Environmentally Safe Photodynamic Control of Aedes aegypti Using Sunlight-Activated Synthetic Curcumin: Photodegradation, Aquatic Ecotoxicity, and Field Trial

Abstract

This study reports curcumin as an efficient photolarvicide against Aedes aegypti larvae under natural light illumination. Larval mortality and pupal formation were monitored daily for 21 days under simulated field conditions. In a sucrose-containing formulation, a lethal time 50 (LT50) of 3 days was found using curcumin at 4.6 mg L−1. This formulation promoted no larval toxicity in the absence of illumination, and sucrose alone did not induce larval phototoxicity. The photodegradation byproducts (intermediates) of curcumin were determined and the photodegradation mechanisms proposed. Intermediates with m/z 194, 278, and 370 were found and characterized using LC-MS. The ecotoxicity of the byproducts on non-target organisms (Daphnia, fish, and green algae) indicates that the intermediates do not exhibit any destructive potential for aquatic organisms. The results of photodegradation and ecotoxicity suggest that curcumin is environmentally safe for non-target organisms and, therefore, can be considered for population control of Ae. aegypti.

The impact of curcumin on livestock and poultry animal's performance and management of insect pests

“…Interestingly, CnCC is the insect ortholog of the transcription factor, Nrf2, which has been mentioned in previous sections to have been studied to be regulated by curcumin (131). Curcumin's effect on insects is depicted in Figure 3 (123, 124,128) and Table 3. Agricultural plant parasite nematodes are microscopic roundworms that live in the soil and feed on plant roots.…”

“…According to Raman microspectroscopy results, D-mannitol showed high permeability to the larva's peritrophic membrane, causing irreversible damage to the simple columnar epithelium of the digestive tube (123). Relatedly, curcumin formulated has photodynamic activity against A.aegypti larvae and yielded a water-soluble, non-toxic byproducts of curcumin as a result of photodegradation (124). In a larvicidal bioassay study with the integration of in silico molecular structural validations in C.pipiens and A. albopictus, curcumin derivatives appeared to have larvicidal effects.…”

Impacts of turmeric and its principal bioactive curcumin on human health: Pharmaceutical, medicinal, and food applications: A comprehensive review

“…Few studies reported that singlet oxygen and superoxide were photogenerated by curcumin in biological systems, probably triggering curcumin phototoxicity. More studies on the mechanisms underlying curcumin photodegradation are required to understand the possible detrimental effects of curcumin phototoxicity (89).…”

Larvicidal activity of the photosensitive insecticides, methylene blue and rose bengal, in Aedes aegypti and Anopheles gambiae mosquitoes

“…The PSIs methylene blue (MB) and rose bengal (RB) have also been used as therapeutic drugs in humans, including in photodynamic therapy, 28,29 which is suggestive of a certain level of safety. The primary environmental advantage of PSIs, however, is that they photodegrade into ecologically harmless byproducts, such as CO 2 , NH 4 + , NO 3 − , and SO 4 2− , in only a few hours 15,30,31 . This is unlike some classical insecticides, which persist in the environment for years 32–36 …”

“…The primary environmental advantage of PSIs, however, is that they photodegrade into ecologically harmless byproducts, such as CO 2 , in only a few hours. 15,30,31 This is unlike some classical insecticides, which persist in the environment for years. [32][33][34][35][36] Under laboratory conditions, the PSIs curcumin, RB, hematoporphyrin and eosin-MB are toxic to Aedes aegypti larvae, and RB is toxic against Anopheles gambiae and Culex quinquefasciatus.…”