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THE EFFECTIVENESS OF LEMONGRASS (CYMBOPOGON CITRATUS) AND
OREGANO (ORIGANUM VULGARE) AS REPELLENT AGAINST MOSQUITOES
A Capstone Project
Presented to the Faculty of Senior High School Department
Gadu National High School
Gadu, Solana, Cagayan
In Partial Fulfilment
Of the Requirements for the Strand
Science, Technology, Engineering and Mathematics
By:
De Leon, Victor T.
Tagacay, Dexter R.
de Salmos, Marina R.
Pasicolan, Sandara A.
Santiago, Rose Marie D.
May 2022
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Chapter I
The Problem and Its Background
Introduction
Mosquitoes are the deadliest critter in the entire animal kingdom and human world, as
these carry serious diseases and viruses, which can be easily transferred to human through
bites. These tiny insects are the primary vectors for major human diseases such as yellow
fever, malaria, dengue, zika and west nile virus, which together infect hundreds of humans
worldwide and kill millions each year. These mosquito-transmitted diseases particularly
dengue continues to cause great problem to the public health situation of tropical countries
like the Philippines. According to the Department of Health, in 2019 there was a total of 437,
563 reported cases and 1, 689 deaths. This reflects a noticeable increase from the previous
year with 216, 190 cases and 1, 083 deaths.
Scientists believed that mosquitoes originated in South Africa and eventually spread
to the rest of the world (Sharkaram, 2022). Mosquitoes have evolved to the point where there
are approximately 2,700 different species. Different species of mosquitoes have different
breeding habits but the majority of them prefer to lay their eggs in or near water. Any
stagnant water body near the house is an invitation for female mosquitoes to lay eggs in it.
These mosquitoes develop dengue fever. Mild dengue fever can cause muscle pain, bone
pain, joint pain, rashes, high fever, throbbing headache, vomiting and nausea. Severe dengue
fever can cause internal bleeding and organ damage. Blood pressure can drop to dangerous
levels, causing shock. In some cases, severe dengue fever can lead to death.
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As humanity experiences relentless pressures from disease-carrying mosquitoes in
many parts of the world, there is an urgent need for new tools to use because these keep
getting scarier. Among of the methods of mosquito control, synthetic insecticides are the
most popular. However, as a result of long-term use of these insecticides, high resistant
mosquitoes and heavy environmental pollution appear (Yang et al., 2017). Thus, eco-friendly
prevention measures are taken into the agenda.
Plant-based repellents have been used for generations in traditional practice as personal
protection measures against host-seeking mosquitoes. Plants produce chemicals that act as
natural deterrents to mosquitoes and other insects. Recently, commercial repellent products
containing plant-based ingredients have gained increasing popularity among consumers, as
these are commonly perceived as “safe”. These natural repellents are the made of
Lemongrass (Cymboppogon citratus) and Oregano (Origanum vulgare).
Lemongrass (Cymboppogon citratus) is a popular herb usually used in cooking, in the
Philippines its local name is “Tanglad”. Its essential oil is known to be an excellent mosquito
repellent, as it contain the compound citronella that helps to mask the scents that mosquitoes
rely on to target hosts which is carbon dioxide and lactic acid. On the other hand, some
gardeners plant oregano (Origanum vulgare) in the garden to repel pests such as mosquitoes,
and others claim the essential oil is a mosquito repellent. Scientific evidence to support this
claim is scarce, but oregano does contain two chemicals with known repellent properties such
as carvacrol and thymol reported being highly effective in repelling mosquitoes.
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Lemongrass and oregano are both easy to grow plant, which can grow in the backyard
or even in a limited space. With that, the researchers gained interest in utilizing the plants as
mosquito repellent.
Mosquitoes are likely to stay away from the plant distinct aroma. It is then important
to know which natural repellent work best to repel mosquitoes and reduce the risk of getting a
disease carried by it. Therefore, this study aims to evaluate the effectiveness of Lemongrass
(Cymbopogon citratus) and Oregano (Origanum vulgare) as mosquito repellent and to
determine which of the two is more effective.
Conceptual Framework
Plant based repellents have been found to effectively repel insects which contributes
to decreased contagious disease proliferation. In fact, these have been used for generations in
traditional practice as a personal measure against host- seeking mosquitoes. Now, these kind
of mosquito repellent are patronized in the market and are preferred than chemical based
mosquito repellents.
Essential oils belonging to various plant species such as Lemongrass and Oregano and
their mixtures have been seen to act as effective repellent against various mosquitoes. Many
