Medicinal Attributes of Major Phenylpropanoids Present in Cinnamon Uma Kant Sharma, Amit Kumar Sharma and Abhay K

Sharma et al. BMC Complementary and Alternative Medicine (2016) 16:156 DOI 10.1186/s12906-016-1147-4 RESEARCH ARTICLE Open Access Medicinal attributes of major phenylpropanoids present in cinnamon Uma Kant Sharma, Amit Kumar Sharma and Abhay K. Pandey* Abstract Background: Excessive production of free radicals has been implicated in many diseases including cancer. They are highly reactive and bring about oxidation of biomolecules i.e., proteins, lipids and nucleic acids which are associated with many degenerative diseases. Natural products acting as antioxidants have ability to neutralize free radicals and their actions and hence they mitigate their harmful effects. The present study was designed to investigate pharmacological properties viz., antioxidant, antibacterial and antiproliferative activities of cinnamaldehyde and eugenol, the two naturally occurring phenylpropanoids present in Cinnamomum spp. and other plants. Methods: The antioxidant potential of test compounds was evaluated by measuring DPPH free radical scavenging, reducing power and metal ion chelating activities. Protection against membrane damage was assayed by inhibition of lipid peroxidation in rat liver homogenate. Antibacterial activity was measured by Kirby-Bauer disc diffusion method while antiproliferative activity of test compounds was measured by sulforhodamine-B (SRB) assay. Results: Eugenol exhibited noticeable antioxidant potential in DPPH radical scavenging (81 %) and reducing power (1.12) assays at 1.0 μM/ml and 0.1 μM/ml concentrations, respectively. IC50 value of eugenol for radical scavenging activity was found to be 0.495 μM/ml. Cinnamaldehyde demonstrated considerable metal ion chelating ability (75 %) at 50 μM/ml and moderate lipo-protective activity in lipid peroxidation assay at 3 μM/ml. In addition cinnamaldehyde also showed appreciable antibacterial activity (zone of inhibition 32–42 mm) against Bacillus cereus (MTCC 6840), Streptococcus mutans (MTCC 497), Proteus vulgaris (MTCC 7299), Salmonella typhi (MTCC 3917) and Bordetella bronchiseptica (MTCC 6838) while eugenol produced moderate activity at 80 μM/disc. Cinnamaldehyde exhibited comparatively better antiproliferative potential against breast (T47D) and lung (NCI-H322) cancer cell lines than eugenol in SRB assay at 50 μM concentration. Conclusion: Cinnamaldehyde possessed metal ion chelating, lipo-protective, antibacterial and antiproliferative activities while eugenol showed potent H-atom donating potential indicating radical quenching and reducing power abilities. Medicinal attributes shown by both the compounds indicated their usefulness in food and pharmaceutical sector. Keywords: Cinnamaldehyde, Eugenol, Phenylpropanoid, Free radical, Antioxidant, Antibacterial, Antiproliferative, Lipoprotective * Correspondence: [email protected] Department of Biochemistry, University of Allahabad, Allahabad 211002, India © 2016 The Author(s). 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/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated. Sharma et al. BMC Complementary and Alternative Medicine (2016) 16:156 Page 2 of 11 Background Spices and aromatic vegetable material of natural origin Free radicals are associated with many degenerative dis- are used in food industries to enhance flavor and fragrance eases including cancer, cardio-vascular diseases, cataract, qualities of food materials. Moreover they are also used as immune system decline and brain dysfunction [1]. Under traditional medicine [14]. Spices are good sources of nat- normal metabolic conditions about 2–5%ofO2 consumed ural antioxidant and antibacterial agents. Cinnamon and by mitochondria is converted to ROS (Reactive oxygen bay leaf are used as spices and obtained from Cinnamo- species) during metabolic process within the body [2]. mum spp. Principle components like cinnamaldehyde, eu- Their excessive production during abnormal conditions is genol, cinnamic acid and cineol etc. are responsible for regulated naturally by antioxidant system [3]. Failure of the antioxidant activity in cinnamon [15]. Very low antioxidant defenses results in a pathophysiological condi- amount of eugenol is usually present in cinnamon bark tion known as oxidative stress. Highly active oxygen and but it is the major component of cinnamon leaf essential nitrogen species (ROS and RNS) are generally considered oil. It is also abundantly present in Syzygium aromaticum to be markers of oxidative stress. They permanently (clove). Both