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In-vitro chemical characterization and mosquitocidal screening of essential oil derived from Mikania scandens (L.) Willd. (Asteraceae) (CVO-MS) against the malarial vector Anopheles gambiae was investigated. GC-MS analysis evidenced a total of 12 bio-active compounds, and maximum at α-bisabolol (39.34%) followed by stigmasterol (13.45%) respectively. The larvicidal activity of CVO-MS against the malarial vector An. gambiae evidenced that the mortality rate was prominent at the maximum dosage of 1000 ppm. The Median Lethal Concentration (LC50) of CVO-MS was established at 488 ± 2.45 ppm, respectively. Enzyme inhibition assay showed that the CVO-MS delivers a significant upsurge in the level of CYP450, GST, and a decline in the level of α-β carboxylesterase activity in both the third and fourth instar (p ≤ 0.0001). The gut-histological examination of CVO-MS showed that there is severe damage in the mid-gut tissues, especially epithelial layer (EL), gut-lumen (GL), and peritrophic membrane (pM). The non-target screening against the mosquito predators (A. bouvieri, D. indicus, and third instar larvae of Tx. splendens) suggests that CVO-MS showed less toxicity as compared to Pestanal® (1 ppm) respectively. The present study has paved a new insight in understanding the bioactivity of CVO-MS as a potential larvicidal agent of malarial vector and non-toxic against mosquito predators.

The present research investigates the toxicological screening of crude methanol extracts Avera lanata (Mx-Al) traditionally used for its medicinal properties, and explored its potential as an insecticidal agent against the lepidopteran pests Spodoptera litura Fab. and Plutella xylostella L. and their non-target impact on Eudrilis eugeniae. Chemical characterization of Mx-Al revealed thirteen phyto-compounds and the peak area percentage is maximum at β-D-mannofuranoside (33.96%) and 1-Tetradecyne (21.46%). The larvicidal toxicity of Mx-AI on S. litura (97.23%) and P. xylostella (96.21%) delivered dose-dependent mortality and was significant at 500 ppm. The minimal dosage (200 ppm) extended the larval and pupal durations and significantly reduced the level of ACP, ALP, and LDH against both pests. The non-target toxicity against earthworm displayed higher toxicity to Cypermethrin (0.1 ppm) as compared to Mx-AI (1500 ppm). Further, the In-silico screening showed that the interpretation has significant implications for developing new and more selective inhibitors for P. xylostella and S. litura. Also, Bee-Tox, pkCSM and insecticide-likeness showed that all derivatives of Mx-Al are mostly nontoxic against Bees, protozoa, and rodents respectively, and obeyed the TICE rule violations. Overall, the present results proved that Mx-Al is target specific and harmless to non-target organisms. [ABSTRACT FROM AUTHOR]

In-vitro chemical characterization and mosquitocidal screening of essential oil derived from Mikania scandens (L.) Willd. (Asteraceae) (CVO-MS) against the malarial vector Anopheles gambiae was investigated. GC-MS analysis evidenced a total of 12 bio-active compounds, and maximum at α-bisabolol (39.34%) followed by stigmasterol (13.45%) respectively. The larvicidal activity of CVO-MS against the malarial vector An. gambiae evidenced that the mortality rate was prominent at the maximum dosage of 1000 ppm. The Median Lethal Concentration (LC50) of CVO-MS was established at 488±2.45 ppm, respectively. Enzyme inhibition assay showed that the CVO-MS delivers a significant upsurge in the level of CYP450, GST, and a decline in the level of α-β carboxylesterase activity in both the third and fourth instar (p ≤ 0.0001). The gut-histological examination of CVO-MS showed that there is severe damage in the mid-gut tissues, especially epithelial layer (EL), gut-lumen (GL), and peritrophic membrane (pM). The non-target screening against the mosquito predators (A. bouvieri, D. indicus, and third instar larvae of Tx. splendens) suggests that CVO-MS showed less toxicity as compared to Pestanal® (1 ppm) respectively. The present study has paved a new insight in understanding the bioactivity of CVO-MS as a potential larvicidal agent of malarial vector and non-toxic against mosquito predators. [ABSTRACT FROM AUTHOR]