing action. Onion extract was subjected to phytochemical screening, Gas Chromatograpgy-Mass Spectral analysis, in silico studies against selected proteins involved in wound healing process. It was assessed further for in vitro cytotoxicity and in vitro scratch assay on mouse fibroblasts cell line. Topical film forming onion extract spray formulations were prepared using Eudragit RS-100 as the film forming polymer using mixture of both stinging and non-stinging solvents. Gels were prepared using carbopol as gelling agent. Topical gels and film forming sprays were prepared and compared for wound healing. Gel formulations prepared with carbopol-940 and hydroxy propyl methyl cellulose showed better physico-chemical properties. The developed formulations were characterized for pH, viscosity, swelling index, spreadability, drug content, density, spray pattern, spray angle, drying time, average weight per dose, drug content and in-vitro permeation studies. The invitro cytotoxicity assay revealed cytocompatibility of the onion extract with L929 cell lines and possessed significant wound healing potential at concentration of 0.062 %v/v when subjected to in vitro scratch wound healing assay.

Effect of Bioactive Compounds of Lemon, Onion and Garlic Extract on Buffalo Semen Quality, Antioxidant Status and Ultrastructure Changes

The present study aimed to compare semen and fertility parameters of frozen-thawed buffalo semen extended in egg yolk based extender and the same extender supplemented with lemon, onion and garlic (LOG) extract as a natural antioxidant agents. The semen samples were re-suspended with basic diluents containing LOG extracts (10, 20, 30, 50, 100, 150; and 200 µl/ml). The control diluents comprised of only extender and lacked any antioxidant agent. Semen was collected from 10 mature buffalo bulls twice a week using artificial vagina. The supplementation of LOG at a concentration of 30 and 50 µl/ml significantly improved post-thawing motility and sperm viability. The status of acrosome and membrane integrity significantly improved in spermatozoa when supplemented with 30 and 50 µl/mlLOG extract. Also, 30 and 50 µl/ml LOG extract significantly reduced lipid peroxidation and increased total antioxidant activity (TAC). The highest rate of conception was observed in spermatozoa treated with 30 µl/ml LOG extract. The application of LOG extract resulted in improvement in the quality and fertility of frozen-thawed spermatozoa. Nevertheless, future studies are wanted to elucidate how the bioactive components in the LOG extract (especially in the low concentration) prevent cryo-damages in spermatozoa.

N-acetylcysteine improves the inhibitory effect of Quercetin-rich onion extract on HT-29 and HCT-116 colorectal cancer migration and invasion through iNOS suppression.

As colorectal cancer (CRC) usually presents at an advanced stage, it responds poorly to traditional surgery and chemoradiotherapy. Reactive oxygen species (ROSs) are a critical factor in cancer progression. Quercetin, a bioflavonoid derived from onion peel extract, provides great anti-oxidant and anti-cancer potential. Therefore, quercetin in combination with N-Acetylcysteine (NAC), a well-known anti-oxidant and adjuvant agent in cancer-chemotherapeutic drugs, was considered as a way of increasing treatment efficacy. Thus, this study aimed to evaluate the improvement effect of quercetin in combination with NAC in human CRC (HT-29 and HCT-116) cell progression, migration and invasion. Firstly, the effects of quercetin, NAC, and the combination of quercetin and NAC on cellular oxidants and glutathione levels were evaluated. Cell viability, anti-migrative activity and invasive activity were determined by MTT, wound healing, and Matrigel invasion tests, respectively. Then, the proteins involved in cell migration, invasion, and cellular oxidants were investigated. Moreover, the gene expression and overall survival were further validated by the GEPIA2 database. The results reveal that the combination was most effective in decreasing cellular oxidants and increasing glutathione levels, while there was a significant decrease in cancer cell migration and invasion involved in the suppression of iNOS, ICAM-1, and MMP-2 proteins. Furthermore, bioinformatic analysis verified that iNOS, ICAM-1, and MMP-2 were highly expressed in CRC tissue and also associated with a poor prognosis. This study demonstrated that Quercetin has higher efficacy when used in combination with NAC, representing a potential combination agent for anti-cancer drug development.

