The Open Parasitology Journal




ISSN: 1874-4214 ― Volume 7, 2019
RESEARCH ARTICLE

Repellence Activity of Cymbopogon Citratus (DC) Extracts on Anopheles Mosquitoes using Swiss Albino Rat and Human Volunteer



Omoya Funmilola Oluyemi*, Adewumi Tunde Ayodele, Ajayi Kehinde Oluyemi
Department of Microbiology, Federal University of Technology, Akure, Ondo State, Nigeria

Abstract

Introduction:

Insect-transmitted disease remains a major source of illness and death worldwide. Anopheles stephensi and Anopheles culicifacies are the important vectors of malaria, malaria continues to be a major public health problem in the tropical world. This study is aimed at carrying out repellence activity of Cymbopogon citratus (Lemon grass) extracts on Anopheles mosquitoes using swiss albino rat and human volunteers.

Methods:

Methanol, chloroform and water were used to extract the bioactive compounds of plant leaves, qualitative and quantitative phytochemical components of plant extracts were determined, twenty-five laboratory-reared 3 day old Anopheles mosquitoes which had been starved for 5 hours were used, extracts and the commercial insecticide N, N-diethyl-3-methylbenzamide (DEET) were applied topically on the skin of uncovered portions of the hand of the human volunteers and abdomen of swiss albino rat after the abdominal hairs has been shaved and the landing rate of mosquitoes were observed to calculate percentage repellency.

Results:

The result revealed that methanol extract had the highest percentage yield of 10.3%, tannin and alkaloid were present in all extracts. DEET had 100% repellency to Anopheles mosquitoes on both human volunteers and rats for 300 minutes post application, in human volunteers, water, chloroform and methanol extracts, has percentage repellency reduced from 100% to 94% after 60 minutes, 100% to 94% after 120 minutes and 100% to 83% after 150 minutes post application respectively while in swiss albino rat, water, chloroform and methanol extracts, percentage repellency reduce from 100% to 87% after 90 minutes, 100% to 87% 150 minutes and 100% to 90% after 180 minutes post application respectively.

Conclusion:

Methanol extracts of C. citratus leaves could be used for the development of topical cream that repels mosquitoes for effective control of malaria.

Keywords: Anopheles mosquitoes, Cymbopogon citratus, Extracts, Repellency, Malaria, Plasmodium.


Article Information


Identifiers and Pagination:

Year: 2018
Volume: 6
First Page: 32
Last Page: 40
Publisher Id: TOPARAJ-6-32
DOI: 10.2174/1874421401806010032

Article History:

Received Date: 30/5/2018
Revision Received Date: 17/7/2018
Acceptance Date: 25/7/2018
Electronic publication date: 31/08/2018
Collection year: 2018

Article Metrics:

CrossRef Citations:
0

Total Statistics:

Full-Text HTML Views: 562
Abstract HTML Views: 447
PDF Downloads: 261
ePub Downloads: 130
Total Views/Downloads: 1400

Unique Statistics:

Full-Text HTML Views: 357
Abstract HTML Views: 187
PDF Downloads: 147
ePub Downloads: 101
Total Views/Downloads: 792
Geographical View

© 2018 Omoya et al.

open-access license: This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International Public License (CC-BY 4.0), a copy of which is available at: https://creativecommons.org/licenses/by/4.0/legalcode. This license permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.


* Address correspondence to the author at the Department of Microbiology, Federal University of Technology, Akure, Ondo State, Nigeria, Tel: +2348033738650; E-mail: fomoya@yahoo.com




1. INTRODUCTION

Malaria remains one of the most prevalent diseases in the tropical world. With 200 million to 450 million infections annually worldwide, it causes up to 2.7 million deaths including 1 child every 30 s [1World Health Organization. 2010.Global information system on alcohol and health. Available from: www.who.int/globalatlas/ DataQuery/default.asp]. Malaria is a mosquito-borne disease is caused by parasitic protozoans (a type of unicellular microorganism) of the genus Plasmodium. Five species of Plasmodium can infect and be transmitted by humans [2Collins WE. Plasmodium knowlesi: A malaria parasite of monkeys and humans. Annu Rev Entomol 2012; 57: 107-21.[http://dx.doi.org/10.1146/annurev-ento-121510-133540] [PMID: 22149265] ]. The vast majority of deaths are caused by P. falciparum, P. vivax, while P. ovale, and P. Malariae [3Nadjm B, Behrens RH. Malaria: An update for physicians. Infect Dis Clin North Am 2012; 26(2): 243-59.[http://dx.doi.org/10.1016/j.idc.2012.03.010] [PMID: 22632637] ].

Malaria is common in tropical and subtropical regions because rainfall, warm temperatures, and stagnant waters provide an environment ideal for mosquito larvae. The rainy season may be important in malaria transmission due to high biting populations. Commonly, the disease is transmitted by a bite from an infected female Anopheles mosquito, which introduces the organisms from its saliva into a person’s circulatory system, parasites can also be transmitted by blood transfusions, although this is rare [4Owusu-Ofori AK, Parry C, Bates I. Transfusion-transmitted malaria in countries where malaria is endemic: A review of the literature from sub-Saharan Africa. Clin Infect Dis 2010; 51(10): 1192-8.[http://dx.doi.org/10.1086/656806] [PMID: 20929356] ].

