Formulation, Characterisation And In Vitro Skin Irritation Studies Of Jasminum Officinale And Anthemis Nobilis Essential Oil Nanoemulsion For Aedes AEGYPTI Repellent Activity

dc.contributor.authorMuttiah, Nithya Niranjini
dc.date.accessioned2020-02-28T08:11:55Z
dc.date.available2020-02-28T08:11:55Z
dc.date.issued2019-08
dc.description.abstractMosquitoes are important vectors responsible for the transmission of many pathogens that cause major human morbidity and mortality. Aedes aegypti is the main species engaged in the transmission of dengue fever. Natural repellents such as essential oils may provide a means of protection from mosquito bites that are safer and more pleasant to use. However, their effectiveness decreases relatively fast over time due to high volatility. Nanoemulsion formulation enables to control the volatility of essential oil and thereby extends the duration of repellency. Therefore, oil-in-water nanoemulsion containing the mixture of Jasminum officinale and Anthemis nobilis essential oils were formulated via ultrasonication, and characterised with respect to droplet size, polydispersity index (PDI), zeta potential and storage stability. Gas chromatography-mass spectrometry (GC-MS) analysis revealed that oxygenated monoterpenes and diterpenes constituted 31.14% and 21.20% of J. officinale, respectively. For A. nobilis, oxygenated monoterpenes accounted for 84.79% of the compounds identified. The combination of J. officinale and A. nobilis in a 1:1 ratio exhibited significantly (p < 0.05) higher repellency against Ae. aegypti using a rat model for 120 min than the individual oils. The droplet size of nanoemulsions; nJC1, nJC2 and nJC3 were 264.23, 291.43 and 351.37 nm, respectively. The zeta potential and PDI of the nanoemulsions were -32.77 to -46.93 mV and 0.232 to 0.264, respectively. Transmission electron microscopy (TEM) images verified the nanosize of oil droplets which appeared spherical in shape. nJC1 showed the highest entrapment efficiency with an adequate loading capacity of the marker compounds, isophytol and 1R-α-Pinene. The nanoemulsions increased in droplet size over 60 days storage at room temperature and refrigeration, however the low PDI and increasing negative potential zeta values indicated a stable colloidal system. All the formulations showed 100% repellency against Ae. aegypti for the first 3 h, and this effect starts to decrease in subsequent hours. Interestingly, nJC1 exhibited significantly (p < 0.05) higher repellency, 81.02% than 10% DEET, 62.10% at 8 h post-treatment. The in vitro release study demonstrated a sustained release of the essential oils from the nanoemulsion via a diffusion-controlled release mechanism. In addition, the nanoemulsions were proven to be non-irritant in the EpiDerm™ skin irritation test, and IL-1α and IL-8 release profiles further confirmed the outcome. The findings of this study demonstrated that nanoemulsion formulation significantly increases the repellency of J. officinale and A. nobilis essential oils with prolonged protection period, suggesting its potential to be utilised as an alternative plant-based mosquito repellent.en_US
dc.identifier.urihttp://hdl.handle.net/123456789/9581
dc.language.isoenen_US
dc.subjectInsect Repellentsen_US
dc.titleFormulation, Characterisation And In Vitro Skin Irritation Studies Of Jasminum Officinale And Anthemis Nobilis Essential Oil Nanoemulsion For Aedes AEGYPTI Repellent Activityen_US
dc.typeThesisen_US
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