Larvicidal Activity of Pentagalloyl Glucose and Mangiferin Isolated from the Waste of Mango Kernel Against Culex pipiens L.

The deadliest insect, Culex pipiens, plays a critical role in the transmission of multiple diseases to livestock, animals, and humans. In the current work, the waste of Mangifera indica (Mango) seed kernels was extracted with ethyl acetate to profile the gallotannins components. Moreover, the major compounds pentagalloyl glucose (PGG) and mangiferin were isolated and their larvicidal activity against C. pipiens was determined. A total of 20 secondary metabolites were annotated based on high-performance liquid chromatography with photodiode array (PDA) detector and mass spectrometry (MS) detection. PGG and mangiferin were isolated and identified depending on different chromatographic and spectroscopic techniques. The extract exhibited good larvicidal activity against the 3rd larval instar of C. pipiens with LC50 value of 64.02 µg/ml, whereas those of pentagalloyl glucose and mangiferin were 169.38 and 232.15 µg/ml, respectively. The tested extract and the two isolated secondary metabolites exploited significant alterations for the tested enzymes (acetylcholinesterase, carboxylesterase, α-esterases, glutathione S-transferase, and cytochrome P-450 monooxygenase) compared to the untreated larvae with p < 0.01. The GST, carboxylesterase, and α-esterase have the main role in the detoxification of PGG and mangiferin. In conclusion, Mango waste could provide a cheap, available, and important source for tackling an environmental problem as an ecofriendly alternative to the currently used chemical insecticides. The strategy of our study using M. indica kernel against C. pipiens larvae.