Evaluation of Codium fragile and Turbinaria conoides seaweeds- extracts as a novel larvicidal agent against the Culex quinquefasciatus

Marine algae possess abundant reserves of bioactive compounds that can host secondary metabolites exhibiting both structural and biological activity. In our present study, the aqueous, ethanol, methanol, and chloroform extract of seaweed such as Codium fragile and Turbinaria conoides was employed to determine the phytochemical, GC-MS, antioxidant, and larvicidal activity. The phytochemical compounds showed C. fragile and T. conoides ethanolic extract revealed the existence of fourteen numbers of compounds compared to the others. The GC-MS analysis was performed on the ethanolic extract of C fragile and T. conoides showed the presence of each of twenty different compounds. C. fragile of Hexadecanoic Acid (27.79%), 4-Methanocycloocta[d]Pyridaz (7.39%), 1,1-Dimethoxy-2-Hepten-7-Al (7.04 %) and Octadecanoic Acid, (5.9%). The T. conaids of Dibutyl phthalate (69.56%), 1,2-Benzenedicarboxylic acid (14.01%) and Phthalic acid (2.58 %) were present as the major constituent with the highest area percentage. The antioxidant activity of different solvents the T. conoides ethanolic extract was found to have the highest DPPH (81.48 ± 1.0%), ABTS (88.29±1.0%) and Hydroxyl radical scavenging (86.51±1.0%) activity followed by other solvent extracts. The chloroform extract of C fragile and T. conoides showed effective Cx. quinquefasciatus larvicidal activity. Therefore, the bioactive substances derived from the ethanolic extracts could be used for the antioxidant and larvicidal activity of chloroform extract which will overcome the synthetic insecticides negative impact on the environment. The seaweed possesses the potential to serve as a promising alternative source for controlling mosquitoes due to its larvicidal properties.