Prevention of malaria includes medications, mosquito elimination and prevention of mosquito bites [5Raghavendra K, Barik TK, Reddy BP, Sharma P, Dash AP. Malaria vector control: From past to future. Parasitol Res 2011; 108(4): 757-79.[http://dx.doi.org/10.1007/s00436-010-2232-0] [PMID: 21229263] ]. The presence of malaria in an area requires a combination of high human population density, high anopheles mosquito population density and high rates of transmission from humans to mosquitoes and from mosquitoes to humans [6Bousema T, Okell L, Felger I, Drakeley C. Asymptomatic malaria infections: Detectability, transmissibility and public health relevance. Nat Rev Microbiol 2014; 12(12): 833-40.[http://dx.doi.org/10.1038/nrmicro3364] [PMID: 25329408] ]. If any of these is lowered sufficiently, the parasite will eventually be eliminated from that area. Furthermore, disease transmission can be reduced by preventing mosquito bites by using mosquito nets and insect repellents, or with mosquito-control measures such as spraying insecticides and draining standing water [7Lengeler C. Insecticide-treated bed nets and curtains for preventing malaria. Cochrane Database Syst Rev 2004; (2): CD000363.[PMID: 15106149] ].

Control of mosquitoes is something of utmost importance in the present day with rising number of mosquito borne illnesses. Chemical control using synthetic insecticides had been favorable so far because of their speedy action and easy application. Certain plant species containing essential oils have proved efficacy as larvicides, adulticides, ovicides and repellents against different species of mosquitoes [8Mansour HA, Newairy AS, Yousef MI, Sheweita SA. Biochemical study on the effects of some egyptian herbs in alloxan-induced diabetic rats. Toxicology 2002; 170(3): 221-8.[http://dx.doi.org/10.1016/S0300-483X(01)00555-8] [PMID: 11788159] ]. Natural pesticides, especially those derived from plants are more promising in this aspect. Aromatic plants and their essential oils are very important sources of many compounds that are used in different respects. Most of the mosquito control programmed target the larval stage in their breeding sites with larvicides [9Knio KM, Usta J, Dagher S, Zournajian H, Kreydiyyeh S. Larvicidal activity of essential oils extracted from commonly used herbs in lebanon against the seaside mosquito, Ochlerotatus caspius. Bioresour Technol 2008; 99(4): 763-8.[http://dx.doi.org/10.1016/j.biortech.2007.01.026] [PMID: 17368893] ]. Personal protective measures including repellents are widely used to prevent the transmission of mosquito-borne diseases by minimizing the contact between humans and vectors [10Pitasawat B, Choochote W, Tuetun B, et al. Repellency of aromatic turmeric Curcuma aromatica under laboratory and field conditions. J Vector Ecol 2003; 28(2): 234-40.[PMID: 14714673] ].

Repellent properties of several leaves extracts appear to be associated with the presence of monoterpenoids and sesquiterpenes [11Jaenson TG, Pålsson K, Borg-Karlson AK. Evaluation of extracts and oils of mosquito (Diptera: Culicidae) repellent plants from sweden and guinea-bissau. J Med Entomol 2006; 43(1): 113-9.[http://dx.doi.org/10.1093/jmedent/43.1.113] [PMID: 16506457] ]. Monoterpenes such as a-pinene, limonene, terpinolene, citronellol, citronellal, camphor and thymol are common constituents of a number of leaves extracts and they have mosquito repellent activity [12Yang YC, Lee EH, Lee HS, Lee DK, Ahn YJ. Repellency of aromatic medicinal plant extracts and a steam distillate to Aedes aegypti. J Am Mosq Control Assoc 2004; 20(2): 146-9.[PMID: 15264623] , 13Park BS, Choi WS, Kim JH, Kim KH, Lee SE. Monoterpenes from thyme (thymus vulgaris) as potential mosquito repellents. J Am Mosq Control Assoc 2005; 21(1): 80-3.[http://dx.doi.org/10.2987/8756-971X(2005)21[80:MFTTVA]2.0.CO;2] [PMID: 15825766] ]. Cymbopogon citratus (lemon grass) is commonly used in teas, soups and curries. This plant has been widely recognized for its enthnobotanical and medicinal usefulness [14Adeniran OI, Fabiyi E. A cream formulation of an effective mosquito repellent: A topical product from lemongrass oil (Cymbopogon citratus) Stapf. J Nat Prod Plant Resource 2012; 2(2): 322-7.]. Hence this study aimed at studying the repellence activity of Cymbopogon citratus (Lemon grass) extracts on Anopheles mosquitoes using Swiss albino rat and human volunteers.

2. MATERIALS AND METHODS

2.1. Collection of Plant Materials

Leaves of Cymbopogon citratus were collected from South gate area of Federal University of Technology, Akure, Ondo State, Nigeria, into a clean sack. The leaves were well screened and the unwanted ones were removed before processing for extraction.