factors are considered in proving its effectiveness such as the number of mosquitoes died,
time of death of mosquitoes, and when it can kill other insects such as flies and cockroaches.
Furthermore, a good and slight strong aroma from these Lemongrass and Oregano
mosquito repellents add to its effectiveness because mosquitoes have strong sense of smell
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and they hate strong scents of these plants. These also have components that are applicable to
all skin type unlike chemical repellent that are actually are toxic against the skin and nervous
system that causes rashes, swelling, eye irritation, and other health problems.
Both lemongrass and Oregano are effective plant based repellent. However these
plants have different components or properties. It is therefore necessary to determine which is
more effective and safer for human consumption. Such reasons form as the drive for the
researcher to undertake this investigation.
Research Paradigm
INPUT
OUTPUT
PROCESS
-Extraction
-Lemongrass
-Oregano leaves
-Oil
-Mixture of oil,
water, and alcohol
-Application
Solution
of
-A more effective
plantbased
mosquito repellent
- 1. Research Paradigm
Figure
The paradigm shows the input, process, and output approach of the study. The inputs
are the independent variables, which include the lemongrass, oregano leaves, and oil. The
process includes the extraction of lemongrass and oregano, mixture of oil, water and alcohol,
and the application of the solution into the cage also known as the experiment. Lastly, the
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output is the mosquito repellent that is proven to be more effective based on the number of
mortality of mosquito and time.
Statement of the Problem
The study aims to evaluate the effectiveness of Lemongrass (Cymbopogon citratus)
and Oregano (Origanum vulgare) as mosquito repellent and to determine which of the two is
more effective. Specifically, it seeks to answer the following:
1. How many mosquitoes died in Lemongrass, Oregano, and Isopropyl Alcohol spray?
2. How quick does the three treatments work in killing or repelling mosquitoes?
3. Is there a significant difference between the effects of lemongrass and oregano when tested
in an experiment?
4. Which of the two treatments is more effective as mosquito repellent?
Research Hypothesis
The following null hypothesis was tested in the study:
1. There is no significant difference on the effects of Lemongrass (Cymbopogon citratus) and
Oregano (Origanum vulgare) solution in repelling mosquitoes.
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Scope and Delimitation
The main objective of the study is to evaluate the effectiveness of Lemongrass
(Cymbopogon citratus) and Oregano (Origanum vulgare) as mosquito repellent and to
determine which of the two is more effective. The study includes the number of mortality and
time of death of mosquitoes. This study is limited to 30 mosquitoes per cage and the
experiment is carried through 5 repetitions. Moreover, this study used of observation to
gather quantitative data where researchers act as complete participants. This is conducted in a
house at Zone 6, Ubong, Solana, Cagayan with a balance temperature and humidity during
the second semester of school year 2021- 2022.
Significance of the Study
The results of this study may prove useful to:
Students. They may be taught on how to make an effective mosquito repellent in easy
steps instead of buying synthetic ones.
Teachers. They may discuss the importance of plant based repellent such as
lemongrass and oregano in repelling mosquito and implement a project using those plants to
be utilized during rainy seasons in school to reduce the risk of students in getting disease.
Parents. They can make their effective DIY lemongrass or oregano extract as
mosquito repellent at home to save more money.
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Business Owners. They may use this as an opportunity to learn more about the
effectiveness of plant based repellent and sell their improved product in the market.
Future Researchers. They may use this study as a basis to enhance their research by
adding more variables and other supplementary materials which will contribute to the
existing information about mosquito repellent.
Definition of Terms
To fully understand the terms used in this study, the following terms are briefly and
operationally defined:
Aedes aegypti. It is a dark coloured mosquito that can spread dengue fever,
chinkungunya, zika fever, and others. Typically four days after being hit by this infected
mosquito, a person will develop viremia, a condition in which there is high level of dengue
virus in the blood. In this study, Aedes aegypti is the subject which is used for the
experiment.
Dengue. It is disease transmitted by mosquitoes to human causing sudden fever and
acute pains in the joint.
Effectiveness. It is the quality of producing the intended or desired result. In this
study, the effectiveness of Lemongrass and Oregano is evaluated.
Experiment. It is the scientific procedure undertaken to make a discovery about the
effectiveness of lemongrass and oregano as mosquito repellent.
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Extraction. It is the process of obtaining or removing the lemongrass or oregano oil
