ReviewReview on emu products for use as complementary and alternative medicine
Introduction
Ratites are a diverse group of flightless birds belonging to the superorder Palaeognathae and order struthioniformes. They have flat breast bones with no keel, giving the wing muscles nothing to anchor to, and thus they are unable to fly. Emus belong to ratite group of flightless birds, along with ostrich, rhea, kiwi, choique and cassowary [1]. The emu (“bush chook”), Dromaius novaehallandiae, is a free-roving, cursorial bird indigenous to Australia for 80 million years [2]. Native aboriginals and white settlers used the liquid fat from emus topically for various ailments such as wound healing, to alleviate pain, and for musculoskeletal disorders. Emu is the second-largest extant bird in the world by height. The only extant species is D. novaehallandiae [3], [4]. An adult emu weighs about 45 kg, of which 10 kg can be attributed to its body fat content. Emus store their fat on their back, which is known as the back pad. Because of where the fat is stored, emu meat is very lean and devoid of fat. Emus have both nutritional value and health benefits [4].
Section snippets
Emu egg
The emu egg is dark green in color and weighs about 400 to 650 g. The color of the egg results from the presence of methyl ester in the pigment biliverdin in the egg shell. Emus lay one egg every 3 or 5 d during breeding season, i.e., between April and October. The egg's shell contains about 95% calcium carbonate in the form of calcite, as well as two different C-type lectin-like proteins that are common among ratite group. Emu eggs contain 29% to 47% albumen. Chemically, albumen contains 0.05%
Emu meat
Emus are a good source of nutrition, and its meat is very flavorful. Emu meat is lean, low in cholesterol, and has a favorable fatty acid profile [5]. Lipids present in emu meat include both ω-3 and ω-6 fatty acids such as α-linolenic, linoleic, arachidonic, and docosahexaenoic acids (DHAs), the levels of which are greater than those present in chicken and beef [6], [7]. The ratio of polyunsaturated fatty acids (PUFAs) to saturated fatty acids was found to be 0.72, which is higher than chicken
Emu oil
Emu oil is obtained from the emu's fat deposits, mainly subcutaneous and retroperitoneal fat. Collected tissues are first subjected to maceration or centrifugation and then liquified fat is passed through various filters to obtain pure oil [9]. Emu oil is a commercially available product in countries such as Australia and the United States. It possesses various beneficial characterisitics. It is an anti-inflammatory, it promotes enhancement of skin permeation, it is moisturizing and has
Mucositis
Mucositis is the most common adverse effect of cancer chemotherapy and is characterized by the depletion of the mucous layer in the alimentary tract [16]. Symptoms associated with mucositis include diarrhea, severe pain, nausea, and bloating [17]. There are currently several unmet needs for the prevention and treatment of chemotherapy-induced gastrointestinal mucositis [18]; however, some agents such as keratinocyte growth factor-1 [19], insulin-like growth factor-1 [20], whey growth factor
Hypocholesterolemic effect
Emu oil possesses hypocholesterolemic activity. A comparative study between emu oil and olive oil concluded that hamsters fed a refined emu oil diet had significantly reduced serum total cholesterol (TC) and low-density lipoprotein (LDL) levels, with no effect on plasma high-density lipoprotein (HDL) and TG levels compared with animals on the olive oil diet. Furthermore, emu oil reduced the ratio of TC to HDL to a significant degree. Hamsters fed a refined emu oil diet showed significantly
Possible mechanism(s) of actions
To our knowledge, no scientific study has been reported for the potential mechanism(s) of action of the therapeutic effects of emu oil. In general, saturated fatty acids are proinflammatory, unsaturated fatty acids are weakly proinflammatory or neutral, and ω-3 fatty acids are anti-inflammatory [43]. It also has been reported that γ-linolenic acid (GLA), an essential ω-6 fatty acid, also contains anti-inflammatory activity [44]. The anti-diabetic and anti-inflammatory properties of oleic acid
Emu oil and diabetes
To our knowledge, there are currently no scientific results available on the effect of emu oil on diabetic conditions; however, the anti-diabetic effect of the fatty acids that are present in the composition of emu oil has been reported previously. Oleic acid was found to reverse the inhibitory effect on insulin production caused by the inflammatory cytokine (TNF-α) in both in vitro and in vivo systems [45]. GLA has proven useful in insulin resistance [44] and in the prevention and treatment of
Conclusions
In this review, we highlighted the importance of emu products, mostly emu oil, as possible use in complementary and alternative medicine. We demonstrated that the main therapeutic effect shown by emu oil is its anti-inflammatory potential, for which it can be used in alternative medicine, and its penetration-enhancing property may be useful as a complement to conventional medicines.