2.2. Processing and Extraction of Cymbopogon Citratus

The fresh leaves were air dried for four weeks in the absence of contaminations until fully crispy. The leaves were crushed and pounded using clean mortar and pestle and pulverized into fine powder by blender. The powdered leaves were kept in an airtight container to avoid the absorption of moisture. The powdered sample was soaked for 72 hours in 70% methanol, chloroform and aqueous water in the ratio 1:10 each (300g of the powdered sample in 3000 millimeter of 70% methanol, chloroform and water) as solvents to extract the bioactive compounds, after which the samples were first sieved using muslin cloth and filtrate was filtered using membrane filter of 0.45µm pore size. The filtrates were vaporized to dryness using rotary evaporator and were preserved in a sterile bottle at temperature of 4°C for further use [15Dabur R, Ali M, Sigh H, Gupta J, Sharma G. A novel antifungal pyrole derivative from Datura metel. Pharmazie CODEN Pharlet. Afr J Microbiol Res 2004; 59(7): 568-70.[PMID: 15296098] ].

2.3. Phytochemical Screening of the Plants’ Extracts

The qualitative and quantitative phytochemical screening of the extracts were carried out using standard procedure as described by [16Sofowora A. Medicinal plants and traditional medicine in africa 3rd ed. 3rd ed.2008., 17Ojo OO, Anibijuwon II. Studies on extracts of three medicinal plants of South- western Nigeria: Hoslundia opposita, Lantana camara and Cymbopogon citratus. Adv Nat Appl Sci 2010; 4(1): 93-8.].

2.4. Reconstitution of the Methanolic, Chloroform and Water Extracts

The crude extract of methanolic, chloroform and water leaves was reconstituted with 30% dimthylsulphoxide (DMSO) at concentration of 400 mg/ml [18Solomon GO, Shittu GA. In vitro antimicrobial and phytochemical activities of Acacia nilotica leaf extract. J Med Plants Res 2010; 4(12): 1232-4.].

2.5. Selection of Anopheles Mosquitoes used in this Study

The Anopheles (Anopheles gambie) mosquitoes were obtained from stagnant water using physical characteristics of the larvae for identification. They were reared and maintained at 27±3°C and 80±10 Relative Humidity (RH) [19Choochote W, Chaiyasit D, Kanjanapothi D, et al. Chemical composition and anti-mosquito potential of rhizome extract and volatile oil derived from Curcuma aromatica against aedes aegypti (Diptera: Culicidae). J Vector Ecol 2005; 30(2): 302-9.[PMID: 16599168] ]. They were reared on a diet of floating catfish feed. The adults’ mosquitoes were maintained in screened cages on 10% sucrose solution for 24 h. Repellency was tested against 3 day-old blood-starved mosquitoes, and for each test, 25 mosquitoes were used [20Karunamoorthy K, Ilango K, Murugan K. Laboratory evaluation of traditionally used plant-based insect repellents against the malaria vector Anopheles arabiensis Patton. Parasitol Res 2010; 106(5): 1217-23.[http://dx.doi.org/10.1007/s00436-010-1797-y] [PMID: 20195634] ].

2.6. Mosquitoes Repellency Experimental Design

Human volunteers used in this study were students of The Federal University of Technology, Akure, Ondo State of Nigeria. The volunteers were educated about this study after seeking their verbal consent. Before the test, the skin of volunteers were washed using unscented soap and the 5.0 ml of extract being tested was applied to the exposed part of the skin. After the application, the hand was not allowed to be rubbed, touched, or wetted. An untreated hand was used as control (Negative control) and the one with DEET was used as a standard (Positive control).

Volunteers were exposed for 5 hours (from 5pm to 10pm) to mosquito bites. Bright torchlights were used to view the volunteers’ reaction to bites. The observations were recorded at 30 minutes intervals. All experiments were run at ambient temperature (27 ± 2 oC) and relative humidity of 80 ± 10%. The numbers of mosquitoes landing on hand were recorded and the mean percentage protection was calculated [21Carroll SP, Loye J. PMD, a registered botanical mosquito repellent with deet-like efficacy. J Am Mosq Control Assoc 2006; 22(3): 507-14.[http://dx.doi.org/10.2987/8756-971X(2006)22[507:PARBMR]2.0.CO;2] [PMID: 17067054] ]. Three replicates were run for each repellent and in each replicate different volunteer were used to nullify any effect of skin differences on repellency.

2.7. Animal Testing

The extracts were tested on laboratory animals. The animals were laboratory rats with average 350 to 400 g weight. A 4 x 8 cm of animal abdomen hairs was shaved then washed and cleaned with 75% ethanol. Treatments were 5 ml of the extracts containing 20% of active ingredients of extracts, 5ml of DMSO (Dimethyl sulphoxide) as Negative control and 0.5 ml DEET (N, N-diethyl-3-methylbenzamide) in the same way were used as a positive control. After treatment, the animal was transferred into the cage in which the treated position was exposed to mosquitoes for 5 hours. Each test was repeated three times, replacing new mosquitoes and new animal and number of bites through the fabrics was recorded.

For each repellent, mosquitoes which had been starved for 24 hour were used. Percentage repellency was calculated using the method of [22Oshaghi MA. Repellent effects of extracts and essential oils of citrus limon (rutaceae) and melissa officinalis (labiatae) against main malaria vector anopheles stephensi (Dipteria: Culicidae). Iran J Public Health 2003; 32(4): 23-9.] as illustrated below,

% repellency = [(Nc – Nt) / Nc] x 100

where Nc = is the number of mosquitoes landing on the control subject,

Nt = is the number of mosquitoes landing on the treated subject used in each of the experiments.

