CINNAMALDEHYDE, THE MAJOR COMPONENT OF CINNAMOMUM ZEYLANICUM, AFFECTS INFLAMMATORY PATHWAYS

CINNAMALDEHYDE, THE MAJOR COMPONENT OF CINNAMOMUM ZEYLANICUM, AFFECTS INFLAMMATORY PATHWAYS

Supratim Mahapatra, Shivam Roy, Pushpita Chakraborty, Namrata Chakraborty, Utpalendu Paul, Pratik Chatterjee, Subhadeep Banerjee, Parthendu Sarkar and Malavika Bhattacharya ^*

Department of Bio-Technology, Techno India University, Kolkata - 700091, West Bengal, India.

ABSTRACT: Cinnamaldehyde is the aldehyde that gives cinnamon its flavour and odour. It occurs naturally in the bark of cinnamon tree (Cinnamomum zeylanicum), a common Indian spice. The essential oil of cinnamon bark contains about 90% of cinnamaldehyde. It exists as a yellow oily liquid with a cinnamon odor and sweet taste and is traditionally known to have many medicinal properties, although the mechanism of action is not completely understood. Macrophages are one of the most important cells of the immune system and play important role in influencing the inflammation cascade process. The current study aimed towards understanding the role of this medicinal plant product on genes of the inflammatory pathways, especially in the context of macrophages. For this purpose, the effects of Cinnamaldehyde were studied on the macrophage cell line J774A.1. Our studies indicate that treatment of these cells with various concentrations of Cinnamaldehyde alters levels of the pro-inflammatory cytokine, IL-12. Further studies are required to get a better understanding of the molecular mechanisms by which Cinnamaldehyde may be able to impart its medicinal effects on the process of inflammatory response.

Cinnamaldehyde, Medicinal use, Inflammation, Signaling pathways, Interleukins

INTRODUCTION: A huge number of studies have shown the protective role played by various dietary plant sources in case of diseases such as diabetes, coronary heart disease, and cancer. Cinnamomum zeylanicum or Cinnamomum verum, belonging to the family Lauraceae, is one such plant ¹. Native to Sri Lanka and a globally known common Indian spice, the bark of the cinnamon tree is traditionally used in Indian cooking. Several medicinal properties of this plant have been reported. They include protective functions such as anti-diabetic, anti-inflammatory, anti-microbial, and anti-cancer activity.

Studies have also shown that this plant can prevent neurological disorders and cardiovascular diseases, and lower levels of cholesterol and lipid ^{2, 3, 4}. Cinnamaldehyde and trans-cinnamaldehyde are organic compounds found in cinnamon bark and are the main active ingredients of cinnamon. They are synthesized via the shikimate pathway and are primarily responsible for the distinctive strong flavor and odor found in the bark of this tree ^{5, 6, 7, 8, 9}.

Non-communicable diseases (NCDs) are referred to as medical conditions that are not acquired through infection or contamination and include Cardiovascular Diseases (CVDs), hypertension (High Blood Pressure), diabetes, stroke, and cancer. There are beneficial health effects of cinnamon against a few of these NCDs. Cinnamaldehyde has shown to be effective against several cardio-vascular diseases. It has been shown to normalize the vascular contractility and prevent development of hypertension in insulin-deficient or resistant animals. It also prevents hyper-responsiveness to vasoconstrictor agents (Phenylephrine or KCl) and the hypo-responsiveness to vasodilatory agents in the aortic rings ¹⁰. Hypertension is one of the common NCDs that affect the world's population. It carries a high-risk factor for cardiovascular diseases, arteriosclerosis, myocardial infarction, end-stage renal disease, and various ocular disorders. Cinnamaldehyde has been known to reduce the risk of hypertension by reducing oxidative stress in mice. Cinnamaldehyde also has aldose reductase inhibition activities ¹¹. With reference to diabetes, it has been found that cinnamon extract has insulin-like properties; the polyphenol type-A polymers from the cinnamon act as an insulin-like molecule. Moreover, another compound from hydroxyl-cinnamic acid derivatives, named naphthalene-methyl ester, has blood glucose-lowering effects ¹². Cinnamaldehyde has also been found to impart protective effects in the case of cancer. Some of those studies have shown that Cinnamaldehyde can block nuclear factor-κB activation in immune cells. In one of those studies, treatment with Cinnamaldehyde was found to inhibit cell viability and proliferation and induce apoptosis concentration-dependently both in primary as well as immortalized immune cells ^{13, 14, 15}. Since the signaling pathways/molecules by which cinnamaldehyde executes most of the actions are not yet understood clearly, the present study was performed to look into whether it has any effect on IL-12 expression levels in macrophages. Macrophages are a type of immune cell that is activated in response to an infection. It also has a critical role in the inflammation process.