We also have demonstrated that the beneficial effect of emu oil appears to be mediated by its unsaturated fatty
Acknowledgments
The authors acknowledge the Department of Pharmaceuticals, Ministry of Chemicals and Fertilizers, government of India for financial support to MKJ, TD, SS, LG, and PSK.
References (51)
A review of ratite nutrition
Anim Feed Sci Technol
(1996)- et al.
Nutritional characteristics of emu (Dromaius novaehollandiae) meat and its value-added products
Food Chem
(2006) - et al.
Amino acid sequence of myoglobin from emu (Dromaius novaehollandiae) skeletal muscle
Meat Sci
(2010) - et al.
Influence of two dietary fats on the composition of emu oil and meat
Poult Sci
(2001) - et al.
Pre-treatment with insulin-like growth factor-I partially ameliorates 5-fluorouracil-induced intestinal mucositis in rats
Growth Horm IGF Res
(2005) - et al.
Dietary supplementation with zinc and a growth factor extract derived from bovine cheese whey improves methotrexate-damaged rat intestine
Am J Clin Nutr
(2003) - et al.
Cellular mechanisms for methotrexate chemotherapy-induced bone growth defects
Bone
(2007) - et al.
Comparative effects of emu and olive oil on aortic early atherosclerosis and associated risk factors in hypercholesterolemic hamsters
Nutr Res
(2004) - et al.
Consequences of burn injuries treatment with 100% pure EMU oil
Burns
(2007) - et al.
Differential modulation of Toll-like receptors by fatty acids preferential inhibition by n-3 polyunsaturated fatty acids
J Lipid Res
(2003)
GPR120 is an omega-3 fatty acid receptor mediating potent anti-inflammatory and insulin-sensitizing effects
Cell
Emu oil (s): a source of non-toxic transdermal anti-inflammatory agents in aboriginal medicine
Inflammopharmacology
Emus
Australian Natural History
The emu (Dromaius novaehollandiae): a review of its biology and commercial products
Avian Biol Res
Ratite meat
Worlds Poult Sci J
Lipid characteristics of emu meat and tissues
J Food Lipids
Comparison of the antioxidant properties of emu oil with other avian oils
Anim Prod Sci
Anti-inflammatory activity of emu oils in rats
Inflammopharmacology
Isolation and characterization of oil from fatty tissues of emu birds farmed in India
J Lipid Sci Technol
Emu oil reduces small intestinal inflammation in the absence of clinical improvement in a rat model of indomethacin-induced enteropathy
Evid Based Complement Alternat Med
Emu oil: a novel therapeutic for disorders of the gastrointestinal tract?
J Gastroenterol Hepatol
Chemotherapy-induced mucositis: the role of gastrointestinal microflora and mucins in the luminal environment
J Support Oncol
Treatment of mucositis, including new medications
Cancer J
Systematic review of agents for the management of gastrointestinal mucositis in cancer patients
Support Care Cancer
Cited by (28)
Fats
2023, Pharmacognosy: Fundamentals, Applications, and Strategies, Second EditionVitamin D composition of Australian game products
2022, Food ChemistryCitation Excerpt :Emu oil is applied topically for cosmetic purposes due to its moisturising and purported anti-inflammatory properties and to promote hair and skin growth (Jeengar et al., 2015). It may also be ingested, and is thought to lower cholesterol and assist in treatment of internal inflammatory conditions such as inflammatory bowel syndrome and mucositis (Jeengar et al., 2015). Despite being a richer source of vitamin D by concentration than other emu products, it is likely to be consumed in much lower amounts (commonly available capsules contain 750–1000 mg emu oil), and may, therefore provide a similar amount of vitamin D per usual dose/serving.
Designer and Functional Food Lipids in Dietary Regimes: Current Trends and Future Prospects
2018, Alternative and Replacement FoodsNutraceuticals for Healthy Skin Aging
2017, Nutrition and Functional Foods for Healthy AgingFats
2017, Pharmacognosy: Fundamentals, Applications and StrategyData on melanin production in B16F1 melanoma cells in the presence of emu oil
2016, Data in BriefCitation Excerpt :However, overproduction of the melanin causes cosmetic problems, such as staining and freckles on the skin. Here, we examined the melanin production in murine B16F1 melanoma cells in the presence of emu oil, which is widely utilized in cosmetics for its moisturizing and transdermal penetration enhancing properties [1]. In this study, we measured the melanin contents in B16F1 cells treated with various concentrations of emu oil.