2.8. Ethical Considerations

Ethical permit for human volunteer assay was granted by the ethical review committee of the Federal University of Technology, Akure, Ondo State of Nigeria while the ethical permit for animal assay was granted by the animal ethical review committee, Department of Animal Production and Health, Federal University of Technology, Akure, Ondo State of Nigeria.

3. RESULTS

3.1. Percentage Yield of Plant Extracts

Table 1 shows the percentage yield of plant extracts. The methanol extract of C. citratus had the highest percentage yield of 10.3% while the least percentage yield was observed in the water extracts 7.2%.

Table 1
Percentage yield of plant extracts.


3.2. Qualitative Phytochemical Result of C. Citratus Extracts

The result of the qualitative phytochemical analysis of C. citratus extracts is showed in Table 2. The result review the presence of tannin and alkaloid in methanol, water and chloroform extract, however, steroid and anthraquinone were absent. Water extract of plant showed the presence of tannin, alkaloids, terpenoid, flavonoid, saponin and glycosides, while chloroform extract review the presence of tannin and alkaloid. Also, methanol extract and chloroform extract showed the presence of tannin, alkaloids, terpenoid and saponin.

Table 2
Results of the qualitative phytochemicals in plants’ extracts.


3.3. Quantitative Phytochemical Result of C. Citratus Extracts

The quantitative phytochemical result showed that methanol extract has high total phenol composition of 43.81±0.15 ppm, this was closely followed by the chloroform extract. Water and methanol extract of C. citratus had higher composition of terpenoid with water having 25.25±0.08 ppm and the methanol extract having 41.03±0.00 ppm.

This is shown in Figs. (1 and 2). The amount of terpenoid in chloroform extract was minute. The phytate content was also found to be higher in the chloroform extracts. The least phytochemical in all the extracts was steroid and glycosides both of which were at minute levels.

Fig. (1)
Percentage Phytochemical Composition of C. citratus (Lemon Grass) extract.
Legends: LG (Water) = Lemon Grass Water, LG (Chloroform) = Lemon Grass Chloroform, LG Methanol = Lemon Grass Methanol.


Fig. (2)
Phytochemical Composition C. citratus (Lemon Grass) extract in (mg/g).
Legends: LG (Water) = Lemon Grass Water, LG (Chloroform) = Lemon Grass Chloroform, LG Methanol = Lemon Grass Methanol


Fig. (3)
Results of percentage repellent of Anopheles mosquito exposed to 400 mg/ml of C. citratus (Lemon grass) extracts using swiss albino rat.
Legends: LG Met = Lemon Grass Methanol extract, LG Chl = Lemon Grass Chloroform extract, LG Water = Lemon Grass Water extract, DEET = Diethyltoluamide


3.4. Repellent Properties of Methanol, Chloroform and Water Extract of C. citratus

Figs. (3 and 4) show the results of laboratory study on animals and human volunteer comparing the repellent properties of methanol, Chloroform and water extract of C. citratus, with the commercial insecticide (DEET) (positive control) against Anopheles mosquitoes. The result shown in Fig. (3) using experimental rat revealed that DEET had 100 percent (%) repellency to Anopheles mosquitoes at 0.5 (30 minutes) to 5 hours, also the percentage repellency of methanol, water and chloroform extract reduces with time, water extract repellency reduce from 100% to 94% after 1 hour post application, percentage repellency of chloroform extract reduce from 100% to 94% after 2 hours post application and percentage repellency of methanol extract reduce from 100% to 83% after 2½ hours (2.5) post application. It also revealed that percentage repellency of methanol and chloroform extracts were reduced to 0% after 5 hours post application. Fig. (4) revealed the percentage repellency of Anopheles mosquitoes exposed to C. citratus extract using human volunteers. The result showed that DEET has 100% repellency at 0.5 (30 minutes) to 5 hours. However, percentage repellency of water extract reduced from 100% to 87% after 1½ hour post application, percentage repellency of chloroform reduced from 100% to 87% after 2½ hours post application while % percentage repellency of methanol extract reduced from 100% to 90% after 3 hours post application.

Fig. (4)
Result of percentage repellent of Anopheles mosquito exposed to 400 mg/ml of C. citratus (Lemon grass) extract using human volunteers.
Legends: LG Met=Lemon Grass Methanol extract, LG Chl=Lemon Grass Chloroform extract, LG Water=Lemon Grass Water extract, DEET=Diethyltoluamide


4. DISCUSSION

The percentage yield of the extract from the solvent extraction showed that methanol solvent gave the highest yield. This may be due to the fact that methanol is a polar solvent and may be able to extract the active ingredients of the plant without denaturing them. This agreed with the findings of Iloki et al., [23Iloki-Assanga SB, Lewis-Luján LM, Lara-Espinoza CL, et al. Solvent effects on phytochemical constituent profiles and antioxidant activities, using four different extraction formulations for analysis of bucida buceras L. and phoradendron californicum. BMC Res Notes 2015; 8: 396-404.[http://dx.doi.org/10.1186/s13104-015-1388-1] [PMID: 26323940] ], who reported that methanolic extracts of some certain plants contained the highest total amounts of phenolics, flavonoids and condensed tannin compounds when compared to percentage yields of the other solvent systems: (chloroform and water). The presence of phytochemicals is an indication that the plants contain bioactive component that might be responsible for the antibacterial and repellency properties of the extracts. This result is in accordance with the report of Soares et al., [24Soares MO, Alves RC, Pires PC, Oliveira MB, Vinha AF. Angolan Cymbopogon citratus used for therapeutic benefits: Nutritional composition and influence of solvents in phytochemicals content and antioxidant activity of leaf extracts. Food Chem Toxicol 2013; 60: 413-8.[http://dx.doi.org/10.1016/j.fct.2013.07.064] [PMID: 23911554] ], who reported the presence of some phytochemical constituents in these plants.