from its leaves. In this study, the lemongrass and oregano were mixed with oil and steamed
for considerable time. Leaves were separated using strainer.
Lemongrass (Cymbopogon citratus). It is stalky plant with a fresh, lemony aroma,
and a citrus flavour used for health, cooking, and most importantly for repelling mosquitoes.
It is one of the variables that was used and tested in this study.
Mixture. It is the substance made by mixing or blending lemongrass and oregano oil
with alcohol and distilled water together.
Mortality. It refers to the death of mosquito. In this study, the mortality of
mosquitoes was recorded to help find the effectiveness of the two plant- based repellents.
Mosquito Repellent. It is a solution that deters mosquitoes from approaching or
settling. In this study, plant based repellents were used such as Lemongrass and Oregano.
Oregano (Origanum vulgare). It is a bushy perennial mint with leaves that are used
as a seasoning but more importantly, as a mosquito repellent. It is one of the independent
variables that was used and manipulated by the researcher to determine if it causes a change
in mosquito.
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Chapter II
Review of Related Literature
Lemongrass
1.1 Insecticidal Property
Lemongrass is an ornamental grass that has insecticidal properties which helps in
deterring insects such as mosquito. Eden et al. (2020) stated that the insecticidal property of
lemongrass is accredited to the various secondary metabolites, such as bioactive cyclic and
acyclic terpenes which disrupt the neurotransmitter in insects. Other secondary metabolites,
such as alkaloids, flavonoids, and carotenoids, have been found in lemongrass extracts,
indicating potential as a bio- insecticide. In addition, tannin compounds maybe used as
inhibitors of the enzyme activities in insect digestion (Rahayu & Mairawita, 2018). Eden et al
(2020) also considered Citral (geranial and neral mixture) for the insecticidal activity of
lemongrass, resulting from its interaction with oxidative stress and intracellular oxygen
radicals (Sanches, 2017).
Aside from that, lemongrass has a poisonous nature (desiscant) which contains
acetylcholine. This chemical compound in the lemongrass extract if accumulated is like
contact poison that can give death due to continuous loss of fluids, so that the body of the
mosquito lacks of fluids (Wells, 2019). At first this insecticide enters the insect's body
through the surface of the body, especially the thin part of the skin, for example in parts of
the area that are related to segments, indentations formed from the body's plates, at the base
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of the hair and respiratory tract. Toxins that have been attached to insects will immediately
enter the body and this is where poisoning begins (Pinheiro et al, n.d).
1.2 Antimicrobial Potential
Lemongrass oil and extract are effective against a wide variety of disease-causing
microbes. LEO has been used as an antibacterial (Silva et al., 2020), antifungal (Lee at al.,
2020) and an antiviral (Silva et al., 2020) agent on many occasions. Similarly, Zulfa et al.
(n.d.) stated that lemongrass extract inhibited the growth of Bacillus cereus, Escherichia coli,
Klebsiella pneumoniae, Candida albicans, and Staphylococcus aureus with different levels of
susceptibility. The EO components with different functional groups exhibit different levels of
antimicrobial potential, where phenols and aldehydes have the highest activities, while esters
and hydrocarbons have the least. However, the antimicrobial activity of lemongrass is
extensively attributed to the citral (aldehyde) present in its oil (Alagawany et al., 2021),
(Sharma et al., 2019). Yet, when a mixture of principal oil components and the whole EO
were tested, the whole EO exhibited enhanced antimicrobial efficacy.
Singh et al. (2017) studied 1114 strains of different microbes including molds, yeasts,
and bacteria from 29 genera and 105 species, and circled out about 425 LEO-sensitive
microbial isolates. It is suggested that a low concentration of Lemongrass essential oil
inhibits microbial growth and development (bacteriostatic, fungistatic, and virustatic), while a
higher concentration renders irreversible destruction leading to microbial death (bactericidal,
fungicidal, and virucidal)(Lu et al., 2017).
Furthermore, one study addressed that
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Lemongrass essential oil has antimicrobial potential against 42 microorganisms, including 20
bacteria, 15 fungi, and 7 yeasts (Negrelle & Gomes, 2017).
1.3 Antibacterial Activity
The antibacterial characteristic of LEO is well established (Cai et al., 2019), (Mishra
et al., 2018). Dewi et al. (2021) found out that the bacteriostatic and bactericidal
characteristics of LEO primarily depend on the bacteria and oil concentration. However,
several other factors, such as oil composition, extraction method, plant developmental stage,
and environmental variables including temperature can influence the oil’s effectiveness.
Therefore, lemongrass oils from different species might exhibit effects of different nature and
