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Title:	Penilaian ekstrak tumbuhan melaleuca cajuputi (powell) sebagai bahan kawalan yang berpotensi terhadap nyamuk aedes aegypti (L.) dan aedes albopictus (SKUSE) di Malaysia
Authors:	Azlinda Abu Bakar (P29910)
Supervisor:	Sallehudin Sulaiman, Prof. Dr.
Keywords:	Melaleuca cajuputi Nyamuk Aedes Dissertations, Academic -- Malaysia Universiti Kebangsaan Malaysia -- Dissertations
Issue Date:	25-May-2012
Description:	Kerintangan insektisid di kalangan vektor artropod terutama nyamuk telah mendorong penyelidik mencari insektisid alternatif dari sumber tumbuhan asli. Objektif kajian ini ialah untuk menilai keberkesanan insektisid daripada tumbuhan tempatan, Melaleuca cajuputi terhadap vektor denggi di Malaysia: Aedes aegypti dan Aedes albopictus di makmal dan suasana lapangan. Peringkat permulaan adalah penyaringan beberapa ekstrak tumbuhan daripada spesies: Jacaranda mimosifolia, Melaleuca cajuputi, Tabebuia chrysantha, Tabebuia pallida, Tabebuia rosea dan Tecoma stans. Hasil menunjukkan ekstrak M. cajuputi adalah paling berpotensi sebagai insektisid. Ekstrak M. cajuputi pada kepekatan 300 mg/L memberikan peratus mortaliti melebihi 50 % iaitu 61 % dan 65 % masing-masing terhadap larva Ae. aegypti dan Ae. albopictus. Ekstrak M. cajuputi kemudiannya diuji sebagai agen larvisid dan adultisid menurut garis panduan WHO; penilaian ketoksikan oral akut minyak pati (OECD); penilaian aktiviti repelan; pengenalpastian komponen bahan aktif minyak pati; penilaian minyak pati sebagai semburan aerosol; impregnasi kelambu dengan ekstrak tumbuhan; dan kesan minyak pati terhadap jadual hayat Ae. albopictus di lapangan. Nilai LC50 ekstrak diklorometana sejuk adalah 101.3 mg/L dan 107.4 mg/L masing-masing bagi larva Ae. aegypti dan Ae. albopictus. LC50 minyak pati terhadap larva Ae. aegypti dan Ae. albopictus adalah masing-masing 114.7 mg/L dan 167.3 mg/L. Ekstrak heksana sejuk paling berpotensi terhadap bioasai dewasa dengan nilai LC50 dan LC90 bagi Ae. aegypti adalah masingmasing 0.015 mg/cm 2 dan 0.221 mg/cm 2 sedangkan Ae. albopictus adalah 0.022 mg/cm 2 dan 0.172 mg/cm 2 . Ujian ketoksikan oral akut minyak pati M. cajuputi terhadap tikus Sprague-Dawley memberikan LD50 3561.98 mg/kg dan mengikut pengkelasan US EPA ia dikategorikan di bawah Toksisiti Kelas III (ketoksikan rendah). Aktiviti repelan minyak pati pada kepekatan 0.0378 mg/cm 2 menunjukkan 100 % dan 91.1 % perlindungan masing-masing terhadap Ae. aegypti dan Ae. albopictus. Analisis kimia menggunakan kromatogram gas spektrometri-jisim (GCMS) mengenalpasti dua komponen utama kimia: caryophyllene (20.0 %) dan asid 2-propenoic (29.5 %). Semburan aerosol di makmal pada kepekatan 5 % dan 10 % menghasilkan mortaliti antara 32.6-64.0 % masing-masing terhadap Ae. aegypti dan Ae. albopictus. Nilai KT50 di lapangan pada kepekatan 10 % adalah 168.8 minit dan 123.7 minit. Impregnasi kain jaring (ITNs) dengan ekstrak heksana pada kepekatan 0.2 gm/m 2 adalah paling berkesan terhadap Ae. aegypti dan Ae. albopictus dengan purata peratus mortaliti 80.0±17.0 % dan 74.0±14.8 % diikuti oleh minyak pati iaitu 77.0±15.7 % dan 63.0±13.0 %. Ujian keberkesanan residu, menunjukkan minyak pati adalah berkesan sehingga 90 hari dengan mortaliti 6.67±5.03 % terhadap Ae. aegypti dan 3.33±3.06 % terhadap Ae. albopictus. Kajian semburan kabut di lapangan terhadap jadual hayat Ae. albopictus mendapati minyak pati pada kepekatan 0.02 gm/m 2 , memberikan kadar kematian harian 0.1638 bagi instar I dan 0.2880 bagi instar II. Perbandingan pelbagai jenis ekstrak dan minyak pati M. cajuputi dengan kawalan positif (bifenthrin, malathion dan temephos) menunjukkan ianya mempunyai potensi sederhana sebagai bioinsektisid. Kesimpulannya, ekstrak dan minyak