Moreover, depending on the type and amount of alkaloids present in the methanolic extract, this could present some kind of toxicity that should be characterized and monitored, if necessary [24Soares MO, Alves RC, Pires PC, Oliveira MB, Vinha AF. Angolan Cymbopogon citratus used for therapeutic benefits: Nutritional composition and influence of solvents in phytochemicals content and antioxidant activity of leaf extracts. Food Chem Toxicol 2013; 60: 413-8.[http://dx.doi.org/10.1016/j.fct.2013.07.064] [PMID: 23911554] ]. Total phenols are secondary metabolites found in high amount in extracts with a very low content of tannin and saponin. This agreed with the work of Iloki et al., [23Iloki-Assanga SB, Lewis-Luján LM, Lara-Espinoza CL, et al. Solvent effects on phytochemical constituent profiles and antioxidant activities, using four different extraction formulations for analysis of bucida buceras L. and phoradendron californicum. BMC Res Notes 2015; 8: 396-404.[http://dx.doi.org/10.1186/s13104-015-1388-1] [PMID: 26323940] ], who reported high total phenol in C. citratus leave extract. Alkaloids are nitrogenous compounds that showed insecticidal properties at low concentration and are often toxic to vertebrates. Tepenoids are among the most widespread, structurally diverse plant produced natural pesticides. A triterpinoid obtained from the Neem tree and several monoterpenes such as citronella, pinene, linolool from essential oils are common terpenoids known to possess insecticidal activities. Generally, the monoterpenoids and sesquiterpenes are associated with repellent properties of several essential oils [25Olivero-Verbel J, Nerio LS, Stashenko EE. Bioactivity against tribolium castaneum herbst (Coleoptera: Tenebrionidae) of cymbopogon citratus and eucalyptus citriodora essential oils grown in colombia. Pest Manag Sci 2010; 66(6): 664-8.[PMID: 20205230] ].

Methanol extract showed better repellent properties than chloroform and water extract. One major observation of the repellent properties of C. citratus is that it induces skin irritation /skin rash on the body of the shaved albino rat and the fore arm of the human volunteers. This observation agreed with the findings of Shine et al., [26Shine JY, Park SC, Kim K, Shin D, Kim S, Kim J. Primary dermal irritation of lemon grass (cymbopogon citratus) essential oil in rabbits. J Toxicol Pub Health 2005; 21(3): 249-53.], who reported on the skin irritation potential of C. citratus extract. Motoyshi et al., and Christopher et al., [27Motoyshi K, Toyoshima Y, Sato M, Yoshimura M. Comparative studies on the irritancy of oils and synthetic perfumes to the skin of rabbit, guinea pig, rat, miniature swine and man. Cosmet Toilet 2011; 94: 41-8., 28Christopher E, Ekpenyong EE, Akpan Nyebuk ED. Phytochemical constituents, therapeutic applications and toxicological profile of Cymbopogon citratus Staph (DC) leaf extract. Journal of Pharmacologonsy and Phytochemistry 2014; 3(1): 133-41.], have also reported that citral, a major component of the C. citratus can induce skin irritation in human.

The result of the repellence potential of the extracts obtained in this study revealed that C. citratus extracts were 100% effective for animal bait and human volunteers for at least 2 hours post application, after which repellence fell slowly from 100%. This is in accordance with the work of Oshaghi [22Oshaghi MA. Repellent effects of extracts and essential oils of citrus limon (rutaceae) and melissa officinalis (labiatae) against main malaria vector anopheles stephensi (Dipteria: Culicidae). Iran J Public Health 2003; 32(4): 23-9.], which stated that 100% repellence of plant-derived repellants rarely exceeds 2 hours. He also stated that plant repellence above 60% will be considered good and that below 60% will be considered poor. Amer and Melhorn [29Amer A, Mehlhorn H. Larvicidal effects of various essential oils against aedes, anopheles, and culex larvae (Diptera, Culicidae). Parasitol Res 2006; 99(4): 466-72.[http://dx.doi.org/10.1007/s00436-006-0182-3] [PMID: 16642386] ] reported that the repellency activity of the plant extracts against mosquitoes could be due to the presence of some phytochemical constituents in the plants. Although, repellent efficacy of plant extract are generally attributed to some particular compounds but if a synergistic phenomenon established among these metabolites, then it may also result in an increased bioactivity compared to isolated components [30Omolo MO, Okinyo D, Ndiege IO, Lwande W, Hassanali A. Repellency of essential oils of some kenyan plants against anopheles gambiae. Phytochemistry 2004; 65(20): 2797-802.[http://dx.doi.org/10.1016/j.phytochem.2004.08.035] [PMID: 15474566] ]. However; Adeniran and Fabiyi [14Adeniran OI, Fabiyi E. A cream formulation of an effective mosquito repellent: A topical product from lemongrass oil (Cymbopogon citratus) Stapf. J Nat Prod Plant Resource 2012; 2(2): 322-7.] reported that the pure lemongrass oil provided 95% repellency for three (3) hours. The extended repellency efficacy reported by Adeniran and Fabiyi [14Adeniran OI, Fabiyi E. A cream formulation of an effective mosquito repellent: A topical product from lemongrass oil (Cymbopogon citratus) Stapf. J Nat Prod Plant Resource 2012; 2(2): 322-7.], compared to this study could be as a result of different repellency efficacy of essential oil and leaf extract because the main phytochemicals responsible for repellency may be concentrated in oil than leaf, also, the oil used has been purified which could also enhance the higher repellent efficacy reported.

