Cinnamon as a Useful Preventive Substance for the Care of Human and Plant Health

Abstract

Cinnamon is widely used as a food spice, but due to its antibacterial and pharmacological properties, it can also be used in processing, medicine and agriculture. The word “Cinnamon” can refer to the plant, processed material, or an extract. It is sometimes used as a substance, and sometimes used as a mixture or as compounds or a group. This article reviews research into the effectiveness of various forms of cinnamon for the control of plant diseases and pests in crops and during storage of fruit and vegetables. Cinnamon acts on pests mainly as a repellent, although in higher doses it has a biocidal effect and prevents egg-laying. Cinnamon and its compounds effectively hinder bacterial and fungal growth, and the phytotoxic effects of cinnamon make it a possible herbicide. This article presents the wide practical use of cinnamon for various purposes, mainly in agriculture. Cinnamon is a candidate for approval as a basic substance with protective potential. In particular, it can be used in organic farming as a promising alternative to chemical pesticides for use in plant protection, especially in preventive treatments. The use of natural products is in line with the restriction of the use of chemical pesticides and the principles of the EU’s Green Deal.

Full text

molecules
Review
Cinnamon as a Useful Preventive Substance for the Care of
Human and Plant Health
Jolanta Kowalska 1, * , Józef Tyburski 2, Kinga Matysiak 3, Magdalena Jakubowska 4, Joanna Łukaszyk 1
and Joanna Krzymi ´nska 1


Citation: Kowalska, J.; Tyburski, J.;
Matysiak, K.; Jakubowska, M.;
Łukaszyk, J.; Krzymi´nska, J.
Cinnamon as a Useful Preventive
Substance for the Care of Human and
Plant Health. Molecules 2021,26, 5299.
https://doi.org/10.3390/
molecules26175299
Academic Editors: Gianfranco
Romanazzi and Silvia Bautista-Baños
Received: 28 June 2021
Accepted: 24 August 2021
Published: 31 August 2021
Publisher’s Note: MDPI stays neutral
with regard to jurisdictional claims in
published maps and institutional affil-
iations.
Copyright: © 2021 by the authors.
Licensee MDPI, Basel, Switzerland.
This article is an open access article
distributed under the terms and
conditions of the Creative Commons
Attribution (CC BY) license (https://
creativecommons.org/licenses/by/
4.0/).
1Department of Organic Agriculture and Environmental Protection, Institute of Plant Protection—National
Research Institute, Władysława W˛egorka 20, 60-318 Pozna´n, Poland; J.Lukaszyk@iorpib.poznan.pl (J.Ł.);
J.Krzyminska@iorpib.poznan.pl (J.K.)
2Department of Agroecosystems and Horticulture, University of Warmia and Mazury in Olsztyn,
Michała Oczapowskiego 2, 10-719 Olsztyn, Poland; jozef.tyburski@uwm.edu.pl
3Department of Weed Science and Plant Protection Techniques, Institute of Plant Protection—National
Research Institute, Władysława W˛egorka 20, 60-318 Pozna´n, Poland; k.matysiak@iorpib.poznan.pl
4Department of Monitoring and Signalling of Agrophages, Institute of Plant Protection—National Research
Institute, Władysława W˛egorka 20, 60-318 Pozna ´n, Poland; M.Jakubowska@iorpib.poznan.pl
*Correspondence: j.kowalska@iorpib.poznan.pl
Abstract:
Cinnamon is widely used as a food spice, but due to its antibacterial and pharmacological
properties, it can also be used in processing, medicine and agriculture. The word “Cinnamon” can
refer to the plant, processed material, or an extract. It is sometimes used as a substance, and sometimes
used as a mixture or as compounds or a group. This article reviews research into the effectiveness of
various forms of cinnamon for the control of plant diseases and pests in crops and during storage of
fruit and vegetables. Cinnamon acts on pests mainly as a repellent, although in higher doses it has a
biocidal effect and prevents egg-laying. Cinnamon and its compounds effectively hinder bacterial
and fungal growth, and the phytotoxic effects of cinnamon make it a possible herbicide. This article
presents the wide practical use of cinnamon for various purposes, mainly in agriculture. Cinnamon
is a candidate for approval as a basic substance with protective potential. In particular, it can be
used in organic farming as a promising alternative to chemical pesticides for use in plant protection,
especially in preventive treatments. The use of natural products is in line with the restriction of the
use of chemical pesticides and the principles of the EU’s Green Deal.
Keywords: basic substance; human health; insecticidal activity; microbial activity; plant diseases
1. Introduction
Cinnamon (Cinnamomum zeylanicum L. and Cinnamon cassia L.), a species of the Lau-
raceae family, is an evergreen tree of the tropics, which is widely used in medicine, and
offers a rich variety of applications worldwide. The word was adopted by English towards
the end of 14th century as a loanword from the old French “cinnamone”, which in term
came from Latin via the Greek-Phoenician word “kinnamomon” and supposed to be from
Semitic cf. Hebrew “qinamon”. The first appearance of the word in print dates to 1430, in
John Lydgate Bochas’ “Fall of Princes” [1].
Cinnamon contains manganese, iron, dietary fibre, and calcium. It has derivatives,
such as cinnamaldehyde (CNAD), cinnamic acid, cinnamate, and many other ingredients,
such as polyphenols and antioxidants, with anti-inflammatory, antidiabetic, antimicrobial,
and anticancer properties. Several reports have shown numerous properties of cinnamon
in the form of bark and bark powder. Essential oils and phenolic compounds in cinna-
mon contribute positively to human health. Studies have recently shown the positive
influence of cinnamon in the treatment of Alzheimer’s disease, diabetes, arthritis, and
arteriosclerosis [2].
Molecules 2021,26, 5299. https://doi.org/10.3390/molecules26175299 https://www.mdpi.com/journal/molecules

Molecules 2021,26, 5299 2 of 13
Wang et al. [
3
] reported other major compounds in cinnamon: coumarin, cinnamyl
alcohol, cinnamaldehyde, cinnamic acid, eugenol, and cinnamyl acetate [
3
]. Tung et al. [
4
]
have also reported the presence of a wide range of essential oils in cinnamon, such
as trans-cinnamaldehyde, cinnamyl acetate, eugenol, L-borneol, caryophyllene oxide, b-
caryophyllene, L-bornyl acetate, E-nerolidol,
α
-cubebene,
α
-terpineol, terpinolene, and
α-thujene. Cinnamon consists of a variety of resinous compounds (Table 1).
Table 1. Various chemical constituents of the cinnamon plant [5].
Part of the Plant Compound
Leaves Cinnamaldehyde: 1.00 to 5.00%
Eugenol: 70.00 to 95.00%
Bark Cinnamaldehyde: 65.00 to 80.00%
Eugenol: 5.00 to 10.00%
Root bark Camphor: 60.00%
Fruit trans-Cinnamyl acetate (42.00 to 54.00%) and
caryophyllene (9.00 to 14.00%)
Buds (C. zeylanicum)
Terpene hydrocarbons: 78.00%
α-Bergamotene: 27.38%
α-Copaene: 23.05%
Oxygenated terpenoids: 9.00%
Flowers (C. zeylanicum)
(E)-Cinnamyl acetate: 41.98%
trans-α-Bergamotene: 7.97%
Caryophyllene oxide: 7.20%
According to other sources, ground cinnamon contains carbohydrates, fibre, moisture,
protein, fat, and ash. It also contains vitamins A, B, C, E, K, and lipids. The composition is
different depending on the geographical origin and the processing methods [6,7].
As a plant, cinnamon contains many substances and substance groups. Among these,
there are essential oils, diterpenes, catechins, proanthocyanidins, tanning agents, colouring
agents, phenolic carboxylic acids, lignans, and mucins. Cinnamon
'
s essential oils mainly
have antifungal and antibacterial properties and, similarly to cinnamon bark extract, are
characterized by antioxidant activity [
8
]. Moreover, essential oils have antiinflammatory, an-
tidiabetic, antitumor, antimutagenic, and memory-enhancing properties. Cinnamaldehyde
and eugenol are active components against Gram-positive and Gram-negative bacteria [
9
].
Sharifi-Rad et al., 2021 [
10
] showed that the bioactive compounds of Cinnamomum
species possess antimicrobial, antidiabetic, antioxidant, anti-inflammatory, anticancer, and
neuroprotective effects.
Incomplete knowledge about the safe consumption of higher doses of cinnamon on
a daily basis makes it necessary to assess the occurrence of this risk, and therefore, the
long-term use of a high amount of cinnamon should be monitored. The tolerable daily
intake for coumarin (0.1 mg/1 kg body weight) can be regarded as safe in terms of daily
cinnamon intake without the risk of adverse effects [
11
]. According to the scientific data
currently available, a risk assessment must be focused on the problematic ingredients
of cinnamon extract, especially on coumarin, trans-cinnamaldehyde, safrol, and styrene,
which are toxic.
Cinnamon bark is obtained twice a year, closely following each of the rainy seasons,
when the air humidity facilitates bark harvesting. The first harvest is done when the trees
are three years old, a year after pruning. The side stems that are about three-years-old
are cut off, and the bark is pulled off. Cinnamon bark is gained only from stems that are
between 1.2 and 5 cm in diameter.

