• Korean Journal of Pharmacognosy
• /
• v.44 no.4
• /
• pp.391-396
• /
• 2013

In this study, we investigated the effects of onion(Allium cepa L.) peel extraction aplication on UVB-induced damage of mouse skin. The male C57BL/6 weeks mice were divided into three groups; the control group(Con), the UVB irradiated group(UVB) and the group treated with onion peel extract after UVB irradiation(UVB+Onion peel). Onion peel extraction were topically treated after UVB irradiation(800 $mJ/cm^2$) to dorsal skin. We were measured TEWL, melanin value, erythema index and histological of mouse skin. In the TEWL, melanin value and erythema index observation, UVB+onion peel group were decreased then in the UVB group and 120 and 168 hr groups were similar to the control group. In the histological observation, UVB+onion peel group were indicated hyperkeratosis then in the UVB. These results showed that onion peel extract as a topical application may have preventive effect against UVB-induced skin damage. Therefore onion peel extract might be good material for UVB-damage skin care.

• Korean Journal of Food Science and Technology
• /
• v.52 no.3
• /
• pp.263-273
• /
• 2020

In this study, in order to confirm the ameliorative effects of onion (Allium cepa L.) flesh and peel on amyloidbeta (Aβ)-induced cognitive dysfunction, we evaluated their in vitro neuroprotection and in vivo cognitive functions. As the result of in vitro neuroprotection, the protective effect of the ethyl acetate fraction of onion flesh (EOF) on Aβ-induced cytotoxicity was similar to that of the ethyl acetate fraction of onion peel (EOP). In the behavioral tests, the EOF and EOP effectively improved the Aβ-induced learning and memory impairments. For this reason, it could be concluded that the EOF and EOP improved the antioxidant activities (superoxide dismutase, oxidized glutathione/total glutathione, and malondialdehyde) in brain tissue. In addition, the EOF and EOP effectively activated mitochondrial functions by protecting the mitochondrial membrane potential, ATP, mitochondria-mediated protein (BAX and cytochrome c), and caspase 3/7 activities. The EOF and EOP also improved the cholinergic system (acetylcholinesterase and acetylcholine). Therefore, we suggest that onion could be used for management of Aβ-induced cognitive dysfunction.

• Applied Chemistry for Engineering
• /
• v.22 no.2
• /
• pp.178-184
• /
• 2011

In this study, the antibacterial, antioxidative and inhibitory effects of Allium cepa peel extracts on tyrosinase and elastase were investigated. MIC values of the ethyl acetate fraction of Allium cepa peel on especially, S. aureus among the skin resident flora (Staphylococcus aureus, S. aureus; Propionibacterium acnes, P. acnes; Pityrosporum ovale, P. ovale; Escherichia coli, E. coli) were 0.06%. The aglycone fraction showed more excellent free radical (1,1-diphenyl-2-picrylhydrazyl radical, DPPH) scavenging activity ($FSC_{50}=5.05{\mu}g/mL$). Reactive oxygen species (ROS) scavenging activities ($OSC_{50}$) of the ethyl acetate fraction and aglycone fraction in the luminol-dependent $Fe^{3+}-EDTA/H_2O_2$ system were 0.05 and $0.03{\mu}g/mL$, respectively. The cellular protective effect of the aglycone fraction on the rose-bengal sensitized photohemolysis of human erythrocytes exhibited more prominent (${\tau}_{50}$, 480 min at $25{\mu}g/mL$). The inhibitory effects ($IC_{50}$) of the ethyl acetate fraction and aglycone fraction on tyrosinase were 9.16 and $8.68{\mu}g/mL$, the inhibitory effect ($IC_{50}$) of the aglycone fraction on elastase was $14.12{\mu}g/mL$ The transepidermal water loss of the cream containing 0.1% ethyl acetate fraction was decreased from $8.3g/m^2h$ in control to $6.8g/m^2h$ in the subjects applied with cream containing the ethyl acetate fraction. These results indicate that extract/fractions of Allium cepa peel can function as antioxidant in biological systems, particularly skin exposed to UV radiation by scavenging $^1O_2$ and other ROS, and protect cellular membranes against ROS, and possibly as antiaging agents. Allium cepa peel extract could be used as a new cosmeceutical for whitening and anti-wrinkle products.