This study also showed that the application of C. citratus repellent compounds gave acceptable percentage biting protection against Anopheles mosquitoes which is not significantly different (P≤0.05) from the protection seen in the commercial insecticides (DEET) used as positive control under similar conditions.

This study has shown that leaf extracts of C. citratus possess repellent properties against Anopheles mosquitoes. The vast and abundant phytochemical content of the extracts should be harnessed for developing and producing novel biological repellents.

CONCLUSION

The presence of bioactive component of the leaf extract suggest that this plants are physiologically active, supporting the claim by traditional healers. Isolation, identification and purification of these phytochemicals and determination of their respective potencies and toxicological evaluation with the view to formulating antibiotics should be the future direction for investigation.

ETHICS APPROVAL AND CONSENT TO PARTICIPATE

Ethical permit for human volunteer assay was granted by the ethical review committee of the Federal University of Technology, Akure, Ondo State of Nigeria while the ethical permit for animal assay was granted by the animal ethical review committee, Department of Animal Production and Health, Federal University of Technology, Akure, Ondo State of Nigeria.

HUMAN AND ANIMAL RIGHTS

All the reported experiments on humans in the study were in accordance with Parra JL, Paye m, EEMCO Group (2003) EEMCO guidance for the in vivo assessment of skin surface PH. Skin Pharmacol Appl Skin Physiol 16:188-202. And all experimentation on animals were in accordance with the Association for the Study of Animal Behavior; Animal Behavior Society 2006. Guidelines for the treatment of animals in behavioral research and teaching. Animal Behaviour, 71: 245-53.

CONSENT FOR PUBLICATION

Written and informed consent was obtained for the study.

CONFLICT OF INTEREST

The authors declare no conflict of interest, financial or otherwise.

ACKNOWLEDGEMENTS

Declared none.