Molecules 2021,26, 5299 3 of 13
Cinnamon is often ground to a powder before sale. The powder should be packed in
moisture-proof wrapping (polypropylene bags) to keep the flavour. Polyethylene packag-
ing is not advisable, as the flavour components diffuse through it [12].
2. Culinary and Medicinal Use
Cinnamon bark is commonly used as a spice. It is principally used in cooking as a
condiment and flavouring agent. It is used in the production of chocolate, especially in
Mexico, which is the biggest importer of true cinnamon (C. zeylanicum L.). It is also added
to desserts, such as apple pie, donuts, and cinnamon buns, as well as spicy candies, tea, hot
cocoa, and liqueurs. True cinnamon and not cassia (C. cassia L.) is better for use in sweet
dishes. In the Middle East, it is often used in savoury dishes of chicken and lamb. In the
USA, cinnamon is often used as an additive to flavour cereals, bread-based dishes, and
fruit, especially apples; and a cinnamon–sugar mixture is on sale in grocery stores. Another
use of cinnamon is in pickling.
Cinnamon bark is one of the rare spices that can be consumed directly; cinnamon
powder has long been an important spice in Persian cuisine, added to various thick soups,
drinks, and sweets. It is often used as a mixture with rosewater or other spices to make a
cinnamon-based curry for stews or just sprinkled on sweet desserts [13].
2.1. Effects in Humans
Cinnamaldehyde (CNAD) lowers inflammatory reactions, oxidative stress, and apop-
tosis of the liver in Salmonella typhimurium-infected mice. Supplementation of CNAD
might be a good preventive method to alleviate the liver damage caused by Salmonella
typhimurium infection in humans and animals [
14
]. Moreover, cinnamon bark essential oils
(EOs) have been shown to cause oxidative stress to Klebsiella pneumoniae, resulting in the
loss of cell viability [
15
]. Both oregano and cinnamon bark EOs have strong antibacterial
properties. Aljaafari et al. [
16
] have shown that the antimicrobial properties of essential
oils (EOs) are based on the mode of action in relation to membrane disruption, efflux
inhibition, the increase in membrane permeability, and the decrease in intracellular ATP.
These essential oil compounds can be used as potential agents against bacteria, fungi, and
viruses. In the future, the integration of EOs uses can lead to many clinical applications.
In medicine, the essential oils in cinnamon behave like other volatile oils. It has also
been used in the treatment of digestive system problems and colds. The essential oils
in cinnamon also have antimicrobial properties and are used as a preservative in some
foods. Cinnamon has been reported to have remarkable pharmacological effects in the
treatment of diabetes type 2 resistant to both mellitus and insulin; however, the plant
material used in the study was mainly from cassia and only some of the plant material
was from C. zeylanicum. Cinnamon has traditionally been used for toothache and to
fight bad breath, and its regular use is thought to cure the common cold and support
digestion [
17
]. It is noted that regular drinking of C. zeylanicum tea made from the bark
could be helpful in oxidative-stress-related illness in humans, since it has considerable
antioxidant potential. Cinnamon may also act as an aphrodisiac. One teaspoon of cinnamon
has as many antioxidants as a cup of pomegranate juice and half a cup of blueberries [
17
].
Nanocapsules with cinnamon-thyme-ginger composite essential oils prepared with
chitosan as the wall via ionic gellification reaction were tested in medicine and revealed
durable antibacterial activity against Escherichia coli,Bacillus subtilis, and Staphylococcus
aureus. Composite essential oil nanocapsules CEO-NPs can be applied as a strong long-
lasting natural preservative [18].
2.2. Adverse Effects Reported in Humans
Scientific research has confirmed the effectiveness of cinnamon in fighting microbes,
viruses, fungi, oxidants, tumours, and hypertension. It also has antidiabetic, gastro-
protective, and immune modulatory potential [
17
]. However, the popular use of cinnamon
has also resulted in several reports of side effects from its short- and long-term use. The

Molecules 2021,26, 5299 4 of 13
most common negative effects were disorders of the stomach and bowels, as well as allergic
reactions, which were self-controlling in most cases. Although cinnamon is safe as a spice
and/or flavour, prolonged and enlarged use may be a health risk, and hence, in medicinal
uses, it should be clinically monitored [19].
Cinnamon coats and dries the mouth and throat, leading to coughing, gagging, vomit-
ing, and the inhalation of cinnamon, causing throat irritation, breathing difficulties, and
a risk of pneumonia or lung collapse [
20
,
21
]. Cinnamon contact stomatitis (CCS) is also
a sporadic reaction to the consumption of foods containing artificial cinnamon flavour.
Physicians who treat patients with oral conditions ought to be aware of CCS to correctly
diagnose and manage this condition [
22
]. Contact stomatitis, which is related to the use
of cinnamon flavourings, is rather rare. The symptoms, as well as the histopathologic
features of this disease are non-specific. They may be similar to other inflammatory ill-
nesses of the oral mucosa, which causes problems in diagnosis. Patients develop white and
erythematous spots of rapid occurrence, with an associated sensation of burning. High
levels of coumarin and cinnamaldehyde might be associated with mouth sores [
23
]. High
levels of coumarin and cinnamaldehyde might be also correlated to liver damage and low
blood sugar [
24
]; such high levels may increase the risk of cancer, breathing problems, and
interaction with certain medications [11].
Oral lesions caused by a reaction to cinnamon flavouring agents are rather uncommon
and are probably unrecognized by many physicians. Most patients feel a “burning sensa-
tion”, which is the primary symptom. Clinically, lesions present as erythematous patches
with different degrees of superimposed keratosis or ulceration. The lesions are usually
limited to the buccal mucosa and lateral border of the tongue. The responsible agent was
most frequently cinnamon-flavouring chewing gum, and symptoms usually eased within 1
to 2 days after the last use of the product containing cinnamon [25].
3. Agricultural Purpose
3.1. Fungicidal Activity
Cinnamon oils and extracts possess antifungal properties against serious plant dis-
eases (Table 2). Wilson et al. [
26
] indicated that, out of 49 essential oils tested, cinnamon
leaf C. zeylanicum showed the strongest antifungal activity against Botrytis cinerea. Montes-
Belmont and Carvajal [
27
] found that Aspergillus flavus was fully inhibited by C. zeylanicum.
In other studies, C. zeylanicum proved to be fungicidal towards pathogens (Colletotrichum
musae,Lasiodiplodia thebromae, and Fusarium proliferatum) isolated from bananas [
28
]. Cin-
namon also had an antifungal effect against Oidium murrayae [
29
] and harnessed conidial
germination of Colletotrichum gloesporioides [
30
]. In
in vitro
tests, it proved to have a signifi-
cant mycelial inhibition in corn rot Fusarium oxysporum f. sp. gladioli [
31
] and to be very
effective against the growth of Rhizoctonia solani [
32
]. Moreover, cinnamon has powerful
antifungal activity towards early tomato blight (Alternaria solani) [
33
]. Botrytis cinerea is a
serious problem, especially in horticultural crops. The investigations of Wang et al. [
34
]
demonstrated that cinnamon microemulsions possessed high
in vivo
control properties
against gray mould of pears, B. cinerea. The influence of C. zeylanicum organic powder on
the growth of B. cinerea and its effect on tomato plants have also been assessed. Cinnamon
bark powder and also its water suspensions and filtrates controlled B. cinerea; moreover,
tomato plants sprayed with cinnamon developed better than the control plants [35].
An
in vitro
study on extracts from the cinnamon bark of C. cassia and clove (Syzygium
aromaticum L.) on the growth of B. cinerea colonies showed their antifungal activity, causing
a slow growth of this pathogen and can be applied to control strawberry gray mould. The
clove extract consisted of 52.88% eugenol, and the cinnamon extract consisted of 74.67%
cinnamaldehyde. The efficacy of the extracts on detached strawberry leaves showed that a
12 mL/L concentration of clove extract was effective in suppressing grey mould infection.
It is worth noting that the results indicate that the antifungal properties of the clove extract
were more effective (even applied in a lower concentration) than that of the cinnamon
extract. Grey mould infection on detached strawberry leaves was inhibited by the use of

