Antibacterial activity and mechanism of cinnamon essential oil against Escherichia coli and Staphylococcus aureus

Antimicrobial natural preparations involving cinnamon, storax and propolis have been long used topically for treating infections. Cinnamic acids and related molecules are partly responsible for the therapeutic effects observed in these preparations. Most of the cinnamic acids, their esters, amides, aldehydes and alcohols, show significant growth inhibition against one or several bacterial and fungal species. Of particular interest is the potent antitubercular activity observed for some of these cinnamic derivatives, which may be amenable as future drugs for treating tuberculosis. This review intends to summarize the literature data on the antimicrobial activity of the natural cinnamic acids and related derivatives. In addition, selected hybrids between cinnamic acids and biologically active scaffolds with antimicrobial activity were also included. A comprehensive literature search was performed collating the minimum inhibitory concentration (MIC) of each cinnamic acid or derivative against the reported microorganisms. The MIC data allows the relative comparison between series of molecules and the derivation of structure-activity relationships.

Natural cinnamic acids, synthetic derivatives and hybrids with antimicrobial activity.

Herbs and the essential oils derived from them have been used from the beginning of human history for different purposes. Their beneficial properties have been applied to mask unpleasant odors, attract the attention of other people, add flavor and aroma properties to prepared dishes, perfumes, and cosmetics, etc. Herbs and essential oils (EOs) have also been used in medicine because of their biological properties, such as larvicidal action, analgesic and anti-inflammatory properties, antioxidant, fungicide, and antitumor activities, and many more. Many EOs exhibit antimicrobial properties, which is extremely important in fields of science and industry, such as medicine, agriculture, or cosmetology. Among the 250 EOs which are commercially available, about a dozen possess high antimicrobial potential. According to available papers and patents, EOs seem to be a potential alternative to synthetic compounds, especially because of the resistance that has been increasingly developed by pathogenic microorganisms. In this review we summarize the latest research studies about the most-active EOs that are known and used because of their antimicrobial properties. Finally, it is noteworthy that the antimicrobial activities of EOs are not preeminent for all strains. Further investigations should, thus, focus on targeting EOs and microorganisms.

https://www.mdpi.com/1420-3049/24/11/2130/pdf

Essential Oils as Antimicrobial Agents-Myth or Real Alternative?

Characterization of sodium caseinate-based edible films incorporated with cinnamon or ginger essential oils

Cinnamomum has long been regarded as a food or medicinal plant. Leaves of five species of Cinnamomum, namely C. burmanni, C. cassia, C. pauciflorum, C. tamala and C. zeylanica, were chosen to investigate their antioxidant activities in this study. C. zeylanica exhibited the highest total phenolic content while C. burmanni had the highest flavonoid content among the five species. These five species were then screened for their antioxidant potentials using various in-vitro models such as total antioxidant capability, 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical scavenging activity, reducing power and superoxide anion scavenging activity at various concentrations. C. zeylanica showed the highest DPPH radical scavenging activity, total antioxidant activity and reducing power, while C. tamala exhibited the highest superoxide anion scavenging activity. By the analysis of the high performance liquid chromatography coupled to diode array detector (HPLC-DAD), three flavonoid compounds namely quercetin, kaempferol and quercetrin were identified and quantified. This study suggested that Cinnamomum leaf can be used potentially as a readily accessible source of natural antioxidants. Industrial relevance This study was focused to evaluate the antioxidant activities of five species of Cinnamomum leaf which is normally used in medicine and also used in food preparation. This study provided an alternative of utilizing Cinnamomum leaf as a readily accessible source of natural antioxidants in food and pharmaceutical industry.