EFFECTIVENESS TEST OF ONION EXTRACT (Allium cepa L.) ON BACTERIA GROWTH Aeromonas hydrophila IN VITRO

Aeromonas hydrophila is a bacterium that causes MAS disease (Motile Aeromonas Septicemia), often found by cultivators. This study aimed to determine the effectiveness of onion extract (Allium cepa L.) in replacing chemical antibiotics and the correct dosage to inhibit the growth of Aeromonas hydrophila bacteria in vitro. The research method used was a Completely Randomized Design (CRD) with 7 treatments and 3 replications, P1 (Control-), P2 (Control+), P3 (10% onion extract), P4 (25% onion extract), P5 (50% onion extract), P6 (75% onion extract), P7 (100% onion extract). The results showed that 30 ml of onion extract obtained from 101.3 grams of onion powder had a yield value of 29.812%. Some secondary metabolite compounds in onion extract are flavonoids, alkaloids, saponins, tannins, steroids, and phenols, which function as antibacterial compounds. The diameter of the clear zone of 10% onion extract has a value of 26 mm and has a value that is not significantly different from the use of 50% chloramphenicol antibiotics with an inhibition zone diameter of 26.67 mm, treatment with onion extract with a concentration of 100% gives the same inhibition zone diameter. The highest is 34.17 mm.

The Effect Of Kind Of Manure With Stale Rice and Onion Extra Biovactors on Growth And Production Of Waxy Purple Corn (Zea mays var. ceratina Kulesh)

This study aimed to find out the interaction and effect of various kinds of manure with stale rice bioactivator and red onion extract. This study was conducted in Tanjung Perdana Village, Pondok Kubang District, Central Bengkulu Regency, Bengkulu Province. The design used was Completely Randomized Design (RAK) treatment 1, which was manure with stale rice bioactivator A0 (Control), A1 (Chicken Manure), A2 (Goat Manure), A3 (Cow Manure). The second treatment was red onion extract B0 (Control), B1 (0.75 ml/l), B2 (1.5 ml/l), B3 (2.25 ml/l). Each treatment was repeated 3 times in order to obtain 48 experimental units with 3 plants in each experimental unit so that 144 plants were obtained. The result indicated that various types of manure treatment with stale rice bioactivator had no significant effect of all abserved parameters. The treatment red onion extract had a very significant effect on cob length and significantly effected stem diameter 56 DAP, plant wet weight, and plant dry weight. Meanwhile, in this study, there was no interaction between various types of manure treatment with stale rice bioactivator and red onion extract on all observed parameters.

Inhibitory Test of Onion Extract (Allium Cepa L.) Against The Growth of Trichophyton rubrum Fungus Causing Tinea Pedis

Tinea pedis is a disease that attacks the area between the fingers, soles of the feet, heels, nails and is a source of infection in other areas. Trichophyton rubrum is the cause of 70 % of cases of tinea pedis. Fungal infections are usually treated using antifungal drugs which mostly have limitations, such as poor penetration into certain tissues, narrow spectrum of fungi, high side effects, and resistance of fungi to certain antifungals. Utilization of natural materials is done as an alternative treatment for fungal infections. One of the natural ingredients that has the potential to be used as antifungal is onion (Allium cepa L.). The aim of the study was to determine the ability of onion extract to inhibit the growth of the fungus Trichophyton rubrum. The type of research is Experimental Laboratory. This study used onion extract concentrations of 70 %, 60 %, 50 %, 40 %, control (+) and control (-). Data analysis using Kruskal Wallis Test and Post Hoc Mann Whitney Test. The average diameter of the inhibition zone at the extract concentration of 70 %, 60 %, 50 %, and 40 %, respectively, was 2,01 mm, 1,75 mm, 0,87 mm, and 0.58 mm. The results of the in vitro test using the disc diffusion method showed that onion extract had the ability to inhibit the growth of Trichophyton rubrum with a weak category.