Molecules 2021,26, 5299 5 of 13
clove oil at the higher investigated concentration (12 mL/L) [
36
]. The cinnamon extract
applied at a rate of 12 mL/L proved to be less effective at inhibiting the spread of grey
mould on strawberry leaves [
37
], and Allam et al. [
38
] reported that a higher concentration
of 20 mL/L of cinnamon entirely inhibited the mycelial growth of B. cinerea in vitro.
Cinnamaldehyde has been used effectively as a bio-fungicide for controlling other
plant fungal diseases. For example, it showed good inhibitory activity against Colletotrichum
lagenarium, a significant plant-pathogenic fungus leading to anthracnose of cucumber.
Other studies indicate that it markedly inhibited zoospore germination and the rapid
mycelial development of Phytophthora capsici, a pathogenic fungus causing phytophthora
blight of pepper [
39
]. Essential oil extracted from C. zeylanicum (CEO) leaves was identified
as having the active constituents eugenol and trans-cinnamaldehyde, which had, respec-
tively, minimal inhibitory concentrations (MICs) of 250 and 62.5
µ
g/mL against Alternaria
alternata, while, under the same conditions, the MICs for a commercial fungicide and CEO
were 1250 and 500 µg/mL, respectively [40].
Cinnamon essential oil proved to be more capable of limiting the incidence and
progress of fungal disease in commercial tangerine orchards than copper fungicide and
was effective at a similar level as a commercial plant activator. Both essential oil and
cinnamaldehyde (additional to the direct way of action, inhibiting fungal growth), posi-
tively influence the plant defense system, causing a significant rise in enzyme levels [
40
].
It was conferred that cinnamon oil has powerful antifungal activity against these four
species of fungi: Aspergillus niger,Penicillium notebookum,Mucora heimalis, and Fusarium
oxysporum. Cinnamon oils and cinnamon extracts have demonstrated good antifungal
properties against economically important plant diseases [41].
The effectiveness of essential oil from clove and cinnamon against fungi resulting
in the postharvest decay of grapes: A. niger,A. alternata,Colletotrichum gloeosporioides,
L. theobromae,Phomopsis viticola, and Rhizopus stolonifer has also been investigated. In the
study of Udomlak Sukatta [
42
] the antifungal activity of clove oil against all the above-
mentioned fungi showed minimal inhibitory concentrations (MICs) of: 200, 200, 400, 800,
200, and 200 mg/mL, respectively, whereas the MICs obtained from cinnamon oil were
50, 100, 200, 200, 100, and 800 mg/mL, respectively. Investigation of the synergistic effect
of clove and cinnamon oil showed three optimum ratios: 3:7, 2:8, and 1:9 and MICs for
all fungi obtained from these ratios for the inhibition of the growth of six fungi was
400 mg/mL. A study of the synergistic effect of clove and cinnamon oil indicated three
optimum proportions: 3:7, 2:8, and 1:9, and the MICs for all fungi obtained from these
ratios to inhibit the development of six fungi was 400 mg/ mL [42].
A further study determined if essential oils can be applied as a contact fungicide seed
treatment for organic maize. The sowing date for organic maize (Zea mays L.) is delayed to
avoid the coldness and wetness of spring soils. Conventional farmers can apply chemical
fungicide seed treatments to protect the emerging seedling but almost no organic fungicides
are on the market. Eighteen plant essential oils were studied for their fungicidal activities
against three common maize pathogens: Penicillium spp., Fusarium spp., and Pythium spp.
Five oils fully controlled all three pathogens
in vitro
. These oils were cinnamon, clove,
oregano, savory, and thyme. The MIC for all pathogens was 800
µ
L/L, and no phytotoxicity
was detected in the germination test at doses up to 16,000
µ
L/L (MIC
×
20). The field
emergence of inbred and hybrid seeds treated with the essential oil were considerably
decreased compared to seed treated with the commercial, conventional fungicides and one
organic fungicide [43].
Fusarium wilt caused by F. oxysporum f. sp. lycopersici is the most serious disease of
the tomato. In the study of Prashant et al. [
44
], seven plant extracts were screened against
F. oxysporum. Among these, the antifungal properties of S. aromaticum and C. zeylanicum
extracts were comparable to the efficiency of chemical fungicides. Methanol (MeOH)
extract of S. aromaticum demonstrated the widest range of inhibition as compared to other
extracts assessed, including those from C. zeylanicum. Solvent extracts of cinnamon and
clove proved to be 100% inhibitory against F. oxysporum spores at 5 and 10 mL/L rates [
44
].