intensity. Nevertheless, the host organism can also decide oil effectiveness to a certain extent
depending on its morpho-physiological attributes (Swammy et al., 2017). Hence, Devi et al.
(2020) discussed that EOs react differently with Gram-positive and Gram-negative bacteria,
owing to their dissimilar cell-wall. Additionally, Costa et al. 2019 examined Cymbopogon
flexuosus EO (µL mL−1) against Listeria monocytogenes, Staphylococcus aureus, and
Salmonella typhimurium and determined their MICs and MBCs as of 3.9 µL mL−1 each. The
MICs of citral against Cronobacter sakazakii strains ranged from 0.27 to 0.54 mg/mL.
Scanning electron microscopy analysis further confirmed that C. sakazakii cell membranes
were damaged by citral (Shi et al., n.d.).
1.4 Effectiveness as Repellent
Billings (2020) as supported by a Thai study published on the Asian Pacific Journal of
Tropical Biomedicine stated that planting lemongrass somewhere heavily infested homes
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won’t work. That’s because even though it contains citronella, it doesn’t release all its oil to
the environment when it it’s alive. Burning the lemongrass also doesn’t guarantee that
mosquitoes will leave. Instead it will irritate nose and eyes. However, lemongrass spray and a
combination of lemongrass oil with other essential oils can help deter mosquitoes when
applied thoroughly.
There appears to be a strong evidence that lemongrass has shown high level of
effectiveness against Aedes aegypti. The study of Zulfikar et al. (2019) entitled “The Effect of
Lemongrass (Cymbopogon nardus) extract as Insecticide against Aedes aegypti” proved that
lemongrass extract can kill the mosquito by fogging as the mortality of mosquitoes reached
100% on the forth replication and the average number of dead mosquitoes by using
lemongrass extracts was 18 out of 20 which equates to 90%. It also suggested that lemongrass
leaves and stems can be used as a substitute for malation in carrying out fogging activities,
besides being cheap and environmentally friendly the smell is also liked by the community.
Furthermore, it is recommended to use extracts in oil preparations rather than liquid due to
their immediate solubility in diesel fuel.
Apart from that, the study of Trivedi et al (2018) revealed that the volume of smoke
exhibited by the mosquito repellent sticks shown successful results and it explains that
natural insecticidal preparations are always effective than synthetic repellents. During the
burning of herbal mosquito stick, it was shown that up to 90% of the mosquito number was
greatly reduced. The formulations contain lemongrass (Cymbopogon spp.) and neem oil
emerged as best composition with good aroma oil like geranium and Palma Rosa. It
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concluded that lemongrass essential oil, alone or in combinations with those obtained from
other mosquito repellent plant species, could be potentially used for the preparation of
mosquito repellent products. These could be in form of spray, cream, liquidator, coil, candle
and sticks, and could be prepared using suitable carries/solvents/diluents, to get better
protection from mosquito bites. Such formulations could help in reducing the harmful effects
of synthetic mosquito repellents on human health. Moreover, the formulation is safe, ecofriendly, cheap, easy to use and has maximum repellence against mosquitoes.
1.5 Side Effects of Lemongrass
Sissons (2019) stated that lemongrass oil may irritate the skin and cause a rash due to
its strong components. She suggested to avoid applying lemongrass oil to skin if a person has
allergies or skin conditions such as eczema or broken/ damaged skin. She also mentioned that
it is necessary to do a skin patch test on a small area of skin and wait 24 hours to see if the
reaction appears before applying the diluted oil more liberally.
Aside from that, lemongrass oil can cause damage and burning into the area of eyes,
ears, nose, and mucous membranes (Johnson, 2019). The oil can corrode tissue, causing
scarring to the sensitive body part. For this reason, it is best not to use it on the face or put
into bathwater.
Additionally, the Web MD (n.d.) stated that lemongrass oils have some toxic effects,
such as lung problems after inhaling lemongrass and a fatal poisoning after a child swallowed
a lemongrass oil- based insect repellent.
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Oregano
1.1 Insecticidal Property
Oregano oil is considered as an excellent insect repellent. According to Simangan
(2017), the plant products of phytochemicals were used as insecticides for killing mosquitoes
or as repellent protection against mosquito bites. Phytochemicals obtained from the whole
plant or specific part of the plant by extraction with different types of solvent such as
aqueous, methanol, chloroform, benzene, and acetone depending on the polarity of the
phytochemical.
Moreover, it has been revealed that essential oil derived from Oregano plants contains
thymol and carvacol which make it effective pest control against houseflies and moths along
with mosquitoes (Green Décor, 2017). Carvacrol and Thymol, the two main phenols that