Flavonoid contents and antioxidant activities from Cinnamomum species

Five cinnamon species, viz. Cinnamomum cassia, Cinnamomum zeylanicum, Cinnamomum tamala, Cinnamomum burmannii, Cinnamomum pauciflorum, were chosen to prepare essential oils by hydrodistillation and to identify and quantify their volatile compound compositions. C. cassia was determined to have the highest yield (1.54%) of essential oil, followed by C. zeylanicum, C. pauciflorum, C. burmannii and C. tamala. Gas chromatography/mass spectrometry (GC/MS) was used to identify and quantify the volatile compound composition. The results indicated the apparent difference in the volatile compound compositions of essential oils between species. The total numbers of volatile compounds identified from C. cassia, C. zeylanicum, C. tamala, C. burmannii and C. pauciflorum leaves were 22, 22, 13, 6 and 21, respectively. trans-Cinnamaldehyde was found in the essential oil of each species, which was also the major volatile component of C. cassia and C. burmannii leaves. Besides trans-cinnamaldehyde, 3-methoxy-1,2-propanediol was the main volatile compound of C. cassia leaf, while eugenol of C. zeylanicumand, C. pauciflorum and C. burmannii leaves, and 5-(2-propenyl)-1,3-benzodioxole of C. tamala leaf were also the main substances. Industrial relevance The essential oil of cinnamon is an important bioactive substance which has many disease prevention effects. In this work, five species of cinnamon leaves were chosen as materials to prepare the essential oils. The yield of essential oil was determined. The volatile compounds of essential oil were identified by GC/MS analysis. The results showed the significant difference of volatile compound composition between species. trans-Cinnamaldehyde was detected to exist in all the species tested as an important volatile component. This work is helpful for extensive development of this medicinal herb.

Extraction of essential oils from five cinnamon leaves and identification of their volatile compound compositions

Cinnamon is an important herbal medicine with good effects of health promotion and disease prevention. In this work, the volatile compounds of cinnamon bark were extracted by hydrodistillation and solid phase microextraction techniques. Gas chromatography/mass spectrometry was used to identify and quantify the volatile compound composition. The results indicated that trans-cinnamaldehyde was the major component with the highest area percentage of 68.67% in the volatile oils extracted by hydrodistillation. The next were glycerol 1-methyl ether and o-methoxycinnamaldehyde with area percentages of 23.29 and 1.44%, respectively. The number of alkenes, alkanes, alcohols, aldehydes, amines, carboxylic acids, ethers, esters and ketones were 17, 1, 12, 8, 2, 2, 6, 3 and 6, respectively. The volatile compounds extracted by headspace solid phase microextraction were apparently different from those by hydrodistillation. Three major volatile compounds were 1,2,3,4,4a,5,6,8a-octahydro-7-methyl-4-methylene-1-(1-methylethyl)-naphthalene, 1,2,3,4a,5,8,8a-hexahydro-4,7-methyl-1-methylene-1-(1-methylethyl)-naphthalene and copaene with area percentages of 20.18%, 17.21% and 16.51%, respectively. Alkenes (31), alcohols (10), aldehydes (4), carboxylic acids (2) and ethers (3) were found in this assay.



PRACTICAL APPLICATIONS

Cinnamon bark has been taken as an important traditional herbal medicine due to its disease prevention effect. The volatile compounds of cinnamon bark contribute much to its bioactivities. In this work, the volatile oils were extracted by hydrodistillation technique. Head space solid phase microextraction technique was also used to detect the volatile compounds. Gas chromatography/mass spectrometry analysis showed the significant difference of volatile compound composition between two extractions. trans-Cinnamaldehyde was confirmed to be the major component of volatile oils that has good pharmacological properties. This work is helpful for extensive development of this medicinal herb.

Comparison of volatile compound composition of cinnamon (cinnamomum cassia presl) bark prepared by hydrodistillation and headspace solid phase microextraction

Rui Wang

Papers

Extraction of essential oils from five cinnamon leaves and identification of their volatile compound compositions

Comparison of volatile compound composition of cinnamon (cinnamomum cassia presl) bark prepared by hydrodistillation and headspace solid phase microextraction