Molecules 2021,26, 5299 6 of 13
Another pathogen, Fusarium verticillioides, is a filamentous fungus and a commonly
occurring pathogen with the ability to infect and destruct economically important crops
by producing fumonisin mycotoxins. Xing et al. [
45
] carried out a study to assess the
inhibitory properties of cinnamon and clove, eucalyptus, anise, spearmint, and camphor
oils on F. verticillioides. Cinnamon oil proved to have the strongest inhibition properties. The
antifungal potential of cinnamon oil was investigated with a special focus on its mechanism
of inhibition of F. verticillioides development at the morphological and ultra-structural
planes. For F. verticiliides, the minimal inhibitory concentrations (MICs) of cinnamon oil
(85% cinnamaldehyde), natural cinnamaldehyde (95%), and synthetic cinnamaldehyde
(99%) were 60, 50, and 45 mL/L, respectively. The same authors [
45
] used scanning
electron microscopy and its transmission version of F. verticillioides in the presence of
MIC of cinnamaldehyde and showed irreversible deleterious morphological and ultra-
structural changes, such as a lack of cytoplasmic content, depravation of integrity and
rigidity of the cell wall, plasma membrane disintegration, mitochondrial destruction,
and the folding of the cell. These alterations caused by cinnamaldehyde may result
from its interference with the enzymatic reactions of cell wall synthesis, thus negatively
influencing the morphogenesis and development of the fungus. These outcomes further
emphasized the toxicity of cinnamon oil towards F. verticillioides attacking grains. It shows
that cinnamon oil can be safely applied as an alternative to chemical fungicides during
grain storage. The cinnamon oil concentration proved to be effective on the development
of F. verticillioides with fumigation. The inhibitory effect of cinnamon oil rose proportionally
to its concentration and proportionally to treatment duration. An increase in cinnamon oil
concentration resulted in a delay in conidia germination and showed different inhibitory
reactions. At a rate of 40 mL per Petri dish after 6 days of incubation, the cinnamon oil fully
inhibited F. verticillioides mycelial growth. After 20 days of incubation, visible development
of F. verticillioides did not take place. These results indicate the fungistatic properties of
cinnamon oil at lower ratios and fungicidal properties at higher ratios [
45
]. The ability of
cinnamon, clove, lemongrass, oregano, and palmarosa essential oils to prevent the growth
of fumonisin B1 (FB1) production by F. verticillioides at different water activities (0.95 and
0.995 aw) and temperatures (20 and 30
◦
C) in irradiated maize grain was also evaluated by
Velluti et al. [
46
]. All of the essential oils inhibited growth of F. verticillioides isolates under
all conditions tested, but FB1 production was only inhibited at 30 ◦C and 0.995 aw.
The antifungal properties of cinnamon against other pathogens have been shown
by other researchers [
47
]. The
in vitro
efficacy of cinnamon essential oil was tested at
application rates of 100, 250, 500, 1000, and 2000
µ
L/L for controlling fruit rot. The
mycelium growth of Colletotrichum gloeosporioides sp., Fusarium solani, and Phytophthora
palmivora was inhibited at application rates of 1000 µL/L [47].
The antifungal effect of cinnamon oil has been studied with special reference to its
mechanism of inhibition on F. verticillioides growth at the morphological and ultra-structural
levels. The MICs of cinnamon oil (85% cinnamaldehyde), natural cinnamaldehyde (95%),
and synthetic cinnamaldehyde (99%) were 60, 50, and 45
µ
L/L, respectively. The antifungal
activity of cinnamon oil was proportional to its cinnamaldehyde concentration [45].
A significant antifungal effect was observed with the essential oil of C. zeylanicum
on mycelial growth using bioassays of Fusarium oxysporum f. sp. gladioli at 100, 150,
200, 250, and 300 ppm [
31
]. The important antifungal potential of cinnamon oil (both
in vitro
and
in vivo
) in proportion to its concentration towards various Fusarium species
was confirmed. In
in vitro
studies by Horváth et al. [
48
], the cinnamon oil effectively
controlled mycelial development of Fusarium head blight of winter wheat. Jiang et al. [
49
]
demonstrated that C. cassia oil has a significant antifungal effect against S. sclerotiorum with
a minimum inhibitory concentration (MIC) of 256
µ
g/mL in agar and 64
µ
g/mL in air.
In a further study, trans-cinnamaldehyde exhibited the highest antifungal activity among
the three cinnamaldehydes tested. Al-Taisan et al. [
50
] noted that cinnamon, clove, and
mint oils completely inhibited
in vivo
mycelial growth of S. sclerotiorum at
10–500 ppm
concentrations. A soil application containing cinnamon oil significantly reduced the

Molecules 2021,26, 5299 7 of 13
incidence of disease caused by S. sclerotiorum, producing 75% plant survival compared
to the control [
43
]. Moraes et al. [
51
] investigated the inhibitory properties of cinnamon
(C. cassia) and citronella (Cymbopogon winterianus) essential oils in the
in vitro
control
of Aspergilus sp. and S. sclerotiorum fungi. The effectiveness of cinnamon and other
essential oils and microelements against Sclerotinia sclerotiorum was shown in
in vitro
tests.
Cinnamon and citronella essential oils were used in doses of 0.2, 0.4, 0.8, and 1.6 mL/L.
The dose of 1.6 mL/L of both oils fully inhibited the mycelial development of Aspergillus
sp. and S. sclerotiorum fungi.
The continuous spread and evolution in the development of natural plant protective
means as alternatives to synthetic fungicides attracts attention today. Combrinck et al. [
52
]
evaluated the antifungal properties of eighteen essential oils and their impact on the growth
of five pathogens
in vitro
(Lasiodiplodia theobromae,Colletotrichum gloeosporioides,Alternaria
citrii,B. cinerea, and Penicillium digitatum) isolated from mango, avocado, citrus, grapes,
and cactus pear. Most of the oils were chosen because of their commercial availability and
the content of a predominant compound. A visual inspection of the fungal growth was
conducted, and the lowest ratio where the fungal growth was fully stopped was noted. Rich
in eugenol (81.2%), cinnamon oil showed a strong fungicidal effect [
45
]. In other research,
the antifungal properties of cinnamon extract (CE) were assessed on banana crown rot
fungi. The antifungal activities of cinnamon extract, pepper extract (PE), and garlic extract
(GE) were evaluated on banana crown rot fungi (Colletotrichum musae,Fusarium spp., and
L.theobromae)
in vitro
. The assay was conducted with extracts of CE, PE, and GE with
concentrations of 0, 0.1, 0.5, 1.0, 5.0, 10.0, and 0.75 g/L of carbendazim (CBZ) on potato
dextrose agar at room temperature. CE completely inhibited the conidial germination and
mycelial growth of all three fungi at 5.0 g/L. PE totally suppressed mycelial growth of all
fungi at 5.0 g/L and conidial germination at 10.0 g/L except for Fusarium spp. GE had no
significant effects, but low concentrations (0.1 and 0.5 g/L) enhanced germ tube elongation
of the three fungi. Crown rot growth was also evaluated during banana storage at 13
◦
C for
7 weeks. The disease development was weakest (25%) on CE-treated fruit after inoculation
and stronger when CE was applied prior inoculation. CE had no negative effects on the
quality of the fruit, but CE used together with hot water treatment led to unacceptable
skin browning [
53
]. The aim of another study was to assess the antifungal potential of
crude extracts of cinnamon and rosemary against three isolates of sclerotinia carrot rot
both under
in vitro
and
in vivo
conditions. The extracts were obtained by applying two
different solvents with ethyl acetate (EA) and ethanol. The results indicated that crude
extracts of cinnamon can reduce the mycelial development of one isolate at the volatile
and contact phase by 35.4% and 78.2%, respectively. Although crude extracts of cinnamon
and rosemary could lower the severity of carrot rot during carrot storage in contrast to
EA, an extract of cinnamon (2 g/L) was confirmed to have a significant effect against this
disease [54].
Table 2. Selected examples of fungicidal activity of cinnamon components for agricultural purposes.
Pathogen Form of Cinnamon Effective Dose Reference No.
Fusarium oxysporium Essential oil 100–300 ppm [31]
Botrytis cinerea Extract C. cassia 20 mL/L [38]
Fusarium verticillioides Essential oil
Cinnamon oil with cinnamaldehyde
60 µL/L
45–60 µL/L [45]
Colletotrichum gloerpoides
Phytophthora palmivora
Fusarium solani
Essential oil 1000 µL/L [47]
Sclerotinia sclerotiorum Essential oil 10–500 ppm [50]
Sclerotinia sclerotiorum C. cassia oil 256 µg/mL of agar [51]