REFERENCES

[1] World Health Organization. 2010.Global information system on alcohol and health. Available from: www.who.int/globalatlas/ DataQuery/default.asp
[2] Collins WE. Plasmodium knowlesi: A malaria parasite of monkeys and humans. Annu Rev Entomol 2012; 57: 107-21.[http://dx.doi.org/10.1146/annurev-ento-121510-133540] [PMID: 22149265]
[3] Nadjm B, Behrens RH. Malaria: An update for physicians. Infect Dis Clin North Am 2012; 26(2): 243-59.[http://dx.doi.org/10.1016/j.idc.2012.03.010] [PMID: 22632637]
[4] Owusu-Ofori AK, Parry C, Bates I. Transfusion-transmitted malaria in countries where malaria is endemic: A review of the literature from sub-Saharan Africa. Clin Infect Dis 2010; 51(10): 1192-8.[http://dx.doi.org/10.1086/656806] [PMID: 20929356]
[5] Raghavendra K, Barik TK, Reddy BP, Sharma P, Dash AP. Malaria vector control: From past to future. Parasitol Res 2011; 108(4): 757-79.[http://dx.doi.org/10.1007/s00436-010-2232-0] [PMID: 21229263]
[6] Bousema T, Okell L, Felger I, Drakeley C. Asymptomatic malaria infections: Detectability, transmissibility and public health relevance. Nat Rev Microbiol 2014; 12(12): 833-40.[http://dx.doi.org/10.1038/nrmicro3364] [PMID: 25329408]
[7] Lengeler C. Insecticide-treated bed nets and curtains for preventing malaria. Cochrane Database Syst Rev 2004; (2): CD000363.[PMID: 15106149]
[8] Mansour HA, Newairy AS, Yousef MI, Sheweita SA. Biochemical study on the effects of some egyptian herbs in alloxan-induced diabetic rats. Toxicology 2002; 170(3): 221-8.[http://dx.doi.org/10.1016/S0300-483X(01)00555-8] [PMID: 11788159]
[9] Knio KM, Usta J, Dagher S, Zournajian H, Kreydiyyeh S. Larvicidal activity of essential oils extracted from commonly used herbs in lebanon against the seaside mosquito, Ochlerotatus caspius. Bioresour Technol 2008; 99(4): 763-8.[http://dx.doi.org/10.1016/j.biortech.2007.01.026] [PMID: 17368893]
[10] Pitasawat B, Choochote W, Tuetun B, et al. Repellency of aromatic turmeric Curcuma aromatica under laboratory and field conditions. J Vector Ecol 2003; 28(2): 234-40.[PMID: 14714673]
[11] Jaenson TG, Pålsson K, Borg-Karlson AK. Evaluation of extracts and oils of mosquito (Diptera: Culicidae) repellent plants from sweden and guinea-bissau. J Med Entomol 2006; 43(1): 113-9.[http://dx.doi.org/10.1093/jmedent/43.1.113] [PMID: 16506457]
[12] Yang YC, Lee EH, Lee HS, Lee DK, Ahn YJ. Repellency of aromatic medicinal plant extracts and a steam distillate to Aedes aegypti. J Am Mosq Control Assoc 2004; 20(2): 146-9.[PMID: 15264623]
[13] Park BS, Choi WS, Kim JH, Kim KH, Lee SE. Monoterpenes from thyme (thymus vulgaris) as potential mosquito repellents. J Am Mosq Control Assoc 2005; 21(1): 80-3.[http://dx.doi.org/10.2987/8756-971X(2005)21[80:MFTTVA]2.0.CO;2] [PMID: 15825766]
[14] Adeniran OI, Fabiyi E. A cream formulation of an effective mosquito repellent: A topical product from lemongrass oil (Cymbopogon citratus) Stapf. J Nat Prod Plant Resource 2012; 2(2): 322-7.
[15] Dabur R, Ali M, Sigh H, Gupta J, Sharma G. A novel antifungal pyrole derivative from Datura metel. Pharmazie CODEN Pharlet. Afr J Microbiol Res 2004; 59(7): 568-70.[PMID: 15296098]
[16] Sofowora A. Medicinal plants and traditional medicine in africa 3rd ed. 3rd ed.2008.
[17] Ojo OO, Anibijuwon II. Studies on extracts of three medicinal plants of South- western Nigeria: Hoslundia opposita, Lantana camara and Cymbopogon citratus. Adv Nat Appl Sci 2010; 4(1): 93-8.
[18] Solomon GO, Shittu GA. In vitro antimicrobial and phytochemical activities of Acacia nilotica leaf extract. J Med Plants Res 2010; 4(12): 1232-4.
[19] Choochote W, Chaiyasit D, Kanjanapothi D, et al. Chemical composition and anti-mosquito potential of rhizome extract and volatile oil derived from Curcuma aromatica against aedes aegypti (Diptera: Culicidae). J Vector Ecol 2005; 30(2): 302-9.[PMID: 16599168]
[20] Karunamoorthy K, Ilango K, Murugan K. Laboratory evaluation of traditionally used plant-based insect repellents against the malaria vector Anopheles arabiensis Patton. Parasitol Res 2010; 106(5): 1217-23.[http://dx.doi.org/10.1007/s00436-010-1797-y] [PMID: 20195634]
[21] Carroll SP, Loye J. PMD, a registered botanical mosquito repellent with deet-like efficacy. J Am Mosq Control Assoc 2006; 22(3): 507-14.[http://dx.doi.org/10.2987/8756-971X(2006)22[507:PARBMR]2.0.CO;2] [PMID: 17067054]
[22] Oshaghi MA. Repellent effects of extracts and essential oils of citrus limon (rutaceae) and melissa officinalis (labiatae) against main malaria vector anopheles stephensi (Dipteria: Culicidae). Iran J Public Health 2003; 32(4): 23-9.
[23] Iloki-Assanga SB, Lewis-Luján LM, Lara-Espinoza CL, et al. Solvent effects on phytochemical constituent profiles and antioxidant activities, using four different extraction formulations for analysis of bucida buceras L. and phoradendron californicum. BMC Res Notes 2015; 8: 396-404.[http://dx.doi.org/10.1186/s13104-015-1388-1] [PMID: 26323940]
[24] Soares MO, Alves RC, Pires PC, Oliveira MB, Vinha AF. Angolan Cymbopogon citratus used for therapeutic benefits: Nutritional composition and influence of solvents in phytochemicals content and antioxidant activity of leaf extracts. Food Chem Toxicol 2013; 60: 413-8.[http://dx.doi.org/10.1016/j.fct.2013.07.064] [PMID: 23911554]
[25] Olivero-Verbel J, Nerio LS, Stashenko EE. Bioactivity against tribolium castaneum herbst (Coleoptera: Tenebrionidae) of cymbopogon citratus and eucalyptus citriodora essential oils grown in colombia. Pest Manag Sci 2010; 66(6): 664-8.[PMID: 20205230]
[26] Shine JY, Park SC, Kim K, Shin D, Kim S, Kim J. Primary dermal irritation of lemon grass (cymbopogon citratus) essential oil in rabbits. J Toxicol Pub Health 2005; 21(3): 249-53.
[27] Motoyshi K, Toyoshima Y, Sato M, Yoshimura M. Comparative studies on the irritancy of oils and synthetic perfumes to the skin of rabbit, guinea pig, rat, miniature swine and man. Cosmet Toilet 2011; 94: 41-8.
[28] Christopher E, Ekpenyong EE, Akpan Nyebuk ED. Phytochemical constituents, therapeutic applications and toxicological profile of Cymbopogon citratus Staph (DC) leaf extract. Journal of Pharmacologonsy and Phytochemistry 2014; 3(1): 133-41.
[29] Amer A, Mehlhorn H. Larvicidal effects of various essential oils against aedes, anopheles, and culex larvae (Diptera, Culicidae). Parasitol Res 2006; 99(4): 466-72.[http://dx.doi.org/10.1007/s00436-006-0182-3] [PMID: 16642386]
[30] Omolo MO, Okinyo D, Ndiege IO, Lwande W, Hassanali A. Repellency of essential oils of some kenyan plants against anopheles gambiae. Phytochemistry 2004; 65(20): 2797-802.[http://dx.doi.org/10.1016/j.phytochem.2004.08.035] [PMID: 15474566]

Endorsements



"Open access will revolutionize 21st century knowledge work and accelerate the diffusion of ideas and evidence that support just in time learning and the evolution of thinking in a number of disciplines."