Characterization of Polyphenol Oxidase (PPO) from Blackberry Thorny Wild Rubus Fruticosus and its Inhibition using Natural Extracts

The Polyphenol oxidase (PPO) leads to the enzymatic browning of fruits and vegetables and needs to be prevented in food browning and quality. The present study aimed to investigate the use of natural extracts and chemical inhibitors to prevent browning of the PPO of blackberries. Purification, characterization, and kinetics of PPO of blackberry parameters for five substrates, namely, pyrocatechol, 4-methylcatechol, Pyrogallol, Gallic acid, and tyrosine, were described. The results showed that the DEAE-Sepharose and Superdex G-200 purification methods, which achieved electrophoretic purity, increased PPO activity by 556 fold. Purification with Sephadex GE-200 and SDS-PAGE reveals two PPO isoenzymes with an apparent molecular weight of 22 kD and 70 kD. The optimum pH and temperature values indicated were 6.6 and 25°C, respectively. The PPO showed variable affinity towards o-dihydroxy phenolic substrates with catecholase activity but without any activity observed with phenol, a monohydroxy substrate, and it was very effective towards pyrocatechol, pyrogallol, and 4-methyl catechol. The results revealed that inhibition of the PPO using both synthetic inhibitors and natural extracts was the most effective method. Quercetin and ascorbic acid showed higher inhibition with the lowest Ki values. Fresh onion (Allium cepa) and wild Arbutus unedo extract were able to inhibit the blackberry PPO activity up to 50% and 60%, respectively. Therefore, the use of natural extracts from Arbutus unedo L as anti-browning agents on the blackberry PPO may provide new insight to overcome the enzymatic browning.

Plasma-treated LDPE film incorporated with onion and potato peel extract – A food packaging for shelf life extension on chicken thigh

This study aimed to develop a new antimicrobial food packaging from low-density polyethylene (LDPE) film containing the natural extract. In this regard, onion and potato peel extract were obtained using the ultrasound-assisted method. The polyethylene film surface was exposed to atmospheric plasma treatment to improve the wettability properties and subsequently increase the attachment of the extract on the film surface. Results showed significant changes in surface hydrophilicity; the contact angle reduced from 89° to 42° after 45 s treatment (350 W). The 10 % and 20 % concentrations of extracts were coated on the plasma-treated film’s surface, separately and in their combinations, by immersing the film into the extract solutions. The absorption and release rate of the film samples containing potato peel extract (PPE) was considerably higher than the other samples. However, the film containing onion peel extract (OPE) showed the highest phenolic content and antioxidant activity. The antibacterial activity of film samples demonstrated the significantly higher antibacterial activity of OPE than PPE. Results introduced the plasma-treated film containing 20 % OPE as the most effective antimicrobial film used for packaging chicken thighs. The chicken thigh samples packaged by antimicrobial film showed a lower value of thiobarbituric acid (0.09 mg MDA/kg sample), total volatile nitrogen (14.27 mg/100 g), and total viable count (4.05 log CFU/g) compared to the control sample (pristine film) during 6 days’ storage period. Our results suggest that plasma-treated film containing 20 % OPE has potential application as a functional food packaging film in food antimicrobial packaging.

Optimization of Wall Material of Freeze-Dried High-Bioactive Microcapsules with Yellow Onion Rejects Using Simplex Centroid Mixture Design Approach Based on Whey Protein Isolate, Pectin, and Sodium Caseinate as Incorporated Variables.

For the food sector, onion rejects are an appealing source of value-added byproducts. Bioactive compounds were recovered from yellow onion rejects using a pulse electric field process at 6000 v and 60 pulses. The onion extract was encapsulated with whey protein isolate (WPI), pectin (P), and sodium caseinate (SC) with a mass ratio of 1:5 (extract/wall material, w/w). A Simplex lattice with augmented axial points in the mixture design was applied for the optimization of wall material for the encapsulation of onion reject extract by freeze-drying (FD). The optimal wall materials were 47.6 g/100 g (SC), 10.0 g/100 g (P), and 42.4 g/100 g (WPI), with encapsulation yield (EY) of 85.1%, total phenolic content (TPC) of 48.7 mg gallic acid equivalent/g DW, total flavonoid content (TFC) of 92.0 mg quercetin equivalent/g DW, and DPPH capacity of 76.1%, respectively. The morphological properties of the optimal encapsulate demonstrated spherical particles with a rough surface. At optimal conditions, the minimum inhibitory concentration (MIC) of the extract (mean diameter of inhibition zone: 18.8 mm) was shown as antifungal activity against Aspergillus niger.

Optimization of a Microwave Assisted Extraction Method for Maximum Flavonols and Antioxidant Activity of Onion Extracts.

