Pendahuluan: Demam berdarah dengue merupakan masalah kesehatan dunia dan vektor DBD, Aedes aegypti sudah resisten terhadap berbagai insektisida. Sebagai alternatif, diperlukan zat alami yang dapat memberantas Aedes aegypti. Tujuan: Mengevaluasi aktivitas larvisida ekstrak murni curcumin terhadap larva Ae. aegypti dan mendeskripsikan mekanisme larvisida tersebut yang dimediasi oleh perubahan ultrastruktur sel epitel midgut dan protein (tiramin/oktopamin). Metode: Larva Aedes aegypti instar III dan IV dipaparkan ekstrak murni curcumin dan ekstrak kasar rimpang kunyit (Curcuma longa) masing-masing dengan konsentrasi 0,25, 0,5, 1, dan 4 ppm dengan ulangan sebanyak 4 kali. Pengukuran efektivitas ekstrak murni curcumin dan kasar C. longa dilakukan dengan menghitung angka mortalitas dan konsentrasi letal 50% dan 90% (bioassay) dilakukan selama 24 jam. Perubahan ultrastruktural sel epitel midgut larva diperiksa dengan Transmission Electron Microscope (TEM). Deteksi protein, tiramin dan oktopamin, dilakukan dengan metode imunohistokimia. Hasil: Ekstrak murni curcumin memperlihatkan aktivitas larvisida yang berbeda bermakna dengan ekstrak kasar dan kontrol (p< 0.05). LC50 ekstrak murni curcumin dan eksrak kasar masing-masing sebesar 1,40 ppm dan 40,32 ppm. Pada kontrol tidak terdapat aktivitas larvisida. Ekstrak murni curcumin menyebabkan perubahan ultrastruktural sel epitel midgut berupa kerusakan mikrovili, membran sel, nukleus, mitokondria, dan organel-organel sel lainnya. Selain itu, ekstrak murni curcumin menurunkan imunoreaktivitas tiramin dan oktopamin pada midgut larva. Kesimpulan: Ekstrak murni curcumin memiliki aktivitas larvisida yang signifikan terhadap larva Ae. aegypti dimediasi oleh perubahan ultrastruktur epitel midgut dan penurunan tiramin dan oktopamin.

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Introduction: Dengue fever is a world health problem and the vector of DHF, Aedes aegypti is already resistant to various insecticides. As an alternative, natural substances are needed that can eradicate the Aedes aegypti mosquito.

Objective: To evaluate the larvicidal activity of pure curcumin extract against Aedes aegypti and describe the mechanism of the larvicide which is mediated by changes in the ultrastructure of the midgut epithelial cells and protein (tyramine/octopamine). Methods: Larvae of Aedes aegypti instar III and IV were exposed to pure extract of curcumin and crude extract of turmeric rhizome (Curcuma longa) with concentrations of 0.25, 0.5, 1, and 4 ppm, with 4 replications. Measurement of the effectiveness of pure and crude extracts of curcumin and crude C. longa was carried out by calculating the mortality rate and lethal concentrations of 50% and 90% (bioassay) carried out for 24 hours. The ultrastructural changes of larval midgut epithelial cells were examined with a Transmission Electron Microscope (TEM). Detection of protein, tyramine and octopamine, was carried out by immunohistochemical method. Results: Pure extract of curcumin showed significantly different larvicidal activity with control and crude extract (p<0.05). The LC50 of pure curcumin extract and crude extract were 1.40 ppm and 40.32 ppm, respectively. There was no larvicide activity in the control. Pure extract of curcumin caused ultrastructural changes in midgut epithelial cells in the form of damage to microvilli, cell membranes, nucleus, mitochondria, and other cell organelles. In addition, pure extract of curcumin decreased the immunoreactivity of tyramine and octopamine in larval midgut. Conclusion: Pure extract of curcumin had significant larvicidal activity against Ae. aegypti was mediated by changes in midgut epithelial ultrastructural and decreased tyramine and octopamine.