• Korean Journal of Medicinal Crop Science
• /
• v.22 no.3
• /
• pp.203-209
• /
• 2014

Onion (Allium cepa L.) is one of the richest sources of flavonoids in human diet. Onion peel contains over 20 times more quercetin than onion flesh. In this study, we studied the effects of onion peel water extract (OPE) on the blood lipid profiles in mice. The onion peel extracts was extracted with hot water. The experimental groups were divided with 3 groups (n = 6) of ICR male mice: normal diet + distilled water (NC), high-fat diet + distilled water (HF), high-fat diet + onion peel water extract 20 mg/kg (OPE-20). The oral administration was conducted daily. The experimental period was 7 weeks. Onion peel water extract showed higher concentration of polyphenol gallic acid and anti-oxidant trolox equivalent than the ethanol extract. The body weight gain and food efficiency ratio was significantly lower in the OPE-20 group as compared with HF group (p < 0.05). The epididymal fat and retroperitoneal fat showed significantly lower weights and sizes in the OPE-20 group as compared with HF group (p < 0.05). The serum levels of total cholesterol, LDL cholesterol and triglyceride were significantly lower in the OPE-20 group as compared with HF group (p < 0.05). The OPE-20 group showed higher HDL cholesterol concentration than HF group (p < 0.05). Atherogenic index was ignificantly lower in as compared with HF group (p < 0.05). The serum levels of glucose, GOT and GPT were significantly lower in the OPE-20 group as compared with HF group (p < 0.05). In these results, we suggests that onion peel water extracts supplementation can reduces the serum lipid components and improves the lipid metabolism in hyperlipidemic mice induced with a high-fat diet.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.32 no.6
• /
• pp.825-828
• /
• 2003

This study was performed to determine the antimicrobial activity of waste food fractions, the Solanum tuberosum Peel (SP) and Allium cepa L. Peel (AP) on several microorganisms. The methanol extracts (SPM, APM) of SP and AP were fractionated to five different types, which were hexane, ethylether, ethylacetate, butanol and water Among the various fractions, ethylether and butanol fractions of AP (APMEE, APMB) showed stronger antimicrobial activity against Pseudomonas aeruginosa and Staphylococcus aureus than the other fractions. The ethylether fraction of SP (SPMEE) also showed the higher antimicrobial activity against Escherchia coli than the other 4 fractions . These results suggest that the waste food fractions, SP and AP may be developed into bioactive antimicrobial health products.

• KSBB Journal
• /
• v.30 no.4
• /
• pp.148-154
• /
• 2015

Onion (Allium cepa) is one of the flavonoids-rich materials in human diet and onion peel, which is the onion by-products, contains over 20 times more quercetin than the flesh. In this study, to examine the anti-inflammatory effects of onion peel hot water extract (OPHWE), the cell viability, nitric oxide (NO), pro-inflammatory cytokines, such as interluekin-6 (IL-6), tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$), and IL-$1{\beta}$, were measured using the murine macrophage cell line RAW 264.7 cells. The Balb/c mice were used for an in vivo acute toxicity test and ICR mice were used for measurement of inhibition effects of croton oil-induced mouse ear edema. As a result, NO levels decreased in a dose-dependent manner. The production of IL-6, TNF-${\alpha}$, and IL-$1{\beta}$ was suppressed by 38%, 41%, and 34% respectively, compared with that of the LPS only group, without any cytotoxicity. The edema formation in the ICR mouse ear was also reduced compared to that in control. Moreover, there were no mortalities occurred in mice administered 5,000 mg/kg body weight of OPHWE. These results suggest that OPHWE has considerable anti-inflammatory activities and can be regarded as a potent candidate material to treat inflammatory diseases.

• The Korea Journal of Herbology
• /
• v.29 no.6
• /
• pp.141-148
• /
• 2014

Objectives : Onion (AlliumcepaL.) is one of the richest sources of flavonoids in human diet. In this study, we studied the effects of onion peel water extract (OPE) on the blood lipid profiles and glucose in rats. Methods : The experimental groups were divided with 5 groups (n = 6) of SD rats: normal diet + distilled water (NC), high-fat diet + Quercetin (PC), high-fat diet + onion peel water extract 4 mg/kg (OPE-4), high-fat diet + onion peel water extract 20 mg/kg (OPE-20), high-fat diet + onion peel water extract 100 mg/kg (OPE-100). Results : The liver fat showed significantly lower weights and size in the OPE-100 group as compared with NC group (p<0.05), The epididymal fat and retroperitoneal fat showed significantly lower weights and sizes in the OPE-4 and OPE-20 group as compared with NC group (p<0.05). The serum levels of total cholesterol, LDL cholesterol and triglyceride were significantly lower in the OPE-4 and OPE-20 group as compared with NC group (p<0.05). The OPE-4 and OPE-20 group showed higher HDL cholesterol concentration than NC group (p<0.05). Atherogenic index of OPE-4 and OPE-20 group was significantly lower in as compared with NC group (p<0.05). The serum levels of glucose significantly lower in the OPE-20 group as compared with NC group (p<0.05). Conclusions : In these results, we suggests that onion peel water extracts supplementation can reduces the serum lipid components and improves the lipid metabolism in hyperlipidemic SD rat induced with a high-fat diet.

