Phyto-chemical screening, insecticidal potential and detoxifying enzyme inhibition of Ficus auriculata (Lour.) extracts, against the mosquito vector and non-target aquatic predator

Abstract

The present research targets to explore the chemical and mosquitocidal screening of Ficus auriculata (Lour.), on arthropod mosquito vectors Aedes aegypti (Linn.) and Anopheles stephensi (Linn.) and their toxicity screening on the mosquito predator. Crude leaf ethanolic extract of F. auriculata (Ex-Fa) was isolated and screened for major bio-active compounds through GC-MS (Gas Chromatography-Mass Spectrometry) and lethal dosages was examined for larvicidal, enzyme inhibition, repellent and non-target toxicological evaluation on the aquatic predator. Chemical screening showed highest peak area in Flavone (51.48%). Larvicidal activity of Ex-Fa deliver that the rate of mortality was detected in dose dependent and it was significant in second instar treated with the maximum dosage (300 ppm) in Ae. aegypti (93.2%) and An. stephensi (95.6%) respectively and mortality is significant in positive control Temephos-1 ppm (97.7%) in second instar. The sub-lethal concentration of Ex-Fa (150 ppm) delivered significant enzyme inhibition action on second instar of α-carboxylesterase (Ae. aegypti: 0.513 mg/protein; An. stephensi: 0.511 mg/protein), β-carboxylesterase (Ae. aegypti: 0.612 mg/protein; An. stephensi: 0.732 mg/protein). The level of detoxifying enzymes uplifted post treatment with Ex-Fa in glutathione s-transferase (GST) (Ae. aegypti: 0.654 μmol/mg; An. stephensi: 0.674 μmol/mg) and cytochrome P450 (CYP450) (Ae. aegypti: 8.379 μmol/mg; An. stephensi: 8.412 μmol/mg) it is significant with the positive control galantamine (1 ppm). The repellent percentage was significant at the higher concentration (300 ppm) in Ae. aegypti (89.6%) and An. stephensi (90.2%) up to 210 min. The non-target toxicity assay delivered that the Ex-Fa are nontoxic to the aquatic predator Toxorhynchites splendens. The present research delivers that herbal based extracts are promoting sustainable and effective vector control strategies.