constitute to about 78- 85 % of oregano essential oil, are principally responsible for their
insecticidal property. Carvacol has a characteristic of pungent, warm odor of oregano which
mosquitoes hate the most.
In addition, other minor constituents such as monoterpene hydrocarbons γ- terpinene
and ρ- cymene also contribute to the insecticidal property of oregano.
1.2 Antibacterial Property
The main components of oregano essential oil are carvacrol and thymol. These two
components have antibacterial properties. In study of Del Valle et al. (2019), it was found out
that carvacrol and thymol prevented various strains of Staphyloccus aureus (S. aureus)
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bacteria from developing in meat and dairy products, suggesting that it could help control
bacterial growth in foods.
Amid growing concerns about diseases becoming resistant to antibiotics, researchers
carried a lab tests to investigate the effects of oregano oil on various microbes that do not
respond to other drugs. The study of Lu et al. (2018) revealed that the oil showed “significant
antibacterial activity” against 11 such microbes. This suggests that substances in oregano
could play a role in fighting diseases that no longer respond to antibiotics. While tests
indicate that compounds in oregano may have antibacterial properties, it does not mean that
eating oregano will prevent infections.
Additionally, research led by University Tun Hussein showed that oregano oils are
able to fight bacteria. In the 24 well cell culture plates, treatment with oregano essential oil at
a concentration of 2 mg/ml resulted in a small reduction in biofilm production in the bottom
of the wells. S.mutans biofilm accumulation at the bottom of the wells in the 24 well cell
culture plates was almost totally prevented by oregano essential oil at concentrations of
4mg/ml, 6mg/ml, 8mg/ml, and 10mg/ml (Badekova et al., 2021).
According to another researcher, thymol and carvacrol monoterpenes derived from
oregano essential oil have excellent bactericidal and antibiotic filtration action against
S.mutans, suggesting that these could be used as a green option to prevent dental caries.
1.3 Anti- inflammatory Activity
The individual components of essential oil of oregano have been studied to better
understand their effect on inflammation. For example, Lima et al. (2017) demonstrated that
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carvacrol exerts anti-inflammatory activity on a typical mice inflammation model. When
carvacrol was administrated to mice (at 50 and 100 mg/kg), presenting paw edema, the levels
of IL-1β and prostaglandin E2 (PGE2) prostaglandins were diminished. The reduction on the
mRNA expression of IL-1β and cyclooxygenase-2 (COX-2) might be responsible for the
effects mentioned. On the other hand, the levels of the cytokine IL-10 in the swollen paw
were improved by carvacrol. So, the anti-inflammatory effect of carvacrol is due to the
reduction of pro-inflammatory mediators but also to the increasing of anti-inflammatory
cytokines (IL-10). Carvacrol has also showed the ability to prevent obesity in mice by
modulating expression of genes involved in inflammation and to attenuate induced liver
injury and ulcer in rats (Rajan et al., 2017). Alberti et al. (2017) also stated that other EOs
components, such as p-cymene and β-caryophyllene have also demonstrated antiinflammatory properties.
The studies mentioned above indicate that diverse oregano species might be used as
anti-inflammatory agents and could be used in formulations for the prevention or the
treatment of inflammation-related diseases. Nevertheless, and since the EOO might exert
toxic effect on cells, several in vivo and clinical studies are needed before the EOs can be
used as an alternative to treat inflammation (López et al., 2017).
1.4 Effectiveness as Repellent
The study of Antero et al (2021) revealed that oregano can be used as mosquito
repellent. It showed that each candle containing higher concentrations of leaf extract provided
high level of mosquito repelling action against mosquito and have shown greater results than
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the lower concentration. The more concentrated it is, the better the mosquito repellent
activity. This was supported by Sharififard (2018) where he considered oregano as excellent
mosquito repellent due to its active component like carvacol and thymol. This coincides with
the study of Bouguerra et al. (2019) and Santos et al. (2018) where oregano oil can be
exploited as bio- insecticide for vector control and was only repellent to mosquitoes, but also
to other insects. However, a mosquito repellent that has any relation to fragrance has poor life
span.
In addition to the aforementioned study, Sharififard et al (2018) revealed that oregano
40% exhibited more repellency compared to commercial insect repellent sticks containing
33% DEET. The high concentration ἃ- terpinene may be responsible for the oil’s repellency.
Further studies are warranted to confirm the effectiveness of oregano essential oil in personal
protecting against bed bug biting.
Lastly, the findings of Benaid (2019) showed that candle repellent with the