• Korean Journal of Food Science and Technology
• /
• v.46 no.3
• /
• pp.364-368
• /
• 2014

This study investigated the antioxidant activity of onion peels extracted from onion byproducts by hot water treatment. Hot water extraction of freeze dried onion peel powder was analyzed for total polyphenol content, 2,2'-diphenyl-1-picryllhydrazyl (DPPH), and 2,2'-azino-bis(3-ehtylbenzothiazoline-6-sulphonic acid) (ABTS) radical scavenging activities, reducing power, oxygen radical absorbance capacity (ORAC). Total polyphenol content was the highest (233.90 mg/g) in onion peel extract mix with ethanol (OPME-1). The DPPH radical scavenging activity ($IC_{50}$), reducing power, and ORAC obtainbed from onion peel extract mix with ethanol precipitation (OPMPE-1) were the highest at 1.15 mg/mL, 1.69 $A_{700}$, and $318,509{\mu}M\;TE/mL$, respectively. The ABTS radical scavenging activity was the highest at 432.78 mg amino acids (AA) eq/g in the OPM. The results of this study suggest that onion peel extracts have marked antioxidant activity, which can have significant health benefits.

• Nutrition Research and Practice
• /
• v.18 no.1
• /
• pp.33-45
• /
• 2024

BACKGROUND/OBJECTIVES: Onion, particularly onion peel, is a quercetin-rich food with, anti-inflammatory and immunomodulatory effects. However, the effect of onion peel extract (OPE) in humans is unclear. Thus, the present study aimed to investigate whether OPE improves natural killer (NK) cell activity and cytokine concentration in a randomized double-blind placebo-controlled trial. SUBJECTS/METHODS: Eighty participants aged 19-64 yrs old with a white blood cell count of 4,000-10,000 cells/µL, symptoms of upper respiratory infection at least once within the previous 12 mon, and perceived stress scale (PSS) over 14 were included. Participants were randomly assigned to take either 1,000 mg/day OPE or a placebo for 8 weeks. RESULTS: Compliance were 87.4 ± 8.6% and 86.9 ± 79.0% in OPE and placebo groups. Compared to the placebo, OPE supplementation improved "Hoarseness" (P = 0.038) of the Wisconsin Upper Respiratory Symptom Survey (WURSS)-21 symptom, and stress scores (P = 0.001; 0.021) of PSS. Supplementation of OPE had no significant effect on NK cell activity and concentrations of cytokines such as interleukin (IL)-2, IL-6, IL-12, IL-1β, interferon-γ, and tumor necrosis factor-α. At baseline, the WURSS-21 symptom and PSS score (P = 0.024; 0.026) were higher in the OPE group than the placebo group. Among participants with higher than median WURSS-21 symptom score, OPE supplementation increased NK cell activity (P = 0.038). Supplementation of OPE had no significant effects on safety measurements and adverse events. CONCLUSIONS: The present study suggested that OPE supplementation improves NK cell activity in participants with moderate upper respiratory symptoms without any significant adverse effects.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.44 no.11
• /
• pp.1612-1620
• /
• 2015

Inflammation is a complex process involving a variety of immune cells, which defend the body from harmful stimuli. However, pro-inflammatory cytokines and inflammatory mediators can also exacerbate diseases such as cancer. Onion peel contains several phenolic compounds, including quercetin at an amount 20 times greater in peel than edible flesh. Therefore, in this study, the anti-inflammatory effects of onion peel ethanol extract (OPEE) were investigated lipopolysaccharide-induced inflammatory response. In our results, NO production decreased in a dose-dependent manner. Secretion of IL-6, $TNF-{\alpha}$, and $IL-1{\beta}$ was suppressed by 44%, 53%, and 60% respectively, at $100{\mu}g/mL$. Moreover, OPEE also suppressed expression of COX-2, iNOS, $NF-{\kappa}B$, and MAPKs in a dose-dependent manner. Formation of mice ear edema was reduced at the highest dose tested compared to the control, and reduction of ear thickness was observed in the histological analysis as well. In the acute toxicity test, no morality was observed in mice administered 5,000 mg/kg body weight of OPEE over a 2-week observation period. These results suggest that OPEE may have significant effects on inflammatory factors and be a potential anti-inflammatory material.