MATERIALS AND METHODS:

Materials: Cinnamaldehyde was purchased from HiMedia (GRM3277-500ML). Dulbecco’s modified Eagle’s medium (DMEM), 10% Fetal Bovine Serum, and 1% penicillin-streptomycin solution were purchased from Gibco (Auckland, New Zealand). Mouse J774A.1 macrophage cell line was obtained from the National Centre for Cell Science (Pune, India). Double distilled deionized water was used throughout the experiment.

Cell Culture: Mouse J774A.1 macrophages were maintained in Dulbecco’s modified Eagle’s medium (DMEM) containing 25 mM glucose supplemented with 10% Fetal Bovine Serum, 100 U/ml penicillin, 100 mg/ml streptomycin and 2 mM L-glutamine at 37 ºC in a humidified incubator  (Heracell, Thermo Scientific, USA) of 5% CO₂. Cells were subcultured every 3-4 days at reaching approximately 80% confluence. Cells plated onto 6-well plates after one to five passages from the original vial.

Cinnamaldehyde Treatment: 5 × 10⁶ cells were plated in 6-well plates and treated with various concentrations of Cinnamaldehyde (10 μM and 50 μM) in the presence of FBS-free medium.

RNA Isolation: Total RNA isolation was done from the cells using Trizol reagent (Invitrogen). 1 ml of Trizol reagent per 1 × 10⁵ cells was added directly to the culture dish, and total RNA was isolated as per manufacturer’s protocol. In the end, the RNA was resuspended in 10 µl of RNase-free water.

cDNA Synthesis: cDNA was synthesized from the RNA isolated by Reverse Transcription Polymerase Chain Reaction. 500 ng of RNA per sample was used for cDNA synthesis, and the process was performed as per the manufacturer’s protocol. Finally, the cDNA, thus synthesized, was stored at -20 ºC.

RT-PCR and Agarose Gel Electrophoresis: RT-PCRs were performed using 1 µl cDNA synthesized (per sample) to study the expression profile of IL-12. β-actin, a housekeeping gene, was used as control. The PCR products were subjected to agarose gel electrophoresis for visualization. The primers sequences used are as follows:

1. IL-12: forward: 5’- GTAACCAGAAAGGTGC GTTCCT-3’; reverse: 5’- CTGAGCTTGCACGCA GACAT-3’
2. β-actin: forward: 5’-TACC-CAGGCATTG CTGACAGG-3’; reverse: 5’-ACTTGCGGTGCAC GATGGA-3’

RESULTS AND DISCUSSION: As observed in Fig. 1, the expression of IL-12 gene increased in a concentration-dependent manner with the lower concentration of Cinnamaldehyde treatment (10 μM) showing lower expression levels compared to the higher concentration of Cinnamaldehyde treatment (50 μM). Levels of β-actin remain unchanged (data not are shown).

FIG. 1: IL-12 EXPRESSION LEVELS AFTER CINNAMALDEHYDE TREATMENT 1-DNA ladder; 2-untreated; 3-cinnamaldehyde treatment (10 μm); 4-cinnamaldehyde treatment (50 μm)

This study was aimed towards understanding whether Cinnamaldehyde, one of the main components present in the bark of a cinnamon tree, has any effect on any of the components of the inflammatory pathway. To date, not much is known about this aspect, although the medicinal roles of this compound have been manifested in various other diseases, such as diabetes, cancer, and cardiovascular diseases. In this study, we have made a preliminary attempt towards understanding the molecular mechanism by which Cinnama-delhyde may be able to impart its effect on inflammation if any. Our observations have revealed that the purified form of this compound increases expression of IL-12 in a concentration dependent manner. In conclusion, these data strongly indicate that Cinnamaldehyde may have a direct effect on various molecules of importance in the inflammatory pathway, and this effect may be carried out through the up-regulation of IL-12 in macrophages.

Since inflammation is demonstrated to play a significant role in regulating various forms of NCDs, it is of vital importance to understand the underlying molecular mechanisms that drive this control. Cinnamon, a traditionally used spice in Indian households, if found to play a protective role through activation of the inflammatory pathway entities, can lead to easily available medicinal source for decreasing various forms of emerging health concerns (including various forms of NCDs, such as diabetes and cancer).

ACKOWLEDGEMENT: The authors are thankful to Chancellor, Techno India University, West Bengal for providing the necessary infrastructural facilities.