Molecules 2021,26, 5299 8 of 13
Table 2. Cont.
Pathogen Form of Cinnamon Effective Dose Reference No.
Sclerotinia scleriotiorum
Aspergillus sp. C. cassia oil 1.5 mL/L [51]
Lasidiploidia theobromae
Colletotrichumgloerpoides
Alternaria citrii
Essential oil 1000 µL/L [54]
Colletotrichum musae
Lasidiploidia theobromae Cinnamon extract 5 g/L [55]
Sclerotinia sclerotiorum ethyl acetate cinnamon extract 2 g/L [56]
Mohammed et al. [
55
] studied the potential of E-cinnamaldehyde (EC) against S. sclero-
tiorum on potatoes and also the induction of glutathione S-transferase genes. The findings
indicated that EC could inhibit the mycelial growth of S. sclerotiorum. E-cinnamaldehyde
decreased white mould on potatoes in greenhouse trials; additionally, E-cinnamaldehyde
considerably strengthened the activity of glutathione S-transferase (GST)-like genes identi-
fied from the pathogen genome [55].
Another
in vitro
study indicated the antifungal activity of five plant extracts, including
C. zeylanicum, conducted with either cold distilled water (CDW) or boiling water (BDW) on
two pathogenic fungi, A. alternata and F. oxysporum. The results indicate that plant extracts,
especially those treated with CDW, revealed a powerful antifungal activity with significant
inhibition of the development of the two tested fungi [56].
3.2. Bactericidal Activity
Imad et al., 2016 [
57
] established that C. zeylanicum possesses remarkable antimicrobial
activity, which is predominantly due to E-cinnamaldehyde. These findings indicate that
the methanolic extract of C. zeylanicum is antifungal and antibacterial. Natural biocides
with C. zeylanicum bark essential oil have major potential as antimicrobials; this potential is
reduced due to volatility and the fast decomposition of the essential oil. To prevent this
and to lengthen the efficacy of this biocide, cinnamaldehyde (CNAD) was encapsulated
into mesoporous silica nanoparticles (MSNPs) in order to handle the problem. To eliminate
seedborne diseases, CNAD-MSNPs were dressed in a sodium alginate seed coating. This
system was tried against Pseudomonas syringae pv. pisi, responsible for pea bacterial blight.
However, the concentration of CNAD in the alginate coating was <0.0000034% (v/v); this
was up to 90,000-fold lower than the concentrations of free cinnamon oil reported earlier to
control some bacterial diseases [58].
3.3. Insecticidal Activity
Cinnamon has been suggested for use as a repellent against insects. Cinnamon oils
and their components, such as cinnamaldehyde, are insecticidal compounds that have been
used against a variety of insects [41] (Table 3).
Cinnamon leaf oil proved to be very effective as a killing agent for mosquito larvae.
The compounds cinnamaldehyde, cinnamyl acetate, eugenol, and anethole, which are
ingredients of cinnamon leaf oil, were found to be the most effective against mosquito
larvae. The insecticidal and fumigant properties of C. cassia bark-derived materials against
the oak nut weevil (Mechoris ursulus) were examined using filter paper diffusion and
fumigation methods. In a test with the filter paper diffusion method, trans-cinnamaldehyde
showed 100 and 83.3% mortality at rates of 2.5 and 1.0 mg/filter paper, respectively. At
2.5 mg/paper, strong insecticidal activity was produced from eugenol (90.0% mortality)
and salicylaldehyde (88.9%), whereas trans-cinnamic acid had a moderate activity (73.3%).
At 5 mg/paper, weak insecticidal activity (50.0%) was produced from cinnamyl alcohol.
In a fumigation study, the cinnamon bark-derived components were considerably more
effective in closed cups than in open ones. The results indicated that the insecticidal activity

Molecules 2021,26, 5299 9 of 13
of the tested compounds was attributable to fumigant action, but significant contact toxicity
also occurred [59].
Table 3. Insecticidal activity of cinnamon.
Insect Pest Cinnamon Substance/Form Effective Dose for LC50 Reference No.
Mosquito larvae
Aedes aegyptii Cinnamon oil C. cassia 58.41 mg/L [59]
Thrips tabaci Essential oil C. zeylanicum Trade product with 70% oil [60]
Mechoris ursulus C. cassia bark extract 2.5–5 mg/paper filter [59]
Plutella xylostella
Tetranychus urticae Essential oil C. cassia 5.96 µg/cm2[61]
Myzus persicae Essential oil C. cassia 6.50 µg/cm2[61]
Sitophilus granarius Essential oil 1000 µL/L [62]
Acanthoscelides obtectus Essential oil C. zeylanicum 46.8 µL/kg beans [63]
Tribolium castaneum
Sitophilus zeamais
Rhyzopertha dominica
Essential oil 0.1–0.2% mixed with flour [63]
Sitophilus oryzae
Callosobruchus chinensis
Extract of C. sieboldii root bark, C. cassia
extract and oil 0.7 mg/cm2[64]
Cydalima perspectalis Cinnamon oil as deterrent 1.5 mL in dispenser [65]
Source: own study.
Cinnamon oil has been applied to control thrips on onions. The effects of orange
and cinnamon oil (from C. zeylanicum) on the presence and damage of Thrips tabaci on
onions was studied. The results (expressed as the number of thrips caught with sweeping
nests) confirm that both orange and cinnamon oil considerably reduced the number of
adults on onion plants [
60
]. To test the controlling potential against agricultural pests,
such as the diamondback moth (Plutella xylostella), green peach aphid (Myzus persicae), and
two spotted spider mite (Tetranychus urticae), the essential oils of Coriandrum sativum and
C. cassia obtained from steam distillation, hexane extraction, and supercritical extraction
were assessed. Using the contact bioassay, the LD
50
values of C. cassia oils prepared by
steam distillation and hexane extraction methods were 5.96 and 4.64
µ
g/cm
2
, respectively,
against T. urticae adults, and the LD
50
value of the essential oil by the supercritical extraction
method was 6.50
µ
g/cm
2
against M. persicae adults. Finally, the research indicated that
C. cassia oils are a promising natural acaricide and insecticide against pests [61].
In other studies the toxicity and deterrence of the terpenoid constituents of cinnamon
oil have been evaluated. The toxic effects, repellent properties, and respiration rate in-
fluenced by terpenoid components of cinnamon essential oil were assessed, as well their
influence on Sitophilus granarius L. The lethal concentrations (LC
50
and LC
90
), repellence
in general, and behaviour repellence reaction of adult S. granarius in the presence of six
concentrations of respective essential oils, as well as terpenoids, were assessed. The chemi-
cal constituents of the cinnamon oil were established, and its primary compounds were
eugenol (10.5%), trans-3-caren-2-ol (10.2%), benzyl benzoate (9.99%), caryophyllene (9.34%),
eugenyl acetate (7.71%),
α
-phellandrene (7.41%), and
α
-pinene (7.14%). The toxicity of
cinnamon essential oil against S. granaries was showed. Among the toxic terpenoid compo-
nents, eugenol has the most powerful contact toxicity against S. granarius in comparison
to, in decreasing order, caryophyllene oxide,
α
-pinene,
α
-humulene, and
α
-phellandrene.
Cinnamon essential oils, as well as their terpenoid compounds, proved toxic and had
repellent properties against adult S. granarius and thus have preventive and retarding
properties for the development of resistance to insecticide [62].
In another study with storage pests, the bean weevil Acanthoscelides obtectus, which is
the cause of heavy post-harvest losses in the common bean, Phaseolus vulgaris, the essential

Molecules 2021,26, 5299 10 of 13
oil of C. zeylanicum was tested for insecticidal (lethal toxicity, disturbances to reproduction,
and persistence of action) and repellent activities. The study revealed toxicity at LD
50
46.8
µ
L/kg beans, steadily reduced the growth rate of A. obtectus in a dose-related manner,
and showed a similar loss of its insecticidal potential with time. Cinnamon oil also repelled
the bean weevil. The results showed that cinnamon essential oil is an effective tool for
protecting stored beans against A. obtectus in small storage facilities. Cinnamon oil inhibited
the reproduction ability of the flour beetle (Tribolium castaneum), the maize weevil (Sitophilus
zeamais), and the lesser grain borer (Rhyzopertha dominica) at a rate of 0.1–0.2%, mixed with
wheat or wheat flour [63].
The insecticidal properties towards adults of S. oryzae L. and Callosobruchus chinensis
were tested by Soon-Il Kim et al. [
64
]. In a test with a filter paper diffusion method at
3.5 mg/cm
2
, an extract from C. cassia bark and oil was used. An extract from C. sieboldii
root bark gave 100% mortality at two days after treatment. At 0.7 mg/cm
2
, extracts from
C. cassia, C. sieboldii, and cinnamon oil were highly effective against both species. In a
fumigation test with S. oryzae adults, the oils were much more effective in closed containers
than in open ones, indicating that the insecticidal activity of the oils was attributable to
fumigant action. The authors concluded that these plant extracts and essential oils could
be helpful in controlling field populations of S. oryzae and C. chinensis. In another paper
on Cydalima perspectalis, the results point to cinnamon oil as a good deterrent with the
strongest oviposition-deterring effect [65].
3.4. Nematicidal Activity
The nematicidal activity of C. cassia and C. zeylanicum oils (bark and green leaf) and
their chemical compounds against adult Bursaphelenchus xylophilus was tested by a direct
contact bioassay. The LC
50
values for cassia oils (0.084–0.085 mg/mL) and for cinnamon oils
(0.064–0.113 mg/mL) were toxic towards adult B. xylophilus. Of 45 tested compounds, trans-
cinnamaldehyde (0.061 mg/mL) was the most active nematicide, followed by ethyl cinnamate,
α
-methyl-trans-cinnamaldehyde, methyl cinnamate, and allyl cinnamate (
0.114–0.195 mg/mL)
.
Potent nematicidal activity was also observed with 4-methoxycinnamonitrile, trans-4-methoxy
cinnamaldehyde, trans-2-methoxy-cinnamaldehyde, ethyl
α
-cyanocinnamate, cinnamonitrile,
and cinnamyl bromide (0.224–0.502 mg/mL). The tested compounds have been described
as potential nematicides to combat B. xylophilus, which causes pine wilt disease [66].
4. Effect of Cinnamon Oil on Plant Growth
The impact of seed dressing with various concentrations of cinnamon oil and tea tree
oil on the field emergence and yield of parsley var. Berlinska and lettuce var. Ewelina
is presented in the literature [
67
]. Cinnamon oil lowered the lettuce and parsley field
emergence. The toxicity was the greatest at 15% concentration. Tee tree oil showed no
toxicity in 55 and 70% concentrations and increased the field emergence ability, particularly
in lettuce. A similar relation was established for the speed and spread of emergence. A
15% concentration of cinnamon oil caused a decrease in the number of plants for both
species [67].
In laboratory and greenhouse investigations, the allelopathic effect of essential oils
extracted from aromatic plants (cinnamon, lavender, and peppermint) on the seed germina-
tion of mediterranean weed species (Amaranthus retroflexus L., Solanum nigrum L., Portulaca
oleracea L., Chenopodium album L., Sinapis arvensis L., Lolium spp., and Vicia sativa L.) was
examined. Each essential oil was examined at four concentrations in controlled conditions
(germination chamber: 0.2, 0.6, 1.8, and 5.4 mg/L) and in a semi-controlled condition (green
house: 5.4, 21.6, 86.4, and 345.6 mg/L). In the controlled conditions, the 1.8 and 5.4 mg/L
concentrations stopped seed germination. In the greenhouse (semi-controlled conditions),
the 345.6 mg/L concentration of cinnamon essential oil stopped the seed germination of
Amaranthus retroflexus L. The concentration of essentials oils had a greater effect on weed
susceptibility than the type of oil used. However, cinnamon oil had drastic inhibitory
effects on germination.