Nowadays, consumers demand bioactive foods that have the potential to limit the risk of suffering from several medical conditions. Onions present these desirable capabilities owing to its high content in antioxidant bioactive compounds. This work has used a Box-Behnken design with a response surface methodology to determine the best conditions in which to extract the polyphenols that are found in onions. Two extraction methods-one for the extraction of total flavonols and another one intended to obtain extracts with the highest possible antioxidant activity-have been developed and optimized. The following factors have been studied: temperature, %methanol in water, solvent pH, and sample-solvent volumetric ratio. The optimal conditions for the extraction of flavonols were 93.8% methanol in water, pH 2, 50 °C extraction temperature and 0.2:17.9 g:mL sample-solvent ratio. The best antioxidant activity levels were registered when using 74.2% methanol in water, pH 2, 99.9 °C extraction temperature and 0.2:18.2 g:mL sample-solvent ratio. Both optimized methods used short extraction times, and presented good precision levels and successful results when used with an assortment of onion varieties. According to total flavonols and antioxidant activity data, with 7.557 ± 0.3261 and 12.08 ± 0.0379 mg g-1, respectively, the developed methods achieved comparable or even superior results to those obtained by other authors.

Anti-Inflammatory and Chondroprotective Effects Induced by Phenolic Compounds from Onion Waste Extracts in ATDC-5 Chondrogenic Cell Line.

Osteoarthritis is a prevalent degenerative condition that is closely related to the destruction and inflammation of cartilage. The high prevalence of this pathology exhorts researchers to search for novel therapeutic approaches. Vegetable-fruit wastes have emerged as a promising origin of anti-inflammatory and antioxidant compounds that, in some cases, may also exert chondroprotective effects. This study aims to decipher the potential of onion waste products in the inhibition of molecular events involved in osteoarthritis. Onion extracts showed a high content of phenolic compounds and antioxidant properties. Cytocompatibility was demonstrated in the chondrogenic cell line ATDC-5, exerting viability percentages higher than 90% and a slight increase in the S phase cycle cell. The induction of inflammation mediated by the lipopolysaccharide and onion extracts' treatment substantially inhibited molecular markers related to inflammation and cartilage degradation, highlighting the promising application of onion extracts in biomedical approaches. The in silico analyses suggested that the results could be attributed to protocatechuic, ellagic, and vanillic acids' greater cell membrane permeability. Our work provides distinctive information about the possible application of waste onion extracts as functional components with anti-inflammatory and chondroprotective characteristics in osteoarthritis.

Effect of different cooking methods on S-Alk(en)yl-L-cysteine sulfoxides profile and antiplatelet activity of onion

• Onions are predominant with organosulfur and phenolic compounds endowed with promising functional effects. • Different cooking methods effects on organosulfur composition and bioactivities of onions. • Cooking methods altered the organosulfur content and antiplatelet activity of onions. • Stir-frying cooking was found effective to retain the high amount organosulfur compounds in onion. • Onion extracts showed significant inhibition on collagen-induced antiplatelet activity. Onions are a significant source of organosulfur compounds with promising biological effects. However, the effects of different cooking methods on organosulfur composition and biological properties in onions remain unclear. Therefore, the objective of this study was to determine the composition of organosulfur compounds and the antiplatelet effect of six different onion varieties processed using different cooking methods (boiling, stir-frying, and steaming).The organosulfur compounds were quantified by measuring the S-Alk(en)ey-L-cysteine sulfoxides (ACSOs) contents utilizing and high-pressure liquid chromatography (HPLC). Results showed no significant differences in ACSOs contents among onion varieties. However, ‘Guigum' (GG) and ‘Turbo’ (TB) varieties showed the highest amount of ACSOs at 100.6 and 98.0 mg/100 g fresh weight (FW), respectively. Total ACSOs contents in the other four varieties were 62.7∼72.4 mg/100g FW, showing similar contents. Stir-fried (without the addition of water) onions retained the highest content of total ACSO, followed by steamed treated onions. However, with the boiling method, sulfur compounds were eluted and lost in the cooking water, resulted in a 46.8% loss of ACSOs. Onion extracts showed significant inhibition of the collagen-induced aggregation of rat blood platelets. The highest effect of platelet aggregation was observed in stir-fried onion extracts, whereas the lowest was in boiled extracts. Results demonstrated that stir-frying is an effective cooking method to retain the highest amount of health-beneficial organosulfur compounds in onion.

