Extracts of Welsh Onion Allium Fistulosum for Treatment of Obesity

by | Mar 18, 2019 | 2018, Fruits and Vegetables, Obesity

Written by Joyce Smith, BS. Aqueous and ethanolic extracts of Welsh onion significantly decreased the body weights of mice fed a high-fat diet.

fruits and vegetablesObesity is a risk factor for type 2 diabetes, hypertension, heart disease and certain cancers 1. Treatment interventions for obesity such as the drug orlistat are fraught with complications 2; conjugated linoleic acid (CLA) used excessively can lead to metabolic syndrome and diabetes 3, and Garcinia cambogia rich in hydroxycitric acid (HCA) can harm the liver 4

Allium fistulosum, often referred to as Welsh onion or bunching onion, is a perennial onion from Eastern Asia 5 that is used primarily as a scallion or salad onion 6. As a medicinal herb, it confers health benefits for colds, influenza, abdominal pain, headache, constipation, parasitic infections, ulcers, arthritis and even heart disease. 7 In addition, the Welsh onion has demonstrated antifungal, antioxidative, antiplatelet and antihypertensive properties 8 and is a rich source of vitamins B2, B6, and niacin, as well as folic acid and iron.9

In a preclinical study, 10 Sung et al compared the anti-obesity effects of aqueous and ethanolic extracts of Welsh onion to the clinical weight-loss drug, orlistat (ORL), an extract of the weight-loss herb, Garcinia cambogia, and linoleic acid (CLA), the naturally occurring fatty acid also known to help with weight loss. Male 8-week-old C57BL/6 J mice were allocated to seven groups (n=6 per group): a high-fat diet (HFD), a normal control diet, and five high-fat diet (HFD) groups treated with either G. cambogia, CLA, ORL, an aqueous Welsh onion extract or ethanolic Welsh onion extract.

The mice receiving G. cambogia, CLA, or ORL served as positive controls. Following a 6-week treatment protocol, body weight and the following obesity-related parameters were determined: liver and adipose weight, adipocyte size, serum lipid profiles, liver expression of adenosine monophosphate-activated protein kinase (AMPK), and adipose tissue expression of uncoupling protein 2 (UCP2). AMPK is a cellular energy sensor that contributes to energy homeostasis. It stimulates catabolic pathways such as glucose transport and fatty acid β-oxidation, and inhibits anabolic pathways such as fatty acid, cholesterol, and protein synthesis. UCP2 is a mitochondria inner membrane transporter that promotes fatty acid oxidation in adipose tissue and reduces body weight.

After 6 weeks, the HFD-fed mice had a final body weight that was 31.4% higher than the normal controls. However the final body weights of the HFD-fed mice who received HCA, CLA or ORL (positive controls) were significantly decreased (p< 0.05) by 11.9%, 17.4% and 21.2% respectively compared to the HFD-control group, while the final body weights of the HFD-fed mice receiving aqueous and ethanol Welsh onion extracts decreased by 14.8% and 15% (p<0.05) respectively compared to the HFD- control group.

Both aqueous and ethanolic Welsh onion extracts greatly improved the high-fat-diet-induced changes in serum levels of leptin and insulin-like growth factor, as well as changes in the liver expression of AMPK, and adipose tissue expression of UCP2. Both onion extracts also caused high HDL-cholesterol and adiponectin levels, while only the ethanolic Welsh onion extract improved the total cholesterol and LDL-cholesterol.

High-performance liquid chromatography acid confirmed that both the aqueous and ethanol Welsh onion extracts contain ferulic acid and quercetin, which are naturally-occurring polyphenolic flavonoid compounds found in fruits and vegetables and are known to suppress body weight, fat accumulation, and hyperlipidemia in obese mice by enhancing antioxidant activities. Overall, the study suggested that Welsh onion can be used as a functional food or therapeutic agent for treating obesity and obesity-associated metabolic syndrome.

Source: Sung, Yoon-Young, Dong-Seon Kim, Seung-Hyung Kim, and Ho Kyoung Kim. “Aqueous and ethanolic extracts of welsh onion, Allium fistulosum, attenuate high-fat diet-induced obesity.” BMC complementary and alternative medicine 18, no. 1 (2018): 105.

© The Author(s). 2018 Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/) The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/)

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Posted March 18, 2019.

Joyce Smith, BS, is a degreed laboratory technologist. She received her bachelor of arts with a major in Chemistry and a minor in Biology from the University of Saskatchewan and her internship through the University of Saskatchewan College of Medicine and the Royal University Hospital in Saskatoon, Saskatchewan. She currently resides in Bloomingdale, IL.

References:

  1. Watanabe T, Hata K, Hiwatashi K, Hori K, Suzuki N, Itoh H. Suppression of murine preadipocyte differentiation and reduction of visceral fat accumulation by a Petasites japonicus ethanol extract in mice fed a high-fat diet. Bioscience, biotechnology, and biochemistry. 2010;74(3):499-503.
  2. Bray GA. Medical therapy for obesity. Mount Sinai Journal of Medicine: A Journal of Translational and Personalized Medicine. 2010;77(5):407-417.
  3. Clément L, Poirier H, Niot I, et al. Dietary trans-10, cis-12 conjugated linoleic acid induces hyperinsulinemia and fatty liver in the mouse. Journal of lipid research. 2002;43(9):1400-1409.
  4. Sethi A. A review on “Garcinia cambogia-a weight controlling agent”. Int J Pharm res dev. 2011;3:13-24.
  5. Dong Y, Cheng Z, Meng H, Liu H, Wu C, Khan AR. The effect of cultivar, sowing date and transplant location in field on bolting of welsh onion (Allium fistulosum L.). BMC plant biology. 2013;13(1):154.
  6. Fritsch R, Friesen N. Evolution, domestication and taxonomy. Allium crop science: recent advances. 2002:5-30.
  7. Chen J-H, Chen H-i, Wang J-S, Tsai S-J, Jen CJ. Effects of Welsh onion extracts on human platelet function in vitro. Life sciences. 2000;66(17):1571-1579.
  8. Yamamoto Y, Aoyama S, Hamaguchi N, Rhi G-S. Antioxidative and antihypertensive effects of Welsh onion on rats fed with a high-fat high-sucrose diet. Bioscience, biotechnology, and biochemistry. 2005;69(7):1311-1317.
  9. Sung Y-Y, Kim S-H, Kim D-S, Park SH, Yoo BW, Kim HK. Nutritional composition and anti-obesity effects of cereal bar containing Allium fistulosum (welsh onion) extract. Journal of functional foods. 2014;6:428-437.
  10. Sung Y-Y, Kim D-S, Kim S-H, Kim HK. Aqueous and ethanolic extracts of welsh onion, Allium fistulosum, attenuate high-fat diet-induced obesity. BMC complementary and alternative medicine. 2018;18(1):105.