Molecules 2021,26, 5299 11 of 13
The possible use of essential oils as natural herbicides to control different weeds for
the sustainable cropping system has been discussed in relation to their low persistence (due
to biodegradability and easy catabolism in the environment); they have no toxicity towards
vertebrates, fishes, birds, and mammals and are of importance in plant protection [68].
In conclusion, cinnamon is a suitable candidate for approval as a basic substance
with protective potential. In particular, it can be used in organic farming as a promising
alternative to chemical pesticides for use in plant protection, especially in preventive
treatments. The use of natural products is in line with the restriction on the use of chemical
pesticides and the principles of the EU’s Green Deal [69].
Author Contributions:
J.K. (Jolanta Kowalska), J.Ł. and J.T. designed and drafted the work. K.M.
and J.K. (Joanna Krzymi´nska) contributed to the revision of the manuscript. M.J. substantively and
technically adapted the final version of the manuscript to the requirements of the editorial office. All
authors have read and agreed to the published version of the manuscript.
Funding:
The funding body had no role in the design of the study; in the collection, analyses or
interpretation of data; in the writing of the manuscript; or in the decision to publish the results.
Institutional Review Board Statement: Not applicable.
Informed Consent Statement: Not applicable.
Data Availability Statement: Not applicable.
Acknowledgments:
This study was a part of the statutory activity of the Institute of Plant Protection—
National Research Institute in Poland. The project “Development of a strategy for the use of microor-
ganisms and natural products in organic farming” (No. EKO 01) was supported by the Polish Ministry
of Science and Higher Education. The work was prepared as part of the Eupresco BasicS project.
Conflicts of Interest: The authors declare no conflict of interest.
References
1.
Lankage, J. Cinnamon, tree that gave the name to the country and changed the course of history. J. Organ. Prof. Assoc. Sri Lanka
2013,28, 40–48.
2.
Hariri, M.; Ghiasvand, R. Cinnamon and chronic diseases. Drug discovery from mother nature. Adv. Exp. Med. Biol.
2016
,929,
1–25.
3. Wang, Y.-H.; Avula, B.; Nanayakkara, N.D.; Zhao, J.; Khan, I.A. Cassia cinnamon as a source of coumarin in cinnamon-flavored
food and food supplements in the United States. J. Agric. Food Chem. 2013,61, 4470–4476. [CrossRef]
4.
Tung, Y.-T.; Yen, P.-L.; Lin, C.-Y.; Chang, S.-T. Anti-inflammatory activities of essential oils and their constituents from different
provenances of indigenous cinnamon (Cinnamomum osmophloeum) leaves. Pharm. Biol.
2010
,48, 1130–1136. [CrossRef] [PubMed]
5.
Rao, P.V.; Gan, S.H. Cinnamon: A multifaceted medicinal plant. Evid. Based Complement. Altern. Med.
2014
,2014, 642942.
[CrossRef]
6.
United States Department of Agriculture; Agricultural Research Service. National Nutrient Database for Standard Reference
Release Legacy April 2018. Basic Report 02010, Spices, Cinnamon, Ground. Available online: https://Www.Ars.Usda.Gov/
Arsuserfiles/80400525/Data/SR-Legacy/SR-Legacy_Doc.Pdf (accessed on 13 May 2021).
7.
Senanayake, U.M.; Wijesekera, R.O.B. Chemistry of cinnamon and cassia. Cinnamon and cassia. The genus cinnamomum, 80–121.
In Medicinal and Aromatic Plants—Industrial Profiles; Ravindran, P.N., Ed.; CRC Press LLC: Boca Raton, FL, USA, 2004; p. 379.
8.
Perdones, A.; Vargas, M.; Atarés, L.; Chiralt, A. Physical, antioxidant and antimicrobial properties of chitosan-cinnamon leaf oil
films as affected by oleic acid. Food Hydrocoll. 2014,36, 256–264. [CrossRef]
9.
Sanla-Ead, N.; Jangchud, A.; Chonhenchob, V.; Suppakul, P. Antimicrobial activity of cinnamaldehyde and eugenol and their
activity after incorporation into cellulose-based packaging films. Packag. Technol. Sci. 2011,25, 7–17. [CrossRef]
10.
Sharifi-Rad, J.; Dey, A.; Koirala, N.; Shaheen, S.; El Omari, N.; Salehi, B.; Goloshvili, T.; Cirone Silva, N.C.; Bouyahya, A.; Vitalini,
S.; et al. Cinnamomum species: Bridging phytochemistry knowledge, pharmacological properties and toxicological safety for
health benefits. Front. Pharmacol. 2021,12, 600139. [CrossRef] [PubMed]
11.
Abraham, K.; Wöhrlin, F.; Lindtner, O.; Heinemeyer, G.; Lampen, A. Toxicology and risk assessment of coumarin: Focus on
human data. Mol. Nutr. Food Res. 2010,54, 228–239. [CrossRef] [PubMed]
12.
Azam-Ali, S. Practical Action. Cinnamon Processing. 2007. Available online: https://Core.Ac.Uk/Download/Pdf/48027458.Pdf
(accessed on 13 May 2021).
13. Cinnamon. Available online: https://Recipes.Fandom.Com/Wiki/Cinnamon (accessed on 12 May 2021).
14.
Wang, R.; Li, S.; Jia, H.; Si, X.; Lei, Y.; Lyu, J.; Dai, Z.; Wu, Z. Protective effects of cinnamaldehyde on the inflammatory response,
oxidative stress, and apoptosis in liver of Salmonella typhimurium-challenged mice. Molecules
2021
,26, 2309. [CrossRef] [PubMed]