pati M. cajuputi berpotensi digunakan sebagai agen kawalan vektor denggi,Insecticide resistance among arthropod vectors mainly mosquitoes has forced researchers worldwide to seek alternative insecticides from natural botanical sources. This study is important as it provides an alternative and cost-effective insecticide. The objective of this study is to evaluate the insecticidal efficacies of a local plant species, Melaleuca cajuputi against dengue vectors in Malaysia: Aedes aegypti and Aedes albopictus in a laboratory and under field conditions. Initial stage was to screen various plant extracts from various species viz: Jacaranda mimosifolia, Melaleuca cajuputi, Tabebuia chrysantha, Tabebuia pallida, Tabebuia rosea and Tecoma stans. Results showed that the extract of M. cajuputi was the most promising as an insecticide. Extract of M. cajuputi at 300 mg/L was effective with mortality values more than 50 % i.e 61 % and 65 % on Ae. aegypti and Ae. albopictus larvae respectively. M. cajuputi extract was then tested as a larvicidal and adulticidal agent following the WHO guidelines; acute oral toxicity test (OECD) of the essential oil; evaluation of repellent activity; identification of active component of essential oil; evaluation of essential oil as aerosol spray; impregnation of bednets with plant extract; and the effect of essential oil on the life table of Ae. albopictus in the field. Cold dichloromethane extract indicated LC50 values of 101.3 mg/L and 107.4 mg/L against Ae. aegypti and Ae. albopictus larvae respectively. The essential oil's LC50 was 114.7 mg/L against Ae. aegypti and 167.3 mg/L against Ae. albopictus larvae. Cold hexane extract was the most promising as adulticidal with LC50 and LC90 values for Ae. aegypti were 0.015 mg/cm 2 and 0.221 mg/cm 2 , whilst values for Ae. albopictus were 0.022 mg/cm 2 and 0.172 mg/cm 2 respectively. Acute oral toxicity test of essential oil on Sprague-Dawley rats indicated LD50 of 3561.98 mg/kg and according to US EPA classification was categorized in Toxicity Class III (low toxicity). Repellent activity of essential oil produced 100 % and 91.1 % protection at concentration of 0.0378 mg/cm 2 against Ae. aegypti and Ae. albopictus. Chemical analysis using gas chromatography mass-spectrometry had identified two main chemical components viz: caryophyllene (20.0 %) and 2-propenoic acid (29.5 %). Aerosol at 5 % and 10 % concentrations produced mortality between 32.6-64.0 % towards Ae. aegypti and Ae. albopictus. KT50 values (in the field) at 10 % concentration were 168.8 minutes and 123.7 minutes respectively. Impregnated net (ITNs) with hexane extract at 0.2 gm/m 2 was the most effective with mean percentage mortality of 80.0±17.0 % and 74.0±14.8 % on Ae. aegypti and Ae. albopictus, followed by essential oil with 77.0±15.7 % and 63.0±13.0 % for both species respectively. Evaluation on residual efficacy, showed the essential oil was most effective lasting up to 90 days with mean mortality of 6.67±5.03 % on Ae. aegypti and 3.33±3.06 % on Ae. albopictus. Field studies on the life table of Ae. albopictus using fogging treatment with essential oil at 0.02 gm/m 2 showed proportion dying daily for instar I was 0.1638 and 0.2880 for instar II. As a whole, comparative observations of various extracts and essential oil of M. cajuputi with positive controls (bifenthrin, malathion and temephos) showed that they possess moderate potential as a bioinsecticide. Thus, M. cajuputi extract and the essential oil has the potential to be used as dengue vector control agent.,Ph.D.
Pages:	415
Call Number:	QX525.A995p 2012 9 tesis
Publisher:	UKM, Kuala Lumpur
Appears in Collections:	Faculty of Health Sciences / Fakulti Sains Kesihatan

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