Effect of Cinnamomum zeylanicum Essential Oil on Antioxidative Status in Broiler Chickens

The experiment was conducted to investigate the effects of Cinnamomum zeylanicum essential oil on antioxidant status of chickens. Thirty-two female Ross 308 hybrid broilers were fed one of four diets supplemented with 0%, 0.1%, 0.05% and 0.025% of essential oil for 38 days. Blood, liver, kidney and duodenal epithelium were collected for the subsequent evaluation of antioxidant status. Feeding of adiet supplemented with 0.1% of essential oil significantly decreased the concentration of malondialdehyde (MDA) in plasma and duodenal mucosa in comparison with the control group (0%). The activities of glutathione peroxidase (GPx) were significantly higher in blood of chicks fed the diet containing 0.1% of essential oil. Diets containing 0.05% and 0.025% of essential oil reduced alanine amino transferase (ALT) activity in plasma in comparison with the control group. Blood phagocytic activity significantly increased in chickens fed the diet supplemented with 0.1% and the index of phygocytic activity was affected by the diet containing 0.025% of essential oil in comparison with the control group. The present investigation shows that Cinnamomum zeylanicum essential oil exhibits a significant antioxidant activity in fattening chickens and can be used as a source of antioxidant in dietary supplement. Essential oil, lipid peroxidation, antioxidant enzymes, phagocytosis Cinnamomum zeylanicum is one of the oldest herbal medicines known, having been mentioned in Chinese texts as long as 4,000 years ago. It is often used for medicinal purposes due to its unique properties. The essential oil from Cinnamomum zeylanicum bark is rich in trans-cinnamaldehyde with antimicrobial effects against animal and plant pathogens, food poisoning and spoilage bacteria and fungi (Mastura et al. 1999). Until now, more than 300 volatiles were found as constituents of essential oils of cinnamon. The essential oil derived from cinnamon leaves is rich in eugenol, that from the roots in camphor and that from the buds shows a high amount of sesquiterpenes (α-bergamotene and α-copaene) (Jayaprakasha et al. 2002). It has been established that the oils and extracts from cinnamon possess a distinct antioxidant activity, which is especially attributed to the presence of phenolic and polyphenolic substances (Jayaprakasha et al. 2006; Tomaino et al. 2005). These main properties of cinnamon are astringent, warming, stimulating, carminative, antiseptic, antifungal, antiviral, blood purifying, and aiding digestion. All of these properties of cinnamon make it a good medicinal plant. Cinnamon is more often used as a non-essential addition to other remedies than as a remedy by itself. The medicinal effects of cinnamon oil are very powerful, and there are many uses for it. However, principally it is used as an aromatic to cover the unpleasant taste of other drugs. The various terpenoids found in the spice essential oil are thought to be the reason for cinnamon’s medicinal properties. Eugenol and cinnamaldehyde are two very important terpenoids found in cinnamon. Cinnamaldehyde and cinnamon oil vapors act as potent antifungal agents. The diterpenes found in the cinnamon oil have shown antiallergenic activity. The numerous uses of cinnamon as a medicinal herb imply the widespread appreciation of its healing ACTA VET. BRNO 2009, 78: 411-417; doi:10.2754/avb200978030411 Address for correspondence: Doc. MVDr. Štefan Faix, CSc. Institute of Animal Physiology SAS Šoltésovej 4-6 040 01 Košice Slovak Republic Phone: +421 557 287 841 Fax: +421 557 287 842 E-mail: [email protected] http://www.vfu.cz/acta-vet/actavet.htm effects by herbalists worldwide. Unfortunately, often there is no scientific research to backup the claims that cinnamon does in fact have healing powers. Along with the medicinal effects come the side effects and interactions that medicinal cinnamon causes. Recent trends and developments in the area of animal nutrition have been characterized by an increasing interest in the potential impact of plants, herbs and spices on the immune function and antioxidant status