Molecules 2021,26, 5299 12 of 13
15.
Yang, S.-K.; Yusoff, K.; Ajat, M.; Thomas, W.; Abushelaibi, A.; Akseer, R.; Lim, S.-H.E.; Lai, K.-S. Disruption of kpc-producing
Klebsiella pneumoniae membrane via induction of oxidative stress by cinnamon bark (Cinnamomum verum) essential oil. PLoS ONE
2019,14, e0214326. [CrossRef]
16.
Aljaafari, M.N.; Alali, A.O.; Baqais, L.; Alqubaisy, M.; Alali, M.; Molouki, A.; Ong-Abdullah, J.; Abushelaibi, A.; Lai, K.-S.; Lim,
S.-H.E. An overview of the potential therapeutic applications of essential oils. Molecules 2021,26, 628. [CrossRef] [PubMed]
17. Encyclopedia of Life EOL. Cinnamon. 2018. Available online: https://eol.org/pages/490672 (accessed on 12 May 2021).
18.
Jing, H.; Yudi, Z.; Zuobing, X.; Xuge, W. Preparation and properties of cinnamon-thyme-ginger composite essential oil nanocap-
sules. Ind. Crops Prod. 2018,122, 85–92. [CrossRef]
19.
Hajimonfarednejad, M.; Ostovar, M.; Raee, M.J.; Hashempurd, M.H.; Mayer, J.G.; Heydari, M. Cinnamon: A systematic review of
adverse events. Clin. Nutr. 2018,38, 594–602. [CrossRef]
20. Cinnamon Challenge. Available online: Https://En.Wikipedia.Org/Wiki/Cinnamon_Challenge (accessed on 13 May 2021).
21.
Grant-Alfieri, A.; Schaechter, J.; Lipshultz, S.E. Ingesting and aspirating dry cinnamon by children and adolescents: The
“cinnamon challenge”. Pediatrics 2013,131, 833–835. [CrossRef] [PubMed]
22. Georgakopoulou, E.A. Cinnamon contact stomatitis. J. Dermatol. Case. Rep. 2010,4, 28–29. [CrossRef] [PubMed]
23.
Vivas, A.P.M.; Migliari, D.A. Cinnamon-induced oral mucosal contact reaction. Open Dent. J.
2015
,9, 257–259. [CrossRef]
[PubMed]
24.
Deng, R. A review of the hypoglycemic effects of five commonly used herbal food supplements. Recent Pat. Food Nutr. Agric.
2012,4, 50–60. [CrossRef]
25.
Allen, C.M.; Blozis, G.G. Oral mucosal reactions to cinnamon-flavored chewing gum. J. Am. Dent. Assoc.
1998
,116, 664–667.
[CrossRef]
26.
Wilson, C.L.; Solar, J.M.; Ghaouth, A.E.; Wisniewski, M.E. Rapid evaluation of plant extracts And essential oils for antifungal
activity against Botrytis cinerea.Plant Dis. 1997,81, 204–210. [CrossRef]
27.
Montes-Belmont, R.; Carvajal, M. Control of Aspergillus flavus in maize with plant essential oils and their components. J. Food Prot.
1998,61, 616–619. [CrossRef]
28.
Ranasinghe, L.; Jayawardena, B.; Abeywickrama, K. Fungicidal activity of essential oils of Cinnamomum zeylanicum (L.) and
Syzygium aromaticum (L.) Merr et L.M. Perry against crown rot and anthracnose pathogens isolated from banana. Lett. Appl.
Microbiol. 2002,35, 208–211. [CrossRef]
29.
Chu, Y.L.; Ho, W.C.; Ko, W.H. Effect of Chinese herb extracts on spore germination of Oidium murrayae and nature of inhibitory
substance from Chinese rhubarb. Plant Dis. 2006,90, 858–861. [CrossRef]
30.
Barrera-Necha, L.L.; Bautista-Ba ´nos, S.; Flores-Moctezuma, H.E.; Rojas-Estudillo, A. Efficacy of essential oils on the conidial
germination, growth of Colletotrichum gloeosporioides (Penz.) Penz. and Sacc and control of postharvest diseases in papaya (Carica
papaya L.). Plant Pathol. J. 2008,7, 174–178. [CrossRef]
31.
Barrera-Necha, L.L.; Garduno-Pizana, C.; Garcia-Barrera, L.J. In Vitro antifungal activity of essential oils and their compounds on
mycelial growth of Fusarium oxysporum f. sp. gladioli (Massey) Snyder and Hansen. Plant Pathol. J. 2009,8, 17–21. [CrossRef]
32.
Nguyen, V.-N.; Seo, D.-J.; Park, R.-D.; Jung, W.-J. Antimycotic activities of cinnamon-derived compounds against Rhizoctonia
solani In Vitro. BioControl 2009,54, 697–707. [CrossRef]
33.
Yeole, G.J.; Teli, N.P.; Kotkar, H.M.; Mendki, P.S. Cinnamomum zeylanicum extracts and their formulations control early blight of
tomato. J. Biopestic. 2014,7, 110.
34.
Wang, Y.; Zhao, R.; Yu, L.; Zhang, Y.; He, Y.; Yao, J. Evaluation of cinnamon essential oil microemulsion and its vapor phase for
controlling postharvest gray mold of pears (Pyrus pyrifolia). J. Sci. Food Agric. 2014,94, 1000–1004. [CrossRef] [PubMed]
35.
Kowalska, J.; Tyburski, J.; Krzymi ´nska, J.; Jakubowska, M. Cinnamon powder: An In Vitro and In Vivo evaluation of antifungal
and plant growth promoting activity. Eur. J. Plant Pathol. 2020,156, 237–243. [CrossRef]
36.
Oliveira, M.S.; Costa, W.A.; Pereira, D.S.; Botelho, J.R.S.; Menezes, T.O.A.; Andrade, E.H.A.; Silva, S.H.M.; Filho, A.P.S.S.; Carvalho
Junior, R.N. Chemical composition and phytotoxic activity of clove (Syzygium aromaticum) essential oil obtained with supercritical
CO2.J. Supercrit. Fluids 2016,118, 185–193. [CrossRef]
37.
Sernaite, L.; Rasiukeviˇci
¯
ut
˙
e, N.; Valiuškait
˙
e, A. The extracts of cinnamon and cloves as potential biofungicides against strowbery
grey mould. Plants 2020,9, 613. [CrossRef] [PubMed]
38.
Allam, S.A.; Elkot, G.A.; Elzaawely, A.A.; El-Zahaby, H.M. Potential control of postharvest gray mold of pomegranate fruits
caused by Botrytis cinerea.Environ. Biodivers. Soil Secur. 2017,1, 145–156. [CrossRef]
39.
Yan-Feng, X.; Meng, Z.; Zhong-Qiang, Q.; You-Qin, L.; Zhiqi, S.; Jian, C. Cinnemaldehyde promotes root branching by regulating
endogenous hydrogen sulfide. J. Sci. Food Agric. 2015,96, 909–914. [CrossRef]
40.
Perina, F.J.; Lage De andrade, C.C.; Intra Moreira, S.; Nery, E.M.; Ogoshi, C.; Alves, E. Cinnamomun zeylanicum oil and trans-
cinnamaldehyde against alternaria brown spot in tangerine: Direct effects and induced resistance. Phytoparasitica
2019
,47,
575–589. [CrossRef]
41. Haddi, K.; Faroni, L.R.A.; Oliveira, E.E. Cinnamon oil. In Green Pesticides Handbook. Essential Oils for Pest Control; Nollet, L.M.L.,
Rathore, H.S., Eds.; CRC Press: New York, NY, USA, 2017; Chapter 7; p. 570. [CrossRef]
42.
Udomlak, S.; Vichai, H.; Walairut, C.; Panuwat, S. Antifungal activity of cinnamon oil and their synergistic against postharvest
decay fungi of grape In Vitro. Kasetsart J. Nat. Sci. 2008,42, 169–174.