Antiallergic activities of shallot (Allium ascalonicum L.) and its therapeutic effects in allergic rhinitis.

Onion has antiallergic activity but lack of evidence for shallot. To determine whether shallot owns similar antiallergic activity to onion and its therapeutic effects in allergic rhinitis when added to standard treatment. In-vitro β-hexosaminidase inhibitory activities of shallot was compared with onion on RBL-2H3 cells. In clinical study, a randomized, double-blind, placebo-controlled trial was performed. Sixteen AR patients were randomized equally into the controls who received cetirizine 10 mg once daily and placebo capsules for 4 weeks, and the treatment who received 3g of oral shallot per day (equivalent to 1 ½ bulbs) and cetirizine. Visual analog scores of overall symptoms (VAS), total nasal and ocular symptom scores (TNSS and TOSS), nasal airway resistance (NAR), and adverse events were assessed. Shallot extract at 200 μg/mL had an average β-hexosaminidase inhibition rate of 97% while onion extract had 73%. HPLC chromatograms (λ = 290nm) of both plants showed nearly identical patterns of quercetin compounds, such as quercetin 3,4'-diglucoside, quercetin 4'-glucoside, and quercetin. After 4-week of treatment, 62.5% of patients in shallot group and 37.5% of patients in control group showed improvement of post-treatment VAS. TNSS were significantly reduced in both groups, however no difference between groups (P = 0.18). TOSS were significantly improved only in the shallot group (P = 0.01). Adverse events from shallot were not different from placebo. Shallot had antiallergic activity and similar quercetin compounds to onion. The shallot oral supplement and cetirizine was shown to improve the overall AR symptoms more than cetirizine alone.

Phytonutrient screening and evaluation of in-vitro antibacterial activity of onion and garlic peels: A comparative study with the prospects of waste to wealth

The current world survey states that it has become a major issue of huge wastage of fruits and vegetables in our ecology and economy. The by-products of these vegetables can be a major source of nutrients with having potential phytochemical, antioxidant, and antimicrobial potential. Hence, the significance of our study is to do the comparative analysis of phytonutrients and in-vitro medicinal activity by using the discarded onion and garlic peels as sustainable resources. The results of the current study depict onion peel extracts contain highest concentration of polyphenols (174.95 ±20.42 mg GAE/g DW), flavonoids (49.97±1.77 mg QE/g DW), tannins (31.72±0.02 mg TAE/g DW), carbohydrates (30.39±1.30 mg GE/g DW), proteins (38.07±0.86 mg BSAE/g FW), whereas, garlic peel extracts contain highest concentration of antioxidants (37.54±1.05 mg AAE/g DW). Both the onion and garlic peel extract show the maximum zone of inhibition against E. coli. The outcome of the study comes up as a very innovative and beneficial way to cope up with the current life-style disorder and to reduce the risk of diseases.

Antioxidant activity and protective effect of the outer scales hydroalcoholic extract of Allium cepa L. var. Tropea on toxicity damage induced by Cadmium in Caco-2 cells.

The characterization of bioactive metabolites and the protective effects against Cadmium (Cd) of the hydroalcoholic extract from Allium cepa var. Tropea (Tropea red onion) in human Caco-2 colon adenocarcinoma cells and in vitro antioxidant effects were investigated. Tropea red onion extract showed high levels of bioactive compounds and a strong activity as radical scavenger and inhibitor of lipid peroxidation. The most abundant specialized metabolites were quercetin derivatives. In addition, the extract inhibited NO release in a dose-dependent manner. Exposure of Cd treated human Caco-2cells to the Tropea red onion extract resulted in a higher cytoprotection with a significant falloff of cells damage produced by Cd. The effect of Tropea red onion evaluated with the MTT assay and LDH test, was time-dependent and more evident after 24h of treatment. Caco-2cells treated with the Tropea red onion extract and CdCl2 at 24h showed a significant cytoprotection at concentrations equal to 50μg/mL + 25μM and 100μg/mL + 25μM while at 72h at a concentration of 25μg/mL + 25μM. We observed with MTT and LDH assays that treatment of cells with Tropea red onion extract at 24h was able to significantly prevent Cd-induced cytotoxicity alone.