of humans and animals. Research activities have been intensified; however, understanding of the specific mode of action and the functional aspects of phytogenic additives still needs many more in depth studies. Cinnamomum zeylanicum essential oil was tested for an effect on intestinal cell viability (Fabian et al. 2006). Antioxidant activities of volatile extracts isolated from cinnamon were evaluated by various in vitro assays (Lee and Shibamoto 2002). The contents of glutathione (GSH) and lipid-conjugated dienes were studied in rats fed a high-fat diet along with cinnamon and it was reported that cinnamon stimulates the activity of antioxidant enzymes (Dhuley 1999). In addition, the effect of cinnamate, a phenolic compound found in cinnamon bark and other plant materials, on lipid metabolism and antioxidant enzyme activities in rats fed a high cholesterol diet has been studied and indicated that cinnamon suppresses lipid peroxidation via the enhancement of hepatic antioxidant enzyme activities (Lee at al. 2003). In a study of the wound healing action of an ethanol extract of cinnamon, the significant increase in wound healing was attributed to the antioxidant activity (Kamath et al. 2003). Cinnamon constituents possess antioxidant action and may prove beneficial against free radical damage to cell membranes (Dragland et al. 2003). Cinnamon has a marked antioxidant potential and may be beneficial in alleviating the complications of many illnesses related to oxidative stress in humans (Ranjbar et al. 2006). Cinnamon extracts are used regularly as food antioxidants, also improving food palatability (Mancini-Filho et al. 1998). The aim of this experiment was to investigate the effects of diets supplemented with Cinnamomum zeylanicum essential oil on some indicators of blood and tissue antioxidant status and blood phagocytic activity in fattening chickens. Materials and Methods Animals, diets and treatments The experimental protocol was approved by the local Ethics Committee; the principles of animal protection were strictly followed. Thirty-two 1-day-old female Ross 308 hybrid broilers were obtained from the breeding company LP (Parovske Haje a.s., Slovakia) and divided into four groups. Each group contained 8 birds that were placed in pens (2.5 m × 1.5 m) with wood shavings. Temperature and lighting regimens were in accordance with the recommendation of the breeder. Rearing of the chickens started with a lighting regimen of 23 h light to 1 h dark and lasted for 4 weeks. The initial room temperature 32–33 °C was reduced weekly by 1 °C to a final temperature of 28 °C. Birds were fed a basal diet obtained from Agrokonzult s.r.o. (Nove Zamky, Slovakia). The composition of this diet is presented in Table 1. All birds had free access to water and feed. The control group was fed a basal diet; the second, third and fourth groups were fed the same basal diets supplemented with 0.1%, 0.05% and 0.025% essential oil, respectively. Cinnamomum zeylanicum essential oil was purchased from Calendula (Calendula a.s., Nova Lubovna, the Slovak Republic), certificate of quality No. 610. Essential oil was diluted with sunflower oil and the final concentration of sunflower oil was 1% of diet. Sample collections At 38 days of age, 8 randomly chosen chickens from each group were anaesthetised by intraperitoneal injection of xylazine (Rometar 2%, SPOFA, Czech Republic) and ketamine (Narkamon 5%, SPOFA, Czech Republic) at 0.6 and 0.7 ml·kg-1 body weight, respectively. After laparotomy, blood was collected into heparinised tubes by intracardial punction and centrifuged for plasma specimens at 1 180 g for 15 min. Samples of blood and plasma for analysis were frozen and stored at -65 °C. Following euthanasia, samples of liver, kidney and duodenal mucosa tissues were collected and stored also at -65 °C until analysis. Sample analysis The activity of blood glutathione peroxidase (GPx, EC 1.11.1.9) was determined using the method of Paglia and Valent ine (1967) with a Ransel kit (Randox, UK). To analyse the activities of GPx in liver, kidney and duodenal mucosa, pieces of tissue were homogenised in phosphate buffer saline with pH 7.4 and 412