Molecules 2021,26, 5299 13 of 13
43.
Christian, E.J. Plant Extracted Essential Oils as a Contact Fungicide Seed Treatment for Organic Corn. Master’s Thesis, Iowa State
University, Ames, IA, USA, 2007. [CrossRef]
44.
Yeole, G.J.; Kotkar, H.M.; Teli, N.P.; Mendki, P.S. Herbal fungicide to control fusarium wilt in tomato plants. Biopestic. Int.
2016
,
12, 25–35.
45.
Xing, F.; Huijuan, H.; Selvaraj, J.N.; Yueju, Z.; Lu, Z.; Xiao, L.; Yang, L. Growth inhibition and morphological alterations of
Fusarium verticillioides by cinnamon oil and cinnamaldehyde. Food Control 2014,46, 343–350. [CrossRef]
46.
Velluti, A.; Sanchis, V.; Ramos, A.J.; Marín, S. Effect of essential oils of cinnamon, clove, lemon grass, oregano and palmarosa on
growth of and fumonisin B1 production by Fusarium verticillioides in maize. J. Sci. Food Agric. 2004,84, 1141–1146. [CrossRef]
47.
Sarkhosh, A.; Schaffer, B.; Vargas, A.I.; Palmateer, A.J.; Lopez, P.; Soleymani, A. In Vitro evaluation of eight plant essential oils for
controlling Colletotrichum, Botryosphaeria, Fusarium and Phytophthora fruit rots of avocado, mango and papaya. Plant Prot. Sci.
2018,54, 153–162. [CrossRef]
48.
Horváth, A.; Kovács, B.; Nagy, G. Application of mint and cinamon against fusarium disease of winter wheat. Episteme Czasopismo
Naukowo-Kulturalne 2013,18, 297–304.
49.
Jiang, Z.; Jiang, H.; Xie, P. Antifungal activities against Sclerotinia sclerotiorum by Cinnamomum cassia oil and its main components.
J. Essent. Oil Res. 2013,25, 444–451. [CrossRef]
50.
Al-Taisan, W.A.A.; Bahkali, A.H.; Elgorban, A.M.; El-Metwally, M.A. Effective influence of essential oils and microelements
against Sclerotinia sclerotiorum.Int. J. Pharmacol. 2014,10, 275–281. [CrossRef]
51.
Moraes, S.P.C.B.; Bucker, M.W.; Bucker, M.W.; De Resende, C.G.; Maciel, K.S.; De Lima, P.A.M. Cinnamon and citronella essential
oils in the In Vitro control of the fungi aspergillus sp. and Sclerotinia sclerotiorum.Afr. J. Agric. Res.
2018
,13, 1811–1815. [CrossRef]
52.
Combrinck, S.; Regnier, T.; Kamatou, G.P.P. In Vitro activity of eighteen essential oils and some major components against
common postharvest fungal pathogens of fruit. Ind. Crops Prod. 2011,33, 344–349. [CrossRef]
53.
Kyu Kyu Win, N.; Jitareerat, P.; Kanlayanarat, S.; Sangchote, S. Effects of cinnamon extract, chitosan coating, hot water treatment
and their combinations on crown rot disease and quality of banana fruit. Postharvest Biol. Technol. 2007,45, 333–340.
54.
Ojaghian, M.R.; Chen, Y.; Chen, S.; Cui, Z.-Q.; Xie, G.L.; Zhang, J. Antifungal and enzymatic evaluation of plant crude extracts
derived from cinnamon and rosemary against sclerotinia carrot rot. Ann. Appl. Biol. 2014,164, 415–429. [CrossRef]
55.
Mohammad, R.; Ojaghian, X.; Liang, Z.; Xiaolin, L.; Guan-Lin, X.; Jingze, Z.; Li, W. Effect of E-Cinnamaldehyde against Sclerotinia
sclerotiorum on potato and induction of glutathione s-transferase genes. Physiol. Mol. Plant Pathol. 2015,91, 66–71. [CrossRef]
56.
Fawzi, E.M.; Khalil, A.A.; Afifi, A.F. Antifungal effect of some plant extracts on Alternaria alternata and Fusarium oxysporum.Afr. J.
Biotechnol. 2009,8, 2590–2597.
57.
Imad, H.H.; Huda, J.A.; Ghaidaa, J.M. Evaluation of antifungal and antibacterial activity and analysis of bioactive phytochemical
compounds of Cinnamomum zeylanicum (Cinnamon Bark) using gas chromatography-mass spectrometry. Orient. J. Chem.
2016
,32,
1769–1788. [CrossRef]
58.
Bravo, C.M.; Preston, G.M.; Renier, A.L.; Van Der Hoorn, R.A.; Flanagan, N.A.; Townley, H.E.; Thompson, I.P. Enhancing cinnamon
essential oil activity by nanoparticle encapsulation to control seed pathogens. Ind. Crops Prod. 2018,124, 755–764. [CrossRef]
59.
Il-Kwon, P.; Hoi-Seon, L.; Sang-Gil, L.; Ji-Doo, P.; Young-Joon, A. Insecticidal and fumigant activities of Cinnamomum cassia
bark-derived materials against Mechoris ursulus (Coleoptera: Attelabidae). J. Agric. Food Chem. 2000,48, 2528–2531.
60.
Pobo˙
zniak, M.; Grabowska, D.; Olczyk, M. Effect of orange and cinnamon oil on the occurrence and harmfulness of Thrips tabaci
Lind on onion—Preliminary results. Acta Horticult. Regiotect. 2016,19, 13–14. [CrossRef]
61.
Bueyong, P.; Myung-Ji, L.; Sang-Ku, L.; Sang-Bum, L.; In-Hong, J.; Se-Keun, P.; Ye-Jin, J.; Hoi-Seon, L. Insecticidal activity of
coriander and cinnamon oils prepared by various methods against three species of agricultural pests (Myzus persicae, Tetranychus
urticae and Plutella xylostella). Appl. Biol. Chem. 2017,60, 137–140. [CrossRef]
62.
Plata-Rueda, A.; Campos, J.M.; Rolim, G.S.; Martínez, L.C.; Santos, M.H.D. Terpenoid constituents of cinnamon and clove
essential oils cause toxic effects and behavior repellency response on granary weevil, Sitophilus granarius.Ecotoxicol. Environ. Saf.
2018,156, 263–270. [CrossRef]
63.
Jumbo, L.O.V.; Faroni, L.R.A.; Oliveira, E.E.; Pimentel, M.A.; Silva, G.N. Potential use of clove and cinnamon essential oils to
control the bean weevil, Acanthoscelides obtectus say in small strong units. Ind. Crops Prod. 2014,56, 27–34. [CrossRef]
64.
Soon-Il, K.; Jung-Yeon, R.; Do-Hyoung, K.; Han-Seung, L.; Young-Joon, A. Insecticidal activities of aromatic plant extracts and
essential oils against Sitophilus oryzae and Callosobruchus chinensis.J. Stored Prod. Res. 2003,39, 293–303. [CrossRef]
65.
Szelényi, M.O.; Erdei, A.L.; Jósvai, J.K.; Radványi, D.; Sümegi, B.; Vétek, G.; Molnár, B.P.; Kárpáti, Z. Essential oil headspace
volatiles prevent invasive box tree moth (Cydalima perspectalis) oviposition—Insights from electrophysiology and behaviour.
Insects 2020,11, 465. [CrossRef]
66.
Kong, J.-O.; Lee, S.-M.; Moon, Y.-S.; Lee, S.-G.; Ahn, Y.-J. Nematicidal activity of cassia and cinnamon oil compounds and related
compounds toward Bursaphelenchus xylophilus (Nematoda: Parasitaphelenchidae). J. Nematol. 2007,39, 31–36. [PubMed]
67.
Orzeszko-Rywka, A.; Rochalska, M.; Lewicka, J. Wpływ zaprawiania nasion olejkiem cynamonowym i olejkiem z drzewa
herbacianego na wschody polowe i plonowanie pietruszki i sałaty. J. Agric. Eng. Res. 2012,57, 52–58.
68.
Cavalieri, A.; Caporali, F. Effect of essential oils of cinnamon, lavender and peppermint on germination of mediterranean weeds.
Allelopath. J. 2010,25, 441–451.
69.
The EU Green Deal—A Roadmap to Sustainable Economies. Available online: https://www.switchtogreen.eu/the-eu-green-
deal-promoting-a-green-notable- circular-economy/ (accessed on 3 August 2021).