cinnamaldehyde and eugenol belong to phe- modify the genetic material leading to numerous nylpropanoid class of phytochemicals. Cinnamaldehyde degenerative or chronic diseases [4]. Mis-repair of bears an aldehyde group on benzene ring via three carbon DNA damage results in mutations such as base substitu- chain while eugenol has one hydroxy and one methoxy tion and deletion which lead to carcinogenesis [5]. group which are directly attached to the ring (Fig. 1). Antioxidants are a group of substances which are either Eugenol has a wide range of application in perfumes, produced in situ or supplied through food and supple- flavorings, essential oils and in medicine as a local antisep- ments. They protect free radical mediated membrane tic and anesthetic [16]. Present study reports antioxidant, damage because of their scavenging and chelating proper- antibacterial and antiproliferative activities of cinnamal- ties [6, 7]. Butylated hydroxyanisole (BHA) and butylated dehyde and eugenol, the two flavoring phenylpropanoid hydroxytoluene (BHT) are commonly used as synthetic compounds. antioxidant but their uses are restricted by legislative rules because of doubts over their toxic and carcinogenic effects Methods [8]. Antioxidants derived from plants are presumed to be Chemicals safe since they are natural in origin and have capability to Cinnamaldehyde (3-phenyl-2-propenal), eugenol (2-meth- counteract the damaging effect of ROS [9]. oxy-4-(2-propenyl) phenol), DPPH (2, 2-diphenyl-1-picryl Many microorganisms cause food spoilage which is hydrazyl), tert-butyl-4-hydroxytoluene (BHT), butylated one of the most important concerns of the food industry hydroxyanisole (BHA) were obtained from Himedia, Pvt. [10]. Initially, synthetic chemicals were used to prevent Ltd Mumbai, India. microbial contamination as well as oxidation of dietary components so that they remained in their natural form. Assessment of antioxidant ability by in vitro assays Because of the growing concern of consumer about the Free radical (DPPH) scavenging assay side effects of synthetic compounds and want of safer The hydrogen-donating ability of cinnamaldehyde and material for preventing and controlling pathogenic mi- eugenol was examined in the presence of DPPH, a croorganisms in food, natural products are currently stable radical using the method of Singh et al. [17]. being used to prevent microbial contamination [11]. One ml cinnamaldehyde (0.4–4.0 mM/ml) and eugenol Phytochemicals have been reported to modulate human (0.4–4.0 μM/ml) prepared in DMSO were taken in metabolism in a manner beneficial for the prevention of different test tubes and 3 ml of 0.1 mM DPPH solution infectious and degenerative diseases [12, 13]. prepared in methanol was added. The content was mixed Fig. 1 Chemical structures of cinnamaldehyde (3-Phenyl-2-propenal) and eugenol (2-Methoxy-4-(2-propenyl) phenol) Sharma et al. BMC Complementary and Alternative Medicine (2016) 16:156 Page 3 of 11 and allowed to stand at room temperature for 30 min in in vitro lipid peroxidation inhibition assay. 100 μl of dif- dark. Final concentration of cinnamaldehyde and eugenol ferent concentrations of samples was taken in different in reaction mixture was 0.1–1.0 mM/ml and 0.1–1.0 μM/ tubes, followed by addition of 1.0 ml KCl (0.15 M), ml, respectively. The reduction of DPPH free radical was 0.3 ml phosphate buffer and 0.5 ml of tissue homogen- measured by recording the absorbance at 517 nm. BHA ate. Peroxidation was initiated by adding 100 μl FeCl3 was used as standard for comparison. Control tubes con- (0.2 mM). Final concentration of cinnamaldehyde, eu- tained 1 ml DMSO and 3 ml DPPH reagent in reaction genol and BHA (standard) in reaction mixture was mixture. The radical scavenging activities (%) at different 1.0–3.0 μM/ml. After incubation at 37 °C for 30 min, lipid concentrations of the test samples were calculated using peroxidation was monitored by the formation of thiobar- the following formula. bituric acid reactive substances which were estimated by adding 2 ml of ice-cold hydrochloric acid (0.25 N) Free radical scavenging activityðÞ% containing 15 % TCA, 38 % TBA and 0.5 % BHT. ¼ ½ÂðÞAC−AS =AC 100 The reaction mixture was incubated at 80 °C for 1 h followed by cooling and centrifugation. The absorbance of where AC and AS are the absorbance values of the con- the pink supernatant was measured at 532 nm. All analyses trol and the sample, respectively. IC50 value, the concen- were carried out in triplicate and results were expressed as tration of sample exhibiting 50 % free radical scavenging mean ±

Load more