CONFLICTS OF INTEREST: Nil

SOURCE OF FUNDING: Self

REFERENCES:

1. Ranasinghe P, Pigera S, Premakumara SGA, Galappaththy P, Constantine GR and Katulanda P: Medicinal properties of ‘true’ cinnamon (Cinnamomum zeylanicum): a systematic review. BMC Complement Alternative Medicine 2013; 13: 275.
2. Elizabeth DLTJ, Gassara F, Kouassi AP, Brar SK and Belkacemi K: Spice use in food: Properties and benefits. Critical Reviews in Food Science and Nutrition 2017; 57(6): 1078-88.
3. Santos HO and da Silva GAR: To what extent does cinnamon administration improve the glycemic and lipid profiles? Clinical Nutrition ESPEN 2018; 27: 1-9.
4. Davari M, Hashemi R, Mirmiran P, Hedayati M, Sahranavard S, Bahreini S, Tavakoly R and Talaei B: Effects of cinnamon supplementation on expression of systemic inflammation factors, NF-kB and Sirtuin-1 (SIRT1) in type 2 diabetes: a randomized, double blind, and controlled clinical trial. Nutrition Journal 2020; 19(1): 1.
5. Yeh HF, Luo CY, Lin CY, Cheng SS, Hsu YR and Chang ST: Methods for thermal stability enhancement of leaf essential oils and their main constituents from Indigenous cinnamon (Cinnamomum osmophloeum). Journal of Agricultural and Food Chemistry 2013; 61(26): 6293-8.
6. Chen BJ, Fu CS, Li GH, Wang XN, Lou HX, Ren DM and Shen T: Cinnamaldehyde analogues as potential therapeutic agents. Mini-Reviews in Medicinal Chemsitry 2017; 17(1): 33-43.
7. Zhu R, Liu H, Liu C, Wang L, Ma R, Chen B, Li L, Niu J, Fu M, Zhang D and Gao S: Cinnamaldehyde in diabetes: A review of pharmacology, pharmacokinetics and safety. Pharmacological Research 2017; 122: 78-89.
8. Friedman M: Chemistry, Antimicrobial mechanisms, and antibiotic activities of cinnamaldehyde against pathogenic bacteria in animal feeds and human foods. Journal of Agricultural and Food Chemistry 2017; 65(48): 10406-23.
9. Logashina YA, Korolkova YV, Kozlov SA and Andreev YA: TRPA1 channel as a regulator of neurogenic inflammation and pain: structure, function, role in pathophysiology and therapeutic potential of ligands. Biochemistry (Moscow) 2019; 84(2): 101-18.
10. de Andrade TU, Brasil GA, Endringer DC, da Nóbrega FR and de Sousa DP: Cardiovascular activity of the chemical constituents of essential oils. Molecules 2017; 22: 1539.
11. Singh A, Khan SA, Choudhary R and Bodakhe SH: Cinnamaldehyde attenuates cataractogenesis via restoration of hypertension and oxidative stress in fructose-fed hypertensive rats. Journal of Pharmaco-puncture 2016; 19(2): 137-14.
12. Rao PV and Gan SH: Cinnamon: A multifaceted medicinal plant. Evidence-Based Complementary and Alternative Medicine 2014; 1-12 Article ID 642942.
13. Roth-Walter F, Moskovskich A, Gomez-Casado C, Diaz-Perales A and Oida K: Immune suppressive effect of cinnamaldehyde due to inhibition of proliferation and induction of apoptosis in immune cells: Implications in Cancer. PLOS ONE 2014; 9(10): e108402.
14. Sadeghi S, Davoodvandi A, Pourhanifeh MH, Sharifi N, ArefNezhad R, Sahebnasagh R, Moghadam SA, Sahebkar A and Mirzaei H: Anti-cancer effects of cinnamon: Insights into its apoptosis effects. European Journal of Medicinal Chemistry 2019; 178: 131-40.
15. He W, Zhang W, Zheng Q, Wei Z, Wang Y, Hu M, Ma F, Tao N and Luo C: Cinnamaldehyde causes apoptosis of myeloid-derived suppressor cells through the activation of TLR4. Oncology Letters 2019; 18(3): 2420-6.
    

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    How to cite this article:

    Mahapatra S, Roy S, Chakraborty P, Chakraborty N, Paul U, Chatterjee P, Banerjee S, Sarkar P and Bhattacharya M: Cinnamaldehyde, The major component of Cinnamomum zeylanicum, affects inflammatory pathways. Int J Pharm Sci & Res 2020; 11(11): 5788-91. doi: 10.13040/IJPSR.0975-8232.11(11).5788-91.

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