Abstract
National and international organizations are working together with the World Health Organization to control vector-borne diseases. The extensive uses of synthetic insecticides have led to the development of insect resistance and cause adverse health effects on humans and ecosystem. The current study aimed to study the potential larvicidal activity of microalgae (Amphora coffeaeformis and Scenedesmus obliquus) against the mosquito Culex pipiens. Toxicity on rats and an eco-toxicology study using the Microtox(R) test was performed. Liquid chromatography (HPLC) and gas chromatography-mass spectrometry (GC-MS) showed that A. coffeaeformis and S. obliquus extracts have high concentrations of polyphenolic compounds and unsaturated fatty acids. Both A. coffeaeformis and S. obliquus extracts had larvicidal activity with different mechanisms of toxic action against C. pipiens and the LC50 was 513.63 and 855.66 mu g mL(-1) compared with 173.16 mu g mL(-1) of the insecticide lambda-cyhalothrin. From toxicological studies on male rats and acute toxicity on bacterial strain of Vibrio fischeri using Microtox toxicity test, the A. coffeaeformis extract can be considered non-toxic to experimental animals and eco-friendly. Therefore, these findings propose the prospect use extracts of microalgae such as A. coffeaeformis as a safe and eco-friendly larvicide against C. pipiens.