combination of oregano oil extracts and lemongrass are more effective repellent than candles
with lemongrass oil or oregano oil extract only. Also, in 15 minutes, 100% of the mosquitoes
inside the experiment aquarium repelled with candles consists of the combination of oregano
and lemongrass; and the degrees of repellency of the treatments studied are significantly
different among each other whether 5, 10, and 15 minute- experiment.
1.5 Side Effects of Oregano
The Drugs and Lactation Database (2021) mentioned that even though oregano oil is
usually well- tolerated, it can still pose threats to human health. This may be due in part of
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thymol, one of the phenols it contains (Whelan, 2018). In high doses, thymol is a mild irritant
which might affect the skin and may lead to cardiac and respiratory collapse, convulsions,
and even coma. It can also cause internal organs and if intake may lead to gastrointestinal
distress.
Besides, oregano oil may lead to hypoglycemia. The carvacrol in oregano could be
responsible for this effect. In rat studies of Bayramoglu et al. (2013), it was found to show
reduction in serum glucose level. Thought this could be good news, individuals who are
already in medications to lower blood sugars may experience hypoglycemia, a disease
characterized by an excessive low blood sugar levels (Tadimalla, 2022). Similarly, Talpur et
al. (n.d.) stated that oregano can impact glucose sensitivity. It is then suggested to avoid
taking high amount of oregano products when on diabetes medication as it may further
accentuate the effects.
There is no doubt oregano oil is beneficial to human health. But taking it in excess
can have detrimental effects (Tadimalla, 2022).
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Chapter III
Methodology
This chapter contains the methodologies that are utilized in the conduct of the study.
It includes the research design, locale of the study, respondents and sampling procedure,
research instrument, data gathering procedure, and analysis of data.
Research Design
This study used experimental design to arrive at the quantitative components of the
study. The experiment was done in order to find the effectiveness of lemongrass and oregano.
The researchers observed the effectiveness by listing the mosquitoes died after spraying
lemongrass and oregano solution. This research followed the scientific procedure of Zulfikar,
Wiwit Aditama and Frans Yosep Sitepu (2019) in their study.
Locale of the Study
The study was conducted in a house at Zone 6, Ubong, Solana, Cagayan which is a
place with a balance temperature and humidity and free from any disturbance. It is situated in
the Western portion of the municipality of Solana. This study was conducted during the
second quarter of the second semester of school year 2021- 2022.
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Respondents and Sampling Procedure
The respondents are the researchers from the Grade- 12 Science, Technology,
Engineering, and Mathematics (STEM) strand who are conducting this study. They all live in
the same barangay. Two belong to Zone 4, another 2 for Zone 6, and 1 for the Zone 1 that
yielded to a total of 5 Grade 12 researcher- respondent. They are ones who performed the
experiment and at the same time observed and recorded the result since the study is
experimental.
Meanwhile, the subject of the study is the mosquitoes. These mosquitoes are reared in
the oviposition cup and collected using the pipettes in a span of a week and a half.
The sampling procedure in this study is convenience sampling where mosquitoes
were collected by the researchers based on convenience.
Research Instrument
The research instrument that was used in this study is observation. The solution of
Lemongrass, Oregano, and the Alcohol were applied or sprayed in a cage. After that,
researchers observed the mosquito and recorded the number of mortality of mosquito as well
as the time. Every detail was listed in a table. The observation was strictly done and camera
was present to record everything which serves as a proof and will be used just in case
uncertainty happens.
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Preparation of Materials for Experiment
Collection and Rearing of Mosquitoes
The procedure from the Science for Global Goals (2018) was utilized in this study.
1. The 15 Oviposition cups were prepared and labeled with its corresponding name, exact
location, date, and time. Three small holes were poked in each cup to drain the excess water.
The holes were 2/3 of the way up from the bottom of the cup.
2. The 15 Oviposition Substrates were prepared. Popsicle sticks served as substrate and the
tips of each stick were labeled. Each stick was placed inside the corresponding cup.
3. Each cup were filled with water about 2/3 of the way up. Excess water was drained out the
holes. There were plants within a 5 foot radius of cup.
4. Each cup was observed and checked every day and refilled with water.
5. After 7 days, the germination substrate was removed out of the cup and eggs were
collected. Water was checked for any larva moving around. Larvae in the water was taken
and moved into the new container.
Extraction of Lemongrass Oil
Materials:

Lemongrass

Stainless bowl
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
Sunflower oil

Container

Mortar and pestle

Strainer
Lemongrass was chopped into small pieces and moved into a stainless bowl to rise
and dry. After that, the lemongrass was grinded and pounded using the mortar and pestle.
Oils were mixed. The mixture was placed into the pan and boiled for 30 minutes. The
lemongrass oil was then strained using the stainless strainer to remove the grass and was
placed in a container.
Extraction of Oregano Oil
Materials:

Oregano leaves

Stainless bowl

Sunflower oil

Container

Strainer
Oregano leaves were finely chopped. The chopped leaves were mixed with 170 ml of
cooking oil. The mixture was boiled in low fire for 15 minutes. In that way, oregano oil was
extracted from the leaves.
Making Lemongrass and Oregano Spray
Materials:

200 ml Lemongrass Oil
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
200 ml of Oregano Oil

25 ml of Isopropyl Alcohol

75 ml of Distilled water

250 ml of Spray Bottle

Funnel
1. A small funnel was set on a 250 ml spray bottle and 200 ml of lemongrass oil was poured
together with 37.5 ml of distilled water, and 12.5 ml of isopropyl alcohol (Treatment 1).
Another spray bottle was prepared and 200 ml of oregano oil, 37.5 ml of distilled water, and
12.5 ml of isopropyl alcohol (Treatment 2) was mixed. Distilled water was used instead of
tap water to prevent the spray from spoiling.
2. The lid was screwed on the bottle and the spray was shaked for 10 seconds. The lids then
were put on the two bottles and were screwed tightly so that the bottles were completely
sealed. The spray bottles was shaked for at least 10 seconds to help the oil combine with the
water.
3. Repellents were stored at a balance room temperature. These were kept out of the
children’s reach.
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TREATMENTS
Treatment 1 (Lemongrass)
CONTENT
80% Lemongrass Oil, 15% Distilled water, 5%
Isopropyl alcohol
Treatment 1 (Oregano)
80% Oregano Oil, 15% Distilled water, 5%
Isopropyl alcohol
Treatment 3 (negative control group)
100% Isopropyl alcohol
Experiment (Study Proper)
The three cages were positioned. Twenty mosquitoes were placed inside each cage
and stored for 15 minutes so that the mosquitoes will become stable and adjust to the
environment. The lemongrass solution, oregano solution, and the pure isopropyl alcohol were
sprayed to their designated cages. This was done evenly throughout the cage. This process
was carried out for 3 repetitions.
Ethical considerations were observed in the study. There was no human involved in
the test of the effectiveness of the treatments inside the cage. There was no human skin
exposed to mosquito biting.
Data Gathering Procedure
The number of dead mosquitoes was counted and the exact time where the first and
last mosquito died were listed. The efficacy criteria for an insecticide was determined based
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on the percentage of mosquito deaths tested. Effective efficacy in accordance with World
Health Organization (WHO) criteria, if the percentage of mosquito mortality was equal to or
greater than 80%. The mortality of the test mosquitoes was the number of test mosquito
deaths when checked multiplied by 100%. The percentage of mosquitoes obtained was
corrected by the Abbot formulation since there are deaths in the control group of 5%- 20%.
Analysis of Data
The data gathered were tabulated, analyzed, and interpreted using the following statistical
tools:
Percentage is used to describe the total number dead mosquito from the total population.
Analysis of Variance (ANOVA) is used to determine the difference between the mortality
number of mosquitoes and time.
Least Significant Difference (LSD) is used to calculate the smallest significant between two
means as if a test had been run on those two means. This is developed by Fisher in 1935.
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Chapter IV
Results and Discussion
This chapter provides the presentation of statistical data relative to the problems
posted on the statement of the problem. The corresponding analysis and interpretation of data
are incorporated in this portion of this study.
Comparability of efficacy, durability, and elasticity of the two groups based on the
percentage of ingredients; to strengthen the result t-test was applied.
Table 3.0 Result of the mean for the two groups
Ingredients
Tap water
Cassava starch
Glycerine
Acetic acid
Food color
First Mixture (X1)
%
50
0.07
0.02
0.02
0.02
Total = 30.67
M = 6.134
Second Mixture (X2)
%
30
0.05
0.02
0.02
0.02
Total = 30.65
M = 6.13
As shown in Table 1 glycerine, acetic acid, and food coloring in the two groups
obtained 0.02 percent. Tap water is about 50 percent in the first group while on the second
group it is 30 percent. Cassava starch in the first group were 0.07 percent, on the other hand
second mixture obtained 0.05 percent.
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As gathered from table 1, the first set group of mixture had a mean of 6.134 while the
second mixture had a mean of 6.13. It shows that almost both groups had the same mean.
To gain further insight into the differences in two compared mixtures of
biodegradable food containers t-test is applied.
Table 4.0 Significant differences between the result of first and second mixtures.
Group
First
Mixture
Second
Mixture
N
5
Mean
6.134
SD
462.40
5
6.13
142.44
df
p-value
8
.00033
Decision
Reject
Interpretation
Significant
Ho.
As we gleaned from Table 2, the p-value of 0.00033 was less than the significance
level of 0.05; hence, with 8 degrees of freedom, there was significant difference between the
first and second mixtures of biodegradable plastic food container. This revealed that the two
groups exhibited not the same level of efficacy, elasticity, and durability.
Table 5.0 Differences between biodegradable food container and commercialized plastics
Biodegradable Food Container