Daniel Pesut
(Indiana University School of Nursing, USA)

"It is important that students and researchers from all over the world can have easy access to relevant, high-standard and timely scientific information. This is exactly what Open Access Journals provide and this is the reason why I support this endeavor."


Jacques Descotes
(Centre Antipoison-Centre de Pharmacovigilance, France)

"Publishing research articles is the key for future scientific progress. Open Access publishing is therefore of utmost importance for wider dissemination of information, and will help serving the best interest of the scientific community."


Patrice Talaga
(UCB S.A., Belgium)

"Open access journals are a novel concept in the medical literature. They offer accessible information to a wide variety of individuals, including physicians, medical students, clinical investigators, and the general public. They are an outstanding source of medical and scientific information."


Jeffrey M. Weinberg
(St. Luke's-Roosevelt Hospital Center, USA)

"Open access journals are extremely useful for graduate students, investigators and all other interested persons to read important scientific articles and subscribe scientific journals. Indeed, the research articles span a wide range of area and of high quality. This is specially a must for researchers belonging to institutions with limited library facility and funding to subscribe scientific journals."


Debomoy K. Lahiri
(Indiana University School of Medicine, USA)

"Open access journals represent a major break-through in publishing. They provide easy access to the latest research on a wide variety of issues. Relevant and timely articles are made available in a fraction of the time taken by more conventional publishers. Articles are of uniformly high quality and written by the world's leading authorities."


Robert Looney
(Naval Postgraduate School, USA)

"Open access journals have transformed the way scientific data is published and disseminated: particularly, whilst ensuring a high quality standard and transparency in the editorial process, they have increased the access to the scientific literature by those researchers that have limited library support or that are working on small budgets."


Richard Reithinger
(Westat, USA)

"Not only do open access journals greatly improve the access to high quality information for scientists in the developing world, it also provides extra exposure for our papers."


J. Ferwerda
(University of Oxford, UK)

"Open Access 'Chemistry' Journals allow the dissemination of knowledge at your finger tips without paying for the scientific content."


Sean L. Kitson
(Almac Sciences, Northern Ireland)

"In principle, all scientific journals should have open access, as should be science itself. Open access journals are very helpful for students, researchers and the general public including people from institutions which do not have library or cannot afford to subscribe scientific journals. The articles are high standard and cover a wide area."


Hubert Wolterbeek
(Delft University of Technology, The Netherlands)

"The widest possible diffusion of information is critical for the advancement of science. In this perspective, open access journals are instrumental in fostering researches and achievements."


Alessandro Laviano
(Sapienza - University of Rome, Italy)

"Open access journals are very useful for all scientists as they can have quick information in the different fields of science."


Philippe Hernigou
(Paris University, France)

"There are many scientists who can not afford the rather expensive subscriptions to scientific journals. Open access journals offer a good alternative for free access to good quality scientific information."


Fidel Toldrá
(Instituto de Agroquimica y Tecnologia de Alimentos, Spain)

"Open access journals have become a fundamental tool for students, researchers, patients and the general public. Many people from institutions which do not have library or cannot afford to subscribe scientific journals benefit of them on a daily basis. The articles are among the best and cover most scientific areas."


M. Bendandi
(University Clinic of Navarre, Spain)

"These journals provide researchers with a platform for rapid, open access scientific communication. The articles are of high quality and broad scope."


Peter Chiba
(University of Vienna, Austria)

"Open access journals are probably one of the most important contributions to promote and diffuse science worldwide."


Jaime Sampaio
(University of Trás-os-Montes e Alto Douro, Portugal)

"Open access journals make up a new and rather revolutionary way to scientific publication. This option opens several quite interesting possibilities to disseminate openly and freely new knowledge and even to facilitate interpersonal communication among scientists."


Eduardo A. Castro
(INIFTA, Argentina)

"Open access journals are freely available online throughout the world, for you to read, download, copy, distribute, and use. The articles published in the open access journals are high quality and cover a wide range of fields."


Kenji Hashimoto
(Chiba University, Japan)

"Open Access journals offer an innovative and efficient way of publication for academics and professionals in a wide range of disciplines. The papers published are of high quality after rigorous peer review and they are Indexed in: major international databases. I read Open Access journals to keep abreast of the recent development in my field of study."


Daniel Shek
(Chinese University of Hong Kong, Hong Kong)

"It is a modern trend for publishers to establish open access journals. Researchers, faculty members, and students will be greatly benefited by the new journals of Bentham Science Publishers Ltd. in this category."


Jih Ru Hwu
(National Central University, Taiwan)


Browse Contents



Webmaster Contact: info@benthamopen.net
Copyright © 2019 Bentham Open