Cassava starch-based polymers.
Commercialized Plastic
Mainly composed of polyolefins such as
polyethylene (PE) and polypropylene (PP).
Biodegraded by microorganisms in their Contains chemical additives intended to
natural environment.
accelerate degradation.
Low electrical conductivity, transparency, Manufactured and used in large quantities
and the ability to be molded.
due to its price.
Less stable and have a lower diffusion More stable and have a higher diffusion
barrier.
barrier.
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Table 5 presents that commercially made plastics are typically had more additives like
chemicals compared to biodegradable container which mainly composed of starch-based
polymers that can be degraded by microorganisms in just only a few weeks on the other hand
conventional plastics took years for it to be decomposed. When it comes to stability and
diffusion barrier commercialized plastics had a higher level. As a result almost all of the
population in the Philippines are using commercially made plastics. The researchers of this
study find out that biodegradable containers are more preferable and effective to use rather
than commercialized plastics due to its ability to degrade in small amount of weeks. Although
when it comes to stability bio containers are for one-time use only.
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Chapter V
Summary, Conclusion, and Recommendation
This chapter presents the summary and conclusion derived in the conduct of the study
which is to probe the effectiveness of cassava starch based biodegradable plastic food
container as an alternative to commercialized plastic. It also provides recommendations that
can be pursued by the administration and future researchers. The study was conducted at the
premises of Allacapan Cagayan. It employed quantitative research and utilized quasiexperimental research. Data were obtained thru experimental t-test and observations. The
statistical tool used is independent sample t-test.
Summary of Findings
The findings of the study were summarized according to the statement of the
problems stated in Chapter I.
1. Is there a significant difference in the efficacy of the biodegradable food container if 1/3
cup of cassava starch is compared with 1/4 cup of cassava starch that is added in the mixture?
The amount of the cassava on the first mixture is 1/3 cup while on the second is 1/4
cup. On the actual product it showed that there is a significant effect of cassava starch. The
data also reveals that the first mixture has a mean of 6.134 and the second mixture has a mean
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of 6.134 which means that these two mixtures have a significant effect on the efficacy of the
biodegradable plastic container.
2. Is there a significant change in the elasticity and durability of the biodegradable food
container, if the amount of tap water is 250 ml compared with 150 ml of tap water?
In the actual test where we added 250 ml water to the first mixture and 150 ml water
on the second mixture. The outcome products showed that there are changes in the elasticity
and durability of the product. But when we added to much water it made the product brittle
and weak. In short, there is a significant difference between the two compared group of
mixtures.
3. Does biodegradable container more preferable and effective for everyday use rather than
commercially made plastics?
It is shown in the comparison of their characteristics that biodegradable plastic food
container can be degraded in a shorter amount of time and is also made out of cassava starch
making it less toxic, but it is less stable compared to commercially made plastics which is
made out of different additives and chemicals making it more stable but takes years to
decompose and making it harmful and toxic in the long use. The cassava-starch based bio
container is preferably used because of its ability to degrade itself in a shorter amount of
time, but when it comes to durability bio plastic container fall behind commercialized plastic
because bio plastic is more suited for one time use only.
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Conclusion
Based on the indicated findings, the following conclusions were drawn.
1. The results on the comparison between the two mixtures prove that there are both
differences on its outcomes.
2. Biodegradable container is more preferable compared to commercially made plastics if we
are to pertain with single use plastic, because of the ability of the biodegradable container to
decompose faster than commercialized plastics.
3. The researchers concluded that biodegradable container is preferably used if it is a single
use or disposable plastic because of its characteristics which can be dissolved just by using
water, and its ability to decompose in a shorter amount of time compared to commercially
made plastics, which prevents more usage of non-bio plastics.
Recommendation
This study revealed the effectiveness of cassava starch based biodegradable plastic
food container as an alternative to commercially made plastics. Thus, the following
recommendations are hereby presented:
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1. Since the effectiveness of cassava-starch based bio plastic has been proven. We may use it
to substitute single use plastics.
2. Implementation of substituting single use plastics with biodegradable cassava starch based
bio plastic should be encouraged by administrators and embraced by citizens in an effort to
reduce non-biodegradable plastic wastes.
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Kille, L.W., Stephens, R. (2014). Plastics, human health and environment impacts:
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WOIMA Corporation (2021). “DROWNING IN WASTE – CASE MANILA, THE
PHILIPPINES.”
https://woimacorporation.com/drowning-in-waste-case-manila-the-philippines/
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